多因素控制下渭北旱地小麦产量寻优的研究

Research on best factor combination for wheat yield on dry-land of Weibei

在陕西渭北旱塬进行了连续三年定点小麦田间试验，通过栽培模式、氮肥水平、种植密度三因素的不同处理，研究多因素小麦栽培优化组合。结果表明：采用垄沟、覆膜、秸杆疆盖栽培模式对小麦穗数不产生影响；施用氮肥能极显著地影响小麦穗数，在施纯氮0～240kg／hm^2范围内，每增减纯氮1kg，增减穗数4288；增加播量，极明显地提高小麦穗数；不同的栽培模式、氮肥用量和小麦种植密度对小麦的穗粒数不产生影响；覆膜栽培与垄沟栽培之间千粒重差异显著，种植密度对小麦千粒重在不同的条件下影响明显，覆膜栽培条件下，高氮肥水平，低密度（播种量180kg／hm^2）的千粒重大于高密度（播种量225kg／hm^2），垄沟模式下，高氮水平（施纯氮240kg／hm^2）与中氨水平（施纯氮120kg／hm^2）之间差异不显著，但与不施氮肥相比，千粒重明显提高，秸秆覆盖模式下，高密度（播种量225kg／hm^2）与不施氮、高氮水平组合的平均千粒重最低，两者差异不显著，但与其它各组合差异显著。正常降水年份，旱地小麦采用一定的农业栽培模式，能够显著影响小麦的产量，尤其是覆膜下，产量显著高于对照；降水量多的年份，采用垄沟模式及秸秆疆盖模式对小麦产量甚至产生负效应。施用氮肥对小麦产量有极显著影响，在施纯氮0～240kg／hm^2范围内，每增减纯氮1kg．增减籽粒产量5．7kg；种植密度对小麦籽粒产量与生物产量的影响显著，秸秆覆盖栽培和常规栽培（对照）模式下籽粒产量差异显著，产量排列次序都为高密度（播种量225kg／hm^2）大于低密度（播种量180kg／hm^2），低氮和不施氮时，增加密度，可提高产量。

Field experiments of wheat on Weibei Highland of Shaanxi Province were carried continuously for three years. The treatment factors included cultivation pattern, nitrogenous fertilizer level, and plant density. The results indicated as follows： the application of ditch, plastic film covers, and straw mulch cultivation did not influence the wheat ear number, whereas nitrogenous fertilizer remarkably affected the wheat ear number; within N application rate 0- 240 kg/hm^2, every N increased 4 288 wheat ear number; increasing broadcasts extremely obviously enhanced the wheat ear number; nitrogenous fertilizer amount used and plant density did not influence grain number per ear; weight of a thousand grains was remarkable different between film covering and ditch cultivation, plant density obviously affected the weight of a thousand grains under the different condition; under the plastic film cover cultivation with high nitrogenous fertilizer level, the low density had larger weight of a thousand grains than that under the high density; under the ditch pattern, the weight of a thousand grains between the high nitrogen level（N 240 kg/hm^2） and middle nitrogen level（N 120 kg/hmz） had no remarkable difference, but was increased compared with that without nitrogenous fertilizer; under straw mulch pattern, the weight of a thousand grains by the high-density （seeds 225 kg/hm^2） without nitrogen and with high nitrogen （N 240 kg/hm^2） was the lowest, and had no remarkable differences between them, but had remarkable difference to other combinations; in the normal precipitation years, cultivation patterns could remarkably affect wheat yield on arid land, the wheat yield under plastic film cover is remarkably higher than that of ck; in the precipitation rich years, the ditch pattern and the straw stalk cover pattern even had negative effect on wheat yield; the nitrogenous fertilizer had extremely influence on wheat yield, within 0-240 kg N/hm^2, every kg pure nitrogen could increase 5.7 kg grain yield; the influence of plant density on wheat grain and biological yield was significant, the yield difference between the grass cover cultivation and the conventional cultivation （ck） also was significant; generally the yield under high density （seeds 225 kg/hm^2） was bigger than under low density （seeds 180 kg/hm^2）; under low and no nitrogen application, the wheat yield could be enhanced through increasing plant density.