Pesticide Leaching Research Articles

Modeling atrazine molecule dynamics in rhodic ferralsol: calibration and testing of the MACRO 5.2 model

Assessing the risks of pesticide use in the environment, especially in groundwater, requires predicting their movement. Pesticide leaching models represent an accessible and economical method to predict groundwater and surface water pollution and should be calibrated based on experimental data to better understand the dynamics of pesticides in soil and ensure their efficiency. This long-term study explored the ability of the MACRO model to describe water movement and atrazine distribution along the profile of a Rhodic Ferralsol cultivated with corn in western Paraná, Brazil, using data from a drainage lysimeter under high intensity simulated rainfall (150 mm h-1). The soil parameters analyzed in the laboratory were used as pedotransfer functions. The initial simulations showed significant differences, due to the particularities of the model and the complexity of the soil and its pore space, so the tests adjusted the retention curve and the sorption parameters. After final adjustments to the model, the simulated atrazine mass results were evaluated. Calibration of pesticide concentrations required small changes in sorption and degradation rates, and the results were compared to quantities measured at a specific depth. The simulation of atrazine transport was considered acceptable, estimating 0.71, 4.63, and 3.05% of the total mass of atrazine in percolate, runoff and retained in the profile, respectively.

The impact of managed aquifer recharge on the fate and transport of pesticides in agricultural soils

Groundwater aquifers worldwide experience unsustainable depletion, compounded by population growth, economic development, and climate forcing. Managed aquifer recharge provides one tool to alleviate flood risk and replenish groundwater. However, concerns grow that intentional flooding of farmland for groundwater recharge, a practice known as Ag-MAR, may increase the leaching of pesticides and other chemicals into groundwater. This study employs a physically based unsaturated flow model to determine the fate and transport of residues of four pesticide in three vadose zone profiles characterized by differing fractions of sand (41 %, 61 %, and 84 %) in California's Central Valley. Here, we show that the complex heterogeneity of alternating coarse and fine-grain hydrogeologic units controls the transit times of pesticides and their adsorption and degradation rates. Unsaturated zones that contain a higher fraction of sand are more prone to support preferential flow, higher recharge rates (+8 %), and faster (42 %) water flow and pesticide transport, more flooding-induced pesticide leaching (about 22 %), as well as more salt leaching correlating with increased risks of groundwater contamination. Interestingly, considering preferential flow predicted higher degradation and retention rates despite shorter travel times, attributed to the trapping of pesticides in immobile zones where they degrade more effectively. The findings underscore the importance of considering soil texture and structure in Ag-MAR practices to minimize environmental risks while enhancing groundwater recharge. The study also highlights that selecting less mobile pesticides can reduce leaching risks in sandy areas.

Enhanced retention of hydrophobic pesticides in subsurface soils using organic amendments

The rapid global population growth since the early 2000s has significantly increased the demand for agricultural products, leading to widespread pesticide use, particularly organophosphorus pesticides (OPPs). This extensive application poses severe environmental risks by contaminating air, soil, and water resources. To protect groundwater quality, it is crucial to understand the transport and fate of these pesticides in soil and sediment. This study investigates the effects of hydrochars and biochars derived from sugar beet shreds (SBS) and Miscanthus×giganteus (MIS) on the retardation and biodegradation of OPPs in alluvial Danube sandy soil. The research is novel in its approach, isolating native OPP-degrading bacteria from natural alluvial sandy soil, inoculating them onto chars, and reapplying these bioaugmented chars to the same soil to enhance biodegradation and reduce pesticide leaching. The amendment of chars with immobilized Bacillus megaterium BD5 significantly increased bacterial abundance and activity. Metabarcoding of the 16S rRNA gene revealed a dominance of Proteobacteria (48.0–84.8 %) and Firmicutes (8.3–35.6 %). Transport modeling showed retardation coefficients (Rd) for OPPs ranging from 10 to 350, with biodegradation rates varying between 0.05 % and 75 %, indicating a positive correlation between retardation and biodegradation. The detection of biodegradation byproducts, including derivatives of phosphin, pyridine, and pyrazole, in the column leachate confirmed that biodegradation had occurred. Additionally, principal component analysis (PCA) revealed positive correlations among retardation, biodegradation, specific surface area (SSA), aldehyde/ketone groups, and bacterial count. These findings demonstrate the potential of biochar and hydrochar amendments to enhance OPP immobilization in contaminated soils, thereby reducing their leaching into groundwater. This study offers a comprehensive approach to the remediation of pesticide-contaminated soils, advancing both our fundamental understanding and the practical applications of environmental remediation techniques.

The role of soil amendments in limiting the leaching of agrochemicals: Laboratory assessment for copper sulphate and dicamba

Agriculture is among the major contributors to soil and groundwater pollution, primarily through the widespread leaching of pesticides and fertilizers from crops, as well as accidental releases from point sources. Therefore, alongside restrictions on the use of highly soluble agrochemicals and enhanced application guidelines, there is a significant demand for low-impact and cost-effective solutions aimed at reducing the mobility of agrochemicals in the soils. This study evaluates the potential of soil amendments—commonly used to enhance soil structural properties, water holding capacity, and fertility—to also absorb highly soluble pesticides, thereby controlling their leaching into the subsoil. Specifically, zeolite, biochar, and milled corncob were examined in laboratory tests under static (batch tests) and dynamic (column leaching tests) conditions to assess their effectiveness in adsorbing two widely used pesticides, copper sulphate and dicamba. Batch adsorption tests were performed using the amendments as pure materials and in mixtures with sand at various application rates (1–20% by weight). The highest affinity to copper sulphate was recorded for biochar, while dicamba exhibited a higher affinity to corncob, thanks to its higher content of organic carbon. Column leaching tests, performed at an amendment application rate of 5%, confirmed the different affinity observed in batch tests among pesticides and amended soil. Less than 2% of copper sulphate leached out from biochar- and zeolite-sand columns, while a recovery of 10% and 56% was observed for the corncob-sand mixture and for pure sand, respectively. Dicamba leaching from biochar- and corncob-sand columns was halved compared to pure sand. In conclusion, the tested soil amendments resulted highly effective in reducing pesticide leaching, opening the way for their possible applications in agriculture to reduce or prevent both diffuse and punctual contamination.

Adsorption of dinotefuran using TpBDMe COF nanoparticles for soil leaching reduction and bee safety

Dinotefuran (DIN) contaminates groundwater and is toxic to bees, so designing a novel pesticide loading system for dinotefuran is of great significance. In this paper, dinotefuran was loaded into TpBDMe COF with a mesoporous hollow structure, and the TpBDMe COF loaded with dinotefuran exhibited initial burst and subsequent sustained release behavior. The results showed that the product effectively suppresses wheat aphid development, with virtually no infestation occurring for 7–14 days, whereas other commercially available formulation had lost their usefulness. Our TpBDMe COF carrier effectively immobilizes dinotefuran, reducing pesticide leaching in soil by 70 % and enhancing the application efficiency of neonicotinoid insecticides. The LD50 of this product for acute exposure of honey bees doubled the LD50 of the original furosemide at 24 h and was equally effective at 48 h, reducing the toxicity to bees and promoting ecological safety. The results of this work show that this nanocarrier system is highly stable, loadable, insecticidal active, and environmentally friendly, showing great potential in the development of new nanocarriers for use.

Agricultural film-derived microplastics elevate the potential risk of pesticides in soil ecosystem: The inhibited leaching by altering soil pore

The residue of mulch film is a crucial source of microplastics (MPs) in agricultural fields. The effects of mulch film-derived MPs on the environmental behavior of pesticides in agriculture remain unclear. In the present study, the effects of MPs of different sizes (5 mm, 1 mm, 30 µm, and 0.3 µm) at environmentally relevant concentrations on pesticide transport were evaluated, and the mechanism was explored with respect to adsorption and pore structure using fluorescence visualization, the extended Derjaguin–Landau–Verwey–Overbeek model, and microcomputed tomography. MPs were found to be retained in the soil due to size limitation, pore capture, and surface adhesion. The presence of mm-sized MPs (5 and 1 mm) at a concentration of 0.25 % inhibited the leaching behavior of atrazine, metolachlor, and tebuconazole. MPs did not significantly alter the pesticide adsorption ability of the soil. The reduced leaching originated from the impact of MPs on soil pore structure. Specifically, the porosity increased by 16.2–25.0 %, and the connectivity decreased by 34.5 %. These results demonstrate that mm-sized MPs inhibit pesticide leaching by obstructing the pores and altering the transport pathways, thereby potentially elevating environmental risks, particularly to the soil ecosystem.

Fabrication of ionic liquid self-assemblies based on dicamba with improved herbicidal activity and reduced environmental risks

The off-target loss of pesticide formulations caused by volatilization and leaching has reduced effective utilization and increased risks to the ecological environment and human health. Self-assembly of pesticides has been widely concerned due to the improved bioactivity and environmental compatibility. Herbicidal ionic liquids (HILs) could effectively decrease off-target loss and increase efficacy and environmental safety by improving the physicochemical properties of herbicides. Herein, HILs were prepared by pairing dicamba with quaternary ammonium salts containing different alkyl chain lengths and aromatic groups and subsequently self-assembled into spherical nanoparticles (HIL NPs) via electrostatic interaction and hydrophobic effect. Compared with dicamba, the obtained HIL NPs with an average particle size of 6–55 nm exhibited improved physicochemical properties, including high zeta potential values (+20.3 to +27.8 mV), low volatilization rate (2.4–3.9 %) and surface tension (22.83–33.07 mN m−1), decreased contact angle (32.25–41.55°) and leaching potential (76.2–86.5 %), and high soil adsorption (12.1–23.8 %), suggesting low risks to the environment. The control efficacy against Amaranthus retroflexus of HIL3 NPs pairing dicamba with octadecyl-trimethyl ammonium chloride was better than that of dicamba sodium salt at different concentrations. Therefore, the ionic liquid self-assembly developed by a facile and green preparation approach to reduce the volatility and leaching of pesticides would have enormous potential in sustainable agriculture.

Adjuvant use for the management of pesticide drift, leaching and runoff.

Adjuvants are included in many pesticide spray mixtures to enhance the performance of the applied chemical. Many adjuvants which modify the emulsion or extensional viscosity of the tank-mixture have been found to offer benefits in drift management, primarily by eliminating or reducing the 'Fine' droplets included in the spray with diameters <100-200 μm that can move off-target in unfavorable conditions during ground, airblast and aerial pesticide applications. Among wind tunnel and field studies conducted around the world, there is consensus that while some adjuvants are effective for drift management, the performance varies on a case-by-case basis, requiring verification for each adjuvant which could be achieved through a programme such as certification based on showing a reduction in Fine droplets and/or a reduction in airborne drift. These can be measured in wind tunnel studies according to international standards. This article provides a review of the current science in this subject area, from the approaches to data collection to a review of existing data and regulatory application for encouraging and rewarding the use of appropriate adjuvants that have been demonstrated to reduce airborne spray drift potential and therefore the size of no-spray buffer zones appropriate to protect nontarget sensitive areas from drift exposure. Some adjuvants can offer the same reduction in drift as offered by hooded sprayer retrofits. A drift reduction programme based on adjuvant use could include testing candidate adjuvants for their effect on droplet size and reduction in Fine droplets when sprayed through reference nozzles and compared against sprays without the adjuvant. Testing could also be based alternatively on measurements of drift potential on collectors such as monofilament line in wind tunnel or field studies. Once shown to be effective in reducing 'Fines' or spray drift, adjuvants could be certified and then referenced on pesticide labels and/or regulatory or best management practice schemes to encourage their use and offer reductions in use restrictions or no-spray buffer zone sizes based on drift management. Studies have shown that some adjuvants can reduce pesticide leaching into soils and contamination of groundwater, as well as runoff of active ingredients from plants into the environment. Performance depends on the adjuvant type, the pesticide with which it is used, the soil or plant type, the timing and mass of water input from rainfall and climatic factors. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A web-based pesticide risk assessment tool for drinking water protection zones in Sweden

To protect human health, wildlife and the aquatic environment, “safe uses” of pesticides are determined at the EU level while product authorization and terms of use are established at the national level. In Sweden, extra precaution is taken to protect drinking water, and permits are therefore required for pesticide use within abstraction zones. This paper presents MACRO-DB, a tool for assessing pesticide contamination risks of groundwater and surface water, used by authorities to support their decision-making for issuing such permits. MACRO-DB is a meta-model based on 583,200 simulations of the physically-based MACRO model used for assessing pesticide leaching risks at EU and national level. MACRO-DB is simple to use and runs on widely available input data. In a qualitative comparative assessment for two counties in Sweden, MACRO-DB outputs were in general agreement with groundwater monitoring data and matched or were more protective than the national risk assessment procedure for groundwater.

Leaching of unexpected cyazofamid degradation products into groundwater demonstrates gaps in current pesticide risk assessment

To investigate the formation and leaching potential of degradation products N,N-dimethylsulfamide (DMS) and dimethylsulfamic acid (DMSA) from cyazofamid under real-world agricultural conditions, the fungicide cyazofamid was applied in a potato crop as part of the Danish Pesticide Leaching Assessment Programme (PLAP). Leaching of DMS, DMSA, 4-chloro-5-(4-methylphenyl)-1H-imidazole-2-carbonitrile (CCIM), and 4-chloro-5-(4-methylphenyl)-1H-imidazole-2-carboxylicacid (CTCA) was monitored in water from the variably saturated zone (suction cups) and groundwater for more than two years following the applications. In total, 424 samples were analyzed for the content of the four degradation products. An additional laboratory study was executed in parallel with the field monitoring study. Here, cyazofamid was applied to soil columns and leaching of the four degradation products was studied under controlled conditions.In the EFSA conclusion on cyazofamid, CCIM and CTCA are mentioned as major relevant metabolites; DMS is not mentioned in the risk assessment and DMSA is only included in acute oral toxicity studies and an in vitro bacterial mutation assay. In contrast to the EFSA conclusion on cyazofamid, our studies showed no leaching of the two major metabolites, CTCA and CCIM, but instead, major leaching of DMS and DMSA in both the field and laboratory studies was observed. That is, both DMS and DMSA leached to the groundwater in concentrations >0.1 μg/L for more than half a year. Based on this, we suggest improvements to the current pesticide risk assessment.

Application timing as a mitigation tool for pesticide leaching to drains in northwest Europe

Study regionArtificially drained agricultural land in northwest Europe. Study focusThe use of application timing as a mitigation tool for pesticide leaching to drains was investigated by simulating pesticide fate after application every day in a pesticide-specific application window, using the agro-hydrological model DAISY. The simulations were carried out for six combinations of pesticide-crop-seasons using three synthetically generated climate series and 800 soil profiles. The simulated drain concentrations were transformed to normalized pesticide concentrations in a hypothetical adjacent stream. Each application day was then characterized by the maximum normalized hourly pesticide concentration in the stream, expressed as the maximum hourly toxic unit (mTU), occurring within 300 days after application. New hydrological insights for the regionThe result showed that if the pesticide was applied consistently every year at the best application day, pesticide leaching, in terms of the 90th percentile of mTU, could be reduced by up to 62% compared to a random application. If the pesticide application day was restricted to vary in a five-day period, the 90th percentile of mTU could be reduced by up to 21%. Thus, our study shows that there is a significant mitigation potential for reducing pesticide leaching to drains by tailoring the timing of pesticide application to weather conditions.

Experimental study on photodegradation and leaching of typical pesticides in greenhouse soil from Shouguang, Shandong Province, East China

BackgroundPesticide use contributes to national food security. The dissipation pathways and degradation mechanisms of pesticides have been widely studied and pesticide residues have remained a focus of public concern. However, studies on the migration and transformation behaviors of pesticide residues in real-world greenhouse soils are insufficient. Therefore, in this study, we collected greenhouse soil from Shouguang, Shandong Province, and investigated the photodegradation and leaching of 17 common pesticides, which leave residues in the soil and are the most frequently used pesticides in Shouguang. The environmental behavior of pesticides in greenhouse soils will provide new information on pesticide residues in the real environment and provide a scientific basis for the prevention and control of pesticide pollution in greenhouse soils.ResultsThe photodegradation of trifloxystrobin followed a first-order kinetic equation, whereas those of emamectin benzoate, chlorantraniliprole, buprofezin, difenoconazole, pyraclostrobin, boscalid, tebuconazole, isoprothiolane, metalaxyl, and oxadixyl followed second-order kinetics. The half-lives of 17 pesticides under light and dark conditions ranged from 2.5–104 (mean: 36.2) and 2.6–110 (mean: 31.4) days, respectively. The half-lives of emamectin benzoate, pyraclostrobin, and metalaxyl in the light were 86.6%, 68.5%, and 94.5% of their half-lives in the dark, respectively. Chlorantraniliprole, metalaxyl, nitenpyram, diethofencarb, acetamiprid, carbendazim, and oxadixyl were leached to ≥ 90% in aqueous solution. Six pesticides, avermectin B1A, emamectin benzoate, trifloxystrobin, difenoconazole, pyraclostrobin, and buprofezin, were difficult to leach from aqueous solutions.ConclusionsThe degradation rate of some pesticides was higher in the light environment than in the dark. The leaching potential of the leachable pesticides was nitenpyram ≫ metalaxyl > acetamiprid > carbendazim > diethofencarb ≈ chlorantraniliprole > isoprothiolane > oxadixyl > boscalid ≈ tebuconazole > hexaconazole. Pesticides that are easy to leach but not easily degraded, such as chlorantraniliprole and metalaxyl, have a high potential risk of groundwater pollution, and additional degradation technologies should be used to reduce their pollution risk. The study of the photodegradation and vertical migration behavior of various pesticides is conducive to providing references for the agricultural use and pollution control of pesticides.

Empirical model to assess leaching of pesticides in soil under a steady-state flow and tropical conditions

An empirical model of leaching of pesticides was developed to simulate the concentration of fungicides throughout unsaturated soil. The model was based on chemical reactions and the travel time of a conservative tracer to represent the travel time required for water to flow between soil layers. The model’s performance was then tested using experimental data from dimethomorph and pyrimethanil applied to the soil under field and laboratory conditions. The empirical model simulated fungicide concentration on soil solids and in soil solution at different depths over time (mean square error between 2.9 mg2 kg−2 and 61mg2 kg−2) using sorption percentages and degradation rates under laboratory conditions. The sorption process was affected by the organic carbon, clay, and the effective cation exchange capacity of the soil. The degradation rate values of dimethomorph (0.039 d−1–0.009 d−1) and pyrimethanil (0.053 d−1–0.004 d−1) decreased from 0 to 40 cm and then remained constant in deeper soil layers (60–80 cm). Fungicide degradation was a critical input in the model at subsurface layers. The model was determined to be a reliable mathematical tool to estimate the leachability of pesticides in tropical soil under a steady-state flow. It may be extended to other substances and soils for environmental risk assessment projects.Graphical abstract

A Comprehensive Review on the Effect of Sugarcane Trash Ash on the Sorption, Degradation and Leaching of Atrazine and Fipronil in Agricultural Soils

Burning of surplus sugarcane trash for land clearing is a common practice followed by the farmers. The ashes generated from sugarcane trash burning will results in change in the physico-chemical properties of soils due to their alkaline nature. Ashes, due to presence of unburnt carbon, have exhibited potential to adsorb pesticides; therefore, might affect degradation, leaching and sorption of pesticides. Atrazine (Atz) and fipronil are commonly used pesticides in sugarcane. Due to their extensive application and their potential eco-toxicological effects, the global scientific interest focusing on the research of the environmental fate and behavior of pesticides after their entrance in the environmental matrices is undiminished. A comprehensive review on the effect of sugarcane trash ash on the sorption, degradation and leaching of atrazine (Atz) and fipronil in agricultural soils is so far not available. The objective of this review is thus to systematically summarize the impact of sugarcane trash ash on fate of atrazine (Atz) and fipronil in agricultural soils. Notably, the mechanisms and factors influencing were also extensively elucidated. This review helps better understand the effects of sugarcane trash ash on sorption, leaching, and degradation of atrazine (Atz) and fipronil in agricultural soils.

Strategies for reducing inputs and emissions in turfgrass systems

AbstractTurfgrass systems (e.g., home lawns, commercial properties, golf courses, athletic fields, roadsides, sod farms, parks, and other green spaces) in the US employ 820,000 individuals, have a $60 billion economic impact, and cover nearly 2% (∼63,250 mi2; 163,800 km2) of the US. Turfgrass systems provide ecosystem services such as carbon sequestration, oxygen production, water and air purification, improved soil health, pollinator habitat, and evaporative cooling. Associated disservices with turfgrass systems include nutrient and pesticide leaching, greenhouse gas and particulate matter emissions, low plant diversity, and site‐specific, high water consumption. The goal of recent research efforts is to maximize the services and minimize the disservices by focusing on sustainability initiatives to develop best management practices such reducing management inputs (e.g., mowing, irrigation, fertilizer, and pesticides), incorporating pollinator‐friendly spaces, adopting new technologies, quantitatively assessing ecosystem services provided, minimizing energy inputs and greenhouse gas emissions, and increasing carbon sequestration. This part‐review, part‐management guide summarizes these efforts, identifies knowledge gaps, and outlines how turfgrass systems can adapt to and mitigate climate change.

Assessment of potentially toxic elements in groundwater through interpolation, pollution indices, and chemometric techniques in Dehradun in Uttarakhand State.

Providing safe drinking water for the entire world's population is essential for ensuring sustainable development. The presence of harmful compounds in aquifers, majorly toxic elements, is a serious environmental concern around the globe. This research aimed to quantify for the initial period the amounts of toxic elements in freshwater in the Dehradun Industrial Region of Uttrakhand, India, as well as the associated health risks. The PTEs (potentially toxic elements) Fe, Cd, Mn, Cu, Cr and Pb, Zn, Ni is measured by AAS and compared to BIS and WHO requirements for drinking safety. The order of mean trace element values in all groundwater samples were determined as Fe > Zn > Cu > Ni > Co > Cd > Pb. HPI was discovered to be higher than high class during the research period (HPI > 30), but under the severe contamination criterion of 100. Iron's MI and PI values were consistently over the threshold limit during the research period, and certain toxic elements were discovered exceptionally near the threshold limit, indicating a severe future influence on groundwater quality. According to PCA (principal component analysis), CM (correlation matrix), and potential health hazard, maximum levels of toxic elements in groundwater in the Dehradun region are attributed to land use patterns, anthropogenic activity, industrial activity, fertilizer and pesticide leaching, and residential waste into the aquifer system. The findings of this study could aid local planners and policymakers in preventing health risks from contaminated aquifers through the deployment of suitable monitoring and mitigation measures.

Emerging contaminants in the aquatic environment: phytoplankton structure in the presence of sulfamethoxazole and diclofenac.

Chemicals from anthropogenic activities such as domestic sewage, pesticide leaching, and improper chemical disposal have caused groundwater contamination. The presence of these emerging contaminants in the aquatic environment can change water quality and biota composition. Thus, this study investigates the effect of two emerging contaminants, anti-inflammatory drug diclofenac (DCF) and antibiotic sulfamethoxazole (SMX), on the aquatic environment, evaluating the phytoplankton community structure. A microcosm experiment was conducted with 16 sampling units, each one with 500 mL of water sample containing phytoplankton exposed to these drugs at different concentrations (0.1, 0.5, and 1.0 mg L-1). The experiment lasted 15 days, and samples were collected on days 0, 3, 5, 7, and 14 to evaluate the phytoplankton community, the concentrations of the drugs, and the nutrients in the samples. Six phytoplankton groups were identified, and diatoms and green algae were the most diverse and abundant groups. For the entire community, we identified differences between the days of the experiment, varying in the diversity and density of organisms, but not between the concentrations of the two drugs. Evaluating the groups separately, we identified differences in the abundance of cyanobacteria for the treatment with diclofenac and desmids for the treatment with sulfamethoxazole. We demonstrated that the presence of pharmaceuticals in freshwater ecosystems can somehow affect the phytoplankton community, especially the diversity and abundance of cyanobacteria and desmids. Therefore, our study indicates the importance of evaluating the presence of pharmaceuticals in freshwater ecosystems and their influence on aquatic organisms, as well as pharmaceuticals may be changing the structure of the aquatic environment.

Current approaches for modeling ecosystem services and biodiversity in agroforestry systems: Challenges and ways forward

Limited modeling studies are available for the process-based simulation of ecosystem services (ESS) and biodiversity (BD) in agroforestry systems (AFS). To date, limited field scale AFs models are available to simulate all possible ESS and BD together. We conducted an extensive systematic review of available agroforestry (AF), BD, and soil erosion models for the simulation potential of seven most desirable ESS in AFS. Simple to complex AF models have an inherent limitation of being objective-specific. A few complex and dynamic AF models did not meet the recent interest and demands for the simulation of ESS under AFS. Further, many ESS modules especially soil erosion, GHGs emission, groundwater recharge, onsite water retention, nutrients and pesticide leaching, and BD are often missing in available AF models, while some existing soil erosion models can be used in combination with AF models. Likewise mechanistic and process-based BD diversity models are lacking or found limited simulation potential for ESS under AFS. However, further efforts of model development and improvement (integration and coupling) are needed for the better simulation of complex interactive processes belonging to ESS under AFS. There are different possibilities but a proficient modeling approach for better reliability, flexibility, and durability is to integrate and couple them into a process-based dynamic modular structure. Findings of the study further suggested that crop modeling frameworks (MFW) like SIMPLACE and APSIM could be potential ones for the integration and coupling of different suitable modeling approaches (AF, soil protection, GHGs emission, flood prevention, carbon sequestration, onsite water retention, ground recharge, nutrient leaching, and BD modules) in one platform for dynamic process based ESS estimation on daily basis at the field scale.

Soil and crop management practices and the water regulation functions of soils: a qualitative synthesis of meta-analyses relevant to European agriculture

Abstract. Adopting soil and crop management practices that conserve or enhance soil structure is critical for supporting the sustainable adaptation of agriculture to climate change, as it should help maintain agricultural production in the face of increasing drought or water excess without impairing environmental quality. In this paper, we evaluate the evidence for this assertion by synthesizing the results of 34 published meta-analyses of the effects of such practices on soil physical and hydraulic properties relevant for climate change adaptation in European agriculture. We also review an additional 127 meta-analyses that investigated synergies and trade-offs or help to explain the effects of soil and crop management in terms of the underlying processes and mechanisms. Finally, we identify how responses to alternative soil–crop management systems vary under contrasting agro-environmental conditions across Europe. This information may help practitioners and policymakers to draw context-specific conclusions concerning the efficacy of management practices as climate adaptation tools. Our synthesis demonstrates that organic soil amendments and the adoption of practices that maintain “continuous living cover” result in significant benefits for the water regulation function of soils, mostly arising from the additional carbon inputs to soil and the stimulation of biological processes. These effects are clearly related to improved soil aggregation and enhanced bio-porosity, both of which reduce surface runoff and increase infiltration. One potentially negative consequence of these systems is a reduction in soil water storage and groundwater recharge, which may be problematic in dry climates. Some important synergies are reductions in nitrate leaching to groundwater and greenhouse gas emissions for nonleguminous cover crop systems. The benefits of reducing tillage intensity appear much less clear-cut. Increases in soil bulk density due to traffic compaction are commonly reported. However, biological activity is enhanced under reduced tillage intensity, which should improve soil structure and infiltration capacity and reduce surface runoff and the losses of agro-chemicals to surface water. However, the evidence for these beneficial effects is inconclusive, while significant trade-offs include yield penalties and increases in greenhouse gas emissions and the risks of leaching of pesticides and nitrate. Our synthesis also highlights important knowledge gaps on the effects of management practices on root growth and transpiration. Thus, conclusions related to the impacts of management on the crop water supply and other water regulation functions are necessarily based on inferences derived from proxy variables. Based on these knowledge gaps, we outlined several key avenues for future research on this topic.

Co-existence of Pesticides and Fertilizers in Agricultural Soil Environment

Pesticides and fertilizers are of utmost importance in suppression of pests and meeting food requirements. However, the excessive and inefficient use has ended up in severe environmental damage, in which soil health has intensively witnessed most critical part of harmful problems. Exposure of pesticides and fertilizers adversely affects soil nutrient content, enzyme activities, predominant non-target organisms, structural and functional biodiversity of microbial populations. It has been observed that the adsorption-desorption, leaching and degradation behaviors of pesticides can be modified in response to fertilizers, which regulate microorganisms for assimilated pollutes. Application of optically pure, bio-based pesticides and fertilizers for soil amendment is a sustainable and low cost option to avoid combined contamination in the soil environment. The practices of organic wastes as cost-effective biochar loaded fertilizers can also further achieve a double win targets in the formation of green production mode for pesticides and fertilizers. Additionally, more studies are needed to help identify opportunities for new agro-ecosystem.