水分亏缺和施氮对冬小麦生长及氮素吸收的影响

Effects of water deficit and nitrogen fertilization on winter wheat growth and nitrogen uptake

利用管栽试验研究了不同生育期,水分亏缺和施氮对冬小麦生长及氮素吸收的影响.结果表明:任何生育期水分亏缺都会影响冬小麦的株高、叶面积、干物质累积及对氮素的吸收.冬小麦对水分亏缺的敏感期为拔节期,其次为开花期、灌浆期和苗期.苗期干旱后复水对后期生长有显著的补偿效应,开花期适度干旱后复水对生物量形成和氮素吸收有一定的补偿作用,拔节期干旱对小麦的生长影响明显.相同氮肥处理下,与不亏水处理比较,苗期水分亏缺、拔节期水分亏缺、开花期水分亏缺、灌浆期水分亏缺的根系氮素积累量分别平均降低25.82%、55.68%、46.14%和16.34%,地上部氮素积累量分别平均降低33.37%、51.71%、27.01%和2.60%.在相同水分处理下冬小麦含氮量、累积吸收氮量都表现为高氮处理(0.3gN·kg-1FM)>中氮处理(0.2gN·kg-1FM)>低氮处理(0.1gN·kg-1FM).水分逆境条件下施用氮肥对冬小麦植株生长和干物质累积及氮吸收具有明显的调节效应.

Winter wheat plants were cultured in vitro tubes to study their growth and nitrogen uptake under effects of water deficit at different growth stages and nitrogen fertilization. Water deficit at any growth stages could obviously affect the plant height, leaf area, dry matter accumulation, and nitrogen uptake. Jointing stage was the most sensitive stage of winter wheat growth to water deficit, followed by flowering stage, grain-filling stage, and seedling stages. Rewatering after the water deficit at seedling stage had a significant compensation effect on winter wheat growth, and definite compensation effect was observed on the biomass accumulation and nitrogen absorption when rewatering was made after the water deficit at flowering stage. Under the same nitrogen fertilization levels, the nitrogen accumulation in root with water deficit at seedling, jointing, flowering, and grain-filling stages was reduced by 25.82% , 55.68% , 46. 14% , and 16. 34% , and the nitrogen accumulation in aboveground part was reduced by 33.37% , 51.71% , 27.01% , and 2.60% , respectively, compared with no water deficit. Under the same water deficit stages, the nitrogen content and accumulation of winter wheat decreased with decreasing nitrogen fertilization level, i. e. , 0. 3 g N·kg^-1 FM 〉0. 2 g N·kg^-1 FM 〉0. 1 g N·kg^-1 FM. Nitrogen fertilization had obvious regulation effect on winter wheat plant growth, dry matter accumulation, and nitrogen uptake under water stress.