耕作方式对东北春玉米农田土壤水热特征的影响

针对东北春玉米农田春季低温冷害和季节性干旱发生频率高的问题,于2009年-2010年设置3种耕作处理,即传统垄作(LL)、平作播种中耕起垄(PL)和全生育期平作(PP),研究大田条件下耕作方式对土壤水分、土壤温度和玉米产量的影响。2a试验结果表明,耕作方式对0～40cm土层储水量有显著影响,其中PL和PP处理播种时的初始储水量比LL处理高8.7和6.0mm,而苗期则分别高4.1和3.4mm;玉米生育中后期PL和LL处理储水量则呈高于PP处理的趋势。3种耕作方式下土壤温度的差异以苗期为主,即5cm土层的平均温度PL和PP处理显著低于LL处理,但最低温度则以PL和PP处理显著高于LL处理,分别高1.6和1.2℃。总体来看,PL处理不仅可提高玉米苗期土壤的最低温度和耕层土壤储水量,而且可增加中后期土壤积蓄雨水量,促进作物生长发育,因而籽粒产量比LL和PP处理分别高7.6%和6.4%。

Effects of surface tillage regimes on soil moisture and temperature of spring corn farmland in Northeast China

Concerning the high frequency of chilling injury and seasonal drought during spring corn growth season in Northeast China,a field experiment were conducted in 2009-2010 to determine the effects of different soil surface tillage treatments on soil moisture,soil temperature and corn yield.Three treatments including ridge tillage(LL),ridge tillage after seedling(PL) and shallow tillage without ridge(PP) was designed.The results obtained in two-year experiments showed that soil water storages of the depth of 0-40 cm in the PL and PP plots were significantly higher than that in the LL plot by 8.7 and 6.0 mm before sowing,and 4.1 and 3.4 mm during corn seedling stage,respectively.Whereas soil water storages of 0-40 cm soil depth in the PL and LL plots were higher than that in the PP plot in medium-late growth period of corn.The daily mean temperatures in the soil depth of 5 cm of PL and PP plot were significantly lower than that in the LL plot in seedling stage.However,the daily minimum temperature in the soil depths of 5 cm of the PL and PP plots was 1.6 and 1.2℃,respectively,and higher than that in the LL plot in seedling stage.The above evidences suggested that ridge tillage after seedling(PL) might increase the soil minimum temperature and soil water storage in seedling stage as well as improve soil moisture conditions in medium-late growth stage,which contributeed to the higher grain yield in the PL plot than that in LL and PP by 7.6 % and 6.4 %,respectively.