Abstract:

This research evaluated different mixed cropping options for planting oats after wheat in the Ningxia Yellow River irrigation area. Two mixed planting patterns and three sole crop planting treatments were established with oats （Avena sativa）， common vetch （Vicia sativa） and hairy vetch （Vicia villosa）， to study the effects on interspecific competition， yield performance and economic benefits over two years. The results showed that oats sown in mixtures with vetch outperformed oats sown as a sole crop in terms of land resource utilization， productivity enhancement， nutritional quality improvement， and economic benefit. The land equivalent ratio （LER） of the replanted oat mixed cropped with vetch was greater than 1， and the land use efficiency increased by 21% on average. The effect of replanting oat with common vetch on crop productivity was substantial. In this mixture， the hay yield was 8.37 t·ha^-1， crude protein yield was 1049.58 kg·ha^-1 and economic benefit was 8817 CNY·ha^-1. These values were increased （P<0.05） by 16.97%， 42.49% and 30.89%， respectively， compared to oat monoculture. Similarly， the crop nutritional value was improved in mixed crops of oats with hairy vetch. In this mixture， the relative feeding value was 114.55 and crude protein content was increased （P<0.05） by 29.92% compared to oats alone， where crude protein content was 13.33%. In conclusion， different modes of replanting after wheat can be selected according to the actual forage demand. When the forage demand is high， oat-common vetch mixtures offer higher yield； when it is desired to optimize forage nutritional quality oat-hairy vetch mixtures are recommended. The results of the study provide practical guidelines for improving the potential of arable land resources and adjusting the planting mixture according to forage requirement in the Yellow River irrigation area of Ningxia.

Key words: Yellow River irrigation area, mixture sowing, crude protein yield, nutritional quality, land equivalent ratio, economic benefits