Sustainable forage yield improvement through perennial grass–legume intercropping in degraded grasslands

Grasslands constitute one of the largest terrestrial biomes, providing essential ecosystem services such as biodiversity preservation, food production, and climate change mitigation. Globally, the desertification and degradation of grasslands have been accelerated by intensified land use and climate change. It is crucial to conserve and restore grasslands to address climate and biodiversity challenges. However, due to their diverse nature and undervalued benefits for humans, grasslands have often been overlooked in terms of preservation, conservation, and restoration compared to forests. In sustainable agriculture, intercropping grasses with legumes can enhance crop nutritional quality, increase productivity, and impact soil microbiological activity, ultimately leading to higher yields from subsequent crops. Including forage legumes is essential to improve both the quantity and quality of feed, which is crucial for livestock farmers aiming to enhance animal performance. One practical strategy to boost production, protein supply, herbage value, and species diversity in grasslands is the incorporation of forage legumes and herbs. This review examines the impact of grass–legume intercropping on soil nitrogen levels, species recruitment, and forage productivity, as well as the imperatives and opportunities for transforming agriculture and how grasslands respond to global changes.