【摘要】 在黄土高原南部旱地土壤上进行大田试验,设置常规、补灌、覆草、覆膜、垄沟5种栽培模式种植冬小麦,研究了不同栽培模式对冬小麦产量和干物质累积、转运及氮素吸收转运的影响。结果表明,地膜覆盖栽培能显著提高拔节期小麦分蘖数,促进小麦生长过程中干物质的累积及其向穗部的转移,从而提高小麦生物量和籽粒产量。同时,地膜覆盖也可以提高植株对氮素的吸收,促进生长后期茎叶氮素向穗部的转移,转移量占穗吸氮量增加值的86.3%。相反,常规、覆草、补灌和垄沟栽培模式干物质累积量和氮素吸收量均明显较低,生长后期穗部的干物质主要来源于抽穗后茎叶新形成的碳水化合物,茎叶氮素的转移对穗部氮素累积所起作用亦明显低于地膜覆盖模式。更多还原

【Abstract】 A field experiment was conducted to study the effects of cultivation types on grain yield,dry matter accumulation and translocation,nitrogen uptake and remobilization of winter wheat at 240 kg N·hm-2 on dryland soil in southern region of the Loess Plateau from 2002 to 2003.Five treatments,plastic film mulching,straw mulching,supplemental irrigation,ridge-furrow cultivation and control(no mulching on soil surface and no supplemental irrigation),were designed.The results showed that plastic film mulching could significantly increase tillers at jointing stage,enhance dry matter accumulation in the aboveground part during the whole growth stage,and promote the contribution of pre-heading assimilation from vegetative parts(stem and leaf) to ears,therefore improve the biomass and grain yield.At the same time,winter wheat could uptake more N under plastic film mulching,and N translocation from stem and leaf to ears was enhanced after heading.Nitrogen from vegetative parts could account for 86.3% of that accumulated in the ears.On the contrary,dry matter accumulation and N uptake were significantly lowered under other four cultivation types.Furthermore,dry matter accumulated in ears was mainly from the carbohydrate assimilated in the stem and leaf after heading,and N translocated from the vegetative parts played a less important role,compared to the plants grown in the plots with plastic film mulch.更多还原