Arable Soils Research Articles

Permaculture Management of Arable Soil Increases Soil Microbial Abundance, Nutrients, and Carbon Stocks Compared to Conventional Agriculture

Conventional agricultural practices severely deplete the soil of essential organic matter and nutrients, increasing its vulnerability to disease, drought, and flooding. Permaculture is a form of agroecology adopting a whole ecosystem approach to create a set of principles and design frameworks for enriching soil fertility, but there is little scientific evidence of its efficiency. This study compares two permaculture managed sites with a conventional arable site to investigate the effect of permaculture management on soil fertility. We used phospholipid fatty acid analysis to estimate microbial abundance and diversity and related these to measured soil nutrients and carbon stocks. The potential of permaculture management to mitigate soil greenhouse gas emissions was assessed during a laboratory soil incubation and measurement of greenhouse gases via gas chromatography. Overall, the permaculture managed allotments had three times higher microbial biomass, one and a half times higher nitrogen, and four times higher carbon content than the arable site. Permaculture soils had larger carbon dioxide and nitrous oxide fluxes compared to arable soil, but all sites had a mean negative flux in methane. Permaculture management by use of organic amendments and no-dig practices provides a constant slow release of nutrients and build-up of organic matter and carbon and consequently promotes greater bacterial and fungal biomass within the soil.

The impact of arable soil management on physical functions – The ratio of air capacity and air permeability or hydraulic conductivity as a document of harmful soil compaction

Soil health or soil degradation criteria are until now not well documented for a greater number of soil profiles under conventional and conservation tillage management in the literature. In order to evaluate the compaction status of more than 700 arable sites analyzed within the last 40 years, the Compaction Verification Tool (CVT) was applied according to Zink et al. (2011). Besides the ratio of air capacity (AC, at a matric potential of −6 kPa) and saturated hydraulic conductivity (Ks), the ratio of AC and air conductivity (Ka, at a matric potential of −6 kPa) was considered for evaluating the compaction status with respect to potentially harmful soil alterations. The compaction status was classified into the CVT classes I–IV, where a harmful subsoil compaction was assumed, if both values of AC and Ks or AC and Ka simultaneously exceeded (are smaller than) their defined critical value indicating limited conditions for plant growth (CVT class IV). We analyzed the compaction status of soil profiles with respect to clay content, soil type, structural stage (aggregate forms) and time span of sampling (1980–1999, 2000–2020) under conventional and conservation tillage for top- and subsoil horizons. While also some of the annually plowed topsoils under conventional tillage showed critical values of AC, Ks and Ka, the occurrence of harmful soil compaction is most dominant in the subsoil horizons (> 30 cm depth) because of a higher proportion of class IV which increased with the clay content (from < 12 % to > 12 % clay), irrespective of the applied ratio used for verification (AC/Ks or AC/Ka). Especially the highly productive Luvisols showed a high percentage of harmful compaction in the subsoil (30–41 % in CVT class IV). Soil profiles under conservation tillage management are less affected by harmful compaction. The more aggregated subsoils showed smaller proportions of class IV, which was further influenced by the clay content.

Microbial Activity and Diversity in Soil Sown with Zea mays and Triticosecale

The ongoing scientific debate on the selection of the best bioindicators to reflect the quality of arable soils indicates both their microbiome and biochemical parameters. Consideration has also been given to the fact that Zea mays has achieved the status of a crop used in the feed industry and for energy purposes, and Triticosecale is attracting increasing interest in this area. Therefore, the aim of this study was to determine the wide range of effects of Zea mays and Triticosecale cultivation on soil microbial and biochemical activity. The assessment of these parameters was based on the determination of microbial abundance, colony development index (CD), ecophysiological index of microbial diversity (EP), soil enzyme activities (dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase, β-glucosidase, and arylsulfatase) as well as soil physicochemical properties. The innovative nature of the research was achieved by extending the pool of analyses to include both microbial biodiversity and analysis of soil samples at three depths: 0–20 cm; 21–40 cm; and 41–60 cm. It was found that the highest activities of soil enzymes and the abundance of organotrophic bacteria and fungi, as well as their colony development indices (CD), occurred within the rhizosphere and that their values decreased with increasing depth of the soil profile layers. Two phyla, Actinobacteria and Proteobacteria, representing the microbiome of arable soils, were identified independently of soil management practices. Unique bacterial genera in the soil under Triticosecale cultivation were Pseudonocardia, whereas Rhodoplanes, Nocardioides, and Rhodanobacter were found under Zea mays cultivation. The activity of all enzymes, especially urease and arylsulfatase, was significantly higher in the soil under Triticosecale. This was influenced by the more favorable physicochemical properties of the soil.

Soil organic carbon fractions and storage potential in Finnish arable soils

AbstractUnderstanding the factors affecting the total amount and distribution of soil organic carbon (OC) across different functional carbon pools is important to better define the future management of soil OC stocks. The interactions between soil management practices, local physicochemical soil properties and climate are essential for determining the OC content of the soil. Nevertheless, how these factors affect the total amount of OC and its distribution across carbon pools, i.e., more labile particulate (POC) and more stable mineral‐associated (MAOC) organic carbon, is only partly known. In this study, we assessed topsoil (0–20 cm) samples from 93 arable farms in the southern half of Finland to determine the total amount of OC, and its distribution in MAOC and POC, along with relevant soil properties (amount of clay and silt, aluminium and iron oxides and pH), climate (precipitation and temperature) and fertilization (mineral versus organic). The fertilization did not affect the total soil carbon content (12–58 g OC kg−1 soil). The share of OC in the MAOC fraction (on average 86% of total OC) was relatively stable across the large range of OC contents and clay contents (2%–68%). We assessed the highest feasible MAOC of the soils with boundary line analyses and their OC saturation state with Hassink's equation (Hassink, 1997). Only soils with the lowest clay content (&lt;10% clay) were assumed to be carbon‐saturated, suggesting that most of the studied soils have a capacity to accrue more MAOC. Simple linear regression showed that clay, aluminium and iron oxides explained 9%, 21% and 22% of the variation in MAOC, respectively. Multiple regression analyses including the amount of clay, clay+silt, aluminium and iron oxides, pH, type of fertilization, precipitation and temperature as explanatory variables explained 33%–53% of the variation in OC and MAOC. In all soils, aluminium oxides were important explanatory variable for MAOC, whereas Fe oxides were significant only in soils with higher clay content (&gt;30%). In soils with a low clay content (&lt;30%), pH had added value in explaining MAOC. Altogether, it seems that various climatic, edaphic and soil management‐related factors are context‐dependently controlling OC and that soil textural information alone is not necessarily an adequate predictor to assess the MAOC saturation state of the soil.

Plant Cadmium Toxicity and Biomarkers Are Differentially Modulated by Degradable and Nondegradable Microplastics in Soil.

The impact of microplastics (MPs) as emerging pollutants on plant heavy metal toxicity has been extensively reported in vegetable-soil systems over recent years. However, little attention has been given to cultivar variations between degradable and non-degradable MPs. This study investigated the effects of degradable polylactic acid (PLA) and nondegradable polypropylene (PP) MPs on plant growth and biomarker (malonaldehyde (MDA) and antioxidant enzymes) performance in Cd-contaminated arable soil. The results show that both types of MPs significantly impacted plant biomass and biomarker contents across all three Cd levels. The degree of impact was significantly sensitive to both the type and dose of MPs, as they reduced the soil pH and cation exchange capacity (CEC) while increasing soil dissolved organic carbon (DOC), microbial biomass carbon, and nitrogen. PP exhibited greater root growth inhibition and phytotoxicity at higher doses of 1% and 5% compared to PLA. Specifically, the highest MDA contents were 1.44 and 2.20 mmol mg-1 protein for shoots and roots, respectively, in the 5% PLA treatment under a 10.1 mg kg-1 Cd level, which were 1.22 and 1.18 times higher than those in corresponding treatments of 5% PP. Overall, PLA had less significant effects on plant phytotoxicity, Cd availability, and soil properties compared to PP. Regression pathway analysis indicated that MPs increased shoot Cd uptake by altering both soil physical-chemical and microbial characteristics. Among the soil variables, pH, CEC, and Cd bioavailability were found to play vital roles. Yet, no single variable acts alone in the mechanism for plant Cd uptake. PLAs are suggested to replace conventional non-biodegradable plastics to control environmental MP pollution, particularly in agricultural systems with higher Cd contamination. However, the long-term effects of the by-products generated during the biodegradation process require further investigation.

Pesticide residues in boreal arable soils: Countrywide study of occurrence and risks

Large volumes of pesticides are applied every year to support agricultural production. The intensive use of pesticides affects soil quality and health, but soil surveys on pesticide residues are scarce, especially for northern Europe. We investigated the occurrence of 198 pesticide residues, including both banned and currently used substances in 148 field sites in Finland. Results highlight that pesticide residues are common in the agricultural soils of Finland. A least one residue was found in 82% of the soils, and of those 32% contained five or more residues. Maximum total residue concentration among the conventionally farmed soils was 3043 μg/kg, of which AMPA and glyphosate contributed the most. Pesticide residues were also found from organically farmed soils, although at 75–90% lower concentrations than in the conventionally farmed fields. Thus, despite the application rates of pesticides in Finland being generally much lower than in most parts of central and southern Europe, the total residue concentrations in the soils occurred at similar or at higher levels. We also established that AMPA and glyphosate residues in soil are significantly higher in fields with cereal dominated rotations than in grass dominated or cereal–grass rotations. However, risk analyses for individual substances indicated low ecological risk for most of the fields. Furthermore, the total ecological risk associated with the mixtures of residues was mostly low except for 21% of cereal dominated fields with medium risk. The results showed that the presence of mixtures of pesticide residues in soils is a rule rather than an exception also in boreal soils. In highly chemicalized modern agriculture, the follow-up of the residues of currently used pesticides in national and international soil monitoring programs is imperative to maintain soil quality and support sustainable environment policies.

Soil Acidity Causes in Ethiopia, Consequences and Mitigation Strategies-A Review

Soil acidity is a serious land degradation problem and worldwide danger, impacting approximately 50% of the world's arable soils and limiting agricultural yield. Soil acidification is a complicated series of events that lead to the production of acidic soil. In its widest sense, it can be defined as the total of natural and human processes that reduce the pH of soil solutions. Soil acidity affects around 43% of agricultural land in Ethiopia's humid and sub humid highlands. Acid soils in western Ethiopia are mostly caused by topsoil erosion caused by heavy rains and high temperatures. This results in the loss of organic matter and the leaching of exchangeable basic cations (Ca2+, Mg2+, Na+, and K+). Because ammonium-based fertilizers are easily converted to nitrate and hydrogen ions in the soil, they play a significant role in acidification. One of the reasons of soil acidity is inefficient nitrogen usage, which is followed by alkalinity exports in crops. Soil acidity in Ethiopian highlands is mostly caused by the clearance of crop residues, continuous crop harvest without sufficient fertilization, cation removal, and usage of acid-forming inorganic fertilizers. Acid soil reduces nutrient availability and produces Al and Mn toxicity. In addition to these effects, soil acidity may rapidly degrade soil physicochemical qualities such as organic carbon (OC), cation exchange capacity (CEC), soil structure, porosity, and texture. Liming, the use of organic materials as ISFM, and the adoption of crop types that are resistant to Al toxicity are all alternatives for correcting acid soils. Liming can minimize toxicity by lowering concentrations, improving the availability of plant nutrients like P, Ca, Mg, and K in the soil, and reducing heavy metal solubility and leaching. Application of organic matter has a liming impact because of its abundance in alkaline cations (such Ca, Mg, and K) that were released from OM during mineralization. The pH of the soil is raised by soil organic matter, which helps with soil acidity supplements.

Дослідження міграції сучасних пестицидів амікарбазону, біциклопірону та підіфлуметофену з ґрунту до ґрунтових вод (результати експериментальних досліджень)

ABSTRACT. The expansion of the range and volume of application of plant protection products in agriculture increases the risk of contamination of soil, and subsequently of underground and surface water sources, especially with highly persistent pesticides in the soil. Аim. Establishing and comparative assessment of migration characteristics of new pesticides — representatives of different chemical classes, from soil to groundwater when modelling different initial concentrations and irrigation regimes. Materials and Мethods. In a laboratory experiment, the migration of the investigated substances in the soil – ground water system was studied with the help of filtration columns designed by the Academician E.H. Honcharuk. Soil Standard Model no 1 (SSM no 1) and leached chernozem were used as arable soil layers. Three hydraulic regimes were simulated: annual, three-month, or monthly precipitation rates were supplied to the column for 30 days. The initial concentrations of amicarbazone, bicyclopyrone, and pydiflumetofen corresponded to both one maximum consumption rate (m.c.r.) and 0.5, 0.2 and 5 m.c.r. respectively. Quantitative determination of the studied substances in the filtrate was carried out by the method of high-performance liquid chromatography. The results. It was established that with higher initial concentrations of all three substances in the topsoil and greater hydraulic load on the filtration column in the case of both herbicides, the concentrations of compounds in the filtrate were higher. At the same time, with the same arable soil layer (SSM no 1) and hydraulic load (maximum) and almost the same initial concentration in the soil (0.05 and 0.06 mg/kg), bicyclopyrone appeared in the filtrate much earlier and in in larger quantities, its maximum concentration in the filtrate was reached much faster, it was 17 times higher. It took much more time to detect pydiflumetofen than bicyclopyrone. The migration levels of bicyclopyrone were almost independent of the type of arable soil layer, while pydiflumetofen in leached chernozem retained longer and migrated more slowly than in SSM no 1. Conclusions. Both general regularities and significant differences in the migration of the studied substances to the ground water depending on the soil profile were revealed. It has been proven that, compared to bicyclopyrone, pydiflumetofen is less mobile, appears in the filtrate much later and migrates from SSM no 1 more slowly. Compared to bicyclopyrone, amicarbazone is more mobile, migrates from leached chernozem longer and more intensively. The highest potential danger of groundwater contamination due to vertical migration from chernozem, the most common soil type in Ukraine, is inherent to amicarbazone, the lowest — to pydiflumetofen. Keywords: plant protection products, herbicide, fungicide, soil, groundwater, migration, pollution, threshold limit value.

Combustion-Derived Pollutants Linked with Kidney Disease in Low-Lying Flood-Affected Areas in the Balkans.

Tens of thousands of people in southern Europe suffer from Balkan endemic nephropathy (BEN), and four times as many are at risk. Incidental ingestion of aristolochic acids (AAs), stemming from the ubiquitousAristolochia clematitis(birthwort) weed in the region, leads to DNA adduct-induced toxicity in kidney cells, the primary cause of BEN. Numerous cofactors, including toxic organics and metals, have been investigated, but all have shown small contributions to the overall BEN relative to non-BEN village distribution gradients. Here, we reveal that combustion-derived pollutants from wood and coal burning in Serbia also contaminate arable soil and test as plausible causative factors of BEN. Using a GC-MS screening method, biomass-burning-derived furfural and coal-burning-derived medium-chain alkanes were detected in soil samples from BEN endemic areas levels at up to 63-times and 14-times higher, respectively, than in nonendemic areas. Significantly higher amounts were also detected in colocated wheat grains. Coexposure studies with cultured kidney cells showed that these pollutants enhance DNA adduct formation by AA, - the cause of AA nephrotoxicity and carcinogenicity. With the coincidence of birthwort-derived AAs and the widespread practice of biomass and coal burning for household cooking and heating purposes and agricultural burning in rural low-lying flood-affected areas in the Balkans, these results implicate combustion-derived pollutants in promoting the development of BEN.

Material flow analysis of heavy metals in large-scale cattle farms and ecological risk assessment of cattle manure application to fields

This study bridges the knowledge gap pertaining to the pathways of heavy metal accumulation and migration within the industrial chain of large-scale cattle farms. Two such farms in Shaanxi serve as a basis for our exploration into Zn, Cu, Cr, Pb, As, and Cd dynamics. Employing material flow analysis complemented by predictive models, we evaluate the potential ecological risks of arable soil from heavy metal influx via manure application. Our findings indicate that Zn and Cu predominate the heavy metal export from these operations, composing up to 60.00%–95.67% of their total content. Predictive models based on 2021 data reveal a potential increase in Cd soil concentration by 0.08 mg/kg by 2035, insinuating a reduced safe usage period for cattle manure at less than 50 years. Conversely, projections from 2022 data point towards a gradual Cu rise in soil, reaching risk threshold levels after 126 years. These outcomes inform limitations in cattle manure utilisation strategies, underscoring Cu and Cd content as key barriers. The study underscores the criticality of continuous heavy metal surveillance within farm by products to ensure environmental protection and sustainable agricultural practices.

Enhanced reduction of Cd uptake by wheat plants using iron and manganese oxides combined with citrate in Cd-contaminated weakly alkaline arable soils

Iron (Fe) and manganese (Mn) oxides can be used to remediate Cd-polluted soils due to their excellent performance in heavy metal adsorption. However, their remediation capability is rather limited, and a higher content of available Mn and Fe in soils can reduce Cd accumulation in wheat plants due to the competitive absorption effect. In this study, goethite and cryptomelane were first respectively used to immobilize Cd in Cd-polluted weakly alkaline soils, and sodium citrate was then added to increase the content of available Mn and Fe content for further reduction of wheat Cd absorption. In the first season, the content of soil-available Cd and Cd in wheat plants significantly decreased when cryptomelane, goethite and their mixture were used as the remediation agents. Cryptomelane showed a better remediation effect, which could be attributed to its higher adsorption performance. The grain Cd content could be decreased from 0.35 mg kg−1 to 0.25 mg kg−1 when the content of cryptomelane was controlled at 0.5%. In the second season, when sodium citrate at 20 mmol kg−1 was further added to the soils with 0.5% cryptomelane treatment in the first season, the content of soil available Cd was increased by 14.8%, and the available Mn content was increased by 19.5%, leading to a lower Cd content in wheat grains (0.16 mg kg−1) probably due to the competitive absorption. This work provides a new strategy for the remediation of slightly Cd-polluted arable soils with safe and high-quality production of wheat.

Evaluation of Soil Quality of Pingliang City Based on Fuzzy Mathematics and Cluster Analysis

Pingliang City has a complex topography and diverse soil types. To realize the improvement of soil according to local conditions and the reasonable and sustainable use of soil resources, an evaluation of soil quality in Pingliang City was carried out, based on the soil distribution situation in Pingliang City, adopting a method combining fuzzy mathematics and cluster analysis of the main evaluation factors, such as soil organic matter, topsoil depth, soil erosion intensity, soil moisture regime, effective soil thickness, soil texture, soil profile structure, soil nutrient status and topographical parts, to carry out a comprehensive evaluation. A comprehensive evaluation of soil quality was conducted in seven counties under the jurisdiction of Pingliang City, and the evaluation results were compared and analyzed against the national standard, “Cultivated land quality grade”, to provide a basis for the selection of scientific soil improvement methods. The results of the arable land quality grades indicate that the quality of farmland in Pingliang City is divided into three to ten grades, and the average quality grade of farmland is 6.83, which is in the middle–lower level, and the overall grade distribution shows the characteristics of low in the middle and high in the east and west. The results of fuzzy mathematics combined with cluster analysis indicated the following trends in soil quality for the 12 soil genera: Chuan black gunny soil &gt; yellow moist soil &gt; sandy soil &gt; silt soil &gt; mulching helilu soil&gt; loessal soil&gt; loamy soil &gt; slope loessal soil &gt; arenosol &gt; tillage leaching gray cinnamon soil &gt; calcareous gray cinnamon soil &gt; red clay soil. The results of the combination of fuzzy mathematics and clustering were significantly correlated with the results of the evaluation of the soil quality of arable land; the correlation coefficient was 0.884. This indicates that the method can accurately and objectively review the advantages and disadvantages of arable land soil and can be effectively applied to the evaluation of the soil quality of agricultural soils in other regions. It is a complement to the existing evaluation of the soil quality of arable land and at the same time provides a reference for the improvement of soil quality in agricultural regions.

Simulated soil erosion predominantly affects fungal abundance in the rapeseed rhizosphere

Eroded agricultural soils have reduced soil organic carbon (SOC) levels that may affect the plant-microbiome interactions in the rhizosphere. We explored the impact of simulated erosion on major microbial groups in a pot experiment with rapeseed (Brassica napus L.) grown on arable soil with the potential to capture SOC. An erosion gradient was simulated by admixture (0%, 12%, 24%) of subsoil horizon (Bt) to topsoil (Ap) material. Rapeseed plants were pulse-labeled with 14CO2 at three growth stages and two soil compartments (bulk and rhizosphere soil) were sampled. Fungal ITS copy numbers were consistently higher in the rhizosphere and decreased with progressing plant growth stages. A significant increase of bacterial 16S rRNA gene copies in the rhizosphere only occurred at flowering. A response of fungal abundance to subsoil admixture was found detectable based on fungi:Bacteria and fungi:Archaea ratio at flowering. Archaea were neither affected by soil compartment nor subsoil admixture. 14C activity of microbial biomass, an indicator for relative input of freshly assimilated C into soil microbiome, was impacted by growth stage and compartment and decreased with ongoing growth stage. During the rosette growth stage, the 14C activity of the microbial biomass was elevated in the rhizosphere of the eroded soil indicating a plant response to the erosion factor. Our experiment revealed a compositional separation of the fungal community along the simulated erosion gradient and a selection of fungi for the two different soil compartments at flowering. Olpidimycetes, Fusarium and Rhizopus and putative pathogens were enriched in the rhizosphere at flowering. Fungi may have a competitive advantage in the rhizosphere of strongly eroded and nutrient diluted soils due to ecological adaptation and morphological traits i.e. hyphae that can bypass soil areas with low nutrient availability.

Enhanced Natural Attenuation Technique, Edaphic and Microbiological Changes in Oil-Impacted Soil of Odhiaje Community, Rivers State

Oil spills in the Niger Delta could exert environmental pressures on the soil component. We investigated the impacts of oil spills and the effect of the Enhanced Natural Attenuation (ENA) remediation method on contaminated soil and resident microbial populations in the Odhiaje community in Rivers State, Nigeria. Soil samples for microbiological studies were collected weekly during a 17-week remediation period, while those for edaphic parameters were taken before and after remediation, all at 4 sampling points (SPs). Serial dilution of the oil-impacted soils for microbial density enumeration was carried out according to standard methods. Results revealed that mean concentrations of Total Petroleum Hydrocarbon Contents (THC) (Sig.value = 0.009), SO42- ions (Sig.value = 0.001), and sand compositions (Sig.value = 0.045) all differed markedly across the sampling points at p&lt;0.05. Mean levels of EC (Sig.tvalue = 0.039) and ΣN (Sig.tvalue = 0.058) &amp; K+ ions (Sig.tvalue = 0.004) differed significantly before and after the remediation exercise at the 95% confidence interval. Application of nutrients was rapidly accompanied by microbial population increases, leading to the consumption of oil contaminants in soils to levels comparable to control over the remediation period. Total Heterotrophic Bacteria counts correlated with pH (r = 0.501) and SO42- ions (r = 0.500) (p&lt;0.05), and K+ ions (r = -0.800) (p&lt;0.01); Total Heterotrophic Fungi correlated with pH (r = 0.520) (p&lt;0.05), and Mg2+ ions (r = 0.820) (p&lt;0.01); Hydrocarbon Utilizing Bacteria correlated with available P (r = 0.530) and silt composition (r = -0.504) (p&lt;0.05), and K+ (r = 0.626) and Mg2+ ions (r = 0.733) (p&lt;0.01); and Hydrocarbon Utilizing Fungi correlated with K+ (r = 0.500) &amp; Mg2+ ions (r = 0.506) (p&lt;0.05). Results indicate improvement in C/N ratios and effectiveness of the current cost-effective bioaugmentation technique in the restoration of arable soil productivity in the Odhiaje community.

Water consumption of corn under different methods of primary tillage after row-crop predecessors on an energy-storage soil maintenance system

The object of research was the light chestnut soil of the Chokh Agrofirm of the Gunibsky district in the Kizilyurt transhumance zone of the Republic of Dagestan. The humus content in the arable layer is 2.77%, P2O5–2.21, K2O – 32.8 mg/100 g, the density of the arable soil layer is 1.24 g/cm3, the lowest moisture capacity (MC) is 29.2% (layer 0–0.6 m). The effectiveness of two row-crop predecessors was studied: sunflower for seeds and corn for grain, and the use of skimmers in the main tillage for corn. Soil moisture, watering and irrigation standards, incoming and outgoing items of the water balance and the coefficient of water consumption for corn were determined. In the second ten days of May, the plant remains of predecessors were crushed using double disking with heavy disc harrows BDT-3, plowing was carried out to a depth of 0.28–0.30 m with a PLN-4-35 plow with and without skimmers, the field was leveled with a small leveler MV – 6 and watered at the rate of moistening the soil layer of 0–0.6 m in strips with lateral release of water manually, vegetation irrigation was carried out in furrows. Sunflower sowing was carried out with seeds of the VNIIMK-8883 variety, corn – hybrid ROSS-299, the seeding rate for both crops was 72 thousand seeds/ha. Fertilizers for sunflower were applied at the rate of N90Р40К90, including N40Р24К74for plowing, N16Р16К16– when sowing with seeds, N34for fertilizing in the phase of 5–6 leaves when cutting furrows, for corn – N90Р40, of which N40Р24for plowing, N16Р16К16when sowing with seeds, N30in fertilizing in the phase of 3–5 leaves. It has been established that in the areas of irrigated agriculture of the Western Caspian region, when selecting row-crop predecessors for corn for grain, preference should be given to early-ripening varieties of sunflower for seeds, which are harvested in the third decade of July, and after harvesting it remains in the soil more than 15 t/ha of plant mass. At the same time, the maximum corn yield is achieved – 9.16 t/ha of grain, exceeding the control by 33.1%, due to which, with the same total water consumption as the control option, the water consumption coefficient is reduced by 23.7%.

Green manuring alters reactive N losses and N pools in arable soils: A meta-regression study

Green manuring is a conservation agricultural practice that improves soil quality and crop yield. However, increasing the active nitrogen (N) and carbon (C) pools during green manure (GM) amendment may accelerate soil N transformation and stimulate N loss. Previous studies have reported the effects of cover crop incorporation on N2O emission; however, the driving mechanisms and other N losses remain unclear. Therefore, we conducted a comprehensive meta-analysis of 109 published articles (517 paired observations) to clarify the effects of GM amendment on soil reactive N (Nr) losses (N2O emissions, NH3 volatilization, and N leaching and runoff), N pools, and N cycling functional gene abundance. The results showed that green manuring increased soil microbial biomass N (MBN) and NO3−-N concentrations and stimulated N2O emission but significantly lowered N leaching and yield-scaled NH3 volatilization. Practices of green manuring made a dominant contribution to the variation in N2O emissions and NH3 volatilization after GM application. Furthermore, applying legume-based GM, using N derived from GM (GMN) as an additional input, and short-term GM amendment each stimulated N2O emissions. In contrast, adopting non-legume GM, using GMN to partially substitute mineral N, and applying GM to the soil surface or paddy field mitigated NH3 loss during GM amendment. Additionally, the variation in NH3 volatilization was positively related to soil pH and N application rate (NAR) but had a negative relationship with mean annual precipitation (MAP). This study highlighted the marked effects of green manuring on soil N retention and loss. Agricultural operations that adopt GM amendment should select suitable GM species and optimize mineral N inputs to minimize N loss.

Spatial heterogeneity of soil potassium geochemistry: A case study from Tianfu New Area, Chengdu, China

Urban-rural integration zones, situated at the interface between urban and rural environments, undergo profound alterations in arable soil quality attributed to rapid urbanization and intensified agricultural practices. However, there is still insufficiency research on potassium depletion from a spatial perspective, despite the increasing demand for vegetables. To address this gap, the spatial distribution characteristics of soils potassium in Tianfu New District, Chengdu Plain, China, were studied based on geochemistry, geostatistics and Earth system science. The results showed that: (1) Spatial heterogeneity existed in both soil total potassium (STP) and soil available potassium (SAP). However, there was no obvious spatial correlation between STP and SAP, and their spatial extents exhibited minimal overlap. (2) The STP levels are mainly affected by the altitude, slope, stratum exposure and geological background. (3) The SAP content is obviously affected by anthropogenic input, and the enrichment is significantly affected by fertilizers. This study reinforces the notion that the human intervention has strongly affected arable soil quality. The availability of fertilizer (e.g., potash) may significantly affecting food security within China.

The Use of Spectroscopic Methods to Study Organic Matter in Virgin and Arable Soils: A Scoping Review

The use of modern spectroscopic methods of analysis, which provide extensive information on the chemical nature of substances, significantly expands our understanding of the molecular composition and properties of soil organic matter (SOM) and its transformation and stabilization processes in various ecosystems and geochemical conditions. The aim of this review is to identify and analyze studies related to the application of nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy techniques to study the molecular composition and transformation of organic matter in virgin and arable soils. This article is mainly based on three research questions: (1) Which NMR spectroscopy techniques are used to study SOM, and what are their disadvantages and advantages? (2) How is the NMR spectroscopy technique used to study the molecular structure of different pools of SOM? (3) How is ESR spectroscopy used in SOM chemistry, and what are its advantages and limitations? Relevant studies published between 1996 and 2024 were searched in four databases: eLIBRARY, MDPI, ScienceDirect and Springer. We excluded non-English-language articles, review articles, non-peer-reviewed articles and other non-article publications, as well as publications that were not available according to the search protocols. Exclusion criteria for articles were studies that used NMR and EPR techniques to study non-SOM and where these techniques were not the primary methods. Our scoping review found that both solid-state and solution-state NMR spectroscopy are commonly used to study the structure of soil organic matter (SOM). Solution-phase NMR is particularly useful for studying soluble SOM components of a low molecular weight, whereas solid-phase NMR offers advantages such as higher 13C atom concentration for stronger signals and faster analysis time. However, solution-phase NMR has limitations including sample insolubility, potential signal aggregation and reduced sensitivity and resolution. Solid-state NMR is better at detecting non-protonated carbon atoms and identifying heterogeneous regions within structures. EPR spectroscopy, on the other hand, offers significant advantages in experimental biochemistry due to its high sensitivity and ability to provide detailed information about substances containing free radicals (FRs), aiding in the assessment of their reactivity and transformations. Understanding the FR structure in biopolymers can help to study the formation and transformation of SOM. The integration of two- and three-dimensional NMR spectroscopy with other analytical methods, such as chromatography, mass spectrometry, etc., provides a more comprehensive approach to deciphering the complex composition of SOM than one-dimensional techniques alone.

ОПТИМИЗАЦИЯ СИСТЕМЫ ПРОТИВОЭРОЗИОННЫХ МЕРОПРИЯ-ТИЙ В ООО «АГРОФИРМА «ЧЕРНОВСКОЕ» НИЖЕГОРОДСКОЙ ОБ-ЛАСТИ

In modern conditions, it becomes necessary to improve a complex system of anti-erosion measures in connection with the development of erosion processes that have arisen as a result of the intensification and commercialization of agricultural production. According to various estimates, in the Nizhniy Novgorod region, the area of eroded lands ranges from 141.02 thousand hectares to 667.6 thousand hectares or from 5.2% to 24.7% of the area of agricultural land [1, 2, 3]. The main negative as-pect of the manifestation of water erosion on arable soils is a decrease in soil fertility and crop yields. It should be noted that erosion processes in the region are developing unevenly. The development of water erosion of the Right Bank is facilitated by the geological structure of the area, the hilly–rocky type of relief and the high ploughing of the territory. The article presents the results of solving the economic and mathematical problem of planning anti-erosion measures in an agricultural enterprise located in the Right-bank part of the Nizhniy Novgorod region. It is shown that due to the implementation of the project of anti-erosion organization of the territory, soil fertility will significantly increase, and the net income from increasing the economic efficiency of production in the agricultural firm will amount to 212.6 million rubles, which is 41% higher than income without carrying out a complex of anti-erosion measures.

New aspects on the determination of soil‐specific respiration quotients of arable soils for the application in the barometric process separation technique

AbstractBackgroundThe respiratory quotient, that is, the CO2–O2‐exchange ratio during aerobic heterotrophic soil respiration, (RQAHR) is one of the key variables of the barometric process separation (BaPS) technique. For reliable application, the BaPS method requires the adjustment of RQAHR to soil‐specific substrate conditions.AimThe objective of the present study was to determine RQAHR in five arable soils varying between pH 4 and 8 and carbon/nitrogen (C/N) ratios between 8.4 and 11.9 using the BaPS–15N method. Further, we aimed to elucidate whether RQAHR can be estimated from basic soil properties.ResultsDetermined RQAHRs were soil specific and ranged between 0.74 and 1.53. RQAHR particularly affected the calculation of gross nitrification rates but not soil respiration rates. Based on a multiple linear regression analysis, soil pH and the C/N ratio of the soil organic matter pool were identified to explain well (R2 = 0.984) the measured RQAHRs. Applying the thus derived RQMLR to the calculation procedure led to good agreement between gross nitrification rates derived by the 15N pool dilution technique.ConclusionsFuture studies are needed to test whether this empirical relationship between RQAHR, pH, and C/N ratio is generalizable. If this would be the case, the BaPS method could be applied without the use of a stable isotope and thus, being less resource demanding than the 15N pool dilution technique.