A comprehensive appraisal of four kinds of forage under irrigation in Xilingol, Inner Mongolia, China

摘要

Planting of forage can alleviate grazing pressure on natural ecosystems. In the Inner Mongolian environment, higher forage yields can be expected under irrigation because water is a key factor that limits plant growth. Lower grass yield caused by land degradation and climatic change highlight the potential importance of irrigated forage for maintaining livestock production in this environment. The present study in the Xilingol area of Inner Mongolia aimed to identify forage varieties producing high-yielding, quality forage. Three lucerne (alfalfa) varieties (Medicago saliva L. cvv. Aohan and Zhaodong, Medicago varia Martyn) and a grass (Elymus nutans Griseb) were assessed. Irrigation commenced when soil moisture at 10 cm depth reached the wilting coefficient, and ceased when soil reached field capacity. After 4 months, irrigation had significantly increased specific leaf area, tiller numbers and yield under irrigation (P & 0.05) in all varieties. Yield of cv. Zhaodong was highest at 5111 kg ha(-1). Forage quality was evaluated by using yield, leaf: stem ratio and crude fibre, crude protein and crude fat contents. Forage quality was significantly higher in the three lucerne varieties than in the grass, under both irrigation and natural rainfall, with no significant difference among the three lucerne varieties. Cost-benefit analysis showed that irrigation was much more profitable for the three lucerne varieties than for the grass because of the lower market value and yield of the grass.