秸秆覆盖对农田土壤水分及玉米生长的影响

秸秆覆盖的土壤剖面含水量与裸地显著不同,与前者相比,裸地土壤水分无明显的层次性变化,受降水及蒸发等因子影响明显。由于覆盖状况和土壤物理性质不同,土壤水分变化幅度也有明显差异,秸秆覆盖土壤水分含量较高,玉米拔节期0~40cm土层达到18%。苗期根长小并主要分布在0~30cm土层,孕穗期和灌浆期根长大大增加,主要分布在0~60cm和0~90cm土层。秸秆覆盖可以显著地增加土壤水分利用率和蓄水量,促进玉米根系生长,提高玉米单产32.1%。

Effects of Stubble Mulching on the Field on Cropland Soil Moisture Content and Spring Corn Growth

Based on the results of the long term and position research, the soil moisture content in the soil profiles that covered stubble differ from the soil moisture content in bare profiles. Compared with the former, the soil moisture content has no obvious horizon variety in bare profiles but it is greatly influenced by the precipitation and evaporation. The variable range of soil moisture content distribution is obviously because the situation of stubble cover and soil physical features are different. Compared with the Check, the covered stubble has higher soil moisture content, the maximum is 18% in 0~40cm soil layer in shooting stage. In seedling stage, corn root was mainly in 0~30 cm and the root length was very small. Root length dramatically increased in booting stage and filling stage and root mostly distributed in 0~60cm and 0~90cm soil layer, respectively. The covered stubble could increase water utilization and the capability of storage water and, it could prompt the root growth of spring corn obviously and raise the per unit yield of 32.1%.