摘要
西南冬麦区气候冬干春旱频发、土壤速效磷缺乏,限制冬小麦氮素吸收.本研究探究秋闲期秸秆覆盖与施磷对小麦根系NO3-吸收动力势、氮素吸收利用、叶绿素含量和籽粒产量的影响,以期为小麦高产稳产及养分的高效利用提供理论依据.试验于2020-2022年在四川仁寿进行,采用二因素裂区设计,以秸秆覆盖(SM)和不覆盖(NSM)为主区;3个磷水平0(P0)、75(P75)和120(P120)kg hm-2为裂区.结果表明:秸秆覆盖与施磷显著提高地上部磷素积累量,SM较NSM的小麦根尖NO3-净吸收速率、籽粒氮积累量、氮素转运量、氮素同化量、氮肥偏生产力和籽粒产量分别增加28.2％、8.4％、9.0％、41.9％、23.3％和21.9％.与P0相比,P75和P120增加幅度分别达到35.1％～37.6％、12.6％～19.0％、7.1％～9.3％、35.7％～60.5％、17.6％～23.8％、17.2％～23.6％.与 NSM 相比,SM 的小麦旗叶灌浆期叶绿素含量上升,进而提高籽粒产量.综上所述,秸秆覆盖与施磷可促进小麦根尖NO3-吸收,提高叶绿素含量,从而显著增加花后氮素的吸收及营养器官临时贮存氮素向籽粒的再分配,最终提高籽粒产量.考虑经济效益和产量回报,西南地区小麦高产高效栽培时,推荐采用秋闲期秸秆覆盖配施磷肥75 kg hm-2.
Abstract
Frequent occurrence of drought in winter and spring,combined with soil P deficiency limits nitrogen absorption of winter wheat in southwest wheat.This study aims to investigate the effects of straw mulching from autumn fallow and phosphorus application on root NO3-uptake dynamic potential,nitrogen uptake and utilization,chlorophyll content,and grain yield in wheat,which provides the theoretical basis for high and stable yield of wheat as well as efficient use of nutrients.The experiment was carried out at Renshou in Sichuan province from 2020 to 2022.Two factors spilt-plot design was employed with main plot of maize straw mulching(SM)and no mulching(NSM),and three phosphorus levels 0(P0),75(P75),and 120(P120)kg hm-2were set as sub-plot.Results showed that straw mulching and phosphorus application significantly increased above-ground phosphorus accumulation.Compared with NSM,SM increased root tip NO3 net absorption rate,grain nitrogen accumulation,nitrogen transport,nitrogen assimilation,nitrogen partial productivity and grain yield by 28.2％,8.4％,9.0％,41.9％,23.3％,and 21.9％,respectively.Compared with P0,P75 and P120 increased by 35.1％-37.6％,12.6％-19.0％,7.1％-9.3％,35.7％-60.5％,17.6％-23.8％,17.2％-23.6％,respectively.Compared with NSM,SM increased the content of chlorophyll in flag leaf at grain filling stage,thus improving grain yield.In summary,straw mulching and phosphorus application can promote NO3-absorption in root tip of wheat and chlorophyll content,significantly increase post anthesis nitrogen absorption and reserved N remobilized to developing grains,and ultimately improve grain yield.Considering the economic benefits and yield returns,it is recommended to apply 75 kg hm-2 of phosphate fertilizer with straw mulching for high yield and efficiency cultivation of wheat in southwest China.
维普
万方数据