小麦玉米与苜蓿间作模式对盐碱地土壤含盐量及周年产量的影响

Effects of Wheat-Maize‖Alfalfa Intercropping Mode on Soil Salinity and Annual Yield in Saline-Alkali Field

盐碱地是我国重要的后备耕作资源,构建合理的耕作制度是其绿色开发的重要一环。为了有效利用及改良盐碱地,本研究于2017—2018年以小麦复种玉米、苜蓿单作为对照,分别设置小麦玉米与5行、10行苜蓿间作处理,研究其对土壤含盐量及各作物产量、土地当量比的影响。结果表明,小麦玉米间作苜蓿可以降低0~40cm土层含盐量,提高小麦玉米的穗粒数、粒重和净面积单产,提高苜蓿周年干物质产量。对小麦玉米来说,两种间作模式均表现出种间互补作用大于种间竞争作用;对苜蓿而言,虽然不利于净面积单产提高,但减产均不显著。小麦季间作5行苜蓿的土地当量比低于间作10行苜蓿,但其玉米季和周年土地当量比较高。从周年来看,小麦玉米间作5行苜蓿是较佳的种植模式。

Saline-alkali lands are important reserved cultivation resources in China,and constructing a reasonable cropping system is very important for its development.In order to utilize and improve saline-alkali lands effectively,the effects of wheat-maize intercropped with 5 or 10 rows of alfalfa on soil salt content,crop yield and land equivalent ratio were studied using wheat-maize multiple cropping and alfalfa monoculture as the controls in 2017-2018.The results showed that wheat-maize intercropping with alfalfa could reduce the soil salinity in 0~40-cm layer,increase the grain number per ear,grain weight and single yield net area of wheat and maize and the annual dry matter output of alfalfa.For wheat and maize,the complementarity under intercropping modes was greater than the competition.For alfalfa,although it was not good for the increase of biomass yield net area,the yield reduction was not significant.The land equivalent ratio in wheat season was lower under intercropped with 5 rows of alfalfa than that under intercropped with 10 rows of alfalfa,while that increased in maize season and the annual value was higher.From the annual output,wheat-maize intercropping with 5 rows of alfalfa was better.