不同栽培模式旱作春玉米农田土壤水分时空动态和产量效应

摘要

于2012年和2013年连续两年进行田间定位试验，研究在全膜双垄沟覆盖条件下不同施肥和开花期揭膜处理对春玉米农田土壤水分时空变化特征、土壤含水量和水分利用效率的影响。试验设农户模式（施N 200 kg·hm－2，半膜，CK）、高产栽培（施N 380 kg·hm－2，T1）、高产高效栽培（施N 225 kg·hm－2＋有机肥，T2）、再高产高效栽培（施N 225 kg·hm－2＋有机肥＋开花期揭膜，T3）等4个处理，以先玉335为供试玉米品种，分别在玉米各个关键生育期测定土壤含水量，收获测定实际产量。结果表明，T2、T3处理在生育前期、中期不仅能够高效利用浅层（0～100 cm ）土壤水分，而且有利于促使深层（100～200 cm ）土壤水分向上迁移，为玉米生育后期雨季充分蓄纳降雨腾出库容；从播前到收获0～200 cm土壤贮水量均降低，收获时各处理贮水量依次为CK＞T1＞T2＞T3，差值均小于5 cm ，没有显著差异。土壤含水量在0～60 cm土层变化幅度大，而深层（160～200 cm ）比较稳定。四种处理间耗水量、产量和水分利用效率存在不同差异，表现为T3＞T2＞T1＞CK。尤其2013年四个处理产量和水分利用效率均达到显著水平，T1、T2、T3产量分别比CK高27．4％、34．8％、42．4％，CK处理水分利用效率比 T1、T2、T3分别低21．7％、29．9％、23．7％。高产高效栽培，特别是开花期揭膜的再高产高效栽培模式，在玉米整个生育期不仅没有导致土壤剖面土壤水分显著降低，而且可显著提高籽粒产量和水分利用效率，是该地区值得推广的旱作春玉米栽培模式。%To assess the impacts of different cultivation systems on the characteristics of space-time dynamics on soil moisture and water use efficiency (WUE ) ,which could be helpful for increasing grain yield and WUE in dryland maize production in semi-arid regions ,a field trial was conducted at the Changwu experimental station in 2012 and 2013 .Four treatments were carried out including farmers’ practice(N 200 kg·hm-2 ,ridges covered with plastic film ,CK) ,T1 treatment (N 380 kg·hm-2 ,ridges and furrows both covered with plastic film ) ,T2 treatment (N 225 kg·hm-2+ Or-ganic fertilizer ,ridges and furrows both covered with plastic film ) ,T3 treatment (N 225 kg·hm-2+ Organic fertilizer , ridges and furrows both covered with plastic film and removing plastic film at silking stage ) .Compared to farmers’ prac-tice ,T1 ,T2 and T3 treatments could not only efficiently use water in the 0~100 cm soil layers ,but also use water in the 100~200 cm soil layers .At harvest ,no significant differences in soil water content were observed between treat-ments .Water consumption levels during the whole growing stage of the four treatments were in the order of T 3>T2>T1>CK ,and the grain yields followed the same .Because the rate of yield increase was higher than that of water consump-tion ,the water use efficiencies of the four treatments were also found to be in the same order as T 3>T2>T1>CK .In conclusion ,the cultivation systems that ridges and furrows both were covered with plastic film improved not only grain yield but also water use efficiency ,especially in the plots where plastic film was removed at the silking stage .This culti-vation system could be helpful for increasing grain yield and WUE of dryland maize in semi-arid regions .