陇东旱原小麦玉米组合种植的增产增效研究

Research on Yield Increase and Benefit Improvement of Complex Wheat Corn System on Rainfed Highland in the East Gansu Province

１９９１～１９９５年研究了陇东旱原冬小麦玉米组合系统的增产增收、土壤水分利用、组合耗水量及补偿供水效应。结果表明：（１）小麦玉米组合系统具有增产增收和水资源集约利用的优势，土地当量比，收益当量比分别达到１．２１５、１．１９９。（２）在组合系统中，冬小麦边行优势总值达到９４．９％～１４４．５％，其补偿率为１８．９０％～２８．９９％。（３）冬小麦对土壤水分的竞争利用是玉米带土壤水分不足的主要原因，系统组合耗水量明显小于小麦、玉米单作耗水量的累加值，水分缺额１１０．２～１５３．８ｍｍ。（４）玉米根际补偿供水具有明显的增产效果。

Yield increase and benefit improvement,soil water use,water consumption of the complex system and supplementary water supply effects in the complex wheat corn system were studied on the rainfed highland in the east Gansu Province during the years of 1991～1995.The results showed in the following:(1)the complex wheat corn system had the great advantages of yield increase and benefit improvement and intensive use of water resources so that the land equivalent ratio and the income equivalent ratio were 1.215 and 1.199 respectively.(2)Total value of wheat marginal effect in the system reached 94.9%～144.5%,whose supplementary water supply ratio reached 18.9%～28.9%.(3)The competitive use for soil water by wheat was the main cause resulting in serious water stress to corn plant.Water consumption of the system was less than the accumulative by mono cultutivation of wheat and corn.The amount of water stress in the system ranged from 110.2mm to 151.8mm.and (4)Supplementary water supply to corn root zone can improve corn yields by a wide margin,but supplementary water supply effects varied greatly in the rainfall year types.