黑土区土壤水分含量对大豆产量构成因素的影响

本研究旨在分析黑土区（黑龙江）土壤有效水分贮存量对大豆产量构成因素的影响，以期为大豆生产防灾减灾提供科学依据。利用1994—2017年黑龙江省大豆主产区的发育期、土壤水分、产量结构资料分析了大豆不同发育阶段土壤有效水分贮存量的时空分布规律、基于土壤相对湿度指数（R_sm）的干旱等级划分规律及有效水分贮存量对大豆不同发育阶段产量结构各因素的影响。结果表明：1994—2017年研究区各发育阶段平均有效水分贮存量在14—18 mm之间变化，共发生干旱82站次，其中轻旱77站次，中旱5站次，没有发生重旱和特旱，其中开花—结荚期、结荚—鼓粒期发生干旱频次较高，且1994—2017年研究区域发生干旱的频次是逐年降低的。大豆的气象产量、株结实粒数、株籽粒重与不同发育期的各层次的土壤有效水分贮存量相关性不大；百粒重与三叶至开花期的20—50 cm土层、结荚—鼓粒期的0—20 cm土壤有效水分贮存量相关性较大；茎秆重与播种至出苗期的30—50 cm土壤有效水分贮存量呈显著正相关；播种至开花期土壤中的有效水分贮存量尤其是深层土壤在一定范围内越多，株荚数越多；空秕荚率与播种至出苗期的0—20 cm和30—40 cm、出苗至三叶期的30—40 cm土壤有效水分贮存量相关性较大。

Effects of soil moisture on yield components of soybean in black soil area

The purpose of this study is to analyze the effects of effective soil water content (ESWC) on soybean yield in the black soil region (Heilongjiang),so as to provide the scientific basis for disaster prevention and mitigation of soybean production.Based on the data of development period,soil water content and yield components during 1994-2017 in the main soybean producing areas of Heilongjiang province,the variation characteristics of ESWC in different development stages of soybean and the classification of drought grades based on the relative soil moisture index were investigated.Meanwhile,the effects of ESWC on soybean yield components in different development stages were analyzed.The results show that the average ESWC in different development stages of soybean is between 14 mm and 18 mm and there are 82 times of droughts including 77 times of mild droughts and 5 times of moderate droughts and there is not severe and special drought from 1994 to 2017.More specifically,the drought more frequently occurs during the period of flowering to pod setting and the period of pod setting to filling and its amount is decreasing year by year in the studied time.The meteorological yield of soybean and the kernels and grain weight per plant have little correlation with the ESWCs at different soil depths,while the hundred-grain weight has a significant correlation with the ESWC at the depth of 20-50 cm from three-leaf to flowering stage and at the depth of 0-20 cm from pod setting to filling stage.In addition,the stem weight indicates a positive correlation with the ESWC at the depth of 30-50 cm from sowing to seedling stage.The higher the ESWC is,especially in deep soil in a certain range from sowing to flowering,the more pods per plant are.Besides,there is a significant correlation between the percentage of empty chaff pods and the ESWCs at the depth of 0-20 cm and 30-40 cm from sowing to seedling and that at the depth of 30-40 cm from seeding and three-leaf stage.