水分调控对苹果-大豆间作生理特性及水分利用的影响

为探求适于晋西黄土区果农间作系统的水分调控措施,通过2 a试验并结合覆盖与调亏灌溉措施,分析了水分调控措施对苹果和大豆叶片生理特性、水分利用和产量等指标的影响.试验设置灌水上限三水平为田间持水量的55%(W1),70%(W2)和85%(W3),两种覆盖:秸秆覆盖(M1)和地膜覆盖(M2),另设清耕(CK0)、秸秆覆盖不灌水(CK1)和地膜覆盖不灌水(CK2)作为对照.结果表明:水分调控措施提高了生育期内苹果和大豆叶绿素相对含量(SPAD)、净光合速率(P_n)和叶片水分利用效率(LWUE),其中,处理M2W2的P_n和LWUE均高于其余调控措施.果树的遮荫抑制了大豆P_n和LWUE,即距离树行越近值越小.灌水、覆盖以及交互作用对大豆产量和水分利用效率(WUE)影响均在0.01水平下具有统计学意义,与其余处理相比,处理M2W2可增产9.48%~103.90%,WUE提高了11.07%~118.08%.通过多指标综合评价分析得出,节水增产效益最高的处理为M2W2,由此建议幼龄苹果-大豆间作采用地膜覆盖措施,同时在分枝期和鼓粒期采取田间持水量的70%为灌水上限的灌溉制度.

Effects of water regulation on physiological characteristics and water use of apple-soybean intercropping system

In order to investigate the effects of water regulation on the leaf physiological characteristics,water use and grain yield in an apple(Malus pumila)-soybean(Glycine max)intercropping system,a two-year field experiment combined mulching with regulated deficit irrigation was carried out in the Loess Plateau of Shanxi Province.Three levels of irrigation thresholds were set:55%(W1),70%(W2),and 85%(W3)of field capacity,two kinds of mulching materials included straw mulching(M1)and plastic film mulching(M2),and three control treatments were clear tillage(CK0),straw mulching without irrigation(CK1)and plastic mulching without irrigation(CK2),respectively.The results indicate that the water regulation increases the chlorophyll relative content(SPAD),net photosynthetic rate(Pn)and leaf water use efficiency(LWUE)of apple and soybean during the growth period,and the maximum value of Pn and LWUE is observed in M2W2 treatment.Apple shading inhibits the Pn and LWUE of soybean,showing that a reducing trend with the decrease of tree row.Irrigation,mulching and interaction have very significant effects on soybean yield and water use efficiency(WUE).Compared with other treatments,M2W2 treatment can increase the yield by 9.48%-103.90%,and WUE can increase by 11.07%-118.08%.The multi-index comprehensive eva-luation shows that the optimum water-saving regulation method is as follows:covering plastic film in young apple-soybean intercropping system,combined with irrigation with the upper limit of soil moisture of 70%field capacity at the branching stage and the grain filling stage.