Forage Quality and Yield Enhancement via Wolfberry (Lycium barbarum L.)–Forage Intercropping System

The agroforestry system, which integrates the strategic intercropping of trees and grasses, is profoundly shaped by complex ecological interactions that dynamically reshape microclimatic environments and significantly impact the growth of understory forage species. Wolfberry–forage intercropping patterns have the potential to improve soil quality and orchard productivity, but their effects on forage cover crops are still unclear. Therefore, this study selects wolfberry and nine forage grass as research subjects to examine the effects of intercropping these species on the morphological characteristics, yield, quality, photosynthetic capacity, and plant physiology of forage grass. Based on experimental data, cover cropping facilitated plant growth, maintained fruit yield, and promoted leaf photosynthesis in forage compared with monocropping. This was exemplified by a notable increase in forage plants under the intercropping system, for the number of primary branches or tillers, and an improvement in the drying ratio of forage grasses, while reducing plant height, leaf-to-stem ratio, and photosynthetic rate (p < 0.05). Furthermore, the intercropping system significantly enhances the dry weight yield of alfalfa, ryegrass, and mangold, with increases of 60%, 64%, and 70%, respectively (p < 0.05). Additionally, it improves forage quality by increasing the crude protein content in ryegrass and mangold by 32% and 10%, respectively, and decreasing acid detergent fiber content by 10% and 18% (p < 0.05). Collectively, the results indicated that mangold, ryegrass, and alfalfa were the optimal cover crops for sustainable wolfberry production in the study area. The use of appropriate wolfberry–forage cover crops enhanced hay yield and the quality of forage by stimulating photosynthetic capacity and biotic stress resistance. Our research elucidates the mechanisms underlying the effects of intercropping systems on forage grass growth, aiming to provide a scientific basis for the development of animal husbandry and the rational utilization of land resources in the Ningxia region.