粉碎秸秆对冬小麦棵间蒸发的影响

利用秸秆粉碎还田配施化肥(S)和常规施肥(R)2种措施下的大田试验数据,对比分析了2种措施下冬小麦全生育期内棵间蒸发量的变化,棵间蒸发量占蒸发蒸腾量的比例与叶面积指数的关系以及土壤含水量与叶片含水量的关系.结果表明:S,R 2种措施下冬小麦全生育内的棵间蒸发量变化均呈现为"大—小—大—小—大"的"W"型变化规律,相比较R措施,S措施可有效抑制冬小麦棵间蒸发,全生育期内平均抑制蒸发率为9.96%,抑制蒸发率随着生育期变化,呈现出"高—低—高—低"的趋势.同时冬小麦全生育期内S措施下的叶面积指数均高于R措施下的,棵间蒸发量占蒸发蒸腾量的比例均小于R措施下的,可见,S措施有利于叶片生长,并可减小棵间蒸发量占蒸发蒸腾量的比例.冬小麦封行后,通过监测40~60 cm和60~80 cm土层的土壤含水量可反映S,R 2种措施下冬小麦的水分状况.

Effect of straw on soil evaporation of winter wheat

Based on the data of two fertilization treatments in field experiments( matching use of straw and chemical fertilizer( S) and general chemical fertilizer( R)),soil evaporation,the correlation between the proportion of soil evaporation in evapotranspiration and leaf area index,together with the correlation between soil water content and leaf water content throughout the growing period of winter wheat,were compared and analyzed. The results show that,under both treatments of "S"and "R",the soil evaporation of winter wheat during the whole growing period can be indicated with the changing law of "W",i. e. "high- low- high- low- high". Treatment method "S"could restrain the soil evaporation of winter wheat effectively,with averaging inhibition rate of evaporation 9. 96% during the whole growing period,and the inhibition rate of evaporation can be indicated with the changing trend of"high- low- high- low"along with the growing period. Moreover,the leaf area index is much higher,while the proportion of soil evaporation in evapotranspiration is much lower under the treatment method "S"than the treatment method "R". So the treatment method "S"is beneficial to the leaf growth and can help to reduce the proportion of soil evaporation in evapotranspiration. After closing the row of winter wheat,the leaf water status of winter wheat could be understood by monitoring the water content of soil in depth of 40- 60 cm and 60- 80 cm.