Although compacted soil can be recovered through root development of planted seedlings, the relationship between root morphologies and soil physical properties remain unclear. We investigated the impacts of soil compaction on planted hybrid larch F1 (Larix gmelinii var. japonica×L. kaempferi, hereafter F1) seedlings with/without N loading. We assumed that N loading might increase the fine root proportion of F1 seedlings under soil compaction, resulting in less effects of root development on soil recovery. We established experimental site with different levels of soil compaction and N loading, where two-year-old F1 seedlings were planted. We used a hardness change index (HCI) to quantify a degree of soil hardness change at each depth. We evaluated root morphological responses to soil compaction and N loading, focusing on ectomycorrhizal symbiosis. High soil hardness reduced the total dry mass of F1 seedlings by more than 30%. Significant positive correlations were found between HCI and root

In this study, influence of land-use type on soil respiration was investigated in poplar plantation, apple orchard (apple trees with understory grasses) and adjacent grassland sites in SeyitlerArea,Artvin, Turkey. Soil respiration was measured approximately monthly in three sampling plots in each land use type from January 2005 to November 2005 using the soda-lime technique. Mean daily soil respiration ranged from 0.63-3.59 g C m-2 d-1. Mean soil respiration in apple orchard, poplar plantation and grassland sites were 1.98, 1.45 and 1.12 g C m-2 d-1, respectively. Mean soil respiration wassignificantly greater in apple orchard than in poplar plantations and grasslands. Seasonal changes in soil respiration were related to soil moisture and temperature changes. Mean soil respiration rate correlated strongly with subsurface soil (15-35cm) pH (R = -0,73; p,0.05), sand content (R= 0.96, p,0.001), soil silt content (R= -0.75; p,0.05), soil clay content (R= -0,83; p,0.001) and organic matter content ...

Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. The study was conducted to assess the quality of the soils under arable cultivation, locally irri-gated and non-irrigated, forestry plantations of teak (Tectona grandis Lin.) and gmelina (Gme- lina arborea Roxb.), and cashew (Anacardium occidentale Lin.) plantation agro ecosystems using soil organic carbon (SOC), soil total ni-trogen (STN) and soil microbial biomass C (SMBC) and N (SMBN) at Minna in the southern Guinea savanna of Nigeria. Soil samples were collected from soil depths of 0-5 cm and 5-10 cm in all the agro ecosystems and analyzed for physical, chemical and biological properties. All the agro ecosystems had similar loamy soil texture at both depths. The soils have high fer-tility status in terms of available phosphorus and exchangeable calcium, magnesium and po- tassium. The irrigated arable land had significantly (P | 0.05) higher SOC and STN in both soil

A study to evaluate the effect of Ficus thonningii (Blume) on soil physicochemical properties was conducted in Ahferom district of Tigray, Ethiopia. For the soil physico-chemical property study, two factors (distance from the tree trunk and soil depth from the ground level) arranged in randomized complete block design (RCBD) with six replications was involved. The distance factor had three levels viz. at half of the canopy radius under the tree, canopy edge (radius of the canopy) and at three times canopy radius away from the trunk outside the canopy. The depth factor had two levels viz. surface (0 - 15 cm) and subsurface (15 - 30 cm) soil layers. Data were collected on soil physicochemical properties viz. soil texture, bulk density, moisture content, soil N, soil P and soil K, %OC, pH and electrical conductivity (EC). The collected data were subjected to ANOVA using the general linear model of SAS. Results of soil physicochemical properties revealed that except for soil texture, the

Rainfall pattern effect on soil erosion in soils with different texture and mineralogy. No significant main or interaction effects on soil erosion were observed (Table 3). Nevertheless, IR treatment caused higher soil erosion than SR. Soil erosion was higher in SCL compared to SL. Equally, kaolinitic soils eroded more than quartz-dominated soils.. Rainfall pattern effect on steady-state infiltration rate in soils with different texture and mineralogy. The SSIR was 10.57 mm.h-1 in SCL kaolinitic soils under IR compared to 4.68 mm.h-1 in SL kaolinitic soils. However, under the same rainfall pattern, SSIR was 2.99 mm.h-1 in SCL and 2.87 mm.h-1 in SL in quartz-dominated soils. Moreover, the dominance of quartz resulted in lower SSIR than for kaolinitic soil within the same rainfall pattern and texture class. In the SR treatment, SSIR was 5.79 mm-h-1 in kaolinitic SCL soils compared to 3.67 mm.h-1 in quartz-dominated SCL soils. Therefore, both IR and SR rainfall patterns reduced SSIR in SCL and SL ...

Cadmium (Cd) concentration in soil solution and its bioavailability is controlled by sorption-desorption reactions. The objective of this research was to compare Cd adsorption behavior in six calcareous and four acid soils. Soil samples were equilibrated with 0.01 M Ca(NO3)2 containing 25 to 3200 mg Cd L−1. Results showed that the tendency for adsorption was high at low Cd concentrations (0-400 mg L-1), but decreased as the Cd increased (400-3200 mg L-1). Among five equations evaluated, Freundlich, Langmuir, and Gunary equations best described Cd adsorption in both calcareous and acid soils as indicated by high values for coefficient of determination (R2) and low values for standard error of estimate (SE). Stepwise regression equations between constants of the best-fitted models and soil properties revealed that cation exchange capacity (CEC) and clay content were the most important soil properties affecting Cd adsorption behavior in calcareous soils, whereas in acid soils Cd adsorption was mainly

Soil food webs of the McMurdo Dry Valleys, Antarctica are simple. These include primary trophic levels of mosses, algae, cyanobacteria, bacteria, archaea, and fungi, and their protozoan and metazoan consumers (including relatively few species of nematodes, tardigrades, rotifers, and microarthropods). These biota are patchily distributed across the landscape, with greatest faunal biodiversity associated with wet soil. Understanding trophic structure is critical to studies of biotic interactions and distribution; yet, McMurdo Dry Valley soil food web structure has been inferred from limited laboratory culturing and micro- scopic observations. To address this, we measured stable isotope natural abundance ratios of C (13C/12C) and N (15N/14N) for di erent metazoan taxa (using whole body biomass) to determine soil food web structure in Taylor Valley, Antarctica. Nitrogen isotopes were most useful in di erentiating trophic levels because they fractionated predictably at higher trophic levels. Using ...

polyphenols; aluminum accumulator; near natural forest management; chloroform fumigation extraction; soil structure; soil enzymes; manure pelleting; microbial biomass; Oxisol; biolability; soil nutrients; second production cycle; PLFA; pyrolysis; Eucalyptus sp.; Cunninghamia lanceolata plantation; carbon; the Three Gorges Reservoir; revegetation; carbon distribution index; climate change; seasons; annual increment average; topography; humic substances; litter N; soil fertility; climate zone; nutrient cycling; Daxingan Mountains; carbon mineralization; nitrification; 31P nuclear magnetic resonance spectroscopy (31P NMR); organic matter; throughfall; forest soil; dissolved organic carbon (DOC); P species; stoichiometric homeostasis; dissolved organic matter (DOM); soil organic matter fraction; variable-charge soils; ammonium; nitrate; soil degradation; soil P fractions; seasonal trends; ammonia-oxidizing bacteria; nitrogen dynamics; net primary productivity; soil microbial communities; beech ...

A kinetic study for the phosphorus release of a formulated CaHAP-Z fertilizer was done to observe its behavior when applied to clay loam soil. The study of release kinetics of CaHAP-Z was done along with CaHAP and the control fertilizer Solophos™ to determine whether the formulated fertilizer can be an alternative for the conventional fertilizer. Results showed that the formulated fertilizer CAHAP-Z contains 3.73% phosphorus with 513.10 nm particle (Dynamic Light Scattering) indicating that the formulated fertilizer can be classified as a nanofertilizer. The formulated CaHAP-Z fertilizer showed the slowest release kinetics compared to the controls. In addition, this study showed that the simple Elovich kinetic model is the general equation that best fits to describe the phosphorus release of fertilizers. ...

The potential of a plant species to acquire nutrients depends on its ability to explore the soil by its root system. Co-cultivation of different species is anticipated to lead to vertical root niche differentiation and thus to higher soil nutrient depletion. Using a qPCR-based method we quantified root biomass distribution of four catch crop species in vertical soil profiles in pure vs. mixed stands. Pure stands of mustard and phacelia robustly reached 70 cm soil depth, while oat preferably colonized upper soil layers, and clover developed the shallowest and smallest root system. Analysis of residual nitrate pools in different soil depths and correlation with root biomass showed that, besides rooting depth also root biomass determines soil nitrogen depletion. While occupying the same vertical niches as in pure stands, mustard and phacelia dominated total root biomass of the mix. In contrast, root biomass of clover and oat was severely suppressed in presence of the other species. Below-ground biomass

Soil respiration is a key component of the global carbon cycle, and even small changes in soil respiration rates could result in significant changes in atmospheric CO2 levels. The conversion of tropical forests to rubber plantations in SE Asia is increasingly common, and there is a need to understand the impacts of this land-use change on soil respiration in order to revise CO2 budget calculations. This study focused on the spatial variability of soil respiration along a slope in a natural tropical rainforest and a terraced rubber plantation in Xishuangbanna, SW China. In each land-use type, we inserted 105 collars for soil respiration measurements. Research was conducted over one year in Xishuangbanna during May, June, July and October 2015 (wet season) and January and March 2016 (dry season). The mean annual soil respiration rate was 30% higher in natural forest than in rubber plantation and mean fluxes in the wet and dry season were 15.1 and 9.5 Mg C ha-1 yr-1 in natural forest and 11.7 and ...

TY - JOUR. T1 - Chronic nitrogen fertilization and carbon sequestration in grassland soils: evidence of a microbial enzyme link. AU - Cenini, Valeria L.. AU - Fornara, Dario A.. AU - McMullan, Geoffrey. AU - Ternan, Nigel. AU - Lajtha, Kate. AU - Crawley, Michael J.. PY - 2015/12/1. Y1 - 2015/12/1. N2 - Chronic nitrogen (N) fertilization can greatly affect soil carbon (C) sequestration by altering biochemical interactions between plant detritus and soil microbes. In lignin-rich forest soils, chronic N additions tend to increase soil C content partly by decreasing the activity of lignin-degrading enzymes. In cellulose-rich grassland soils it is not clear whether cellulose-degrading enzymes are also inhibited by N additions and what consequences this might have on changes in soil C content. Here we address whether chronic N fertilization has affected (1) the C content of light versus heavier soil fractions, and (2) the activity of four extracellular enzymes including the C-acquiring enzyme ...

The silty soils of the intensively used agricultural landscape of the Saxon loess province, eastern Germany, are very prone to soil erosion, mainly caused by water erosion. Rainfall simulations, and also increasingly structure-from-motion (SfM) photogrammetry, are used as methods in soil erosion research not only to assess soil erosion by water, but also to quantify soil loss. This study aims to validate SfM photogrammetry determined soil loss estimations with rainfall simulations measurements. Rainfall simulations were performed at three agricultural sites in central Saxony. Besides the measured data runoff and soil loss by sampling (in mm), terrestrial images were taken from the plots with digital cameras before and after the rainfall simulation. Subsequently, SfM photogrammetry was used to reconstruct soil surface changes due to soil erosion in terms of high resolution digital elevation models (DEMs) for the pre- and post-event (resolution 1 × 1 mm). By multi-temporal change detection, the digital

We investigated the influence of soil drainage class and tree species on nitrogen (N) mineralization and nitrification rates in two forest catenas in southern Quebec. Monthly net N mineralization and nitrification rates were determined along transects running from well-drained to poorly drained soils for 2 years through in situ incubation of homogenized soils. Potential N transformation rates in soils under American beech, sugar maple, and eastern hemlock trees were determined through incubation of homogenized soils in the laboratory under two different moisture regimes (50 and 100% water by volume) mimicking well-drained and poorly drained soil conditions in the two watersheds. Field-based N mineralization rates averaged 38 ± 6 mg m−2 d−1 in well-drained soils, while those in the poorly drained soils averaged 17 ± 5 mg N m−2 d−1. Similarly, net nitrification rates in well-drained soils (18 ± 4 mg N m−2 d−1) were 3 times greater than those in poorly drained soils (6 ± 3 mg N ...

Introduction. Soil nutrient dynamics in seasonal floodplain ecosystems are highly complex1 as a result of flood pulses and changing redoximorphic state.2,3 Flood pulse refers to the alternating dry and wet conditions in floodplain ecosystems.4 It facilitates soil nutrient exchange between rivers and their associated seasonal floodplains.5 During floods, soil nutrients dissolve in floodwaters and are transported from seasonal floodplain surfaces into adjacent rivers.4 Soil nutrients may also be transported from the river into seasonal floodplains through lateral flow.4 Flooding can lead to both increases and decreases in soil nutrient content. During flooding the soil becomes highly reduced, resulting in a decrease in pH which leads to an increase in the mobility of soil nutrients such as P N, Mg, Ca, Na and K.2 These nutrients include those that were deposited by the previous flood and those released from organic matter decomposition accumulated during dry periods.6 Soil flooding can cause ...

INTRODUCTION. The constant and significant weight increase of agricultural and forest vehicles over the last decades in Brazil has caused concern in view of the possible long-term consequences on eucalyptus yield in soils under traffic. The imminent loss in forest productivity is great since traffic is a repeated action in stands (Balbuena et al., 2000). Machine traffic is admittedly one of the main origins of soil compaction, which has a negative knock-on effect on tree growth (Wert & Thomas, 1981; Froehlich et al., 1985; Startsev & McNabb, 2000).. Repeated traffic in a same area intensifies the damage done to the soil structure with consequent reductions in crop yields in the first as well as in the following years of production (Håkansson & Reeder, 1994; Lal, 1996; Jorajuria et al., 1997). During the removal of the wood from forest stands the machines drive along one and the same row several times. This can cause soil compaction and, consequently, hinder root growth. It was observed that in ...

Feb 20, 2017. Abstract:. Urban agriculture has been recently highlighted with the increased importance for recreation in modern society; however, soil quality and public health may not be guaranteed because of continuous exposure to various pollutants. The objective of this study was to evaluate the soil quality of urban agriculture by soil microbial assessments. Two independent variables, organic and inorganic fertilizers, were considered. The activities of soil enzymes including dehydrogenase, ?-glucosidase, arylsulfatase, urease, alkaline and acid phosphatases were used as indicators of important microbial mediated functions and the soil chemical properties were measured in the soils applied with organic or inorganic fertilizer for 10 years. Fatty acid methyl ester analysis was applied to determine the soil microbial community composition. Relatively higher microbial community richness and enzyme activities were found in the organic fertilizers applied soils as compared to the inorganic ...

Organic amendment is a good alternative to improve soil fertility to maintain or increase crop forage and grain production. After several times of organics application (crop cycles) is important to follow soil physical and chemical parameters to avoid soil pollution such as salinity and nitrate. The main objective of this study was to maintain good triticale forage production and soil quality after seven years in plots where two factor were studied:caw manure amendments; 0, 40, 80, 120 and 160 t ha -, and one chemical level with 150-100-00 kg ha-1 of Nitrogen, Phosphorus and potassium, respectively just to compare manure amendments. After This time to decrease soil salinity and high levels of nitrate triticaleforage was planted in the same plots using two varieties without manure and chemical fertilizer application. Triticale variables measured were green forage and soil parameters such as; Electrical Conductivity (EC), Organic Matter (OM), Hydrogenpotential (Ph) and Nitrates (NO-3). Results ...

Clonal white clover growing in pots was inoculated with Heterodera trifolii, Meloidogyne hapla, Meloidogyne trifoliophila, Pratylenchus sp., or Xiphinema diversicaudatum, pulse-labelled with 14C and after 15 days the distribution of 14C in compartments of the soil: plant: nematode system determined. Nematode inoculation had no effect on shoot, root and soil microbial biomasses, but the nematode treatments significantly affected the distribution of 14C in these compartments. The greatest translocation of 14C to the soil was in pots with X. diversicaudatum, M. hapla or M. trifoliophila. The percentage of 14C in the microbial biomass varied significantly, being highest with X. diversicaudatum and Pratylenchus sp., and lowest in control pots. Nematodes of all species from the soil consistently had lower specific activity than those from roots. It has now been demonstrated for a range of nematodes and soils that nematode infection increases translocation of photosynthate to soil microbial biomass. As the

Objective:Investigating the microbes and interactions of the beneficial symbiotic relationships between the components of the system ecology in the food chains and life cycles is one of the modern sustainable agriculture topics. In this regard, to evaluate the effects of bacteria and vermicompost on morphological characteristics and yield of soybean an experiment was conducted as split plot in a completely randomized block design with three replications. Methods: Main plots of experiment were at two levels including the non-use and the use of bacteria and the subplots were at three levels including the non-use of vermicompost (control), the use of 5 tons of vermicompost per acre and the use of 10 tons of vermicompost per acre. Results: The results of mean comparison showed that the treatment including 10 tons of vermicompost had the highest amount of oil content (11%) and the lowest amount was obtained from the treatment including use of 5 tons with the amount of 9.77%. Increasing the seed growing and

ABSTRACT Human food chain toxicity, soil fertility and agricultural output have been shown to be influenced by application of various types of fertilizers. This research studied the influence of multiple fertilizer application on soil quality and plant heavy metal accumulation, proximate and phytochemical compositions. The different fertilizer samples used were NlSPlSKlS (CFI), N20PIOKIO (CF2), N27P13PI3 (CF3), pig manure (AMI) and chicken manure (AM2). Plant species used were Telfairia occidental is and Talinum triangulare. The experiment had four treatments and each treatment had 0.0, 2.0 and 4.0glkg soil. The seeds of the vegetables were planted and allowed to grow for a period of 12 weeks. The first sets of the experimental pots were left for a latent period of 12 weeks after the first harvest for second fertilizer application. The heavy metal composition of the different fertilizers and control soil as well as the plant species were studied using Atomic Absorption Spectrophotometry (AAS). ...

List of Environmental Soil Sampling Kit (Soil Sampling) companies, manufacturers and suppliers serving Bahrain on Soil and Groundwater - Environmental XPRT

General soil characteristics; Soil series descriptions; General soil characteristics; Soil series descriptions; Middle Cuba; Eastern Cuba; Western Cuba; Isle of pines; Salt in Cuban soils; Soil moisture studies; Climate; The relation of soils to agriculture in Cuba; Soil Classification; Soil classes; Classification of soils based on mechanical composition; Conversion table for sugar cane yields ...

Decomposing alfalfa (Medicago sativa L.) shoots and roots generate large amounts of NO3-N available to the next crop but also susceptible to deep leaching. This study was aimed at determining the specific contributions of above- and belowground alfalfa biomass to soil N pools. Dynamics of soil and plant N pools were studied in a Kalamanzoo loam soil (fine-loamy, mixed, mesic Typic Hapludalfs) over a 2-yr period under bare fallow (BF), bare fallow to which alfalfa shoot mulch was applied (BFSM), living alfalfa plants with shoots removed after harvest (A), and living alfalfa with shoot mulch remaining on the soil surface after harvest (ASM). Organic N pools were monitored in alfalfa plant parts, soil-incorporated debris, and soil organic matter to depths of 150 cm. Inorganic N pools were monitored by suction lysimeters, soil extraction, and evaluation of soil denitrification rates. Living alfalfa stands kept soil inorganic N at very low levels, whether shoot mulch was applied or not. Soluble ...

A number of potential benefits of humic substances are well known recognized and its generation has been concerned with miscellaneous factors. In Thailand, one of Southeast Asia countries, agricultural areas can be normally found in the country parts. Variety soil practices have been done to improve soil fertilities. Those outcomes, both the properties of soil and organic substances in terms of active and inactive forms, were also raised the question. This study aims to develop the appropriate equation model with particular to some basis of soil properties and the quantity of humic acid extracted from them. To achieve this goal, thirty-four soils from existing agricultural areas in the western part of Thailand were sampled. Soil properties which closely concern with humic substances, including organic matter (OM), total carbon (TC), total nitrogen (TN), percentage of clay and cation exchange capacity (CEC), were analyzed. Humic acid were extracted by the standard of International Humic ...

Four low-cost organic soil amendments (chicken manure, CM; horse manure, HM; yard water, YW; and sewage sludge, SS) that are generated daily in large amounts, and native bare soil were planted with tomato (Solanum lycopersicum var. Mountain spring) seedlings of 52 days old in raised black plastic-mulch. Each of the 5 treatments was also mixed with biochar to make a total of 10 treatments in a randomized complete block design (RCBD). Results revealed that total fresh weight of tomato fruits collected after three harvests from CM and CM mixed with biochar significantly (P < 0.05) increased, whereas yield obtained from HM was the lowest indicating a positive effect of CM on the growth and yield of tomato. HM increased soil urease activity, while CM and SS increased soil invertase activity. Total marketable tomato yield of biochar amended soils was increased by 63 and 20% in HM and YW treatments, respectively compared to other soil treatments. Ascorbic acid (vitamin C) was greatest in fruits of plants

A. K. Helmy, E. A. Ferreiro, S. G. de Bussetti; Cation exchange capacity and condition of zero change of hydroxy-Al montmorillonite. Clays and Clay Minerals ; 42 (4): 444-450. doi: Download citation file:. ...

Tropical forests are vital global reservoirs of biodiversity and carbon (C). Deforestation and degradation of these ecosystems greatly threatens their capacity to provide crucial ecosystem functions and services, by altering complex plant-soil interactions and biogeochemical cycles underpinned by soil microbes. Forest disturbance is accelerating in Southeast Asia, through widespread selective logging (SL) and forest conversion to oil palm plantation (OP). This has major implications for soil microbial communities and functions, although effects of tropical forest disturbance on belowground biodiversity and the resistance and resilience of soil microbial nutrient and C-cycling are unresolved. The potential to restore soil microbial communities and essential functions is also largely unknown. The aim of this thesis was to evaluate impacts of tropical forest modification (degradation, conversion and restoration) on soil microbial community attributes, and implications for ecosystem biogeochemical ...

Abstract. Soil respiration of terrestrial ecosystems, a major component in the global carbon cycle is affected by elevated atmospheric CO2 concentrations. However, seasonal differences of feedback effects of elevated CO2 have rarely been studied. At the Gießen Free-Air CO2 Enrichment (GiFACE) site, the effects of +20% above ambient CO2 concentration have been investigated since 1998 in a temperate grassland ecosystem. We defined five distinct annual seasons, with respect to management practices and phenological cycles. For a period of 3 years (2008-2010), weekly measurements of soil respiration were carried out with a survey chamber on vegetation-free subplots. The results revealed a pronounced and repeated increase of soil respiration under elevated CO2 during late autumn and winter dormancy. Increased CO2 losses during the autumn season (September-October) were 15.7% higher and during the winter season (November-March) were 17.4% higher compared to respiration from ambient CO2 plots ...

A key focus of the BGI department is the development of large scale terrestrial biosphere models (TBM) for a better understanding of biosphere-climate feedbacks, with particular emphasis on interactions between carbon, nutrient and water cycles. A highly important question in this context is the stability of soil organic matter under changing environmental conditions. However, soil processes, their parameterization and soil interactions with vegetation growth are still a major uncertainty in TBMs. Two active areas of research in our department are the effect of altered rhizosphere inputs on the microbial activity and thereby the organic carbon storage, as well as the control that of soil temperature and moisture have on the decomposition process. Our aim is to achieve a better representation of these nutrient and moisture effects on soil carbon storage and turnover in our soil model COMISSION (Ahrens et al. 2015), which is linked to the Earth system Model of the Max-Planck-Society. In this ...

The adsorption and desorption of diuron and fluometuron by the Gezira clay, Kinana clay, and Gerif loamy clay soils were studied. The two herbicides exhibited greater adsorption by the Gerif soil than by the Kinana and Gezira soils. The Kinana soil adsorbed more fluometuron than the Gezira soil. However, only at low and high concentrations of diuron did the Kinana soil show greater adsorption than the Gezira soil. At intermediate range of diuron concentrations the opposite occurred. Since the Gezira soil contained the lowest percentage of organic matter it was argued that organic matter did not play any significant role in the adsorption of these two herbicides by these soils. The Gerif soil has the highest specific surface area than the twos ils. It was thus concluded that in arid-zone soils, very low in organic matter, specific surface area may be a good criterion for determining adsorption. Diuron exhibited greater adsorption on the three soils than fluometuron. Desorption was studied by an ...

1. Bongers, T. 1990. The maturity index: an ecological measure of environmental disturbance based on nematode species compostion. Oecologia 83:14-19.. 2. Bongers, T., and Bongers, M. 1998. Functional diversity of nematodes. Appl. Soil Ecol. 10:239-251.. 3. Cooke, R. C. 1963. Ecological characteristics of nematode-trapping fungi Hyphomycetes. Ann. Rev. Appl. Biol. 52:431-437.. 4. Doran, J. W., Sarrantonio, M., and Liebig, M. A., eds. 1996. Soil health and sustainability, Adv. Agron. 56:1-54.. 5. Ettema, C. H. 1998. Soil nematode diversity, species coexistence and ecosystem function. J. Nematol. 30:159-169.. 6. Ferris, H., Bongers, T., and deGoede, R. G. M. 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis concept. Appl. Soil Ecol. 18:13-29.. 7. Ferris, H., and Matute, M. M. 2003. Structural and functional succession in the nematode fauna of a soil food web. Appl. Soil Ecol. 23:93-110.. 8. Ferris, H., Venette, R. C., and Lau, S. S. 1996. Dynamics of ...

Knowledge of how competition and facilitation affect photosynthetic traits and nitrogen metabolism contributes to understanding of plant-plant interaction mechanisms. We transplanted two larch species, Larix kaempferi and L. olgensis, to establish intra- and interspecific interaction experiments under different types of soil. Experiment 1: Two different soil types were selected, one from a c. twenty years old L. kaempferi plantation (named larch soil) and another from a secondary natural forest (named mixed forest soil). The experiment included three types of plant interactions (L kaempferi + L. kaempferi, L. olgensis + L. olgensis, and L. kaempferi + L. olgensis) and two soil types. Experiment 2: N fertilization was applied to larch soil. The experiment included the same three types of plant interactions as in Experiment 1 and two N treatments. The growth of L kaempferi was negatively affected by larch soil and accelerated by N fertilization, particularly under interspecific interaction. The ...

Soil acidification is a major problem in modern agricultural systems and is an important factor affecting the soil microbial community and soil health. However, little is known about the effect of soil acidification on soil-borne plant diseases. We performed a four-year investigation in South China to evaluate the correlation between soil acidification and the occurrence of bacterial wilt. The results showed that the average soil pH in fields infected by bacterial wilt disease was much lower than that in non-disease fields. Moreover, the proportion of infected soils with pH lower than 5.5 was much higher than that of non-infected soils, and this phenomenon became more obvious as the area of bacterial wilt disease increased at soil pH lower than 5.5 from 2011 to 2014. Then, in a field pot experiment, bacterial wilt disease developed more quickly and severely in acidic conditions of pH 4.5, 5.0 and 5.5. These results indicate that soil acidification can cause the outbreak of bacterial wilt disease.

Arbuscular mycorrhizal fungi (AMF) are soil fungi forming symbiotic associations with majority of land plants. AMF alter soil organic matter (SOM) directly through stabilization of soil aggregates and indirectly providing a path in which plant fixed C02 is transferred below-ground. Understanding contributions of AMF to SOM via protein production and stabilization of soil aggregates will greatly aid our understanding of soil carbon sequestration, nutrient cycling and mitigation of soil erosion. The work presented in chapter 2 challenges the glomalin extraction process and assesses the accuracy of the Bradford and monoclonal-antibody ELISA detection methods. My results clarify the contribution of glomalin to SOM: suggesting the extraction process is not eliminating all non-glomalin proteins. My results indicate that the Bradford is prone to overestimating the presence of glomalin when soils contain large concentrations of SOM, the ELISA is prone to retention and interference biases depending on the amount

A group of leading soil scientists, including the University of Delawares Donald L. Sparks, has summarized the precarious state of the worlds soil resources and the possible ramifications for human security in a paper published Thursday, May 7, in the journal Science.. In a review of recent scientific literature, the article, titled Soil and Human Security in the 21st Century, outlines threats to soil productivity -- and, in turn, food production -- due to soil erosion, nutrient exhaustion, urbanization and climate change.. Soil is our planets epidermis, said Sparks, echoing the opening line of the article. Its only about a meter thick, on average, but it plays an absolutely crucial life-support role that we often take for granted.. Sparks, who is the S. Hallock du Pont Chair in Soil and Environmental Chemistry in the Department of Plant and Soil Sciences at UD, has been chair of the National Academy of Sciences U.S. National Committee for Soil Sciences since 2013.. He and his five ...

Manure additions to cropland can reduce total P losses in runoff on well-drained soils due to increased infiltration and reduced soil erosion. Surface residue management in subsequent years may influence the long-term risk of P losses as the manure-supplied organic matter decomposes. The effects of manure history and long-term (8-yr) tillage [chisel plow (CP) and no-till (NT)] on P levels in runoff in continuous corn (Zea mays L.) were investigated on well-drained silt loam soils of southern and southwestern Wisconsin. Soil P levels (0-15 cm) increased with the frequency of manure applications and P stratification was greater near the surface (0-5 cm) in NT than CP. In CP, soil test P level was linearly related to dissolved P (24-105 g ha?1) and bioavailable P (64-272 g ha?1) loads in runoff, but not total P (653-1893 g ha?1). In NT, P loads were reduced by an average of 57% for dissolved P, 70% for bioavailable P, and 91% for total P compared with CP. This reduction was due to lower sediment ...

1. Introduction. 2. Measurement of Moisture Content.. 3. Measurement of Specific Gravity of Soil Solids.. 4. Measurement of Liquid Limit and Plastic Limit.. 5. Analysis of Grain Size Distribution.. 6. Laboratory Classification of Soil.. 7. Field Classification of Soil.. 8. Laboratory Soil Compaction.. 9. Field Measurement of Dry Unit Weight and Moisture Content.. 10. Measurement of Hydraulic Conductivity of Granular Soil Using a Fixed-Wall Permeameter.. 11. One-Dimensional Consolidation Test of Cohesive Soil.. 12. Direct Shear Strength Test of Granular Soil.. 13. Unconfined Compressive Strength Test of Cohesive Soil.. 14. Unconsolidated-Undrained Triaxial Shear Strength Test of Cohesive Soil.. Appendix A. Laboratory Data Sheets. ...

Dune slacks are biodiverse seasonal wetlands which experience considerable fluctuation in water table depth. They are under threat from lowered water tables due to climate change and water abstraction and from eutrophication. The biological effects caused by the interactions of these pressures are poorly understood, particularly on soil processes. We used a mesocosm experiment and laboratory assays to study the impact of lowered water tables, groundwater nitrogen contamination, and their synergistic effects on soil microbial processes and greenhouse gas emissions. This study showed that just a 10 cm decrease in water table depth led to a reduction in denitrification and to a corresponding increase in soil nitrogen content. Meanwhile N2O emissions occurred for longer durations within dune slack soils subject to higher concentrations of groundwater nitrogen contamination. The results from extracellular enzyme assays suggest that decomposition rates increase within drier soils shown by the increase ...

Dune slacks are biodiverse seasonal wetlands which experience considerable fluctuation in water table depth. They are under threat from lowered water tables due to climate change and water abstraction and from eutrophication. The biological effects caused by the interactions of these pressures are poorly understood, particularly on soil processes. We used a mesocosm experiment and laboratory assays to study the impact of lowered water tables, groundwater nitrogen contamination, and their synergistic effects on soil microbial processes and greenhouse gas emissions. This study showed that just a 10 cm decrease in water table depth led to a reduction in denitrification and to a corresponding increase in soil nitrogen content. Meanwhile N2O emissions occurred for longer durations within dune slack soils subject to higher concentrations of groundwater nitrogen contamination. The results from extracellular enzyme assays suggest that decomposition rates increase within drier soils shown by the increase ...

Soil texture strongly influences the soils ability to retain moisture (available water holding capacity), its general level of fertility and ease or difficulty of cultivation. Water moves easily through sandy soils therefore small amounts of moisture are retained and these soils dry out more quickly than clayey soils. Clayey soils transmit water very slowly; therefore these soils are susceptible to excess soil moisture conditions and to water erosion in undulating landscapes. Sandy soils do not retain plant nutrients as well as clayey soils and are lower in natural fertility; sandy soils often characterized by loose or single grained structure and are very susceptible to wind erosion. Medium-textured (loamy) soils are characterized by properties that fall between the extremes of coarse and fine-textured soils. They are generally fertile, able to retain sufficient moisture for plant use and are relatively easy to cultivate. Mineral particles in soil are grouped according to size into sand (2-0.05 ...

Rainfall is the main resource of soil moisture in the semiarid areas, and the altered rainfall pattern would greatly affect plant growth and development. Root morphological traits are critical for plant adaptation to changeable soil moisture. This study aimed to clarify how root morphological traits of Bothriochloa ischaemum (a C4 herbaceous species) and Lespedeza davurica (a C3 leguminous species) in response to variable soil moisture in their mixtures. The two species were co-cultivated in pots at seven mixture ratios under three soil water regimes [80% (HW), 60% (MW), and 40% (LW) of soil moisture field capacity (FC)]. At the jointing, flowering, and filling stages of B. ischaemum, the LW and MW treatments were rewatered to MW or HW, respectively. At the end of growth season, root morphological traits of two species were evaluated. Results showed that the root morphological response of B. ischaemum was more sensitive than that of L. davurica under rewatering. The total root length (TRL) and root

The increase in soil test phosphorus differs for different soils; the same soil test phosphorus on different soils may support different concentrations of phosphorus in runoff. Soils with higher soil test phosphorus support higher concentrations of phosphorus in runoff. Soil-specific data are lacking for most Missouri soils.. The environmental soil test phosphorus, like agronomic soil test phosphorus, is an index procedure that extracts only a portion of the phosphorus in soil. The extraction procedure and the depth of soil sampling will dramatically effect the soil test value reported on a given soil. Caution should be used when quoting critical soil test levels; always note the extraction method and depth of soil sampling. Environmental soil test values from a Bray-I test on a 6-inch sample and a water extract on a 1-inch sample are not comparable.. Extracts being considered for environmental soil test phosphorus include water, Bray-I P, Mehlich-III P and iron-oxide strip P. Depth of soil ...

Mongol News interviewed senior worker at the Public Health Institute Sh.Batdelger about this issue.. Does the Public Health Institute conduct research on soil contamination each year? If so, which part of the city has research been conducted in lately?. Research in 2012 showed that 80 percent of Ulaanbaatar was affected by third degree soil contamination. Some parts had been found to have top soil contamination.. In 2013, our scientists took soil samples near schools and kindergartens in Bayanzurkh District and the result was at fourth degree contamination.. Recent research done in public areas near Narantuul in the 14th khoroo, Bayanzurkh District found heavy metals in the soil.. In the past we did research in the Ulaanbaatar area, but we are now conducting research in each district.. Does trash cause the soil contamination around Narantuul, and why has the market area been specifically focused on for conducting research?. We cleaned the area surrounding Narantuul on our Trash Bucket ...

Increases in the magnitude and variability of precipitation events have been predicted for the Chihuahuan Desert region of West Texas. As patterns of moisture inputs and amounts change, soil microbial communities will respond to these alterations in soil moisture windows. In this study, we examined the soil microbial community structure within three vegetation zones along the Pine Canyon Watershed, an elevation and vegetation gradient in Big Bend National Park, Chihuahuan Desert. Soil samples at each site were obtained in mid-winter (January) and in mid-summer (August) for 2 years to capture a component of the variability in soil temperature and moisture that can occur seasonally and between years along this watershed. Precipitation patterns and amounts differed substantially between years with a drought characterizing most of the second year. Soils were collected during the drought period and following a large rainfall event and compared to soil samples collected during a relatively average ...

TY - JOUR. T1 - Nitrogen limitation and nitrogen fixation during alkane biodegradation in a sandy soil. AU - Toccalino, P. L.. AU - Johnson, R. L.. AU - Boone, D. R.. PY - 1993/9/17. Y1 - 1993/9/17. N2 - We investigated nutrient limitations during hydrocarbon degradation in a sandy soil and found that fixed nitrogen was initially a limiting nutrient but that N limitation could sometimes be overcome by N2 fixation. Hydrocarbon biodegradation was examined in an unsaturated sandy soil incubated aerobically at 20°C with propane or butane and various added nutrients. Propane and butane degradation proceeded similarly during the first 3 months of incubation. That is, bacteria in soil amended with N oxidized these hydrocarbons more rapidly than in controls without nutrient additions or in soil with added phosphate or trace minerals. Both propane- and butane-amended soil apparently became N limited after the initial available inorganic N was utilized, as indicated by a decrease in the rates of ...

Continuous measurements of soil respiration and its components help us understand diurnal and seasonal variations in soil respiration and its mechanism. We continuously measured CO2 concentration at various depths in the soil and calculated surface CO2 efflux based on CO2 gradients and diffusivity in a young ponderosa pine plantation in the Sierra Nevada Mountains of California. We determined soil respiration both in a control plot that included roots and in a trenched plot that had no roots. The difference between these plots was used to partition soil respiration into root respiration and heterotrophic respiration.We found that both CO2 concentration in the soil and surface CO2 efflux in the control plot were higher than in the trenched plot. The diurnal range of soil respiration in the trenched plot was larger than in the control. We observed dramatic pulses of soil respiration in response to rain events in summer and fall during the dry season. We modeled the seasonal variation in soil ...

Red alder (Alnus rubra Bong.) is well recognized as an effective host plant for the symbiotic fixation of N. While this fixation process leads to the rapid accumulation of N within the ecosystem, it also enhances nutrient accumulation in biomass and soil organic matter and increases nitrification and cation leaching. We hypothesized that changes in soil properties resulting from these processes would decrease site productivity for second rotation red alder. Adjacent stands of 55 yr old alder and Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) were studied at the Thompson Research Center on the Cedar River Watershed in western Washington, USA. The presence of red alder oaused the following soil changes: decreased soil solution pH, increased CEC, increased exchangeable acidity accompanied by a decreased soil pH and base saturation. This decreased soil and soil solution pH resulted in increased A1 concentration in the soil solution and on exchange sites as well as decreased P availability. To

Abstract: Soil vermiculite clays of varying tetrahedral and octahedral composition and cation exchange capacity (CEC) were examined for their ability to fix K+ in both the wet and dry states. Fixation capacity, expressed as per cent of the CEC, in the wet state was fairly high for most samples but it was enhanced greatly upon drying the K saturated samples. This enhancement indicated that each sample contained a number of vermiculite species with different CECs.. The vermiculite clays, as a group, exhibited a much higher fixation capacity at a much lower CEC than those of the coarse grained vermiculites. This enhanced fixation is believed due to the dioctahedral nature of the coarse grained vermiculites. In samples of nearly equal CECs only those containing Al3+ in tetrahedral positions exhibited an enhanced fixation capacity in the dry state but not in the wet state.. In was remarkable to find that the state of oxidation of crystal structure iron strongly affected the fixation and the CEC. ...

Although ammonia-oxidizing archaea (AOA) and bacteria (AOB) coexist in most non-acidic agricultural soils, the factors that influence their relative contributions to soil nitrification activity remain unclear. A 2- to 4-d whole soil microcosm assay was developed, utilizing the aliphatic C₈ alkyne 1-octyne to inactivate AOB-driven nitrification activity without impacting AOA nitrification activity. Responses of AOA- and AOB-supported net nitrification activities (accumulation of NO₂⁻ + NO₃⁻) to different concentrations of extractable NH₄⁺ were examined in four diverse, paired cropped and non-cropped Oregon soils sampled in summer and winter. Maximum AOA-supported net nitrification rates were significantly higher in non-cropped (3.7 mg N kg⁻¹ soil d⁻¹) than in cropped soils (0.9 mg N kg⁻¹ soil d⁻¹) and in summer (3.1 mg N kg⁻¹ soil d⁻¹) compared with winter soils (1.6 mg N kg⁻¹ soil d⁻¹). The NH₄⁺ concentration required to significantly stimulate AOB ...

TY - JOUR. T1 - Effects of plant-soil feedback on tree seedling growth under arid conditions. AU - Meijer, S.S.. AU - Holmgren, M.. AU - Van der Putten, W.H.. N1 - Reporting year: 2011 Metis note: 5220; WAG; TE. PY - 2011. Y1 - 2011. N2 - Aims Plants are able to influence their growing environment by changing biotic and abiotic soil conditions. These soil conditions in turn can influence plant growth conditions, which is called plant-soil feedback. Plant-soil feedback is known to be operative in a wide variety of ecosystems ranging from temperate grasslands to tropical rain forests. However, little is known about how it operates in arid environments. We examined the role of plant-soil feedbacks on tree seedling growth in relation to water availability as occurring in arid ecosystems along the west coast of South America. Methods In a two-phased greenhouse experiment, we compared plant-soil feedback effects under three water levels (no water, 10% gravimetric moisture and 15% gravimetric ...

Many small- and medium-sized mammals dig for their food. This activity potentially affects soil condition and fertility. Digging is well developed especially in Australian mammals, many of which have recently become rare or extinct. We measured the effects of digging by mammals on soil in a Tasmanian temperate dry sclerophyll forest with an intact mammal community. The density of diggings was 5812 ha−1, affecting 11% of the forest floor. Diggings were created at a rate of around 3113 diggings ha−1 yr−1, disturbing 6.5% of the forest floor and displacing 7.1 m3 ha−1 of soil annually. Most diggings were made by eastern bettongs (Bettongia gaimardi) and short-beaked echidnas (Tachyglossus aculeatus). Many (approx. 30%) fresh diggings consisted of re-excavations of old diggings. Novel diggings displaced 5 m3 ha yr−1 of soil. Diggings acted as traps for organic matter and sites for the formation of new soil, which had higher fertility and moisture content and lower hardness than undisturbed ...

Stand establishment plays a significant role in the development and yield of winter wheat (Triticum aestivum L.). Availability of soil moisture to the germinating seed is one of the most critical factors affecting stand establishment. Water injection is a method of applying supplemental moisture to the soil in direct contact with the seed by injecting small amounts of water into seed-zone at planting. The purpose of this study was to evaluate water injection as a means of enhancing stand establishment by improving soil moisture conditions surrounding the germinating seed. Several water injection and combinations of water with liquid starter fertilizer treatments were compared with a check which received no water, under different soil water potential treatments in growth chambers and in field studies. Two soft white winter wheat cultivars, Faro and Stephens, were compared. In preliminary experiments water was added to the seed-zone of dry soil (-11 bars) at rates of 20, 30, 40, 50, and 60 ml/m ...

perfect climate for citrus and by the 1800s, Florida growers were farming citrus commercially. Citrus grows best in well-drained and aerated soils. Most of Central and Southwest Florida has excellent sandy mineral soils low in organic matter with good natural fertility for citrus trees to flourish.. The 2020-21 Florida Citrus Production Guide details several soil characteristics affecting soil fertility including pH, organic matter, and cation exchange capacity. Historically most native Florida soils used for citrus plantings had a low pH in the top 6 inches, but at present most have a high pH. This was caused by most irrigation water being too alkaline which raised the soil pH over time, leading to high pH in soils that have been a part of irrigated crop production.. The optimum pH of soil and irrigation water is between 6.0 and 6.5. Floridas environment seems to work perfectly together to create the best soil pH for citrus. When you account for the ample sunshine and abundant rainfall common ...

Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (&60; 0.01 mg L&178;-1). A onetime application of just 56 kg P ha&178;-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982&59; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978&59; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions. I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization ...

Soil organic carbon (SOC) supports essential functions in terrestrial biomes and global biogeochemical cycles, and tropical tree plantations are often called upon to reverse deforestation-induced SOC loss. Yet the comparative efficacy of different plantation types and associated drivers of SOC restoration remain unclear. Theory suggests that higher chemical and spatial heterogeneity of plant litter should promote greater efficiency of soil microbial communities involved in SOC formation, so we hypothesised that more species-diverse tree plantations should be more effective in accelerating recovery of SOC. To test this, we compared developmental recovery of SOC and soil microbial communities between monoculture (Swietenia macrophylla King, mahogany) and highly diverse and mostly native species plantations (termed rainforestation). All plantation types, which were aged 15 to 20 years, only restored the composition of the soil microbial community to 20-30% of the reference, selectively logged ...

We investigated the seasonal patterns of soil phosphorus (P) fractions under five vegetation types - Ulmus macrocarpa savanna, grassland, Pinus sylvestris var. mongolica plantation, Pinus tabulaeformis plantation, and Populus simonii plantation - in the southeastern Keerqin Sandy Lands of China. The measured P fractions (0-20 cm depth) included: soil total P (TP), total organic and inorganic P (TPo and TPi), bicarbonate extractable organic and inorganic P (BPo and BPi), microbial biomass P (MBP), and in situ resin-adsorbed P (resin-P). Soil TP and TPo concentrations in the savanna and grassland were significantly lower in summer than in spring and autumn. However, they were relatively stable in three forest plantations. Soil labile P fractions showed a significant seasonal pattern under all vegetation types with the peak in summer, except soil MBP that was constant in the savanna and grassland and BPo that decreased over time in the savanna. This pattern of labile P fractions was attributed to a ...

We collected soil samples from 27 study sites across North Central United States to compare the soil carbon of short rotation poplar plantations to adjacent agricultural crops and woodlots. Soil organic carbon (SOC) ranged from 20 to more than 160 Mg/ha across the sampled sites. Lowest SOC levels were found in uplands and highest levels in riparian soils. We attributed differences in bulk density and SOC among cover types to the inclusion of woodlot soils in the analysis. Paired comparison found few differences between poplar and agricultural crops. Sites with significant comparisons varied in magnitude and direction. Relatively greater SOC was often observed in poplar when native soil carbon was low, but there were important exceptions. Woodlots consistently contained greater SOC than the other crops, especially at depth. We observed little difference between paired poplar and switchgrass, both promising bioenergy crops. There was no evidence of changes in poplar SOC relative to adjacent ...

Microbe-mediated ammonia oxidation is a key process in soil nitrogen cycle. However, the effect of maize straw mulching on the ammonia oxidizers in the alkaline purple soil remains largely unknown. A three-year positioning experiment was designed as follows: straw mulching measures as the main-plot treatment and three kinds of nitrogen application as the sub-plot treatment. We found the contents of soil organic carbon (SOC), total nitrogen (TN), available potassium (AK), available nitrogen (AN), available phosphorus (AP), and NH4+-N were increased after straw mulching and nitrogen application in alkaline purple soil, so did the amoA genes abundance of ammonia-oxidizing archaeal (AOA) and bacterial (AOB). Terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that Thaumarchaeote (448-bp T-RF) was dominated the AOA communities, whereas Nitrosospira sp (111-bp T-RF) dominated the AOB communities. The community compositions of both AOA and AOB were altered by straw mulching and

The most important characteristic of stevia is its high sweetness with zero calories which is due to the presence of Steviol glycosides (SVglys). This research aims to address the effect of salicylic acid (SA) and microelements viz. iron (Fe) and zinc (Zn) under different soil water potentials (-0.5, -3.5, -6.5 and -10 atm) on the production of SVglys and total sugar content in the leaves of stevia. The obtained results indicated that the soil water content and the exogenous application of SA and microelements significantly changed the accumulation of these sweet chemicals in the stevia leaves. The highest values of Stevioside (Stev), Rebaudioside C (Reb C), total SVglys and SVglys yield were obtained in SA + Fe + Zn treatment under the potential of -3.5 atm (76. 82, 2.82, 116.71 mg g-1 DW and 0.836 g-1 plant, respectively). Also, the HPLC results indicated that the highest rates of Rebaudioside A (Reb A) and the Reb A/Stev ratio (sweetness quality) belonged to SA + Zn treatment under the potential of

We have since been awarded a Royal Society of Chemistry grant to continue this research, and have developed a project aimed at establishing harmonised methods for both microdialysis sampling in soils and subsequent data interpretation. Despite the potential advantages of microdialysis, considerable effort is required to develop and progress the analytical chemistry and theoretical frameworks to apply the technology to soil solution multi-elemental analysis. By providing accurate and precise data on the bioavailability of beneficial and harmful elements in soil, substantial progress can be made within soil science, botany and agricultural sciences. A better understanding of what is beneath our feet can only help us in tackling real world problems (incorporating the SDGs); microdialysis truly has the potential to pave the way in finding the solutions to widespread food security and nutrition issues, as well as aiding the promotion of sustainable agriculture and good health and well-being.. We aim ...

Soils are facing new environmental stressors, such as titanium dioxide nanoparticles (TiO2-NPs). While these emerging pollutants are increasingly released into most ecosystems, including agricultural fields, their potential impacts on soil and its function remain to be investigated. Here we report the response of the microbial community of an agricultural soil exposed over 90 days to TiO2-NPs (1 and 500 mg kg-1 dry soil). To assess their impact on soil function, we focused on the nitrogen cycle and measured nitrification and denitrification enzymatic activities and by quantifying specific representative genes (amoA for ammonia-oxidizers, nirK and nirS for denitrifiers). Additionally, diversity shifts were examined in bacteria, archaea, and the ammonia-oxidizing clades of each domain. With strong negative impacts on nitrification enzyme activities and the abundances of ammonia-oxidizing microorganism, TiO2-NPs triggered cascading negative effects on denitrification enzyme activity and a deep ...

In order to explore the effects of biochar on saline soil improvement and crop growth,two melon(Cucumis melo L.) varieties Bingxuecui and Yulu were carried out under saline soil with organic fertilizer treatment and biochar treatment.The results showed that compared with organic fertilizer treatment,biochar treatment could effectively drop soil electrical conductivity from 1 232.8 |xS/cm to 940.0 μS/cm during fruit maturation period of Bingxuecui;Soil respiration under biochar treatment was 0.45 g/(m~2? h) in Yulu,it was48.28%lower than organic fertilizer treatment in fruit enlargement period;Net photosynthetic rate and stomatal conductance were increased 14.25%and 69.99%in flowering period of Bingxuecui.The results demonstrated that biochar could reduce soil respiration,soluble salt content in soil,greenhouse gas CO_2 emissions and improve the net photosynthetic rate,fruit weight and quality.But it played little role on melon s biomass and fruit quality.

The course covers soil management and the nutritional requirement for rubber plantation Factors affecting the efficiency of production and management of estates are discussed The course includes soil series identification, soil taxonomy, soil suitability classification and fertilizer recommendation for sustainable rubber plantation. Download full brochure here :. BROCHURE - 17-18.6.2020 - RUBBER PLANTATION SOIL MANAGEMENT & NUTRITIONAL REQUIREMENT. ...

Seeds were planted in microwaved (pathogen-free) and non-microwaved (raw) soil adjusted to moisture levels corresponding to soil water potentials of -30, -50, -400 and -1000 kPa and tested at 10°C for seven days followed by 25°C for five days. A second experiment utilized a cold period temperature range from 4.5 to 13°C at a soil water potential of -40 kPa. Germination of untreated seed in raw soil ranged from 85% at -1000 kPa soil water potential (driest) to 57% at -30 kPa (wettest), with best separation of seed lots occurring at -50 kPa (0.24 kg kg-1 soil moisture). Seed treatment with Captan increased germination and nearly eliminated differences among soil moisture levels. The highest germination for treated and untreated seed lots in raw soil occurred at 4.5°C and 13°C, while the lowest germination (greatest stress) occurred at 9 and 10°C. No germination differences occurred among seed lots or among any experimental treatments (soil moisture, temperature, seed treatment) when ...

TY - JOUR. T1 - Assessing the effect of elevated carbon dioxide on soil carbon. T2 - A comparison of four meta-analyses. AU - Hungate, Bruce A.. AU - van Groenigen, Kees Jan. AU - Six, Johan. AU - Jastrow, Julie D.. AU - Luo, Yiqi. AU - de Graaff, Marie Anne. AU - van Kessel, Chris. AU - Osenberg, Craig W.. PY - 2009/7/15. Y1 - 2009/7/15. N2 - Soil is the largest reservoir of organic carbon (C) in the terrestrial biosphere and soil C has a relatively long mean residence time. Rising atmospheric carbon dioxide (CO2) concentrations generally increase plant growth and C input to soil, suggesting that soil might help mitigate atmospheric CO2 rise and global warming. But to what extent mitigation will occur is unclear. The large size of the soil C pool not only makes it a potential buffer against rising atmospheric CO2, but also makes it difficult to measure changes amid the existing background. Meta-analysis is one tool that can overcome the limited power of single studies. Four recent meta-analyses ...

Four European exotic earthworm fronts, two in Minnesota and two in Wisconsin, were used to examine the effect of earthworm guild assemblages (treatments) on the composition of the bacterial and fungal communities. Four transects, each containing 5 treatments based on ecological guild dominance (epigeic, endogeic, anecic, anecic 50 m, anecic 100 m) were constructed perpendicular to four advancing exotic earthworm fronts. The activity of each dominating guild was confirmed by a continual decrease in the O horizon depth and subsequent increase in A horizon depth. Soil samples collected in the fall of 2013 were used to examine the effect of guild assemblages on the soil microbial community. No biological differences were observed in microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), MBC: MBN, and carbon substrate utilization using Biolog Eco- and FF plates. TRFLP community profiles indicated the bacterial communities among treatments were highly similar, but a partial shift in the ...

Hydrocarbon contamination in soils may be toxic to plants and soil microorganisms and act as a source of groundwater contamination. The objective of this study was to evaluate the fate of diesel in soils with or without added nutrients. The soils examined either had or had not a previous history of hydrocarbon contamination. Particular aspects examined were soil respiration, changes in microbial population, breakdown of diesel hydrocarbons, and phytotoxicity to the germination of perennial ryegrass. Soil respiration was measured as evolved CO2. Bacterial population was determined as colony forming units in dilution plates and fungal activity was measured as hyphal length. The fate of individual hydrocarbons was determined by gas chromatography-mass spectrometry after extraction with dichloromethane. When diesel was added to soil with no previous history of hydrocarbon contamination at rates up to 50 mg/g, the respiration response showed a lag phase of 6 days and maximum respiration occurred at ...

Soil steam sterilization (soil steaming) is a farming technique that sterilizes soil with steam in open fields or greenhouses. Pests of plant cultures such as weeds, bacteria, fungi and viruses are killed through induced hot steam which causes their cell structure to physically degenerate. Biologically, the method is considered a partial disinfection. Important heat-resistant, spore-forming bacteria survive and revitalize the soil after cooling down. Soil fatigue can be cured through the release of nutritive substances blocked within the soil. Steaming leads to a better starting position, quicker growth and strengthened resistance against plant disease and pests. Today, the application of hot steam is considered the best and most effective way to disinfect sick soil, potting soil and compost. It is being used as an alternative to bromomethane, whose production and use was curtailed by the Montreal Protocol. Steam effectively kills pathogens by heating the soil to levels that cause protein ...

Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane), next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA) and denitrifying (nirK) genes), greenhouse gas flow and several soil physicochemical properties were evaluated. Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and

This publication deals with the use of phosphatic fertilizers to increase agricultural production in acid soils worldwide. It presents results obtained in a co-ordinated research project, which generated new information on the chemistry of soil phosphorus, tests for available soil phosphorus, phosphate nutrition of crops, evaluation of the agronomic effectiveness of Phosphate Rocks and recommendations on phosphorus fertilizers with particular emphasis on the utilization of indigenous PR sources. Due consideration was also given to environmental issues.. ...

The phospholipid fatty acid (PLFA) composition of microorganisms in podzolic soils of pine forests was studied in Central Siberia. The live microbial biomass in the 1-m mineral soil layer was found to gradually decrease with depth. Although the biomass decreased by half in the lower horizons, its content remained sufficiently high (12-14 nmol FAs/g soil). The coefficient of similarity in the fatty acid composition between the soils of forest and open (unforested) sites was 0.85. The coefficient of fatty acid richness in the mineral soil layer decreased with depth, while differences in fatty acid profiles increased.. ...

en] The effects of the application of dolomite lime (5 t ha-1) on soil algal communities were investigated in sessile oak (Quercus petraea (MATT.) LIEB.) and Norway spruce (Picea abies (L.) KARST.) plots situated in the Belgian Ardenne. Chlorophyta (60 taxa) were by far the most diverse group, followed by Xanthophyceae (10 taxa), Bacillariophyceae (3 taxa), Cyanophyceae (2 taxa) and Euglenophyceae (1 taxon). In both forest types, liming lead to a significant increase in soil pH, exchangeable magnesium and calcium. In the limed Quercus plots available phosphorus and soil solution nitrate concentrations were also increased. The soil algal diversity was similar in oak and spruce control plots and in limed spruce plots. However, in the limed oak plots a significantly higher algal diversity was observed. On the basis of a CCA analysis, three clusters of plots could be distinguished: a) Picea control plots, b) limed Picea and control Quercus plots, c) limed Quercus plots. Both soil pH and nutrient ...

Turbic Cryosols (permafrost soils characterized by cryoturbation, i.e., by mixing of soil layers due to freezing and thawing) are widespread across the Arctic, and contain large amounts of poorly decomposed organic material buried in the subsoil. This cryoturbated organic matter exhibits retarded decomposition compared to organic material in the topsoil. Since soil organic matter (SOM) decomposition is known to be tightly linked to N availability, we investigated N transformation rates in different soil horizons of three tundra sites in north-eastern Siberia and Greenland. We measured gross rates of protein depolymerization, N mineralization (ammonification) and nitrification, as well as microbial uptake of amino acids and NH4+ using an array of 15N pool dilution approaches. We found that all sites and horizons were characterized by low N availability, as indicated by low N mineralization compared to protein depolymerization rates (with gross N mineralization accounting on average for 14% of ...

The raised-bed soil is a land management technology in South Kalimantan. Adding Ameliorant to the raised-bed soil as an effort to increase the utilization of support for the cultivation land. Chlorophyll or leaf green substances found in all green plants that carry out photosynthesis. Ameliorant applications can increase the chlorophyll content of plants to optimize plant growth. This study aims to look at the effect of giving several types of ameliorant to the content of chlorophyll (chlorophyll-a, chlorophyll-b and total chlorophyll) and the growth of corn planted on raised-bed soil. This research is an experiment in the laboratory and a greenhouse. This research was conducted using a Completely Randomized Design (CRD) Single Factor with the treatment tested was the type of ameliorant soil without treatment (control - K), soil + agricultural lime (dolomite - C), soil + palm empty fruit bunch ash (S), soil + rice husk ash (P) and soil + coal ash (B). All treatments were repeated 5 (five) ...

Soil productivity is one of the most important factors worldwide for agricultural production. Improving soil quality with the use of conservation tillage can preserve soil productivity. Tillage systems are used for many agricultural purposes ranging from weed control to the incorporation of crop residue and amendments, and ultimately are used to prepare a suitable seed bed for better seed germination. Conservation tillage conserves water, improves soil and water quality, lowers input costs, and reduces labor. Therefore, conservation tillage systems must be assessed and evaluated to control negative impacts on soil and water quality, while promoting soil productivity. The major objectives of the study are to evaluate the effect of tillage systems (strip tillage, chisel plow, and no-tillage) on soil quality indices and time of nitrogen application, and tillage systems on ground water quality and use efficiency.

Essential plant nutrients are necessary for plant growth, However, some of these nutrients are added as inorganic fertilizers due to high demand of food arising from fast growth in population which has necessitated the need to expand agricultural activities. This has lead to overuse of commercial inorganic fertilizers leading to drop in soil pH. Low pH reduces the availability of essential nutrients to plants and also low rate of decomposition of organic matter that is required to increase buffering capacity of the soil. Soil acidity is reduced by liming, which is an expensive exercise and does not add fertility to the soil. Leaves and leaf extracts of different plants have been suggested as an alternative to inorganic fertilizer and liming materials. However their efficacy has not been tested. The study, therefore, aimed at investigating the effect of growth rate of non-leguminous plants, including wheat (Triticum aestivum), kale (Brassica oleraceae var acephala) and coriander (Coriandrum ...

Soil Ecology Society Colleagues, Im excited to announce the 2015 Soil Ecology Society Awards:. Career Achievement Award: Josh Schimel. Early Career Award, Jenny Talbot. Service Award, Sherri Morris. Come to the SES meeting where award winners will be given keynote-type talks!. Early Career Research Award. This award recognizes an early career soil ecologist within 5 years of their PhD who has begun making, and shows exceptional promise to continue making, outstanding research contributions to the broad field of soil ecology.. Service Award. This award recognizes a soil ecologist who has demonstrated outstanding and sustained service to SES, the broader scientific community/and or the public at large.. Career Achievement Award. This special award honors a long-term member of SES who has made enduring and outstanding contributions to scientific advancement, student mentoring, and service in the field of soil ecology.. Stuart Grandy. Associate Professor of Soil Biogeochemistry. University of New ...

The microbial biomass consists mostly of bacteria and fungi, which decompose crop residues and organic matter in soil. This process releases nutrients, such as nitrogen (N), into the soil that are available for plant uptake. About half the microbial biomass is located in the surface 10 cm of a soil profile and most of the nutrient release also occurs here. Generally, up to 5% of the total organic carbon and N in soil is contained in the microbial biomass at any one time. When microorganisms die, these nutrients are released in forms that can be taken up by plants.. ...

The interactive effect of biochar, cattle manure and nitrogen (N) fertilizer on the dynamics of carbon (C) mineralization and stabilization was investigated in a sandy soil amended with three sole biochar (0, 20 or 40 t ha−1) or manure (0, 13 or 26 t ha−1) and four combined biochar-manure levels (20 or 40 t ha−1 biochar plus 13 or 26 t ha−1 manure) with or without N fertilizer (0 or 90 kg ha−1) and CO2-C evolution measured over 54-d incubation period. Biochar application, solely or combined with manure resulted in lower applied C mineralized (ACM), indicating C sequestration in the soils. Negative attributable effect (AE) of co-application of biochar and manure on C mineralization was observed relative to the sole treatments. Both ACM and AE were negatively correlated with C/N ratio and mineral N content of the soil-mixtures (r ≥ - 0.573; p ≤ 0.01), indicating microbial N limitation. The double first-order exponential model described CO2-C efflux very well and indicated that ≥94% ...

PhD position in land-sea soil carbon transfer dynamics *Job description* The global carbon cycle represents the collection of complex biogeochemical processes that influence our climate and link all carbon pools on Earth. Soils play a very active and key role in the global carbon cycle, as upon sequestration in marine sediments they act as long-term sink of atmospheric CO2. A large part of organic carbon (OC) stored in soils is continuously mobilized and either returned to the atmosphere or transported by rivers to the oceans. However, little is known about the fate and residence times of soil OC within a river basin. This PhD project will combine organic biomarkers with radiogenic and stable isotopes to study the physical and biological processes that soil OC undergoes during river transport from land to sea, the duration of this transport, as well as the factors that control these processes. The data that are generated in this project should contribute to a better understanding of the role of ...

COP21 Conference in Paris, 2015. Chris van Kessel, a plant sciences professor at UC Davis, with colleagues from Arizona, The Netherlands, and the U.K., reported in the journal Environmental Science and Technology that the carbon sequestration goals set in the COP21 Conference to slow the increase in atmospheric carbon dioxide (CO2) are not achievable.. The 4 per mille (4p1000) initiative targets a yearly 0.4 percent increase in global agricultural soil organic carbon sequestration. If also applied to nonagricultural soils, this could compensate for increases in atmospheric CO2-carbon levels of 4.3 billion tons per year.. But adding carbon to soil organic matter also requires significant amounts of nitrogen to stabilize the carbon. The 4p1000 initiative would require, on global agricultural soils alone, a sequestration rate of 1.3 billion tons of carbon per year, plus 110 million tons of nitrogen.. How much nitrogen is that? A lot. It would be an increase of about 75 percent of current global ...

With its wide scope and focus on soil-plant interactions, the Journal of Plant Nutrition and Soil Science (JPNSS) is one of the leading journals on this topic.. An international journal JPNSS is a Cooperating Journal of the International Union of Soil Sciences (IUSS).. Articles in JPNSS include reviews, high-standard original papers, and short communications covering the entire spectrum of plant nutrition and soil science. They cover the entire spectrum of plant nutrition and soil science. Articles published in JPNSS represent challenging research of international significance. In addition, book reviews and discussions on current literature are provided, as well as news from German Soil Science Society (DBG) and the German Society for Plant Nutrition (DGP).. Some of the subjects that are receiving increasing attention are:. Soil-Plant Interactions. - retention and release of nutrients, pollutants, and water in the soil-plant ...

TY - JOUR. T1 - Long-term N fertilization imbalances potential N acquisition and transformations by soil microbes. AU - Huang, L.. AU - Riggins, C. W.. AU - Rodríguez-Zas, S.. AU - Zabaloy, M. C.. AU - Villamil, M. B.. PY - 2019/11/15. Y1 - 2019/11/15. N2 - Nitrogen (N) fertilization in agricultural soils has been receiving worldwide attention due to its detrimental effects on ecosystem services, particularly on microbial N transformation. However, few studies provide a complete picture of N-fertilization effects on the N transformation cycle within a single agricultural ecosystem. Here, we explored the main steps of the microbial N cycle, using targeted gene abundances as proxies, in relation to soil properties, following 35 years of N-fertilization at increasing rates (0, 202 and 269 kg N/ha) in continuous corn (Zea mays L.) and corn-soybean [Glycine max (L.) Merr.] rotations. We used real-time quantitative polymerase chain reaction (qPCR) for the quantification of phylogenetic groups and ...

Soil microorganisms play an important role in enhancing soil fertility and plant health. Arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria form a key component of the soil microbial population. Arbuscular mycorrhizal fungi form symbiotic association with most of the cultivated crop plants and they help plants in phosphorus nutrition and protecting them against biotic and abiotic stresses. Many species of Bacillus occurring in soil are also known to promote plant growth through phosphate solubilization, phytohormone production and protection against biotic and abiotic stresses. Synergistic interaction between AMF and Bacillus spp. in promoting plant growth compared to single inoculation with either of them has been reported. This is because of enhanced nutrient uptake, protection against plant pathogens and alleviation of abiotic stresses (water, salinity and heavy metal) through dual inoculation compared to inoculation with either AMF or Bacillus alone.

ManagingWholes.com is our sister site, packed with articles and tutorials on decision making, low-stress livestock handling, ranching, farming, consensus building, and more.. Harnessing the water cycle to re-cool the changing climate has fascinating information and links about the little-known influence of lifes processes on the water cycle.. Regenerative Agriculture Association in Sicily which is promoting regenerative agriculture and its models in the Mediterranean basin, as well as initiating some soil carbon measurements.. Gabe and Paul Browns site, rich with videos on soil health, cropping systems, and more.. Chris Gills Circle Ranch website, a rich source of videos and posts about managing range and wildlife in West Texas.. NRCS soil quality site. savoryinstitute.com. Mas Humus, an alliance of professionals who seek to improve the quality of life in the rural world. They work on increasing the capacity of farmers to improve their soil and produce healthy ...

The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, |i|inter alia|/i|, increased the number of cellulolytic bacteria and stimulated the activity of |i|β|/i|-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means

Extreme flooding over southern Louisiana in mid-August of 2016 resulted from an unusual tropical low that formed and intensified over land. We used numerical experiments to highlight the role of the Brown Ocean effect (where saturated soils function similar to a warm ocean surface) on intensification and its modulation by land cover change. A numerical modeling experiment that successfully captured the flood event (control) was modified to alter moisture availability by converting wetlands to open water, wet croplands, and dry croplands. Storm evolution in the control experiment with wet antecedent soils most resembles tropical lows that form and intensify over oceans. Irrespective of soil moisture conditions, conversion of wetlands to croplands reduced storm intensity, and also, non-saturated soils reduced rain by 20% and caused shorter durations of high intensity wind conditions. Developing agricultural croplands and more so restoring wetlands and not converting them into open water can impede