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.