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

Authenticate the accuracy of the indica or japonica attribute for the sake of the exaltation,utilize Cheng's index method from glume hair, phenol reaction length of the first to second rachis internode,glume color at hea- ding, leaf hair and grain length/width ratio to study on the indica or japonica attribution of 173 rice material, according the mark of every index is added up, 0-8 scores is indica(H), 9~13 scores is indica-clinous(H'), 14~17 scores is japonica -clnious(K'), 18~24 scores is japonica(K) ,Use classic indica G46 as a comparisom and divide materials to four classification.