Proportion Of Legumes Research Articles

Mixed cropping of Medicago ruthenica-Bromus inermis exhibits higher yield and quality advantages in the Longxi loess plateau region of Northwest China

Medicago ruthenica is a promising leguminous forage crop due to its lack of saponins, which prevents bloat in livestock from excessive consumption. Legume/grass mixed cropping is an effective forage planting method widely used in agricultural and pastoral regions. However, there is a lack of research on using legume-grass mixed cropping to establish perennial, high-yield, and high-quality cultivated grasslands in the Longxi Loess Plateau. This study conducted a legume/grass intercropping experiment in the Longxi Loess Plateau region of northwestern China, using Medicago ruthenica and Bromus inermis. Experimental plots were established in 2021, with field sampling and laboratory analysis starting in 2022 and 2023, respectively. The research aimed to investigate the effects of intercropping Medicago ruthenica with Bromus inermis on forage yield and quality, and to determine the optimal intercropping ratios. The experiment tested various intercropping ratios of Medicago ruthenica and Bromus inermis in the fall (2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2), with sole crops of each species serving as controls. Results showed that, in the second and third years of mixed cropping, the forage yield under mixed cropping treatments was significantly higher than that of Medicago ruthenica and Bromus inermis monoculture, with increases of 40.89–70.88% and 13.97–38.22% in the second year, and 131.91–199.13% and 44.06–85.82% in the third year. When the legume proportion in the mixed cropping system was around 30%, competition between the two forages reached equilibrium, demonstrating the benefits of mixed cropping. The crude protein and ether extract content of mixed forage were significantly higher than those of monoculture, while the neutral detergent fiber and acid detergent fiber contents were significantly lower, indicating a higher feeding value for the mixed forage. The legume proportion was a key factor influencing the yield of mixed forage. In conclusion, a mixed planting ratio of Medicago ruthenica and Bromus inermis at 3:7 resulted in higher yield and nutritional quality, making it an optimal ratio for establishing cultivated forage fields in the Longxi Loess Plateau.

Marandu palisade grass‐forage peanut mixed pastures: Forage intake, animal behaviour, and canopy structure as affected by grazing intensities

AbstractIntegrating forage legumes into grasslands offers numerous ecosystem services. However, the management of grass‐legume pastures is challenging because the interaction between the defoliation frequency and severity may affect the legume persistence and forage intake by grazing animals. This 2‐year study evaluated the most effective grazing intensity to increase forage intake while maintaining a balanced legume proportion in tropical pastures consisting of Brachiaria brizantha and Arachis pintoi. Three treatments (grazing intensities) were assessed: severe, moderate, and low, corresponding to stubble heights of 10, 15, and 20 cm, respectively, and a pre‐grazing height of 25 cm. Two purebred Tabapua heifers were used for each treatment, and additional put‐and‐take animals were introduced, as required. Canopy structure, grazing behaviour, nutritive value, and forage intake were evaluated. The legume proportion in herbage mass remained consistent across all intensities, averaging 35% pre‐ and 32% post‐grazing. The grazing duration remained consistent across treatments on the first and third days, with an average grazing time of 390 and 440 min, respectively. Under post‐grazing conditions, low‐intensity grazing had a 52% greater intake rate than severe‐intensity grazing, which was attributed to a greater biting rate (37.9 bites/min) and bite weight (0.9 g DM/bite). Moderate grazing intensity (stubble height of ~15 cm associated with a pre‐grazing height of ~25 cm) is recommended to manage a mixture of B. brizantha and A. pintoi when the objective is to couple high forage intake with a balanced legume proportion in the pasture.

Does adding legumes to tall fescue pastures before stockpiling improve productivity and animal performance?

AbstractThe rising prices of N fertilizer led to exploring cost‐saving efforts, such as intercropping cool‐ or warm‐season legumes serving as alternative sources of N for managing fall‐stockpiled tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.; TF]. We aimed to evaluate red clover (Trifolium pratense L.; RC) and sunn hemp (Crotalaria juncea L.; SH) mixed with TF as alternative sources of N for stockpiling TF to increase productivity and animal performance. The experiment was conducted in Crossville, TN, in 2020 and 2021 and consisted of TF pastures mixed with RC (TRC) or SH (TSH), and TF fertilized with urea (TU). The experiment was divided into two periods: the pre‐grazing period (stockpiling) (April–October) and the grazing period (October–December). After the stockpiling period, Black Angus beef (Bos taurus) steers were used for the grazing period. The study evaluated the botanical composition, herbage mass (HM), nutritive value, steer average daily gain (ADG), and net returns (NR). The TRC pastures had a greater proportion of legumes compared to TSH plots in May, October, November, and December of both years. There were no differences among treatments for the total HM and nutritive value in 2020; however, in 2021, TU had greater HM at the beginning of the grazing period and greater average crude protein values compared to the other treatments. In both years, there were no differences among treatments for ADG or NR. Therefore, producers can make the same profit considering the beef steer price and the cost of conventional and alternative N sources.

Статистически анализ на продуктивни, морфологични и качествени показатели при производство на фураж от бобови ливадни треви

In the experimental field of the Research Institute of Mountain Stockbreeding and AgricultureTroyan during the period 2020-2022, the following meadow legume crops were studied: bird’s foot trefoil (Lotus corniculatus L.), hybrid clover (Trifolium hibridum L.), alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.) and white clover (Trifolium repens L.). The purpose of the present research is to make a statistical analysis based on average data on yield, morphological features and quality, and determine dependencies between them. High correlations were found between plant height and crude fiber content (r = 0.88); crude fiber and the relative proportion of legumes in the grass stand (r = 0.77); acid detergent fibers and cellulose content (r = 0.92). These results make it possible to derive regression dependencies between them, which are represented by linear equations and coefficients of determination.

Sorghum–Legume Mixtures to Improve Forage Yield and Nutritive Value in Semiarid Regions

In a continued search for legumes to grow with forage sorghum (FS) [Sorghum bicolor (L.) Moench] in semi-arid environments, studies in 2019 and 2022 at New Mexico State University Rex E. Kirksey Agricultural Science Center at Tucumcari, NM USA, evaluated FS mixed with cowpea [Vigna unguiculata (L.) Walp.], lablab (Lablab purpureus L.), both previously evaluated, and a native legume, big-pod sesbania (Sesbania macrocarpa), for yield and nutritive value in four randomized complete blocks each year. At harvest legume proportions of approximately 15% of the dry matter yield, there were no differences in the yield (mean = 15.97 Mg ha−1, p > 0.40) or land equivalency ratio between sole FS and any mixture or among mixtures; however, the crude protein of FS+Lablab was greater than sole FS, with FS+Cowpea and FS+Sesbania intermediate (67, 77, 87, and 79 g kg−1 for sole FS, FS+Cowpea, FS+Lablab, and FS+Sesbania, respectively; 5% LSD = 14). The neutral detergent fiber digestibility of FS+Sesbania was less than all other treatments (p = 0.0266). Although the sesbania did not improve forage yield or nutritive value when grown with FS and harvested near sesbania maturity, perhaps growing with a shorter season grass and harvesting earlier may show benefit, as sesbania’s nutritive value is known to be greater at earlier stages.

Forage legume responses to climate change factors

AbstractIncorporating forage legumes into grasslands is a recommended climate change mitigation strategy, but accruing desired benefits from legumes is contingent upon their resilience when exposed to climate change factors (CCF). Our objective was to synthesize literature describing responses to CCF of a broad array of forage legume species, including annuals and perennials from both temperate and tropical/subtropical regions. Most‐represented species in the related literature include alfalfa (Medicago sativa L.), various Trifolium and Lotus species, rhizoma peanut (Arachis glabrata Benth.), and capitata stylo (Stylosanthes capitata Vogel). The data indicate that while CCF effects on forage legumes can be generalized, interactions among CCF, species, and site‐specific soil/climate conditions may cause variation from expected responses. In most instances, exposing forage legumes to CO2 enrichment (eCO2) increased forage accumulation (FA), but elevated temperature (eT) often reduced the magnitude of the positive response to eCO2. Photosynthetic acclimation to eCO2 occurs in non‐N‐fixing plants, but legume nodules are large C sinks and drive sustained increases in legume FA to eCO2. Legume N2 fixation and the proportion of legume N derived from N2 fixation increase with eCO2, but the magnitude of the increases lessens with eT. Legume nutritive value (NV) responses to eCO2 are less pronounced than FA responses, but decreased herbage N and greater nonstructural carbohydrate concentrations are common. Exposure to eT negatively affects NV unless intervals between defoliation events are shortened. Limited data on reproductive performance show CCF affect flower number, pollen grain morphology and viability, and behavior of pollinators, potentially influencing legume reproductive success.

Cereal–Legume Intercropping: Which Partners Are Preferred in Northwestern Europe?

To increase Europe’s self-sufficiency for protein sources, boosting plant protein production is a prerequisite. Yield variability is one of the main problems regarding the cultivation of protein crops. In this light, cereal–legume intercropping can offer a solution, as well-balanced intercropping systems are less prone to yield variations. Therefore, in this study the effects of (i) species/genotype combination, (ii) intercropping sowing densities and (iii) fertilizer regime were evaluated under Belgian (Northwestern European) conditions over three years (i.e., the 2020–2021, 2021–2022 and 2022–2023 seasons). Regarding the species combinations, winter barley x winter pea, winter wheat x winter faba bean and winter triticale x winter faba bean, it was observed that the best-performing combination varied from year to year depending on the prevailing weather conditions. A reduced sowing density (i.e., 130 seeds/m2 for the cereal partner and 20 seeds/m2 in the case of faba bean or 40 seeds/m2 in the case of pea) was sufficient to achieve competitive yields under the prevailing conditions. Inoculation with commercial Rhizobium strains did not result in an increased yield. Fertilization with one or two nitrogen fractions significantly increased the total yield thanks to a yield increase in the cereal partner; however, as a consequence, the proportion of legumes in the mixture decreased. In conclusion, it can be stated that with the investigated cereal–legume combinations, a competitive yield and qualitative protein yield can be achieved with a reduced fertilizer input.

Quantification of species composition in grass-clover swards using RGB and multispectral UAV imagery and machine learning.

Growing grass-legume mixtures for forage production improves both yield productivity and nutritional quality, while also benefiting the environment by promoting species biodiversity and enhancing soil fertility (through nitrogen fixation). Consequently, assessing legume proportions in grass-legume mixed swards is essential for breeding and cultivation. This study introduces an approach for automated classification and mapping of species in mixed grass-clover swards using object-based image analysis (OBIA). The OBIA procedure was established for both RGB and ten band multispectral (MS) images capturedby an unmanned aerial vehicle (UAV). The workflow integrated structural (canopy heights) and spectral variables (bands, vegetation indices) along with a machine learning algorithm (Random Forest) to perform image segmentation and classification. Spatial k-fold cross-validation was employed to assess accuracy. Results demonstrated good performance, achieving an overall accuracy of approximately 70%, for both RGB and MS-based imagery, with grass and clover classes yielding similar F1 scores, exceeding 0.7 values. The effectiveness of the OBIA procedure and classification was examined by analyzing correlations between predicted clover fractions and dry matter yield (DMY) proportions. This quantification revealed a positive and strong relationship, with R2 values exceeding 0.8 for RGB and MS-based classification outcomes. This indicates the potential of estimating (relative) clover coverage, which could assist breeders but also farmers in a precision agriculture context.

Impacts of grazing management strategies on forage canopy structure in multi-species pastures during the wet-dry transition period

The condition of pastures during the wet-dry transition period reduces livestock production since there is an increase in dead material and a reduction in green tissues. This study evaluated the influence of grazing management strategies on the structure of the forage canopy during the wet-dry transition period. The pastures were composed of Aruana guineagrass (Megathyrsus maximum Syn. Panicum maximum cv. Aruana) and three legumes: Macrotyloma (Macrotyloma axillare), Calopo (Calopogoinum mucunoides), and Stylo (Stylosanthes macrocephala + Stylosanthes capitata). The treatments corresponded to four forage canopy heights (15, 30, 45, and 60 cm), and the grazing management strategies involved steady or variable stocking rates with sheep. The experiment was conducted in a randomized complete block design with four replications totaling 16 experimental units (paddocks). The masses of grass leaf blades and stems were higher at heights of 45 and 60 cm (P = 0.002), while the proportion of dead material was smaller in these than in the short pastures (15 and 30 cm) (P = 0.0497). There was an increase in the proportion of dead material over the dry-water transition period. The presence of grass and legume leaves was higher in the upper stratum of tall pastures (45 and 60 cm) and the proportion of legumes did not differ between grazing management strategies (P > 0.05). These strategies were represented by canopy heights of 45 to 60 cm and showed more leaf mass, less dead material, and better pasture structure, so these parameters can be used during the wet-dry transition period.

Cattle dry manure fertilization increases forage yield of grass‐legume mixtures, while maintaining the legume proportion and root‐associated microbiota

AbstractThe aim of this study was to find ways to improve the forage yield of grass‐legume mixtures without compromising soil biodiversity. In Argentinean Patagonia, the effects of applying cattle dry manure (M) and urea (U) (0, 60, 120, or 240 kg N ha−1 year−1) were assessed on herbage production of irrigated fescue‐lotus mixtures, as well as on the activity/abundance of autochthonous arbuscular mycorrhizal fungi and N‐fixing rhizobium bacteria. We hypothesised that manure has advantages over urea in increasing forage yields while maintaining the proportion of legumes and root‐associated microbiota. The 120 U, 240 U, and 240 M resulted in the greatest forage production; however, yield varied depending on the source applied. The high productivity of the 120 U and 240 U was probably due to the fast grass growth immediately after fertilization, which resulted in a depressed growth of the legume. The high yield of the swards fertilized with 240 M was probably due to slight and delayed growth of grass without legume yield decline. The highest radiation interception was found in swards with a low legume proportion, suggesting a light competition from grass fertilized with the highest urea doses, which were also consistent with the highest N and P nutritional status. The microbial activity/abundance were not affected by fertilization, but the final number of nodules was positively associated with the legume proportion. In conclusion, manure fertilization increased forage yield of the mixtures, while preserving the legume proportion and the root‐associated microbiota. Our findings aid in reducing synthetic‐N fertilizers applied in pasture‐based livestock systems.

Seedcorn maggot response to planting date, cover crops, and tillage in organic cropping systems.

Seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is an economically important early-season pest of corn and soybean in the United States. Adult seedcorn maggot is attracted to decomposing plant residues for oviposition, creating potential management issues where growers typically use tillage to incorporate fertility amendments and to create a seedbed. The use of growing degree-day models to time planting dates is an important tool for effectively managing this pest, but their use has not been examined in organic crop production. Here, we report the results of experiments to determine the effects of cover crops, tillage, and relative planting date on seedcorn maggot in corn and soybean in 2 experiments: The first during the transition to organic from conventional management and the second during the 3 yr following organic certification in central Pennsylvania, United States. Overall, delaying the planting date by 1-2 wk reduced fly emergence in corn, but not in soybean in both experiments. Seedcorn maggot emergence was also consistently greater in corn than in soybean, with 6 times more flies in corn than in soy. About 15 times more seedcorn maggot flies emerged from corn in treatments in which cover crops were managed with tillage compared to treatments in which cover crops were terminated with a roller-crimper followed by no-till planting of corn. Fly emergence was negatively related to the proportion of legumes in the cover crop mixture preceding corn. These results can help inform soil, cover crop, and crop decisions for organic growers in the Mid-Atlantic United States.

Optimisation of an Industrial Optical Sorter of Legumes for Gluten-Free Production Using Hyperspectral Imaging Techniques

The market demand for gluten-free food is increasing due to the growing gluten sensitivity and coeliac disease (CD) in the population. The market requires grass-free cereals to produce gluten-free food. This requires sorting methods that guarantee the perfect separation of gluten contaminants from the legumes. The objective of the research was the development of an optical sorting system based on hyperspectral image processing, capable of identifying the spectral characteristics of the products under investigation to obtain a statistical classifier capable of enabling the total elimination of contaminants. The construction of the statistical classifier yielded excellent results, with a 100% correct classification rate of the contaminants. Tests conducted subsequently on an industrial optical sorter validated the result of the preliminary tests. In fact, the application of the developed classifier was able to correctly select the contaminants from the mass of legumes with a correct classification percentage of 100%. A small proportion of legumes was misclassified as contaminants, but this did not affect the scope of the work. Further studies will aim to reduce even this small share of waste with investigations into optimising the seed transport systems of the optical sorter.

Modeling future carbon stock in melon cultivation agroecosystems under different climate scenarios

Intensive melon cultivation is based on conventional monoculture models that can inefficiently use natural resources, which, combined with inadequate management, contribute to climate change. The main objective of this study was to model the future carbon stock in melon cultivation agroecosystems under different climate scenarios. The study was conducted at the Bebedouro Experimental Field of Embrapa Semi-arid, Petrolina/PE, Brazil, in an area cultivated with yellow melon cv. Gladial, and eight cultivation cycles were considered. The experimental design was composed of two types of soil management (with and without tillage), two treatments using green manures consisting of 14 species with different proportions of legumes, grasses and oilseeds, and spontaneous vegetation, containing four replications divided into randomized blocks. After 70 days of development, the plants were cut and placed in the soil. Temperature and precipitation data were acquired from the BCC-CSM, MIROC5, CESM1-BGC, IPSL-CM5B-LR, and HadGEM2-AO climate models, following the RCP 4.5 and 8.5 climate scenarios. The carbon (C) stock was estimated until the year 2071 using the RothC model.

A RESEARCH ON THE HAY YIELD AND QUALITY OF ALFALFA CULTIVARS WITH DIFFERENT FALL DORMANCY RATES UNDER MEDITERRANEAN CLIMATE CONDITIONS

This research was carried out as two separate trials established in two different years to determine the effects
 of different seed ratios and harvest stages of different annual companion crop species on the hay yield and
 botanical composition of a pasture mixture under Mediterranean climate conditions. The field trials were
 established in a randomized complete block with a split-plot arrangement in three replications. The research
 results showed that barley, annual ryegrass, and berseem clover can be utilized as companion crops in
 artificial pasture systems. The inclusion of these companion crop species in the pasture mixture resulted in an
 increase in forage yield and a significant decrease in weed infestation. While delaying the harvest stage of the
 companion crop does not have a notable effect on the proportion of legumes and weeds in the total biomass, it
 significantly enhances the dry forage yield and the proportion of grasses in the overall biomass of the mixture.

EFFECTS OF COMPANION CROP ON THE HAY YIELD AND BOTANICAL COMPOSITION OF PASTURE UNDER MEDITERRANEAN CLIMATE CONDITIONS

This research was carried out as two separate trials established in two different years to determine the effects of different seed ratios and harvest times of different annual companion crop species on the hay yield and botanical composition of a pasture mixture under Mediterranean climate conditions. The field trials were established in a randomized complete block with a split-plot arrangement in three replications. The research results showed that barley, annual ryegrass, and berseem clover can be utilized as companion crops in artificial pasture systems. The inclusion of these companion crop species in the pasture mixture resulted in an increase in forage yield and a significant decrease in weed infestation. While delaying the harvest time of the companion crop does not have a notable effect on the proportion of legumes and weeds in the total biomass, it significantly enhances the dry forage yield and the proportion of grasses in the overall biomass of the mixture.

The Effects of Breeding Practices and Fertilization on Vegetation in Barren Pasture The Case of Kastamonu

The research was conducted in the pasture of Alpagut village of Kastamonu center (410 25' 48.52''N, 330 55' 20.54D, altitude 851 m) located in the Western Black Sea Region of Turkey to determine the changes in pasture vegetation caused by pasture soil improvement and management practices. Fertilization was applied according to pasture soil analysis, brush clearing and alternate grazing system was applied. Pasture vegetation change was measured by modified wheeled loop method in the pre- and post-improvement periods. It was determined that breeding practices increased the proportion of legumes, other families and perennial plants and contributed to the formation of a balanced vegetation. The proportions of declining, reproductive, invasive and annual species were 11.50%, 5.10%, 46.75% and 33%, respectively, before pasture topsoil reclamation, while there was a decrease in annual species in the post-reclamation period. There was an increase in declining, reproductive and invasive species. It was found to be 26.66%, 15.39%, 55.86% and 17.00%, respectively. While Bromus sp., Sanguisorba minor, Fumana arabica, Festuca ovina species were dominant in the pasture area in the pre-improvement period, Bothriochloa ischaemum, Teucrium chamaedrys, Festuca ovina and Astragalus frickii species became dominant after the improvement. It was determined that breeding and management practices increased the area covered with vegetation from 74.00% to 98.00%, the proportion of legumes from 1% to 12%, and the pasture condition and health classification from poor-healthy to moderate-healthy category. It is recommended that the grazing plan for pasture sustainability be maintained.

Can low-input agriculture in semi-arid Burkina Faso feed its soil, livestock and people?

Agriculture in semi-arid Burkina Faso is dominated by mixed crop-livestock smallholder farms with limited investment capacity in production factors, such as improved seeds, fertilizer and equipment. Hence, to make a living, farmers try to make the best use of available resources based on principles of agro-ecology, including crop diversity and nutrient and biomass recycling. We investigated farm-level management of resources (soil, crops and livestock) through time to assess whether the current management options were able to sustain crop and livestock production and fulfil household food requirements. We ran a one-year detailed farm monitoring campaign in collaboration with 22 volunteer farmers representing the diversity of the farming system in our study area. We quantified inputs and outputs in the cropping system (177 fields) for one rainy season. In addition, the weekly dynamics of crop residues left on field were quantified. Moreover, inflow and outflow of resources at farm level were quantified weekly. The cropping system was characterized by a negative nitrogen balance of about 12 kg N/ha/year, with market-oriented farms and large livestock owners having the most negative balance. Legumes grown (sole and intercropping) contributed to alleviate the nitrogen depletion by adding 15 kg N/ha/year to the nitrogen inputs through atmospheric fixation. However, cereal-legume intercropping did not significantly reduce the nitrogen deficit in comparison to sole cereal cropping mainly because of the small proportion of legumes (8%) in intercropped fields. Livestock grazed crop residues left on the soil (739 kg dry matter/ha on average) at a rate of 26 − 76 kg/ha/week, thus strongly reducing the potential for mulching in the region. Livestock protein requirements were rarely met from farm-produced feed with average feed gaps ranging between 40% and 89% of the daily requirements for small and large herd keepers respectively. Large livestock (cattle) owners relied on transhumance during the rainy season, grazing and frequent purchase of crop residues and concentrates to feed their livestock. We estimated that grazed biomass provided on average at least 73% and 58% of metabolizable energy and protein feed requirement of livestock respectively. Concerning food availability, the amount of grain produced was generally enough to fulfil household energy requirements (89–175% of required energy, in kcal), even if households with higher people to land ratio were not self-sufficient. We concluded that the current farm management, even if it provides enough food for the majority of investigated farms, results in soil fertility mining and poor crop livestock production and integration. Our detailed farm data indicate that an appropriate diversity of crops and a better integration of legume crops in the cropping system, associated to improved manure and forage management is needed to sustain crop and livestock production.

N2O and CH4 fluxes from intensively managed grassland: The importance of biological and environmental drivers vs. management

Agriculture is the main contributor to anthropogenic nitrous oxide (N2O) and methane (CH4) emissions. Therefore, mitigation options are urgently needed. In contrast to carbon dioxide, eddy covariance measurements of N2O and CH4 fluxes are still scarce, and thus little is known how environmental and biotic drivers as well as management affect the net N2O and CH4 exchange in grasslands. Thus, we investigated the most important drivers of net ecosystem N2O and CH4 fluxes in a temperate grassland, and continued a N2O mitigation experiment (increased clover proportion vs. fertilization with slurry). Random forest gap-filling models were able to capture intermittent emission peaks, performing better for half-hourly N2O than for CH4 fluxes. The unfertilized clover parcel (parcel B) continued to show lower N2O emissions (4.4 and 2.7 kg N2O-N ha−1 yr−1) compared to the fertilized parcel (parcel A; 6.9 and 5.9 kg N2O-N ha−1 yr−1) for 2019 and 2020, respectively. Tier 1 nitrogen (N) emission factors of 2.6 % and 1.9 % were observed at the fertilized parcel during the study period. Lower soil N concentrations indicated a lower N leaching risk at the clover than at the fertilized parcel. Annual CH4 emissions (including periods with sheep grazing) were similar from both parcels, and ranged from 25 to 38.5 kg CH4-C ha−1. The most important drivers of both N2O and CH4 fluxes were lagged precipitation and water filled pore space, but also management (for N2O from parcel B; CH4 from parcel A). Biotic variables such as vegetation height and leaf area index were important predictors for the N2O exchange, while grazing temporarily increased CH4 emissions. Overall, reducing N fertilization and increasing the legume proportion were effective N2O reduction measures. In particular, adjusting N fertilization to plant N demands can help to avoid high N2O emissions from grasslands.

Species and functional diversity of cool-season pastures are influenced by warm-season grazing management

CONTEXTIn southern Brazil, livestock producers often overseed cool-season annual grasses into warm-season perennial pastures to extend the grazing season and improve animal performance. However, the effects of warm-season pasture management on the subsequent cool-season pasture are poorly understood. OBJECTIVEWe aimed to evaluate how grazing height and nitrogen (N) fertilization applied to a mixed-species pasture during the warm season affect forage accumulation and diversity in the cool-season pastures. METHODSThe experiment was conducted in a subtropical climate and consisted of two phases: warm season (November/December – April/May) and cool season (May – October/November). During the warm season, we applied a factorial combination of two pre-grazing heights (0.17 and 0.23 m) and three N rates (50, 150, and 250 kg N ha−1) to a mixed-species pasture. During the cool season, we managed all plots equally and measured forage accumulation and diversity using Simpson's and Rao's indices. RESULTS AND CONCLUSIONSWe found that warm-season N fertilization had no residual effect on cool-season pasture responses, but grazing at 0.17 m height during the warm season resulted in higher forage accumulation during the cool season than grazing at 0.23 m height (5100 vs. 4780 kg DM ha−1). However, grazing at 0.23 m height during the warm season increased species diversity (Simpson's index of 0.49 vs. 0.40) and functional diversity (Rao's index of 0.33 vs. 0.29) during the cool season compared to grazing at 0.17 m height. SIGNIFICANCEThis study provides novel insights into the long-term effects of warm-season pasture management on cool-season pasture diversity and productivity in a subtropical climate. It shows that grazing at a height close to the critical leaf area index during the warm season can increase legume proportion and functional diversity in the cool season, which can improve pasture resilience and sustainability. While this study offers valuable insights, it is important to acknowledge its restriction to a single location, and the need to assess the hypothesis raised here to other sites and conditions.

Tropical insectivorous birds’ predation patterns that promote forest–farmland trophic connectivity for integrated top–down pest biocontrol

Although conversion of natural forest to agriculture can negatively impact biodiversity in many ways, some affected species may respond by dispersing across the forest–farmland eco-zone, thereby facilitating functional connections through food-web interactions beneficial to crop production and forestry. This study examined patterns of Lepidoptera (butterflies and moths), Hemiptera (bugs), and Coleoptera (beetles) herbivory, and insectivorous bird predation within forest-adjacent farms in western Kenya, and how these processes trophically connect the two ecosystems to promote pest biocontrol. Through δ13C and δ15N stable isotope analyses, proportions of maize, farmland legumes and forest trees in pest diets, and pest-prey in bird’s diets were estimated. Birds’ habitat associations and diet specializations’ influence on pest consumption and basal plant carbon levels in birds’ tissues were determined to evaluate birds’ pest-biocontrol potential. Maize was the mostly consumed plant especially by Lepidoptera, but forest trees were peimarily consumed by Coleoptera and Hemiptera. In turn, Lepidoptera were mainly consumed by forest-associated birds, whereas Hemiptera and Coleoptera were mostly consumed by farmland-associated birds. Thus, birds showed cross-habitat pest consumption tendencies, though diet-specialization was unimportant in predicting those tendencies. Muscicapidae (flycatchers and allies); Hirundinidae (swifts and swallows); Motacillidae (pipits and wagtails); and Ploceidae (weavers) birds showed the highest contributory potential for pest biocontrol of Lepidoptera pests, but Estrildidae (manikins and waxbills), Muscicapidae, and Malaconotidae (boubous and gonoleks) birds showed the best potential against Hemiptera and Coleoptera. Furthermore, more maize basal carbon was assimilated by forest-associated compared to farmland-associated birds, whereas most basal carbon from farmland legumes and forest trees were assimilated by farmland birds, suggesting that unlike pest-prey choice, basal plant carbon pathways to avian insectivorous consumers did not strongly mirror birds’ habitat associations. Lepidoptera and Hemiptera were potentially the most significant interhabitat trophic connector arthropods, and for birds, Muscicapidae, Ploceidae, and Estrildidae. These findings show that such functional connectivity may be enhanced through increasing structural cover elements that promote insectivorous birds’ dispersal between farmland and adjacent forests to boost their pest-regulation ecosystem service contribution. The results serve to inform effective management practices by agronomists, foresters, and land-use planners toward promoting landscape-scale-integrated pest management for sustainable agriculture and biodiversity conservation.