根区水肥空间耦合对冬小麦生长及产量的影响

Effects of water-fertilizer spatial coupling in root zone on winter wheat growth and yield

利用管栽试验研究了根区不同湿润方式(整体湿润、上湿下干、上干下湿)、施肥方式(整体施肥、上层施肥、下层施肥)及其耦合对冬小麦不同生育期生长及产量的影响.结果表明:下层施肥方式显著降低了分蘖期冬小麦的株高和叶面积,而不同湿润方式对分蘖期株高和叶面积的影响不显著,拔节期水肥同区方式的株高大于水肥异区方式,表现出协同耦合效应.上干下湿方式和下层施肥方式显著降低了根系干物质量、地上部干物质量和总干物质量,上层施肥方式有利于增加冬小麦生物量,而上湿下干方式与施肥处理对地上部干物质量和总干物质量的耦合效应明显.水肥同区处理的根冠比高于水肥异区处理;上干下湿方式的水分利用效率显著高于整体湿润和上湿下干方式,水肥同区处理的水分利用效率高于水肥异区处理,但下层施肥方式的水分利用效率较低.与上干下湿方式相比,上湿下干和整体湿润方式的冬小麦单穗粒数分别增加了41.7%和61.9%,上层施肥和整体施肥方式的单穗粒数高于下层施肥方式,上湿下干方式与施肥处理对小麦产量及产量构成因素(除千粒重外)的水肥耦合效应明显.不同水肥处理主要通过影响单穗粒数来影响冬小麦产量.

A soil column experiment was conducted to study the winter wheat growth and yield under effects of different soil wetting （ overall wetting,upper part wetting,and lower part wetting） and fertilization （ overall fertilization,upper part fertilization,and lower part fertilization） . The plant height and leaf area at tillering stage decreased significantly under lower part fertilization,compared with those under upper part and overall soil fertilization,but had no significant differences under different soil wetting. At jointing stage,the plant height was higher when the soil wetting and fertilization were at same location than at different location,manifesting a synergistic coupling effect of water and fertilizer. Lower part soil wetting and lower part fertilization decreased the root-,shoot-, and total dry biomass significantly,upper part fertilization benefited the biomass accumulation of winter wheat,and upper part soil wetting combined with upper part fertilization had an obvious coupling effect on the shoot- and total dry biomass. Soil wetting and fertilization at same location induced a higher ratio of root to shoot,compared with soil wetting and fertilization at different location,and lower part soil wetting resulted in the maximum water use efficiency （ WUE） ,compared with upper part and overall soil wetting. A higher WUE was observed in the soil wetting and fertilization at same location than at different location,but a lower WUE was induced by lower part fertilization. The grain number per spike under upper part and overall soil wetting was increased by 41. 7% and 61. 9% ,respectively,compared with that under lower part soil wetting,and this yield component under upper part and overall soil fertilization was also higher,compared with that under lower part fertilization. Upper part soil wetting and fertilization had an obvious coupling effect of water-fertilizer on the yield and yield components （ except for 1000-grain mass） . Different soil wetting and fertilization affected the yield mainly through affecting the grain number per spike.