Agricultural yields have increased continuously over the last few decades. However, a focus solely on production can harm the environment. Diversification of agriculture has been suggested to increase production and sustainability. Biodiversity experiments showed positive effects on ecosystems and productivity. However, application of these results to intensively managed grasslands has been questioned due to differences in plant species and management regimes. Research on whether diversity can benefit multifunctionality, that is, an integrated index of multiple ecosystem functions, under intensive management, is still scarce.
To address this, we manipulated plant species richness from one to six species spanning three functional groups (legumes, herbs, and grasses) in intensively managed multispecies grassland leys and examined seven ecosystem functions.
We found that multifunctionality increased with functional group and species richness. Legume+herb mixtures showed high multifunctionality, while grass monocultures and mixtures with high proportions of grasses had low multifunctionality. Different plant species and plant communities drove different ecosystem functions. Legumes and herbs improved productivity and water availability, while grasses enhanced invasion resistance. These results indicate that multifunctionality and individual ecosystem functions can be promoted through targeted combinations of plants with complementary ecological traits.
Plant diversity can improve multifunctionality also under intensive management, potentially benefitting agroeconomics and sustainability.
Soil and water salinity are increasing problems worldwide, causing significantly reduced crop yields. Alfalfa (Medicago sativa L.) is often listed as salt-sensitive, but field testing of improved cultivars is limited. Forage systems and improved high-quality alfalfa varieties are needed to enable crop production under high salinity (HS) conditions.
The objective of this study was to measure the yield and quality response of alfalfa to high saline conditions in the field and to document the relative saline tolerance of its varieties. HS irrigation water (electrical conductivity of water, or ECw 8.0–11.0 dS m−1) was applied to 33 nondormant alfalfa cultivars and were compared with low salinity (LS) treatments (ECw 0.5–1.2 dS m−1) over 4 years in a Mediterranean environment on a clay loam soil utilizing a split-plot design. Crops were harvested seven to eight times per year, and the forage quality was measured on selected harvests utilizing near-infrared spectroscopy.
The average yield loss due to HS treatment was 23.9% compared with LS treatment, but yields averaged 23.4 Mg ha−1 under HS over the 3 full years of production. This level of production is considered to be economically viable in this region. Differences in salinity tolerance between lines were identified in the field; individual cultivars lost 5%–35% of their LS yield when grown under HS conditions. Forage quality was significantly improved under HS versus LS conditions, but improvements were negatively correlated with biomass yield (R2 > 0.81), similar to responses observed in drought-stressed alfalfa.
These yield results confirm greenhouse studies, indicating that alfalfa is highly salt tolerant once established in the field, with potential for further improvement with tolerant cultivars. Salinity tolerance should be chosen based on total biomass yield as well as on the salinity tolerance index (HS yield relative to LS yield). Agronomic practices to mitigate salinity and sodicity are critical, along with improved cultivars.
Genomic selection has the potential to accelerate genetic gain in perennial ryegrass breeding, provided complex traits such as forage yield can be predicted with sufficient accuracy.
In this study, we compared modelling approaches and feature selection strategies to evaluate the accuracy of genomic prediction models for seasonal forage yield production.
Overall, model selection had limited impact on predictive ability when using the full data set. For a baseline genomic best linear unbiased prediction model, the highest mean predictive accuracy was obtained for spring grazing (0.78), summer grazing (0.62) and second cut silage (0.56). In terms of feature selection strategies, using uncorrelated single-nucleotide polymorphisms (SNPs) had no impact on predictive ability, allowing for a potential decrease of the data set dimensions. With a genome-wide association study, we found a significant SNP marker for spring grazing, located in the genic region annotated as coding for an enzyme responsible for fucosylation of xyloglucans—major components of the plant cell wall. We also presented an approach to increase interpretability of genomic prediction models with the use of Gene Ontology enrichment analysis.
Approaches for feature selection will be relevant in development of low-cost genotyping platforms in support of routine and cost-effective implementation of genomic selection.
Plants of the genus Arachis originated from South America and are cultivated worldwide. The genus Arachis contains 83 species and nine intrageneric taxonomic sections. The cultivated peanut (Arachis hypogaea L.) belongs to the Arachis section, the forage peanut (Arachis pintoi Krapov. & W. C. Greg.) belongs to the Caulorrhizae section, and the perennial peanut (Arachis glabrata Benth.) belongs to the Rhizomatosae section. These three peanut species have been developed for use as fodder crops. This review summarizes the forage value of Arachis species. Forage and perennial peanuts can be intercropped with forage species to feed livestock. The cultivated peanut vines and peanut by-products, such as peanut skins and peanut meal, are also high-quality fodder used to feed sheep, cattle, and poultry. A major limiting factor in terms of adopting forage and perennial peanuts as forage crops is their limited resistance to frosts, resulting from their low winter hardiness. Therefore, the feeding value of cultivated peanuts is higher compared to forage and perennial peanuts. This review suggests that Arachis is a suitable forage crop, focusing on their nutritional properties and breeding to increase their performance under cultivation and feeding value.
Grassland is the largest ecosystem on the Qinghai–Tibetan Plateau (QTP) and provides multiple ecosystem functions and services. Understanding the endowment of the QTP grassland and how to revitalize it have profound implications for the sustainable use and efficient conservation of these unique and globally valuable ecosystems. In this paper, we highlight the importance of the QTP grassland in regional and global settings, stress the values of the QTP grassland in ecological and socioeconomic dimensions, and emphasize the actions needed to restore degraded grassland in the QTP region. The QTP is the largest single area of alpine grassland in the world and an important gene pool of alpine biological resources. The QTP grassland covers two critical ecoregions for conserving the best and most representative habitats for alpine biodiversity on the planet. The QTP grassland is also regarded as one of the best carriers and objects of socio-ecological systems in the world. To promote the resilience and sustainability of the QTP grassland through adaptation, different parties need to work together to find feasible options to resist shock, stresses, and disturbance and to maintain the fundamental functions and basic structures of the QTP grassland.
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