Soil Management Research Articles

Chemical and Physical Analysis of Different Types of Soil in India

This study examines the chemical and physical properties of soils across various regions of India, focusing on their agricultural production and environmental sustainability. Chemical testing revealed notable variations in soil pH and nutrient content. Phosphorus ran from 15 to 47 ppm; potassium from 180 to 270 ppm; nitrogen from 12 to 22 ppm; and pH from 5.4 to 6.8. Revealing the intricate interactions among several components improves correlation analysis and offers important information for the development of concentrated soil management strategies. The soil structure determines water retention capacity and nutrient availability regardless of loam, sand, or clayey. Studies of heavy metals revealed varying degrees of mercury, cadmium, arsenic, and lead all around India. Since it shows the changes in easily available water over time, the moisture content of the soil is vital for irrigation planning and agriculture. Emphasising the need of soil porosity (28.45% to 40.17%) and permeability (7.83 to 11.23 cm/hr) for water movement and root penetration is absolutely vital. These findings support informed decision-making in soil management, promoting sustainable agricultural practices tailored to regional soil characteristics.

Organic Fertilization Leads to N Limitation Rather than P Limitation in Both Vegetable Soils

Organic amendments are widely used to enhance soil fertility and nutrient cycling in greenhouse cultivation, but their effectiveness can vary depending on their origin and composition. This study investigated the impact of four organic materials (rice husk, coconut coir, biochar, and sheep manure) on nutrient cycling and enzyme activities in two of greenhouse tomato soils. The distribution of soil nutrients and enzyme activities was analyzed under controlled conditions during a pot experiment. The addition of organic amendments, regardless of their source, significantly altered the microbial resource allocation, reducing the carbon limitation while increasing the nitrogen demand. The effect on soil nutrient pools was largely determined by the chemical composition of the amendments. In clayey soils, biochar and rice husk additions most effectively promoted enzyme activities related to carbon, nitrogen, and phosphorus acquisition. Under sandy soil conditions, sheep manure increased carbon and phosphorus acquisition enzymes, while biochar most effectively enhanced nitrogen acquisition enzymes. Biochar emerged as a particularly effective amendment, enhancing organic carbon sequestration across different soil types. The chemical composition of the amendments, specifically, the content of carboxyl C, aromatic C, and O-alkyl C, played a crucial role in influencing soil nutrient limitations. In clayey soils, the mean C:N:P ratios for CK, T1, T2, T3, and T4 treatments were 1:1.375:0.625, 1:1.244:0.662, 1:0.839:0.610, 1:1.161:0.689, and 1:1.038:0.549, respectively. In sandy soils, the ratios were 1:1.117:0.698, 1:1.18:0.75, 1:1.096:0.731, 1:1.217:0.689, and 1:1.06:0.669, respectively. These findings suggest that the addition of organic amendments can improve nutrient retention and enzyme activities, but their effects on soil nutrient pools are influenced by both the composition of the amendments and the soil texture. This research enhances our understanding of organic amendments and soil nutrient transformations, and aids in optimizing the application of organic materials for improved soil management in greenhouse cultivation.

SLAKES Smartphone Application to Identify the Difference in Soil Aggregate Stability Under Cover Crop Management for Soils with Fragipan Horizon

ABSTRACT Fragipan subsoil horizons have poor soil aggregate stability that slakes in rise with the water table. The intensity of slaking can be used as a proxy to identify the presence of fragipan horizon in a soil profile. Fairly new, ‘Slakes,’ a smartphone application provides an aggregate stability index (ASI) based on fitting a Gompretz function over changes in area of disintegrating soil peds immersed in water for over 10 min through the analysis of images taken by a smartphone camera. Objectives of this study were twofold: first, to identify changes in ASI values with the adoption of cover crops, and second, to apply Slakes value to identify the fragipan horizon. We compared ASI values for with (CC) and without (NCC) a cover crop mix at two on-farm fields with fragipan subsoil horizons in southern Illinois. The conventional wet aggregate stability method did not show any differences (p = .10) between CC and NCC for the surface Ap horizon at both sites. However, the ASI score of CC was higher than NCC for the site with 10 years under CC, but the opposite trend was observed for the other site. In general, the Ap horizon had the highest ASI score with an average value of 0.48 and it significantly declined for the Bt horizon (0.29). This study showed that the Slake-ASI score has value to identify changes in management practices on surface soils. However, applying Slakes to identify the fragipan horizon would require a shorter time length (<10 min) and large-scale calibration.

Spatial variability of soil organic carbon in Tamil Nadu: Integrating remote sensing and machine learning approaches

Aim: The experiment was carried out to estimate the geographical distribution of soil organic carbon (SOC) in Tamil Nadu, India, using advanced machine learning models. Methodology: High-resolution remote sensing data from Landsat 8, climate indices from TerraClimate, and terrain indices from the Shuttle Radar Topography Mission (SRTM) were integrated to construct reliable SOC estimation models. The models employed in this study included Random Forest (RF), Quantile Neural Network (QNN), Cubist, and Bootstrapped Random Forest (BRF). These models were selected for their ability to capture complex relationships between SOC and environmental covariates. Results: The QNN and Cubist models displayed superior accuracy with mean absolute error (MAE) values of 0.48 and 0.47, respectively. Variogram analysis indicated moderate spatial dependence across all models, with the Cubist model exhibiting the highest partial sill and sill values. Interpretation: These findings demonstrate the effectiveness of combining machine learning with remote sensing for SOC estimation. The results suggest that these models can be valuable tools in improving the accuracy of SOC distribution maps, which are essential for sustainable crop production. By identifying potential SOC sequestration areas, this research contributes to the development of targeted soil management strategies that prioritize soil health and support sustainable agricultural practices. Key words: Carbon sequestration, Digital soil mapping, Estimation models, Environmental covariates, Land management

Postemergence giant ragweed management as affected by soil and cover crop management, soybean planting time, and preemergence herbicide application

Abstract Early soybean planting and cover crop adoption in the US Midwest prompt investigation into the impact of these practices on weed community dynamics and best management practices. While previous research has explored different aspects of giant ragweed control, the specific integration among soil management practices, including cover crop adoption, soybean planting timing, and herbicide use, has not been thoroughly investigated. This study assessed soil management, soybean planting time, and PRE herbicide application on giant ragweed control and soybean yield in Wisconsin and Nebraska in 2022 and 2023. The study included a factorial arrangement of four soil management treatments [conventional tillage, no-till, and fall-planted cereal rye early terminated and terminated at planting (planting green)]; two soybean planting times; and two PRE herbicide treatments (PRE and no PRE). Postemergence (POST) herbicides were applied when ∼50% of giant ragweed plants within each treatment reached ∼10 cm in height. In Nebraska, cereal rye and tillage treatments without a PRE had at least 67% lower giant ragweed density than no-till at POST. In no-till, densities were at least 60% lower with PRE compared to no PRE. In Wisconsin, cereal rye did not reduce giant ragweed density at POST compared to no-till, likely due to relatively low biomass accumulation. In contrast, delayed soybean planting reduced giant ragweed density for most treatments but lowered soybean yield in no-till and planting green treatments. The PRE herbicides had either no or positive effects on reducing giant ragweed density and increasing soybean yield. Overall, this study suggests that soil management and soybean planting timing are crucial for effective giant ragweed management in Wisconsin, where biotypes with a long emergence window during the spring and summer are present, while in Nebraska, soil management and soybean planting timing are less critical due to giant ragweed biotypes with an early and short emergence window in the spring.

Continuous cropping of Patchouli alters soil physiochemical properties and rhizosphere microecology revealed by metagenomic sequencing

Continuous cropping (CC) profoundly impacts soil ecosystems, including changes in soil factors and the structure and stability of microbial communities. These factors are interrelated and together affect soil health and plant growth. In this research, metagenomic sequencing was used to explore the effects of CC on physicochemical properties, enzyme activities, microbial community composition, and functional genes of the rhizosphere soil of patchouli. We found that this can lead to changes in various soil factors, including the continuous reduction of pH and NH4+-N and the unstable changes of many factors. In addition, S-PPO enzyme activity increased significantly with the cropping years, but S-NAG increased in the first 2 years and decreased in the third cropping year. Metagenomic sequencing results showed that CC significantly changed the diversity and composition of rhizosphere microbial communities. The relative abundance of Pseudomonas and Bacteroides decreased substantially from the phylum level. At the genus level, the number of microbial genera specific to the zero-year cropping (CK) and first (T1), second (T2), and third (T3) years decreased significantly, to 1798, 172, 42, and 44, respectively. The abundance of many functional genes changed, among which COG0823, a gene with the cellular process and signaling functions, significantly increased after CC. In addition, NH4+-N, S-CAT, S-LAP, and SOC were the main environmental factors affecting rhizosphere-dominant microbial communities at the phylum level, while pH, SOC, and AK were the key environmental factors affecting rhizosphere functional genes of Pogostemon cablin. In summary, this study showed the dynamic changes of soil factors and rhizosphere microorganisms during CC, providing a theoretical basis for understanding the formation mechanism and prevention of CC obstacles and contributing to the formulation of scientific soil management and fertilization strategies.

Structural quality of a Latosol cultivated with oilseed in succession to soybean

Understanding the changes in soil structure that develop from oilseed crop successions is vital for successful production. The objective of this study was to evaluate the effects of different oleaginous crop successions on the least limiting water range and load-bearing capacity of a clayey Rhodic Hapludox. The following oilseed crops were cultivated under a no-tillage system in autumn-winter: sunflower (Helianthus annuus L.), canola (Brassica napus L. and Brassica rapa), safflower (Carthamus tinctorius L.), crambe (Crambe abyssinica Hochst.) and niger seed (Guizotia abyssinica). They were sown after soybean and soybean/corn (summer/fall-winter). When the autumn-winter crops flowered, soil samples with structure intact were collected at the 0.0–0.5 m and 0.5–0.10 m depths in metal cylinders. It was observed that in terms of water interval, the poorest soil structural quality in the 0.0–0.5 m layer was provided by the corn/safflower and corn/crambe successions. In terms of soil water content, the optimal time for soil management practices varied for the different oilseeds succeeding soybean. Soil load capacity varies inversely with water content and directly with soil density. Niger grown during autumn-winter in succession to soybean improved Rhodic Hapludox structure more than the other crop successions.

Tillage type and sentinel insect species affect the relative prevalence of the entomopathogenic fungus, Metarhizium robertsii, in soil.

Because the use of synthetic agrochemicals is generally not allowed in organic crop production systems, growers rely on natural substances and processes, such as microbial control, to suppress insect pests. Reduced tillage practices are associated with beneficial soil organisms, such as entomopathogenic fungi, that can contribute to the natural control of insect pests. The impacts of management, such as tillage, in a cropping system can affect soil biota in the current season and can also persist over time as legacy effects. We investigated the in-season and legacy effects of soil management in four, three-year organic feed grain and forage production systems that varied in number and intensity of soil disturbances on the relative prevalence of the entomopathogenic fungus, Metarhizium robertsii. Employing sentinel bait assays with Tenebrio molitor and Galleria mellonella, we found that relative prevalence, measured as infection rate of sentinel insects, was lowest in systems utilizing a shallow high-speed disk (G. mellonella: 14%; T. molitor: 23%) in the current and previous seasons compared to systems that included inversion and non-inversion tillage (G. mellonella: 22%; T. molitor: 34%) or no-till planting (G. mellonella: 21%; T. molitor: 30%,). There was no difference in prevalence in systems that included the use of a high-speed disk compared to a perennial hay crop (G. mellonella: 16%; T. molitor: 28%). There were no negative legacy effects of inversion tillage on the prevalence of M. robertsii in subsequent crops. Sentinel assays with G. mellonella (19%) produced overall lower estimates of relative prevalence of M. robertsii than T. molitor (29%) but the association of relative prevalence with environmental variables was greater in assays with G. mellonella. We suggest that the use of occasional inversion tillage is not damaging to populations of M. robertsii in soil and that surveys using assays with multiple sentinel insect species will improve our ability to understand the effects of agricultural practices on entomopathogenic fungi.

Soil Degradation of Sloping Cropland in the Typical Black Soil Region in Northeast China: Risk Assessment and Uncertainty Analysis

ABSTRACTSoil degradation in the typical black soil region in Northeast China poses a threat to agricultural productivity and sustainability. However, little is known about the distribution of soil with different degradation degrees on a regional scale. This study aimed to map soil degradation status based on a newly developed soil degradation index (SDI) and assessed the uncertainty of degradation risk through the combination of ordinary Kriging and sequential Gaussian simulation (SGS) in order to enhance the accuracy and credibility of predictive results. The mean SDI was 0.445, with a coefficient of variation of 30%. The realization with 200 times by SGS was the best showed an increasing pattern of soil degradation degree from north to south in the study area. Slightly and moderately degraded sloping cropland accounted for 35.3% and 52.4% of all sloping cropland, respectively. High‐risk areas were mainly located in the Daxing'an and Changbai Mountains to the Songnen Plain. Proactive measures are necessary to control and mitigate further degradation by improving soil management and weakening the impact of runoff on sloping cropland. The developed risk assessment maps provide baseline information for regional sustainable development.

Enhancing Soil Health in Rice Cultivation: Optimized Zn Application and Crop Residue Management in Calcareous Soils

Enhancing Soil Health in Rice Cultivation: Optimized Zn Application and Crop Residue Management in Calcareous Soils

Synergistic Impact of Biochar and Organic Amendments on Field Bean (Vicia faba) Growth and Soil Characteristics

Many studies have explored the effects of various biochar types and their combinations with inorganic fertilizers, but few have focused on identifying the most effective organic amendments when used with biochar in sandy loam soil. This study aims to determine the impact of different biochar doses combined with organic amendments on plant growth and yield (Vicia faba) in sandy loam soil. Biochar doses of 15, 20, and 25 t/ha were applied in combination with organic amendments such as farmyard manure (FYM), vermicompost (VC), Ghanajeevamruth (GA), and their various combinations. The effectiveness of these treatments was compared to the use of biochar alone. Results indicated that the combination of biochar and organic amendments significantly increased average pod number (by 36.19% to 88.63%) and pod weight (by 24.11% to 83.18%) compared to biochar alone. Higher biochar doses consistently resulted in increased pH levels in the soil, regardless of the organic amendment used. Additionally, biochar combined with organic amendments led to higher nutrient levels, including nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, compared to biochar alone. The study concluded that biochar, particularly in combination with Ghanajeevamruth, had superior effects on plant growth and yield. The choice of amendment and biochar dose significantly influenced soil pH, nutrient availability, bulk density, and water holding capacity. These findings confirm the potential of combining biochar with organic amendments to enhance soil fertility and agricultural productivity, offering valuable strategies for sustainable nutrient management in sandy loam soils.

Combined Impact of Canada Goldenrod Invasion and Soil Microplastic Contamination on Seed Germination and Root Development of Wheat: Evaluating the Legacy of Toxicity

The concurrent environmental challenges of invasive species and soil microplastic contamination increasingly affect agricultural ecosystems, yet their combined effects remain underexplored. This study investigates the interactive impact of the legacy effects of Canada goldenrod (Solidago canadensis L.) invasion and soil microplastic contamination on wheat (Triticum aestivum L.) seed germination and root development. We measured wheat seed germination and root growth parameters by utilizing a controlled potted experiment with four treatments (control, S. canadensis legacy, microplastics, and combined treatment). The results revealed that the legacy effects of S. canadensis and microplastic contamination affected wheat seed germination. The effects of different treatments on wheat seedling properties generally followed an “individual treatment enhances, and combined treatment suppresses” pattern, except for root biomass. Specifically, the individual treatment promoted wheat seedling development. However, combined treatment significantly suppressed root development, decreasing total root length and surface area by 23.85% and 31.86%, respectively. These findings demonstrate that while individual treatments may promote root development, their combined effects are detrimental, indicating a complex interaction between these two environmental stressors. The study highlights the need for integrated soil management strategies to mitigate the combined impacts of invasive species and microplastic contamination on crop productivity and ecosystem health.

Drivers of forest productivity in two regions of the United States: Relative impacts of management and environmental variables.

Climate, environmental conditions, and management strategies are key factors affecting forest net ecosystem production (NEP). However, little is known about the relationship between management approaches and regional to continental-scale forest productivity. In this study, we utilized forests of the U.S. Southeast (SEUS) and Pacific Northwest (PNW), two ecologically and socio-politically distinct regions, to answer the question: Does management exert a stronger influence on NEP than environmental factors? We estimated Geographically Weighted Regression models of NEP derived from the Ecosystem Demography Model as a function of soil, topography, climate, and forest management practices for the period 2000-2015 using 383 and 407 10×10km2 landscapes in SEUS and PNW, respectively. Results showed that forest management practices were important in predicting NEP only in mountainous northeastern areas of the SEUS; in the PNW, NEP had a more complex relationship with management and was positively related to ecological, preservation, and passive management. Management, topography, and soil were more strongly correlated with NEP in the PNW than in the SEUS, in which 81%, 83%, and 83% of PNW locations showed significant relationships with at least one management, topography, or soil variable, repectively. In contrast, seasonal precipitation and temperature were stronger predictors of NEP in the SEUS than other drivers, with 99% and 84% of the locations influenced by at least one seasonal temperature or precipitation variable, respectively. The findings of this study may provide a valuable framework for forest management - climate change strategies that could be extended across regional scales.

STUDY ON NUTRIENT LOSSES IN THE STANDARD EROSION CONTROL PLOTS FROM PREAJBA EXPERIMENTAL POINT, GORJ

Recent studies highlight that controlling nutrient emissions from agricultural sources remains one of the most pressing environmental challenges in safeguarding water bodies. The excessive release of nutrients, particularly nitrogen and phosphorus, can lead to the eutrophication of aquatic ecosystems, disrupting water quality and biodiversity. In this context, the present study focuses on the systematic monitoring of agrochemical soil indicators in designated standard plots at the Preajba experimental point in Gorj County. The primary objective is to evaluate and control nutrient losses originating from agricultural practices, with a particular emphasis on understanding the dynamics of nutrient mobility along different topographical positions. Two soil profiles were established for this purpose: one located at the top of the slope and the other at its base. This setup allows for a comprehensive assessment of nutrient losses influenced by slope position, providing critical insights into erosion-driven nutrient transport and soil fertility dynamics. The findings aim to inform sustainable soil and nutrient management practices tailored to mitigate environmental impacts while supporting agricultural productivity.

Sorption and Transport of Antibiotics in Manured Upland Agricultural Soils

Sorption and transport are important environmental behaviors of antibiotics in soils and can determine the fate of antibiotics in environments； however, limited relevant studies have been conducted on long-term manured soils. In this study, batch and repacked soil column experiments were conducted to examine the sorption and transport behavior of four veterinary antibiotics, including sulfamethazine （SMT）, florfenicol （FFC）, doxycycline （DOX）, and enrofloxacin （ENR）, in red soils, yellow soils, and calcareous soils with long-term amendment of chicken or pig manure collected in Zhejiang Province. The results showed that the sorption isothermal data of the four target antibiotics all conformed well to the linear and Freundlich models. The performance of the linear model was better for the weakly-sorbing antibiotics （SMT and FFC）, whereas the performance of the Freundlich model was better for the strongly-sorbing antibiotics （DOX and ENR）. The sorption of target antibiotics was governed by both soil and manure types. The linear sorption parameter （Kd） of SMT and FFC were positively related to the organic carbon content and pH of soils, and their sorption was mainly controlled by soil organic matter, indicating that non-electrostatic interactions （e.g., hydrogen bonding, hydrophobic interactions） played dominant roles in their sorption to the soils. Contrastingly, DOX and ENR did not show significant relationships with soil pH, organic carbon content, and cation exchange capacity, indicating that multiple mechanisms （e.g., hydrophobic interactions, hydrogen bonding, and electrostatic interactions） worked jointly in their sorption into the soils. SMT and FFC exhibited high recoveries of breakthrough curves （in ranges of 37.5%-92.3% and 45.8%-112.6%, respectively） in column transport experiments, reflecting their high leaching potentials. Contrastingly, no soil column breakthrough of DOX and ENR was observed, reflecting that the injected antibiotics were completely retained inside the soil columns. The maximum relative concentrations and breakthrough recoveries of SMT and FFC showed significant negative linear relationships with Kd. This indicates that the leaching potential of antibiotics can be predicted from sorption parameters using the regression equations established by batch and column experiments.

Exploring management and environment effects on edge-of-field phosphorus losses with linear mixed models.

Evaluating how weather, farm management, and soil conditions impact phosphorus (P) loss from agricultural sites is essential for improving our waterways in agricultural watersheds. In this study, rainfall characteristics, manure application timing, tillage, surface condition, and soil test phosphorus (STP) were analyzed to determine their effects on total phosphorus (TP) and dissolved phosphorus (DP) loss using 125 site-years of runoff data collected by the University of Wisconsin Discovery Farms and Discovery Farms Minnesota. Three linear mixed models (LMMs) were then used to evaluate the influence of those factors on TP and DP losses: (1) a model that included all runoff events, (2) manured sites only, and (3) precipitation events only. Results show that the timing of manure application relative to the timing of a runoff event only had a marginal association with P loads and concentrations, although the majority of the runoff events were collected after 10 days of manure application. Tillage was as influential factor, with greater DP loads and concentrations associated with no-till, especially during frozen conditions. Fields in this study had high STP values, but the model results only showed positive associations between DP load and DP flow-weighted mean concentration (FWMC) loss at the 0- to 15-cm depth. The precipitation event LMM (which included precipitation characteristics) was the model that resulted in the largest R2 value. While the predictive capacity of the LMMs was low, they did illuminate the relative importance of management and environmental variables on P loss, and can be used to guide future research on P loss in this region.

Fungal communities in boreal soils are influenced by land use, agricultural soil management and depth.

Land use and agricultural soil management affects soil fungal communities that ultimately influence soil health. Subsoils harbor nutrient reservoir for plants and can play a significant role in plant growth and soil carbon sequestration. Typically, microbial analyses are restricted to topsoil (0-30cm) leaving subsoil fungal communities underexplored. To address this knowledge gap, we analyzed fungal communities in vertical profile of four boreal soil treatments: long-term (24-years) organic and conventional crop rotation, meadow, and forest. ITS2 amplicon sequencing revealed soil-layer-specific land use or agricultural soil management effects on fungal communities down to the deepest measured soil layer (40-80cm). Forest had higher symbiotroph, meadow higher saprotroph, and crop rotations higher pathotroph and plant pathogen proportions compared to other treatments. The proportion of arbuscular mycorrhizal fungi was higher in deeper (> 20cm) soil than topsoil. Forest soil below 20cm was dominated by fungal functional groups with proposed interactions with plants or other soil biota, whether symbiotrophic or pathotrophic. Ferrous oxide was an important factor shaping fungal communities throughout the vertical profile of meadow and cropping systems. Our results emphasize the importance of including subsoil into microbial community analyses in differently managed soils.

Farming and biochar in the EU and the road to sustainability: Drawing connections through the Common Agricultural Policy and the regulation of organic and carbon farming

AbstractConsidering the significant impact of agriculture on the environment, there is corresponding potential residing in proper management of agricultural soils and in farming. Agricultural systems are instrumental to achieving climate and environmental goals and for paving the road towards sustainability. However, this requires a transition from business‐as‐usual agriculture and farming, which must be supported by policy and legislation through systemic and coordinated measures. Other more pointed measures, such as the targeted use of certain technologies, for example, the proper use of biochar, can also be leveraged. But what is the state of play in the pursuit of sustainability in farming in the EU legislation and policy? How significant are these developments for biochar in the transition towards sustainability? This article considers these issues in relation to three different yet connected policy and legislative fields in the broader agriculture domain: the Common Agricultural Policy, organic farming and the emerging domain of carbon farming.

The Relationship between Lithology and Chemical Characteristics of Soil and Soil Fertility Quality in the Taliabu Island Region, Indonesia

Background: Soil fertility refers to the soil’s ability to provide essential nutrients for plant growth. This is largely determined by the process of lithological weathering, which involves the breakdown of parent rock. As the parent rock weathers, it releases different types of minerals into the soil, ultimately shaping the physical and chemical properties of the soil. These characteristics serve as the foundation for effective soil management, which is crucial for supporting a successful agricultural system. Through research on the impact of lithology and soil chemistry on soil quality, we gained a better understand and improve soil fertility. Methods: The assessment of soil fertility quality is based on two aspects: the type of mineral content in the parent rock and soil chemistry, which includes CEC, BS, pH and elements such as N, P and K. This research was conducted in Taliabu Island Regency, North Maluku Province, Indonesia from May to December 2021. Soil data were obtained through direct observation in the field and by collecting soil samples for laboratory analysis. Result: The research location’s lithology comprised two main groups: sedimentary and volcanic rocks. Sedimentary rocks included young formations (alluvio-marine and alluvio-colluvium) and old formations (limestone, coral, marl mixtures, sandstone, gneiss and schist). Old volcanic rocks present were breccia, tuff, lapilli tuff, granite and granodiorite. Soil chemical analysis revealed low fertility status. Considering the source rock composition and soil chemical properties, the overall soil fertility status was categorized as low.

Wheat cultivar mixtures enhance the delivery of agroecosystem services compared to monocultures under contrasted tillage intensities and fertilization

AbstractWheat cultivar mixtures provide a more complex and functional cropping system than monocultures. Their functionality may result in the delivery of agroecosystem services. However, research on cultivar mixture performance has mainly been done in controlled environments. Greenhouses and laboratory experiments do not account for environmental or agronomic factors that may influence the polyculture’s functionality. To fill this research gap, we set up a novel strip-split-block experimental design with three factors (wheat treatment, tillage, and fertilization) in a field long-term trial. We assessed the performance of the modern wheat cultivar Florence-Aurora and the traditional cultivars Xeixa (Triticum aestivum L. subsp. aestivum) and Forment (Triticum turgidum L. subsp. durum) monocultures and their mixture in providing aphid and weed control and promoting crop yield under contrasting tillage practices (moldboard ploughing vs. chisel ploughing) and fertilization (farmyard manure applied or not applied). We analyzed aphid abundance, number of aphids per tiller, parasitism rate, weed abundance and richness, and crop yield. Additionally, we examined wheat establishment, cover, phenology, and height for cultivar characterization. We observed that soil management practices affected some aspects of the cropping system. The wheat cultivars differed in their aphid susceptibility and weed suppression ability, with Florence-Aurora being less suppressant to weeds and more prone to aphid infestation. Most remarkably, our study shows for the first time that mixing wheat cultivars with distinguished traits enhances associational resistance for aphid and weed control. These benefits were specifically important under high weed infestations generated by reduced tillage. Moreover, the yield of Florence-Aurora monoculture and the mixture was found to be influenced by tillage and fertilization. Our study underscores how soil management practices impact the functionality of cultivar mixtures. This emphasizes the need for further field research to better understand the complexity of farming conditions that influence the delivery of agroecosystem services by cultivar mixtures.