旱作条件下氮肥减施对水稻产量及氮肥偏生产力的影响

Effects of nitrogen fertilizer reduction on rice yield and nitrogen partial factor productivity under dry farming conditions

【目的】研究旱作条件下减量施用氮肥对水稻营养元素含量以及氮肥偏生产力的影响。【方法】以美香粘为材料进行大田试验,设置5个处理:常规淹水施氮(216 kg/hm^(2),CK)、旱作施氮(216 kg/hm^(2),H_(0))、旱作减氮10%(194.4 kg/hm^(2),H_(10))和旱作减氮20%(172.8 kg/hm^(2),H_(20))、旱作减氮40%(129.6 kg/hm^(2),H_(40)),研究不同水分条件和氮肥减施对稻田土壤基础养分、水稻生物量、含氮量以及产量和氮肥偏生产力的影响。【结果】与传统淹水栽培相比,水稻旱作显著提高了土壤有机质含量,显著降低了土壤pH值和速效磷含量,其它养分含量均无显著变化。旱作降低了水稻根、茎、叶、穗生物量、总氮含量以及氮肥偏生产力,水稻单位面积株数、千粒重、产量在旱作处理下无明显变化。在旱作条件下减施氮肥,土壤养分状况变化各异,与旱作和传统淹水栽培相比变化较小。水稻根、茎、叶、穗生物量和含氮量随着氮肥减施程度的增加下降,穗生物量和氮含量在H_(40)处理下相比H_(0)处理显著升高。氮肥偏生产力随着氮肥减施程度增加而提高,在H_(40)时达到最高。与H_(0)相比,H_(10)、H_(20)的产量降低幅度不显著,H_(40)降低幅度大于H_(10)和H_(20),但其产量与H_(0)差异不显著。【结论】在旱作条件下氮肥减施40%,可在产量不显著降低的同时却显著提高肥料生产力。

【Objective】To explore the effects of reducing nitrogen application on nutrient content and nitrogen partial factor productivity of rice under dry farming conditions.【Methods】A field experiment was conducted with Meixiangnian as the material.Five treatments were set up:conventional flooding nitrogen application(216 kg/hm^(2),CK),dry farming nitrogen application(216 kg/hm^(2),H_(0)),dry farming nitrogen reduction 10%(194.4 kg/hm^(2),H_(10)),dry farming nitrogen reduction 20%(172.8 kg/hm^(2),H_(20)),dry farming nitrogen reduction 40%(129.6 kg/hm^(2),H_(40)).The effects of different water conditions and nitrogen fertilizer reduction on soil basic nutrients,rice biomass,nitrogen content,yield and partial factor productivity of nitrogen fertilizer in paddy field were studied.【Results】The results showed that compared with the traditional flooding cultivation,rice dry farming significantly increased soil organic matter content,significantly reduced soil pH value and available phosphorus content,and other nutrient contents did not change significantly.Dry farming reduced the biomass of rice roots,stems,leaves,panicles,total nitrogen content and partial factor productivity of nitrogen fertilizer.There was no significant change in the number of plants per unit area,1000-grain weight and yield of rice under dry farming.Under the condition of reducing nitrogen fertilizer in dry farming,the change of soil nutrient status was different,and the change was slighter than that of dry farming and traditional flooding cultivation.The biomass and nitrogen content of roots,stems,leaves and panicles of rice decreased with the increase of nitrogen fertilizer reduction,and the biomass and nitrogen content of panicles increased significantly under H_(40)treatment compared with H_(0)treatment.The partial factor productivity of nitrogen fertilizer increased with the increase of nitrogen fertilizer reduction,and reached the highest at H_(40).Compared with H_(0),the yield of H_(10)and H_(20)did not decrease significantly,and the decrease of H_(40)was greater than those of H_(10)and H_(20),but the yield was not significantly different from that of H_(0).【Conclusion】Reducing nitrogen fertilizer by 40%under dry farming conditions can significantly increase fertilizer productivity while reducing yield.