Intercropping of orchardgrass and alfalfa improves soil fertility, forage yield, feeding values and land use efficiency while limiting ruminal greenhouse gas emissions

作者：Zhulin Xue, Yunling Wang, Elizabeth M. Palmer, Yingjun Zhang · 发表于：Grass and Forage Science · 年份：2023 · DOI：10.1111/gfs.12602 · 被引用次数：9 · 研究领域：Agronomic Practices and Intercropping Systems、Ruminant Nutrition and Digestive Physiology、Agroforestry and silvopastoral systems

Abstract Intercropping has been a globally accepted practice for forage production, however, consideration of multiple performance criteria for intercropping including forage production, feed use efficiency and ruminal greenhouse gas emissions needs to be further investigated. A two‐year field study was conducted to evaluate forage dry matter (DM) yield, nutritive value, feeding values and land‐use efficiency as well as ruminal carbon dioxide (CO 2 ) and methane (CH 4 ) emissions of intercropped orchardgrass ( Dactylis glomerata ) and alfalfa ( Medicago sativa ) sown in five intercropping ratios (100:0, 75:25, 50:50, 25:75, and 0:100, based on seed weight) and three nitrogen (N) fertilizer levels (0, 50, and 100 kg ha −1 ). Increasing alfalfa proportion and N fertilizer level increased soil nutrients and the two‐year total DM yield. Intercropping increased both land and nitrogen use efficiency (NUE) compared with monocultures. Greater NUE was obtained when N fertilizer was applied at 50 kg ha −1 , compared with 100 kg ha −1 . Increasing the proportion of alfalfa in intercrops increased the crude protein yield and rumen undegraded protein yield. Harvested forage intercrops were incubated with ruminal fluid for 48 h. Degraded DM yield, CO 2 and CH 4 emissions increased with increasing alfalfa proportion in intercrops. Overall, the 75:25 of orchardgrass‐alfalfa intercrops was recommended as the best compromise between high forage productivity, superior feed use efficiency and lo...