Crop Mixtures Research Articles

Crop Mixtures Influence Fall Armyworm Infestation and Natural Enemy Abundance in Maize-based Intercropping Systems

Crop Mixtures Influence Fall Armyworm Infestation and Natural Enemy Abundance in Maize-based Intercropping Systems

The LTAR Integrated Common Experiment at Southern Plains.

The Southern Plains (SP) is one of 18 Long-Term Agroecosystem Research network sites that combine strategic research projects with common measurements across multiple agroecosystems. Projects at the SP site focus on the use of indicator measurements to aid in assessment of land and nutrient management's impact on soil health, water quality, carbon and water balances, and forage biomass-quality in diversified, adaptive crop-livestock systems designed to overcome shifts in natural resources and climate. The prevailing treatment is tilled winter wheat (Triticum aestivum L.) that is grazed, hayed, harvested for grain, or grazed and harvested for grain. The alternative treatment is year-round annual cover crop forage mixes for cattle (Bos taurus) production planted in fall and spring under conservation tillage management. The area is subject to variable weather and climatic shifts that reduce the potential to diversify forage crops and limit grazing in southern tall grass prairies and small grain systems. Incorporation of fertilized, rain-fed, annual cool and warm season mixtures of cover crops could fill forage gaps. The presence of year-round ground cover reduces sediment and nutrient loading to surface waters while enhancing soil health and water holding capacity. Tools to aid agricultural producers and land and water resource managers have been developed and implemented to determine how climate, topography, and varying conservation management practices alter hydrological structures, greenhouse gas emissions, water usage, and soil resources.

The Effect of Rhizobium Inoculation on the Nutritional Value of Crops in the Legume–Cereal Intercropping System in Northern Kazakhstan

In this study, the changes in yield, nutrient content, and amino acid levels in legume–cereal grass mixtures were qualitatively evaluated depending on the legume–cereal combination and inoculation with preparations based on Rhizobium. This study, taking into account the biological characteristics of legume forage crops, used inoculations with strains of nodule bacteria and associative nitrogen fixers to enhance the process of the nitrogen fixation of mixed crops of legumes and cereal. The aim of this study was to compare the yields and nutritional values of monocultures and mixed crops, as well as to determine the effects of preparations based on strains of nodule bacteria and the associated nitrogen fixer on the photosynthetic activity and yield of combined annual legume–grain crops. A comparative study of forage crop biomass was conducted to analyze crude protein, fiber, carotene, and amino acid content in monocultures and legume–cereal mixtures, with and without the use of nodule-bacteria-based preparations (Rhizotorphin, Mizorine, Flavobactrin, and Azolene). The combined effect of crop mixtures and biological products led to increased green mass yield, protein content, and feed productivity. Notably, two-component mixtures with Rhizotorphin inoculation increased green mass yield by 8.79%, while three-component mixtures saw a 16.49% increase. The oat–pea mixture showed the most significant amino acid improvements, with lysine increasing by 6.26% and tyrosine by 3.24%. The general conclusion reached by the two-year experiment of 2022–2023 in the hill–plain zone of northern Kazakhstan is that double grass mixtures treated with nodule bacteria are more productive than monoculture crops in this area. These results suggest that inoculation with bacterial strains can effectively enhance the productivity of forage crops in northern Kazakhstan, providing a basis for future recommendations on optimizing herbaceous crop combinations. It is recommended to grow annual forage crops in mixtures with legumes to produce highly nutritious feeds with high metabolic energy in terms of biochemical composition.

Reduced canopy cover and development compromises weed suppression by buckwheat in cover crop mixtures

Buckwheat (Fagopyrum esculentum Moench) is a common cover crop typically grown for its rapid establishment and superior weed suppression. One challenge of incorporating buckwheat into crop rotations, however, is its short generation time, which requires in-season management to prevent viable seed production and volunteers in subsequent crops. Mixing buckwheat at reduced seeding rates with other cover crop species is one way for producers to reduce volunteer potential; however, this may compromise weed suppression. To investigate mechanisms behind buckwheat weed suppression and how using buckwheat in mixtures can affect suppression, we collected a series of morphological measurements in buckwheat monocultures and in three, two-way and four, three-way cover crop species mixtures and modeled their response over the growing season. We found that while buckwheat height and relative growth rate were unaffected with increasing species richness, there was a significant reduction in maximum leaf area index (3.75 vs. 2.85 vs. 2.82 cm2 cm-2) in mixture. Buckwheat monocultures provided superior season-long weed suppression compared to mixtures (85% vs. 53% vs. 50%). Principal component analysis showed that increased height and leaf area index values were associated with greater weed suppression. The link between reduced leaf area index and weed suppression in mixtures compared to buckwheat monocultures suggests that the rapid leaf development and canopy cover associated with buckwheat is a key mechanism behind weed suppression. In practice, producers should expect a dilution effect and weed suppression to be compromised when the buckwheat seeding rate is reduced in mixtures.

Crop mixtures: yield responses to climate and management and impacts on seed and soil chemical composition in a Scottish-based study

Crop mixtures: yield responses to climate and management and impacts on seed and soil chemical composition in a Scottish-based study

A Mixture of Summer Legume and Nonlegume Cover Crops Enhances Winter Wheat Yield, Nitrogen Uptake, and Nitrogen Balance

Cover crops protecting soil erosion during the summer fallow in the monsoon weather may enhance dryland winter wheat yield and N relations. We examined the effects of four summer cover crops (soybean (Glycine max L., SB), sudangrass (Sorghum sudanense {Piper} Stapf, SG), soybean and sudangrass mixture (SS), and no cover crop (CK)) and three N fertilization rates (0, 60, and 120 kg N ha−1) on winter wheat yield, quality, and N relations from 2017–2018 to 2020–2021 in the Loess Plateau of China. Cover crop biomass and N accumulation, soil mineral N, and winter wheat yield, protein concentration, and N uptake were greater for SB and SS than other cover crops at most N fertilization rates and years. The N fertilization rate had variable effects on these parameters. Winter wheat aboveground biomass and grain N productivities were greater for CK than other cover crops at all N fertilization rates and years. Nitrogen balance was greater for SS than other cover crops at 60 and 120 kg N ha−1 in all years. The SS with 120 kg N ha−1 can enhance soil mineral N, winter wheat yield and quality, and N balance compared to CK and SG with or without N fertilization rates.

Average daily gain in lambs grazing mixed annual forage species compared with single species and relationship to feed on offer

Context Annual forage crops provide high-quality fodder for livestock during typical autumn and winter feed-gaps in the south-east of Australia and benefits through rotations in cropping systems. While benefits from intercropping with cereals and pasture or mixing canola and peas have been studied in Australia, the potential animal-production benefits of grazing mixed annual species forage crops have not been examined. Aims To determine average daily gain (ADG) and rumen fluid parameters when sheep graze mixtures of annual fodder crops compared with a single species. Methods Ninety six Dorset × Border Leicester × Merino lambs (mean = 44.3 ± 0.55 kg) were allocated to one of the following four treatment groups (n = 24/treatment) on the basis of sex and liveweight; a single species brassica control (canola) (Br) or annual forage species mixes containing brassica (canola, turnip, radish) and cereal (wheat, cereal rye) (B + C), brassica and legume (vetch, arrowleaf clove) (B + L) or brassica, cereal and legume (B + C + L). Liveweight and rumen fluid parameters were assessed prior to grazing and again 21 and 35 days after the commencement of grazing. Key results Mean ADG from Day 0 to Day 21 was lower for female, but not male, lambs grazing the Br control (231 ± 23 g head−1 day−1) than for those grazing any forage mix (B + C = 292 ± 23 g head−1 day−1, B + L = 296 ± 23 g head−1 day−1, B + C + L = 310 ± 22 g head−1 day−1). Liveweight change over 35 days of grazing was not different between any forage mixtures. Rumen fluid pH was higher (P < 0.001) for sheep grazing forages containing cereals (B + C = 6.97 ± 0.06, B + C + L = 6.86 ± 0.06) than for those grazing brassica or legume (Br = 6.59 ± 0.06, B + L = 6.68 ± 0.06). Total volatile fatty acid concentration was lower and rumen pH was higher when sheep grazed B + C than when they grazed any other forage mix. Conclusions The higher ADG in females grazing mixtures than in those grazing the Br was related to higher dry matter on offer. Further research should determine whether the lower pH observed when sheep grazed brassica and legume than when grazing mixes containing cereals is associated with subacute rumen acidosis and reduced fibre degradation and forage energy utilisation. Implications Mixed forage species can provide higher DM on offer and ADG. Improved rumen efficiency could be related to improved growth.

394 Cover crops for efficient grazing systems

Abstract Grazing of cool-season cover crops provides a sustainable solution for extending the grazing season while potentially reducing the environmental impact of conventional row-crop farming practices. The primary objective of this study was to evaluate how different mixtures of cover crops affect stocker performance when grazed. The study was conducted across 18 paddocks that were sown with grass [‘Coker’ oat (Avena sativa)], grass + legume [‘Dixie’ crimson clover (Trifolium incarnatum)], or grass + legume + brassica [‘Turnip’ brassica (Brassica rapa subsp.; rapa)] at the Wiregrass Research and Extension Center in Headland, AL. These paddocks were randomly assigned to either grazed or un-grazed conditions (n = 3). In this study, yearling beef steers with an average body weight (BW) of 266 ± 44 kg were grazed in paddocks using the put and take method to maintain a forage allowance of 1 kg dry matter per kilogram of BW. Forage samples were collected biweekly to analyze biomass, botanical composition, and forage nutritive value. Grazing occurred from January 17 to March 22, 2023 (65 d). Steer BW were recorded at the beginning and end of the grazing season to calculate average daily gain. The data were subjected to analysis as a two-way ANOVA using Glimmix in SAS 9.4 (SAS Institute, Cary, NC), harvest date was considered a repeated measure. No treatment × grazing interaction was observed on forage yield performance [average (AVG) forage yield kg DM/ha; P = 0.460]. In addition, no difference was observed among the different cover crop mixtures (AVG forage yield kg DM/ha; P = 0.670). Grazed paddocks had a greater crude protein when compared with ungrazed paddocks (Grazed vs. Ungrazed %; P = 0. 017). However, there was no effect of cover crop mixture on crude protein (CP) concentration (AVG CP %; P = 0.670 for treatment effect). These results indicate that cool-season annual cover crops can provide sufficient forage yield and quality to support sufficient animal gains, even during the relatively short grazing season. Incorporating cover crops not only improves agricultural sustainability but can also enhance the resilience and long-term health of the agroecosystem.

Improving dual cover crop mixtures to increase shoot biomass production and weed suppression potential

IntroductionCover crop services depend on biomass production and species composition of the cover crop stand. In this study, we investigated the interactions in shoot biomass of dual cover crop mixtures and their competitiveness to suppress weeds before winter under different growing conditions.MethodsA field experiment was performed on sandy loam soil in Triesdorf, Germany, for two consecutive years. The cover crop species white mustard (Sinapis alba L.), oil radish (Raphanus sativus var. oleiformis L.), phacelia (Phacelia tanacetifolia J.), Egyptian clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.), field pea (Pisum sativum L.), and field bean (Vicia faba L.) were grown in pure stands or dual mixtures. Cover crops were sown in August, and shoot biomass was harvested at the end of the vegetation period. Cover crop shoot biomass was dried, and the share of each species and the sown test weed (Brassica napus L.) were determined.ResultsThe share of shoot biomass of a cover crop species in dual-species mixtures was closely related to its shoot biomass in its pure stand. In both years, mustard and phacelia showed similar interactions in shoot biomass production when growing with a second species. Regarding competitiveness against weeds, cruciferous species outperformed other cover crop species and could suppress weeds even if they were mixed with a less competitive partner. Weed suppression of mixtures with phacelia depended on the second component in the mixture and was more effective in a dry season. Legume species, especially Egyptian clover and common vetch could not suppress weeds in a pure stand.DiscussionOur results show that species with high weed suppression potential as single stands retain this ability in dual cover crop mixtures, regardless of the suppression potential of the second species that completes the mixture.

How Do Off-Season Cover Crops Affect Soybean Weed Communities?

Weeds compete for environmental resources, leading to reduced soybean yield. In this context, integrated weed management strategies related to cultural control with the use of cover crops are necessary. Our aim was to evaluate weed occurrence in soybean systems with different cover crops. Field studies were conducted at Júlio de Castilhos, Santa Maria, Capão do Leão, Barra do Ribeiro, and Santo Ângelo, Rio Grande do Sul, Brazil. A randomized complete block design with four replications was used. Treatments consisted of black oats (Avena strigosa Schreb.), white oats (Avena sativa L.), rye (Secale cereale L.), hairy vetch (Vicia sativa L.), forage turnip (Raphanus sativus L.), and white clover (Trifolium repens L.) in pure stands or in mixtures. The analyzed variables were relative frequency, density, abundance, and importance value index, similarity index of weeds, dry shoot mass of cover crop, and soybean yield. Cover crops containing white or black oats reduced the relative importance value index of weeds, such as Lollium multiforum, Conyza spp., and Bidens pilosa. Forage turnip, hairy vetch, and white clover showed distinct responses. Black oats and forage turnip did not differ from cover crop mixtures in terms of dry shoot mass and grain yield, being superior to fallow, white clover, and hairy vetch.

Far-red light perception by the shoot influences root growth and development in cereal-legume crop mixtures

Abstract Background and aims Above- and below-ground signals for and responses to competition in mixed-species stands have mostly been studied separately. This leaves unclear if aboveground signals specific to mixed stands have consequences for how plants respond and compete belowground. This study investigated the effect of an aboveground signal, the ratio of red to far-red light (R/FR), on plant biomass allocation and root architecture and morphology when plants grow with different species. Methods A greenhouse experiment with a mixture of wheat (Triticum aestivum) and faba bean (Vicia faba) and their respective mono stands was carried out in deep pots (22.6 L, 72 cm in depth) for 52 days of growth. Light-emitting diode (LED) lights were used to enrich FR levels (i.e., reduce the R/FR) of the light environment. Results Exposure of the shoots to FR-enriched light predominantly affected adventitious roots, with species-specific effects. Especially in species mixtures, increased FR caused wheat to produce more adventitious roots per tiller, while adventitious root mass of faba bean decreased. The influence of FR on rooting depth (D75, i.e. depth of 75% of root biomass) was species specific, with higher FR levels causing a reduction in D75 in wheat, but a greater D75 in faba bean. Conclusions Our findings demonstrate the plasticity of adventitious roots; they are highly responsive to the R/FR level to which the shoot is exposed and to whether neighboring plants are of the same or a different species. This highlights the complexity of plants' responses to environmental cues and how they modify interspecific interactions.

Cover cropping enhanced soil aggregation and associated carbon and nitrogen storage in semi-arid silage cropping systems

Wind and water erosion in arid and semi-arid regions significantly degraded soil, reduced soil organic carbon (SOC) storage, and exacerbated the impact of climate change on agricultural productivity. Cover cropping is one of the approaches to improve soil health and reduce climate change impacts, yet its impacts on soil aggregation and associated SOC and nitrogen (N) storage in water-limited environments are poorly understood. This study aimed to evaluate soil aggregate dynamics and aggregate-associated SOC and soil total N in irrigated silage sorghum [Sorghum bicolor L. (Moench)] − corn (Zea mays L.) rotations with various cover crop mixtures: grasses + brassicas + legumes (GBL), grasses + brassicas (GB), grasses + legumes (GL), and no cover crops (NCC). Results showed in the second year of the study that, at 0–0.1 m depth, mean weight diameter and geometric mean diameter of dry aggregates were 22–23 % and 6 % greater, respectively, with cover crops than NCC. At the same depth, cover crop treatments had 15–17 %, 15–16 %, and 13 % greater SOC in 0.25–2, 0.053–0.25, and < 0.053 mm aggregate classes, respectively, compared to NCC. Similarly, at 0–0.1 m depth, N in < 0.053 mm fraction was 8–10 % greater with cover crops than without. In the fourth year of the study, water-stable aggregates (WSA) percent did not differ among treatments, but WSA-associated SOC was 31–37 % and 12–16 % greater with cover crops at 0–0.1 and 0.1–0.2 m depths, respectively, than without. The WSA-associated N at 0–0.1 m was 21–33 % greater with cover crops than without. Despite the inconsistencies in soil aggregate stability results, cover crop-integrated silage systems showed greater SOC and N within aggregate classes and water stable aggregates. This insight is crucial for advancing sustainability in silage production systems, particularly in the context of increasing climate change and variability in erosion-prone soils of arid and semi-arid regions.

Cover crop mixtures do not assemble markedly distinct soil microbiotas as compared to monocultures in a multilocation field experiment

Cover crops are used in cropping systems to enhance ecosystem services, such as soil resilience to erosion or microbial activity. Different cover crops are selected to steer specific processes, but whether cover crop mixtures have an added value over monocultures remains debated. Here, we investigated if cover crop mixtures accumulate soil microbiotas distinct from those of monocultures, potentially leading to more varied microbially-driven soil functions. We performed a field experiment at three locations in the Netherlands, each including nine cover crop monocultures, five- and eight-species mixtures, and a fallow control. After three months, we measured cover crop biomass and profiled soil bacterial, fungal, and arbuscular mycorrhizal fungal communities via amplicon sequencing. The different crop monocultures produced similar biomass across all three locations, and mixtures had average productivity compared to monocultures. The diversity and community structure of soil microbial communities was primarily determined by the geographical location, and then by cover crop treatment at each location. Although the cover crop species affected the soil microbiome differently, cover crop mixtures did neither increase microbial diversity nor the overall community differentiation compared to monocultures. Our results suggest that mixing cover crop species does not significantly influence microbially-driven soil functions, at least in short-term crop rotations.

Analyzing the gut microbiota and microbial-associated metabolites of tomato-based sauces

Red Cooked Sauce (RCS) and Red Raw Sauce (RRS) are a mixture of natural crops that have a promising content of bioactive compounds (BC). The aim was to determine the effect of the indigestible fraction (IF) during the colonic fermentation in RCS and RRS by studying the two-way relationship between gut microbiota composition and microbial metabolites produced from BC fermented in the TNO in vitro dynamic model of the human colon (TIM-2). Total BC in undigested and predigested RRS, 957 and 715 mg/100 g DW, respectively, was significantly higher (p < 0.05) than in the RCS, 571 and 406 mg/100 g DW, respectively. Catenibacterium and Holdemanella increased during RCS fermentation, while 13 genera showed a clear positive correlation with most microbial phenolic metabolites. Our findings suggest that the mechanisms, pathways, and enzymes involved in producing microbial metabolites exhibited uniqueness among bacterial taxa, even within shared genus/family classifications.

Discrimination of relatedness drives rice flowering and reproduction in cultivar mixtures.

The improvement of performance and yield in both cultivar and species mixtures has been well established. Despite the clear benefits of crop mixtures to agriculture, identifying the critical mechanisms behind performance increases are largely lacking. We experimentally demonstrated that the benefits of rice cultivar mixtures were linked to relatedness-mediated intraspecific neighbour recognition and discrimination under both field and controlled conditions. We then tested biochemical mechanisms of responses in incubation experiments involving the addition of root exudates and a root-secreted signal, (-)-loliolide, followed by transcriptome analysis. We found that closely related cultivar mixtures increased grain yields by modifying root behaviour and accelerating flowering over distantly related mixtures. Importantly, these responses were accompanied by altered concentration of signalling (-)-loliolide that affected rice transcriptome profiling, directly regulating root growth and flowering gene expression. These findings suggest that beneficial crop combinations may be generated a-priori by manipulating neighbour genetic relatedness in rice cultivar mixtures and that root-secreted (-)-loliolide functions as a key mediator of genetic relatedness interactions. The ability of relatedness discrimination to regulate rice flowering and yield raises an intriguing possibility to increase crop production.

Clay soil amendment suppressed microbial enzymatic activities while increasing nitrogen availability in sandy soils

AbstractConservation management practices often produced positive but limited desirable outcomes in US Southeast sandy soils, likely due to their intrinsically low clay contents that constrain the soil's capacity to preserve organic carbon (C) and nutrients. In the field, we tested the effectiveness of a novel approach, that is, clay soil amendment, to improve sandy soils. In October 2017, clay‐rich soils (25% clay) were spread at 25 metric tons ha−1 and tilled onto a sandy soil (1.9% clay) in the field, which was further mixed by light tillage at 0‐ to 15‐cm depth, followed by planting winter cover crop mixtures (cereal rye, crimson clover, and winter pea). The crop rotation was cotton and corn with cover crop mixtures planted in the winter fallow season. Soils (0–15 cm) were collected in August 2021 and subjected to physio‐biochemical analyses. Clay amendment increased soil clay content to 3.4%, which improved nitrogen (N) availability by 51% but inhibited the activities of C (β‐d‐cellubiosidase [CB]; β‐xylosidase [BX]; N‐acetyl‐β‐glucosaminidase [NAG]) and N (leucine aminopeptidase [LAP]) cycling enzymes, resulting in up to 78% reduction in microbial respiration. A follow‐up kinetic study on BG and LAP enzymes suggested that clay addition can have different impacts on enzymes with diverse biological origins through distinct mechanisms. Clay addition can potentially improve sandy soils by stabilizing the organic inputs in soils. However, more research is required to understand its long‐term impacts making this approach practical.

Diversified Cover Crops and No-Till Enhanced Soil Total Nitrogen and Arbuscular Mycorrhizal Fungi Diversity: A Case Study from the Karst Area of Southwest China

The deteriorating soil health under continuous monoculture is commonly found across various cropping systems. This study evaluated the effects of different tillage practices (conventional tillage and no till) and species mixtures (legumes and grasses) on arbuscular mycorrhizal fungi (AMF) community properties, soil nutrients, and enzyme activity in a 3-year experiment. Compared with traditional tillage, the number of AMF species under no-till conditions was increased, with the Glomus group being dominant. Under different tillage conditions, TN (total N) and AN (available N) contents under no till were significantly higher than those under conventional tillage, while no significant differences among other nutrients were found. The activities of soil acid phosphatase (S-ACP), soil dehydrogenase (S-DHA), and soil sucrose (S-SC) under conventional tillage were significantly higher than those under no till, and the cover crop mixtures also had an exclusive advantage in yield. Soil organic matter (SOM) indicated a significant negative correlation with glomalin-related soil protein (GRSP). The increase in diversity associated with the AMF species community was strongly correlated with the increase in three enzyme activities, and AN was negatively correlated with all species. Tillage did not significantly change soil chemistry, except for AN, and the high concentration of AN led to a decrease in AMF species. The results of this study showed that no till was an effective measure for enriching soil micro-organism population. Additionally, soil AMF diversity was improved by cover crop mixtures, and microbial diversity was higher than that under monoculture cover crops. Different AMF groups responded differently to tillage and cover crop mixtures. Across all mixtures, the combination of hairy vetch (Vicia villosa R.) and ryegrass (Lolium perenne L.) performed the best.

Data-driven crop growth simulation on time-varying generated images using multi-conditional generative adversarial networks

BackgroundImage-based crop growth modeling can substantially contribute to precision agriculture by revealing spatial crop development over time, which allows an early and location-specific estimation of relevant future plant traits, such as leaf area or biomass. A prerequisite for realistic and sharp crop image generation is the integration of multiple growth-influencing conditions in a model, such as an image of an initial growth stage, the associated growth time, and further information about the field treatment. While image-based models provide more flexibility for crop growth modeling than process-based models, there is still a significant research gap in the comprehensive integration of various growth-influencing conditions. Further exploration and investigation are needed to address this gap.MethodsWe present a two-stage framework consisting first of an image generation model and second of a growth estimation model, independently trained. The image generation model is a conditional Wasserstein generative adversarial network (CWGAN). In the generator of this model, conditional batch normalization (CBN) is used to integrate conditions of different types along with the input image. This allows the model to generate time-varying artificial images dependent on multiple influencing factors. These images are used by the second part of the framework for plant phenotyping by deriving plant-specific traits and comparing them with those of non-artificial (real) reference images. In addition, image quality is evaluated using multi-scale structural similarity (MS-SSIM), learned perceptual image patch similarity (LPIPS), and Fréchet inception distance (FID). During inference, the framework allows image generation for any combination of conditions used in training; we call this generation data-driven crop growth simulation.ResultsExperiments are performed on three datasets of different complexity. These datasets include the laboratory plant Arabidopsis thaliana (Arabidopsis) and crops grown under real field conditions, namely cauliflower (GrowliFlower) and crop mixtures consisting of faba bean and spring wheat (MixedCrop). In all cases, the framework allows realistic, sharp image generations with a slight loss of quality from short-term to long-term predictions. For MixedCrop grown under varying treatments (different cultivars, sowing densities), the results show that adding these treatment information increases the generation quality and phenotyping accuracy measured by the estimated biomass. Simulations of varying growth-influencing conditions performed with the trained framework provide valuable insights into how such factors relate to crop appearances, which is particularly useful in complex, less explored crop mixture systems. Further results show that adding process-based simulated biomass as a condition increases the accuracy of the derived phenotypic traits from the predicted images. This demonstrates the potential of our framework to serve as an interface between a data-driven and a process-based crop growth model.ConclusionThe realistic generation and simulation of future plant appearances is adequately feasible by multi-conditional CWGAN. The presented framework complements process-based models and overcomes their limitations, such as the reliance on assumptions and the low exact field-localization specificity, by realistic visualizations of the spatial crop development that directly lead to a high explainability of the model predictions.

Consideration of the Disease Complexes, the Missing Link to Correctly Analyze the Impact of Intercropping on Disease Development

Diversification at the plot level, through the use of intercropping (mixtures of crops), is an alternative to the conventional system of intensive agriculture, based on monospecific, usually single-variety canopies. Intercropping has been shown to provide benefits in terms of disease control. However, competition phenomena and the heterogeneity of the associated crops raise new ecological questions, particularly with regard to the dynamics and evolution of parasite populations. No study has assessed the potential impact of these associations on the dynamics of pathogenic species complexes. Changes in the nutritional status of plants and therefore in their physiological susceptibility to infection within intercropping systems could contribute to an increased diversity of ecological niches and thus affect the composition of the parasitic complex and its spatiotemporal dynamics. In this review, focusing on foliar diseases of fungal origin, and after outlining some elements of the biology and epidemiology of these fungal diseases, we will (i) describe the mechanisms that contribute to the composition of disease clusters and that drive interactions, but we will also review the strategies that these foliar diseases have adopted to deal with these co-infections; (ii) define how intercropping can lead to changes in epidemic dynamics, in particular by presenting the mechanisms that have a direct and indirect effect on disease evolution; and (iii) present the approach that should be adopted to properly study intercropping correctly in a multi-infection situation.

Long-term cover crop monocultures and mixtures improve soil multifunctionality and shift microbial communities and functions

Long-term cover crops are an emerging approach for achieving sustainable agriculture by reducing fertilizer use and enhancing soil quality. However, soil microbial communities, multifunctionality (i.e., the ability of soil ecosystems to simultaneously provide and maintain multiple ecological functions), and their relationships in cover crops remain poorly understood, especially in cover crop mixtures. To address these issues, here, we conducted a 15-year field experiment under different cover crop deployments (one legume and one brassica grown in monoculture or in mixture) in Carya cathayensis plantations. We found that cover crops significantly increased soil microbial diversity and multifunctionality, especially in mixtures. The bacterial and fungal compositions was significantly affected by cover crops. Interestingly, some taxa may serve as potential indicator species for nutrient status (i.e., bacterial Subgroup_2, Subgroup_6 and Subgroup_17). Cover crops significantly increased beneficial microbial functions (e.g., nitrogen fixation) but decreased pathogen-related functions (e.g., pathotroph). Bacterial and fungal community assemblages under cover crops were dominated by stochastic processes. Cover crops, especially mixtures, had a higher habitat niche breadth (Bcom). In addition, cover crops have more complex and stable bacterial and fungal networks. Partial least squares path modeling further confirmed that the variations in soil multifunctionality were largely related to nutrient resources. Importantly, the relative abundance of rare microbial taxa was also highly correlated with soil multifunctionality. Overall, our study illustrates that the use of cover crops in the long term can foster soil microbial specific taxa and contribute to improved soil multifunctionality. Our study provides support for the benefits of a legume-brassica mixture over monocultures of either and a theoretical basis for exploring cover crops as an ecological management model.