【作者】 宁东峰；

【导师】 李志杰；

【作者基本信息】 中国农业科学院 ， 植物营养学， 2010， 硕士

【摘要】 本文以黄淮海地区冬小麦为研究对象,以节水灌溉为研究核心,以水肥高效利用为研究目标,在中国农科院陵县试验基地,开展了冬小麦晚播适宜临界期及效应研究,冬小麦节水灌溉模式研究,冬小麦限水灌溉下氮肥用量研究。通过一年的试验研究,主要得出以下结论:(1)四个播期处理冬前积温差异明显,10月10号(D10)冬前积温为581.4℃,10月15号(D15)为501.4℃,10月20号(D20)为406.3℃,10月25号(D25)为329.8℃。根据冬前积温划分,D10处理为中晚播小麦、D15为晚播小麦,D20、D25为过晚播小麦。冬前积温差异对冬前苗情产生显著影响。D10、D15处理小麦冬前达到4～5个叶龄,产生3～4个分蘖,3～4条次生根,麦苗壮而不旺,小麦安全越冬。D20、D25处理小麦冬前无分蘖和次生根产生,麦苗弱小。D10、D15晚播小麦群体穗数、产量、植株吸氮量都显著高于过晚播D20、D25处理。D20、D25处理小麦土壤水消耗量显著低于D10、D15处理,但水分利用效率、氮素吸收效率、氮素生产效率也显著低于D10、D15处理。所以,适宜晚播是应对气候干暖化,提高抵御冻害和抗旱能力最佳播种模式。根据陵县05～08气象数据统计,10月10号至15号冬前积温在450～580℃,是该地区常规年份适宜晚播期,以7.50×106/hm2群体穗数为参照,基本苗宜控制在2.55～3.00×106/hm2。(2)小麦播种至拔节期,以消耗0～40cm土层水分为主。在期间42mm降水条件下,不灌冻水处理在拔节前0～40cm土层达到重度水分亏缺,灌冻水处理只为轻度水分亏缺。前期重度水分亏缺对后期根系吸收深层水分和旗叶光合速率产生显著抑制作用。轻度水分亏缺条件下,气孔导度下降,蒸腾速率随之降低,而光合速率可得以维持,单叶水分利用效率提高。随灌水次数增加,总耗水量加大,土壤水和降水的消耗比例显著降低。拔节期灌水显著提高氮素的吸收效率和生产利用效率,在此基础上增加冻水、开花水、灌浆水等效果不显著。后期增加灌水次数会显著加大硝态氮的淋洗损失。产量、WUE与耗水量均呈二次曲线关系,但变化趋势不一致,两曲线在耗水量360mm处相交,为两者理论上最佳结合点。本试验中冻水+拔节水处理产量最高,达到7753kg/hm2,相对不灌水处理提高40.2%,WUE值为1.9kg/m3,与不灌水处理差异不显著,为本试验的最优节水高产灌溉方案。(3)施用氮肥显著增加小麦穗数和穗粒数,对千粒重无显著影响。作物产量、吸氮量与施氮量均呈抛物线关系,当施氮量超过240kg/hm2,产量、吸氮量随施氮量增加反而略有降低。小麦起身期后,0～100cm土层都有硝态氮分布,相同处理不同土层,含量随土层深度增加而减少;不同处理相同土层,含量随施氮量增加而增加。土壤硝态氮积累量随生育期推进而降低,N0和N120处理分别在拔节期和开花期后表现出氮素亏缺。成熟期,土壤表观盈余以残留为主,表观损失量占小部分。氮肥表观利用率、农学利用率随施氮量增加呈降低趋势,而氮素残留率随施氮量增加呈增加趋势。在本试验条件下,施氮量在180～220kg/hm2水平可以实现产量、氮素表观利用率、氮素残留率的较好结合,为限水灌溉下兼顾经济效益与环境效益的适宜施氮量。综合以上研究,根据陵县05～08气象数据统计,10月10号至15号冬前积温在450～580℃,是该地区常规年份适宜晚播期,以7.50×106/hm2群体穗数为参照,基本苗宜控制在2.55～3.0×106 /hm2。节水灌溉浇1水应把有限的水资源优先用于灌溉效益最大的拔节～挑旗阶段,浇2水有冻水+拔节水,起身水+孕穗水,拔节水+开花水、拔节水+灌浆水四种方案,具体应根据当年的降水分布确定最优灌溉时间。在限水灌溉条件下,施氮量在180～220kg/hm2为兼顾经济效益和环境效益的适宜施氮量。更多还原

【Abstract】 Field experiments were conducted during 2008～2009 in lingxian experimental station of Chinese academy of agricultural science,(located in Huang-Huai-Hai area of north China).The objective of this research was to find integrated cultivation techniques in winter wheat with high yield and high resources utilization efficiency, water-saving is the concentration. It included three experiments. The first experiment was about critical period of delayedsowing in winter wheat responsing climate chang and water-saving demand. The second experiment was about water-saving scheme in winter wheat. The third research was about N application rates under water-saving irrigation in winter wheat. Through one year study got these conclusions:(1)In 2008, accumulated temperature before winter of october 10 treatment (D10)was 581.4℃, october 15 (D15)was 501.4℃, october 20(D20 )was 406.3℃, october 25(D25) was 329.8. D10 treatment belonged to middle-delayedsowing wheat, D15 treatment belonged to delayedsowing wheat, D20 and D25 treatments belonged to exceedingly delayedsowing wheat .This difference had signifigant effects on wheat seedling before winter. Wheat of D10 and D15 treatments formed 4～5 leaf ages, 3～4 tillerings, 3～4 secondary roots before winter. Plant and population were srong and proper , this was the base of safely overwintering and high yielding. Wheat of D20 and D25 treatments had zero tillering and secondary root before winter, plant and population were small and weak. Colony spike numbers、grain yield、nitrogen uptake of D10 and D15 treatments were signifigant higher than D20 and D25 treatments. Soil water consumption of D10 and D15treatments were higher than D20 and D25 treatments, but water use efficiency、N uptake efficiency、N production efficiency of D10 and D15treatments were also higher than D20 and D25 treatments. Proper delayedsowing is optimum sowing model in order to cope with climate change、defense freeze injury and resist drought. According to statistics of Lingxian temperature date, accumulated temperature before winter from october 10 to october 15 were between 450～580℃. So we infer that this period is feasible delayedsowing days in general years. Refering to colony spike numbers 7.50×106/ha, basic seeding numbers shoud be control in 2.55～3.00×106 /ha..(2)During sowing to jointing stages, under 42 mm precipitation condition, available water content of 0～40cm soil layer decreased significantly, 0～40cm soil layer of all treatments (except wintering and jointing treatment) got serious water stress, while wintering and jointing treatment only got light water stress. Serious water stress before jointing stages remarkably affected root to absorb water in deep soil layer and photosynthetic rate of wheat in late stages. With increase of irrigation times, total water consumption increased, but the percentage of soil -water consumption and precipitation consumption decreased. Under light water stress condition, stomatal- conductivity decreased, consequently reduced transpiration rate, but preserved the net photosynthetic rate, so WUE of leaves increased. Irrigation at jointing stage significantly increased N uptake efficiency and N production efficiency, adding other irrigations had no significant elevated effect, moreover, increasing irrigation in later stages raised soil NO-3_N lost probability.There were conic relationships among grain yield, WUE and water consumption, but the two conics did not have the same variation tendency. A point of intersection at 360mm water consumption was found , which indicated the best combining site of grain yield and WUE. Grain yield of wintering and jointing treatment was 7753kg/ha, which increasing 40.2% compared to no irrigation treatment. WUE of wintering and jointing treatment was 1.9kg /m3, which did not differ with no irrigation treatment. So wintering and jointing treatment was the best water-saving and high yielding treatment this year.(3)N application significantly increased spike numbers and per spike grains of winter wheat, meanwhile the effect on thousand-grain-weight was not significant. Relationships among grain yield、N uptake and N application rates were parabolics, when N application rates exceeded 240 kg/ha, grain yield and N uptake reduced with increase of N application rates. Soil NO-3_N was founded in 0～20, 20～40, 40～60, 60～80, 80～100 cm soil layers after raising stage of winter wheat. Soil NO-3_N contents decreased with increase of soil layer depth for the same treatment; different treatments in the same layer, NO-3_N contents increased with increase of N application rates. Soil NO-3_N accumulations decreased with winter wheat growth going forward. N0 and N120 treatments appeared NO-3_N efficiency, respectively after jointing stage and anthesis stage. In harvest stage, residual N in 100 cm soil layer was the main part of surplus N, lost N accounted for little percentage. With increase of N application rates, N utilization efficiency and Nagronomy efficiency appeared downtrend, while N residue efficiency appeared uptrend. Under this experiment condition, N application rates from 180 to 220kg/ha can have good combinations of grain yield、N utilization efficiency and N residue efficiency. So 180～220 kg/ha were ideal N rates levels considering both economic benefit and environmental benefit.In conclusion, according to 05～08 Ling Xian weather data statistics, If seeding date is in october 10 to 15 , accumulated temerature before winter was between 450～580℃, these days are proper seeding date in Huang-Huai-Hai area, and referring to 7.50×106/ha spikes, basic seeding numbers shoud be control in control in 2.55～3.00×106 /ha. If carry out one irrigation, irrigation should be arranged at water critical period, that is jointing～flagging stage. If carry out twice irrigations, there are four combinations, irrigation at wintering and jointing, irrigation at raising and booting, irrigation at jointing and anthesis, irrigation at jointing and grouting. According to precipitation choose the optimum irrigation times. Under water-saving irrigation, N application rates from 180 to 220kg/ha can have good combinations of grain yield、N utilization efficiency and N residue efficiency. So180～220 kg/ha is ideal N rates levels considering both economic benefit and environmental benefit.更多还原