半干旱区全膜覆盖垄沟种植马铃薯/蚕豆间作的产量和水分效应

Effects of potato-fababean intercropping on crop productivity and soil water under a plastic mulch and ridge-furrow planting system in a semiarid area

间套作是提高农田资源利用效率和缓解连作障碍的有效措施,但就旱作全膜覆盖马铃薯豆科作物间作的增产机制及其效应,目前缺乏系统研究认识。试验于2011-2014年在西北黄土高原半干旱区的甘肃省农业科学院定西试验站进行（104°36′E,35°35′N）,以新大坪和临蚕131为试验材料,设马铃薯单作、蚕豆单作和薯蚕间作3个处理,记载生育期、测定年际土壤含水量,作物产量,计算作物生育期耗水量、水分利用效率、资源竞争力、土地当量比等参数,揭示西北黄土高原旱作区马铃薯间作蚕豆对作物生育期、产量、耗水特征和水分利用效率的影响,以评价区域马铃薯/蚕豆间作的产量和水分效应。结果表明,马铃薯/蚕豆间作的共生期长达100d以上,共生期耗水占全生育期耗水总量的42.5%～58.3%,是马铃薯单作总耗水量的68.2%～86.3%;间作显著提高了作物耗水量,并使马铃薯花后耗水量显著降低。尽管间作后使产量较马铃薯单作在2011和2014年下降18.1%～31.2%,并使不同降水年型的作物水分利用效率显著下降,但使2012年的作物产量提高了10.6%,而且4年土地当量比达1.3～1.5,蚕豆对于马铃薯的资源竞争力为0.31～1.15。所以半干旱区全膜覆盖马铃薯垄沟间作种植具有显著提高土地生产效率的潜力,但需要通过科学搭配作物组合才能实现增产增效、改善农田环境的目的。

Intercropping is an efficient way to increase natural resource use efficiency and reduce the obstacles resulting from continuous cropping.However,little research has focused on yield increment mechanisms asso-ciated with potato and legume intercropping utilizing furrow-ridge planting with plastic mulch.A 4 years （2011-2014）field study was conducted at the Dingxi Experimental Station,Gansu Academy of Agricultural Sciences （104＆#176;36′E,35＆#176;35′N）,located on the northwest Loess Plateau.Potato （xindaping）and fababean （lin-can131）were used during the study.Three treatments were imposed：1 ）potato monoculture,2 ）fababean monoculture,and 3）intercropped potato-fababean.Measurements included seasonal and yearly soil water con-tent,crop productivity,crop seasonal water consumption,water use efficiency,individual species competitive-ness and subsequently,land equivalent rate calculated.The paragenesis period of potato and fababean was more than 100 days;evaportranspiration in this period accounted for 42.5%-58.3% of total evaportranspiration of the intercrop treatment,and 68.2%-86.3% of total evaportranspiration for the potato treatment.The inter-crop produced lower yields,18.1 % and 31.2% in 2011 and 2014 respectively compared with the potato treat-ment.Crop water use efficiency was also lower in the intercrop.However,the intercrop yield was significantly higher （10.6%）in 2012 compared with the potato treatment.The land equivalent rate reached 1.3 -1.5 and the competitiveness of fababean relative to that of potato ranged from 0.31 -1.15 through the 4 years of the study.Intercropping could increase potential productivity under plastic mulching and ridge-furrow planting sys-tems in semiarid areas,but selecting appropriate crop species for intercrop systems is necessary to increase both crop productivity and natural resource use efficiency,as well as improve the cropland environment.