Agricultural monoculture negatively impacts soil quality, particularly in fragile soils that yield limited crop production and are highly susceptible to degradation. Increasing plant diversity in production systems can be an alternative for maintaining soil ecosystem services and increasing crop yields. This study investigated the influence of increased plant diversity on soil health and its impact on soybean and cotton yield in an Ultisol in the Brazilian savanna in Mato Grosso State, Brazil. Tested five rates of plant diversity after soybean harvest: (1) very low (VL), (2) low, (3) average, (4) long-term average and (5) high (integrated crop–livestock systems (ICLS)) were tested. Plant diversity improves the health of sandy loam soil, increases C and N fractions in particulate organic matter (POM-C and POM-N) and leads to differences in C utilization by the soil microbial community. High ICLS diversity raises total organic carbon content, being POM-C and POM-N, the labile fractions, more efficient to show changes in sandy loam soil, in the short term, over a period of three years. High diversity promoted yield gains of up to 251 % for cotton and 82 % for soybean in relation to VL plant diversity. Changes in soil microbial composition are able to partially explain crop yield in diversified production systems (R2 ranging from 0.51 to 0.80). Diversifying production components is a sustainable way to maintain biological functions and agricultural quality of loam sandy soil in the Brazilian Cerrado in Mato Grosso.

Reliable seasonal weather forecasts are essential for irrigation management and crop yield prediction, particularly in regions with limited water resources. This study aimed to improve the usability of the North American Multi-Model Ensemble (NMME), an experimental real-time seasonal weather forecast system, for regional crop modelling and irrigation decision-making. Coarse resolution of NMME may introduce bias and uncertainty at regional/local scales. To address this, a statistical downscaling method with bias correction for both mean and variability was used to produce 1-km gridded daily weather projections for temperature and precipitation across the contiguous United States from a representative NMME model, the Canadian Coupled Climate Model version 4 (CanCM4). The daily surface weather and climatological summaries (DAYMET) data were used to calibrate the downscaled hindcast projections of CanCM4. The reliability of downscaled CanCM4 forecasts for local crop modelling was evaluated at lead times of up to six months using a calibrated DSSAT model at a research station in the semi-arid Texas Rolling Plains region. Cross-validation during the hindcast period demonstrated strong forecast skill, with R2 values of 0.72 and 0.71 for maximum and minimum temperatures, respectively. The precipitation forecast remained sensitive to extreme events, with seasonal and annual relative errors of 31 and 1 %, respectively. Crop yield predictions had a relative error of 9 %, and irrigation water requirements closely matched field observations, outperforming both raw CanCM4 and multi-model mean methods. The downscaling method used in this study significantly improved NMME data reliability, although the degree of improvement may vary with time and location.

Grazing management is an important component affecting pasture stability, but the underlying demographic mechanisms remain poorly understood in mixed-species systems. This three-year study investigated how grazing height (15 and 20 cm pre-grazing) and strategic spring defoliation (7 cm) influence stability in mixed pastures composed of complementary C3/C4 grasses (Lolium arundinaceum and Cenchrus clandestinus). Utilising demographic and tiller size/density relationship theories, we examined population dynamics to better understand pasture stability. The results indicated that height management significantly affected the demographic traits, with shorter grazing (15 cm) increasing tiller emergence and population density while reducing individual tiller weight (TW). In addition, higher tiller population density (TPD) and lower TW were observed in the shorter treatments. Despite these contrasting responses, the mixed pasture maintained consistent stability across treatments through compensatory relationships between tiller traits. The stability index remained close to 1 (0.956 ± 0.02) regardless of management, demonstrating robust demographic equilibrium. Individual species showed distinct seasonal stability patterns – L. arundinaceum dominating in winter and C. clandestinus in spring and summer – yet their complementary growth maintained year-round system stability. The self-thinning law effectively revealed stable size-density compensation across treatments, suggesting its utility for assessing mixed sward persistence. These findings demonstrate that mixed pastures can maintain demographic stability under varying grazing regimes through species complementarity and population compensatory mechanisms.

Elephant grass [Cenchrus purpureus (Schum.) Morrone] is a tropical forage grass widely used in ruminant feeding in tropical and subtropical areas, mainly in cut-and-carry systems due to is high potential for herbage accumulation. However, most common genotypes (tall genotypes) generally show an early stem elongation, which contributes to a rapid decline in the forage nutritive value. Dwarf elephant grass types usually present less stem elongation and may be considered an option for the production of high nutritive value forage in cut-and-carry systems. The aims of this study were to evaluate and explain variations in herbage characteristics and kinetics of in vitro gas production of irrigated elephant grass genotypes (two tall-types – Elephant B and IRI-381 – and two dwarf-types genotypes – Mott and Taiwan A-146 2.37) under two harvest frequencies (60 and 90 days) in the dry and rainy seasons of two years. Herbage characteristics varied among genotypes, harvest frequency and seasons. Dwarf genotypes showed better in vitro fermentation parameters with the advancement of maturity compared to the tall size genotypes. Harvesting tall genotypes at a higher frequency (60-day) contributed to improving the fermentation, while dwarf elephant grass maintained greater fermentation when less frequent harvests were adopted (90-day).

Cephalaria joppensis Rchb. (CJ) has recently been domesticated as a new forage crop in Israel. Feeding trials with dairy cows and sheep have shown that CJ silage can replace wheat silage for these animals. The current work tested the effect of row spacing on the growth, yield, chemical composition and digestibility of CJ for forage. Two field trials were performed at a research farm in Acre to test three row spacings: (T1) 16 cm between rows (narrow row spacing), (T2) pairs of adjacent (16 cm apart) rows with 32 cm spacing between pairs (alternated row spacing) and (T3) 32 cm between rows (wide row spacing). T1 row spacing had the advantage of a better area coverage rate, which may be beneficial at the beginning of growth, reflected by the rapid establishment of the plants in the field, as well as in the competition with weeds. The growth rate was more significant in T2 and T3 row spacings. In the first year, a higher yield was obtained for T2 and T3 row spacings; in the second year, no differences in yield were found among the row spacing treatments. Row spacing did not affect the plant’s digestibility or chemical nutrition for ruminants. There was no uniformity in plant quality among the cultivars between the two years. Thus, we should define the phenological stages of Cephalaria joppensis and their relationship to nutritional quality at different sites having different climate conditions, in both small and semi-commercial plots.

The presence of excessive arsenic (As) in paddy fields poses a significant risk to human health due to its accumulation in rice grains. However, the current level of As in Sri Lankan paddy fields remains unclear. Therefore, this research aims to assess the distribution of exchangeable As concentration and investigate the effects of agro-climatic zones (ACZs), soil orders and water sources on exchangeable As concentration in Sri Lankan paddy fields. For this purpose, 7,154 soil samples were collected from paddy fields using a stratified random sampling method representing six ACZs, six soil orders and three water sources. Arsenic extraction was made using 0.01 M CaCl2 followed by the detection with inductive coupled plasma mass spectrophotometry. The concentration of exchangeable As ranged from 0.01 to 392.9 µg/kg with an average of 24.6 µg/kg. Samples from the Low-country Wet zone exhibited higher exchangeable As levels compared to those from the Low country Dry zone (P < 0.05). Among soil orders, Histosols, Inceptisols and Ultisols showed higher exchangeable As concentrations than Alfisols and Vertisols (P < 0.05). Rainfed paddy fields had higher exchangeable As compared to the fields with access to supplementary irrigation. Additionally, exchangeable As concentration was inversely correlated with soil pH and paddy grain yield (P < 0.05). The observed variations in soil-As concentration across ACZs, soil orders and water sources highlight the need for climate, soil order and water source-specific strategies to mitigate further accumulation of As in paddy fields.

A ruminant model, MINDY, was used to explore the impact of grazing patches of tannin-containing legumes on environmental impact of cows grazing on grass-dominated rangelands swards. MINDY was initialised as a pregnant beef cow grazing on a grass (Bromus biebersteinii; meadow brome-Control), with the addition of a patch with tannin-containing legumes (Lotus corniculatus-birdsfoot trefoil-Tre, or Onobrychis viciifolia-sainfoin-Sain). Twenty-five scenarios (treatments) were established as a product of frequency (weekly, fortnightly and monthly) and dietary proportions (0.05, 0.10, 0.15 and 0.20 of total forage allocation) of either Sain or Tre. Methane (CH4) production and nitrogen (N) excretion increased with legume availability. As legume proportion increased, dry matter intake (DMI), animal performance, CH4 production and urinary nitrogen (UN) excretion increased with a greater magnitude for Sain. Methane yield was lower than the Control at weekly allocation of legumes. Environmental costs in terms of CH4 emission increments per unit of production relative to Control were greater at monthly allocations when the levels of legumes in the diet were low (0.5–0.10). Legumes in the diet at 0.15–0.20 yielded the lowest costs regardless of frequency of allocation. Environmental costs in terms of UN increments per unit of production relative to Control were lowest at 0.15–0.20 of legumes in the diet regardless of frequency of allocation. This study suggests that strategic allocation of either sainfoin or birdsfoot trefoil when beef cattle graze grass-dominated rangelands swards can reduce environmental impact while increasing secondary production of the system at the same levels of resource allocation.

DNA barcoding approaches have been successfully applied for estimating diet composition. However, an accurate quantification in the diets of herbivores remains to be achieved. In the current study, we present a novel methodology that reveals the relationship between the actual proportions (by mass) of each herbage species in the diets and the relative proportions of the ITS2 gene sequences obtained from faecal samples to evaluate the diet composition of sheep in a meadow steppe. Nine common and 12 rare species of plants were employed for formulating 6 diets, along with the addition of feed supplements for improving the growth performance of sheep. Faecal samples were collected for DNA analysis over the period spanning days 7–12. A significant positive correlation (Spearman’s ρ = 0.389) was obtained between the actual proportions (by mass) of the herbage in the diet provided and the relative abundance of ITS2 sequences obtained from the faecal samples. A significant regression coefficient was found between the relative abundance of all common species and their respective herbage mass proportions. The accuracy of the relation equations, evaluated by utilizing the similarity coefficient, showed 84.69% similarity between the actual diet composition and the correct percentage. Taken together, the current study has provided empirical evidence for the accuracy and applicability of ITS2 as a DNA barcode for obtaining quantitative information about the diet composition of sheep grazing in species-rich grasslands.