旱地冬小麦产量、养分利用及土壤硝态氮对长期施用氮磷肥和降水的响应

发布时间：2018-06-26 18:45

  本文选题：冬小麦 + 养分利用　； 参考：《西北农林科技大学》2016年博士论文

【摘要】：化肥在粮食生产中发挥着巨大的作用,化肥的大量施用极大地提高了作物产量和经济效益,是实现增产和农业增收的主要措施。但化肥,特别是氮磷肥的大量投入也带来一系列问题,给生态环境和人类健康带来风险。在黄土高原旱地,水分不足与土壤养分缺乏是限制作物生长的两个主要因素,且水和肥是一对相互影响的因子,肥料效应的发挥受土壤水分的限制。同时考虑水、肥两个因子,充分发挥水肥协同效应,减少资源浪费,降低其带来的环境隐患,是我国旱地农业和土壤肥料学科研究的热点和重要发展方向。因此,探明冬小麦生物量、产量、养分吸收利用和需求及收获期土壤硝态氮残留、夏闲期硝态氮淋溶对不同氮、磷肥用量和降水年型的响应,以结合区域降水制定科学合理的施肥方案为旱地小麦获得高产、培肥土壤、保护生态环境并实现农业可持续发展提供理论指导和科学依据。本研究利用黄土高原南部旱作冬小麦不同氮磷肥用量的10年长期定位试验,采用完全随机区组试验设计,包括5个氮水平(0,80,160,240和320 kg N ha-1)和5个磷水平(0,50,100,150和200 kg P2O5 ha-1),重复4次。于2010-2014年进行田间土壤和植物取样与测定,并结合之前的相关测定结果和10年的降水资料,分析研究了长期不同氮磷肥用量和降水对冬小麦生物量、产量、养分吸收利用、养分需求、土壤硝态氮残留及夏闲期淋溶的影响,获得的主要研究结果如下:(1)通过10年田间定位试验,结合多年降水,明确了冬小麦生物量、产量、养分吸收利用及需求在不同降水条件下对氮肥的响应。结果表明:冬小麦生物量、产量、籽粒含氮量及百公斤籽粒需氮量与施氮量均呈显著的抛物线关系;籽粒含磷量、百公斤籽粒需磷量与施氮量呈极显著的负相关关系;而籽粒含钾量、百公斤籽粒需钾量与施氮量呈显著的线性或抛物线关系。氮肥偏生产力、累积利用率及氮素生理效率随施氮量增加均显著降低;磷素生理效率随施氮量增加而增加;钾素生理效率随施氮量增加先增加而后降低。降水量不同,氮肥肥效不同。年降水量高的年份,形成籽粒产量的需氮量偏低,最高值为3.04 kg 100kg-1;年降水量低的年份,形成籽粒产量的需氮量较高,最高值为3.15 kg 100kg-1。(2)基于收获期土壤硝态氮残留的安全阈值,优化了冬小麦合理施氮量。结果表明:土壤硝态氮残留量与施氮量呈抛物线关系,且随施氮量增加而增加;当季土壤硝态氮残留主要发生在0-100 cm土层,施氮0,80,160,240和320 kg N ha-1时,年增加量分别为0,4.4,8.8,13.2和17.7 kg N ha-1;来源于肥料的当季硝态氮残留随施氮量增加线性增加,且施氮80,160,240和320 kg N ha-1时,年增加量分别为0.02,7.1,14.1和21.1kgnha-1。硝态氮残留量,当季和来源于肥料的当季残留量及当季残留深度均受降水影响,但与降水关系不显著。本研究发现,降水每年可使硝态氮向土壤深层移动13.3~33.3cm。考虑到土壤硝态氮残留阈值并保证较高的小麦产量,推荐施氮量可降低到66~92kgnha-1,此时,冬小麦产量为4487~5000kgha-1,0-100cm土层硝态氮残留量可降低至55~67kgnha-1。(3)选取三个典型的降水年份,分析了夏闲期麦田土壤硝态氮淋失及累积,探明了影响硝态氮淋失的主要因子和土壤水氮运移的关系。结果表明:硝态氮淋失主要发生在表层40cm,淋失量受施氮量和降水强度的影响。在2011年湿润年,施氮0~320kgnha-1时,淋失量为14.6~250kgnha-1;在2012年平水年,仅施氮240和320kgnha-1发生淋失,分别为47.6和53.8kgnha-1;而在2013年干旱年没有发生硝态氮淋失,反而发生累积。表层淋失的硝态氮在深层40-300cm发生累积,累积量随施氮量增加而增加,施氮0~320kgnha-1时,深层累积量在2011年为37.7~387kgnha-1;2012年为53.9~193kgnha-1;而在2013年没有发生深层累积。硝态氮在土壤中的向下移动滞后于土壤水分,1mm的夏闲期降水可使硝态氮在土壤剖面向下移动1.6~3.6mm。从调控土壤硝态氮淋溶的角度考虑,当地施氮量不应超过160kgnha-1。(4)通过10年田间定位试验,结合多年降水,明确了冬小麦生物量、产量、养分吸收利用及需求在不同降水条件下对磷肥的响应。结果表明:冬小麦生物量、产量、籽粒氮磷含量与施磷量均呈显著的抛物线关系;而籽粒含钾量与施磷量没有显著相关性。冬小麦磷肥偏生产力随施磷量增加显著降低;磷肥累积利用率在100kgp2o5ha-1时最高,施磷量再增加,其累积利用率降低。施磷量增加,冬小麦氮素生理效率增加,而磷素生理效率降低,钾素生理效率先增加后降低。冬小麦百公斤籽粒需氮量、需磷量与施磷量呈显著的抛物线关系;而需钾量随施磷量增加线性降低。不同降水条件下,磷肥肥效不同。年降水量高的年份,形成籽粒产量需磷量偏低,最高值为0.31kg100kg-1;年降水量低的年份,形成籽粒产量需磷量较高,最高值为0.33kg100kg-1。(5)基于收获期合理的土壤硝态氮残留量,优化了冬小麦合理施磷量。结果表明:施磷量增加,土壤硝态氮残留量先降低而后增加,在施磷0,50,100,150和200kgp2o5ha-1时,当季硝态氮残留量分别为82.1,51.3,46.6,49.8和89.4kgnha-1,且主要分布在0-100cm土层。土壤0-300cm、0-100cm、当季硝态氮残留量随试验年份的增加而增加,其与施磷量、时间的关系均可用二元二次方程描述。由此可见,优化磷肥用量可有效调控土壤硝态氮残留,施磷104~168kgp2o5ha-1时可显著降低土壤硝态氮残留,同时产量保持在5500~5741kgha-1较高水平。(6)选取三个典型的降水年份,分析了夏闲期麦田土壤硝态氮淋失及累积,探明了施磷量对硝态氮淋失的影响。结果表明:冬小麦夏闲期硝态氮淋失主要发生在表层40cm,淋失量受施磷量和降水影响。在2011年湿润年,与其他施磷处理比较,100kgp2o5ha-1显著降低了硝态氮淋失,淋失量为88.2kgnha-1;在2012年平水年和2013年干旱年没有发生硝态氮淋失。土壤表层淋失的硝态氮在深层40-300 cm发生累积,且施用磷肥可降低其累积量,施磷由100 kg P2O5 ha-1增加到200 kg P2O5 ha-1时,深层硝态氮累积量在2011年由196降低到134 kg N ha-1;在2012年由134 kg N ha-1降低到55.9 kg N ha-1;而在2013年没有发生累积。为了有效地防止硝态氮淋失,阻止其在深层的累积,当地磷肥施用量不应低于100 kg P2O5 ha-1。综上所述,在黄土高原旱地农业生产中,根据不同降水条件下作物养分需求规律,结合调控收获期土壤硝态氮残留与夏闲期淋溶,制定合理的氮磷肥用量,对作物增产、土壤培肥和环境友好有重要意义。
[Abstract]:Chemical fertilizer plays a great role in grain production. A large amount of fertilizer application has greatly improved crop yield and economic benefit. It is the main measure to increase production and increase agricultural income. But chemical fertilizer, especially nitrogen and phosphate fertilizer, also brings a series of problems, bringing risks to the ecological environment and human health. In the Loess Plateau dry land, water Water and fertilizer are two main factors restricting crop growth, and water and fertilizer are one of the factors that affect the growth of crops. The effect of fertilizer is restricted by soil moisture. At the same time, two factors of water and fertilizer are considered, and the synergistic effect of water and fertilizer is given full play to reduce the waste of resources and reduce the environmental hidden dangers. Therefore, the response of winter wheat biomass, yield, nutrient absorption, utilization and demand, and the residue of nitrate nitrogen in the harvest period, the response of nitrate leaching to different nitrogen, the amount of phosphate fertilizer and the annual precipitation type in the summer leisure period, and the scientific and rational fertilization scheme for dry land wheat by combining the precipitation with the region area The theoretical guidance and scientific basis for obtaining high yield, fertilizing soil, protecting the soil, protecting the ecological environment and realizing the sustainable development of agriculture were provided. The 10 year long-term location test of different nitrogen and phosphate fertilizer for dry winter wheat in the southern part of the Loess Plateau was designed by the complete random zone test, including 5 nitrogen levels (0,80160240 and 320 kg N HA-1) and 5 Phosphorus levels (0,50100150 and 200 kg P2O5 HA-1) were repeated for 4 times. Soil and plant samples were sampled and measured in 2010-2014 years. Combined with previous correlation determination results and 10 year precipitation data, the biomass, yield, nutrient uptake and utilization, nutrient requirements and nitrate nitrogen of winter wheat were analyzed. The main results were as follows: (1) through the 10 year field location test and combined with years of precipitation, the response of winter wheat biomass, yield, nutrient absorption, utilization and demand to nitrogen fertilizer under different precipitation conditions was clarified. The results showed that the biomass, yield, nitrogen content and 100 kg grain of winter wheat were found. There is a significant parabolic relationship between the amount of nitrogen and the amount of nitrogen applied, and the grain phosphorus content, the amount of phosphorus and the amount of nitrogen have a very significant negative correlation, while the grain potassium content, the quantity of potassium and the amount of nitrogen are linear or parabolic. The partial productivity, cumulative utilization and nitrogen physiological efficiency of nitrogen fertilizer increase with the amount of nitrogen application. The physiological efficiency of phosphorus increased with the increase of nitrogen application, and the physiological efficiency of potassium increased first and then decreased with the increase of nitrogen application. The amount of nitrogen fertilizer was different. The nitrogen content of grain yield was low and the highest value was 3.04 kg 100kg-1 in the year of high precipitation. The nitrogen content was higher, the highest value was 3.15 kg 100kg-1. (2) based on the safety threshold of the residue of nitrate nitrogen in the harvest period. The optimum nitrogen application rate of winter wheat was optimized. The results showed that the residue of nitrate nitrogen in soil was parabolic relation with the amount of nitrogen application, and increased with the increase of nitrogen application; the residue of nitrate nitrogen in the soil mainly occurred in the 0-100 cm soil layer and the nitrogen application was 0,80,16 in the season. The annual increase of 0240 and 320 kg N HA-1, respectively, is 0,4.4,8.8,13.2 and 17.7 kg N HA-1, and the residue of nitrate nitrogen from fertilizer is linearly increased with the increase of nitrogen application, and the annual increment is 0.02,7.1,14.1 and 21.1kgnha-1. nitrate residues when applying nitrogen 80160240 and 320 kg N HA-1. The residual depth of the season was affected by precipitation, but the relationship with precipitation was not significant. In this study, it was found that precipitation could make nitrate nitrogen move to the deep soil 13.3~33.3cm. every year, considering the residue threshold of soil nitrate nitrogen and ensuring higher wheat yield, and the recommended nitrogen rate could be reduced to 66~ 92kgnha-1, at this time, the yield of winter wheat was 4487~5000kgha-1,0-100cm The residue of nitrate nitrogen can be reduced to 55~67kgnha-1. (3) to select three typical precipitation years. The leaching and accumulation of nitrate nitrogen in the soil of wheat field in the summer leisure period were analyzed. The main factors affecting the leaching of nitrate nitrogen and the relationship between soil water and nitrogen transport were explored. The results showed that the leaching loss of nitrate nitrogen mainly occurred in the surface 40cm, and the leaching amount was affected by the amount of nitrogen and reduced. The effect of water intensity. In the year of wetting in 2011, the amount of leaching was 14.6~250kgnha-1 when nitrogen application was 0~320kgnha-1; in 2012, only 240 and 320kgnha-1 were lost, respectively, 47.6 and 53.8kgnha-1, while in 2013, no nitrate leaching was found in dry year, and the accumulated nitrate nitrogen accumulated in the deep 40-300cm. The accumulation of nitrogen increased with the increase of nitrogen application, and the deep accumulation of nitrogen in 0~320kgnha-1 was 37.7~387kgnha-1 in 2011 and 53.9~193kgnha-1 in 2012, but no deep accumulation in 2013. The downward movement of nitrate nitrogen in soil lagged behind the soil moisture, and the reduction of water in the summer leisure period of 1mm could cause the nitrate nitrogen to move down to 1.6~3.6mm. in the soil profile. From the angle of controlling soil nitrate leaching, local nitrogen application should not exceed 160kgnha-1. (4) through 10 year field location test and combined with years of precipitation, the response of winter wheat biomass, yield, nutrient absorption and utilization and demand to phosphate fertilizer under different precipitation conditions was clarified. The results showed that the biomass, yield and nitrogen and phosphorus content of winter wheat were found. There was a significant parabolic relationship with the amount of phosphorus application, but there was no significant correlation between the amount of potassium and the amount of phosphorus applied in the grain. The phosphorus fertilizer partial productivity of winter wheat decreased significantly with the increase of the amount of phosphorus; the cumulative utilization rate of phosphate fertilizer was the highest, the amount of phosphorus increased, and the cumulative utilization rate decreased. The nitrogen application efficiency of winter wheat increased, and the nitrogen application rate of winter wheat increased. The physiological efficiency of phosphorus decreased, and the physiological efficiency of potassium was increased first and then decreased. There was a significant parabolic relationship between the amount of nitrogen for 100 kg of winter wheat and the amount of phosphorus required and the amount of phosphorus, while the amount of potassium needed linearly decreased with the increase of the amount of phosphorus. In the years of low annual precipitation, the grain yield was higher and the highest value was 0.33kg100kg-1. (5) based on the reasonable soil nitrate nitrogen residue in the harvest period. The reasonable amount of phosphorus application in winter wheat was optimized. The results showed that the amount of phosphorus in the soil was increased and the residue of nitrate nitrogen in the soil decreased first and then increased, and the amount of 0,50100150 and 200kgp2o5ha- in the soil was 0,50100150 and 200kgp2o5ha-. At 1, the residual amount of nitrate nitrogen in the season was 82.1,51.3,46.6,49.8 and 89.4kgnha-1, respectively, and mainly distributed in the 0-100cm soil layer. The soil 0-300cm, 0-100cm, the residue of nitrate nitrogen increased with the increase of the experimental year, and the relationship with the amount of phosphorus and the time could be described by two yuan two times equation. Thus, the optimization of the amount of phosphate fertilizer can effectively control the soil. The residue of soil nitrate nitrogen and phosphorus 104~168kgp2o5ha-1 could significantly reduce the residue of nitrate nitrogen in soil, and the yield remained at a high level of 5500~5741kgha-1. (6) three typical precipitation years were selected to analyze the leaching and accumulation of nitrate nitrogen in the soil of wheat field during the summer leisure period, and the effect of phosphorus application on nitrate leaching was explored. The leaching loss of nitrate mainly occurs in the surface 40cm, and the leaching loss is affected by the amount of phosphorus and precipitation. In 2011, 100kgp2o5ha-1 significantly reduced the nitrate leaching loss and the leaching amount of 88.2kgnha-1, compared with other phosphorus application treatments. In the 2012 and 2013 dry years, no nitrite nitrogen was lost. The nitrate nitrogen in the soil surface was deep. The accumulation of layer 40-300 cm, and the application of phosphate fertilizer to reduce its accumulation and increase the amount of phosphorus from 100 kg P2O5 HA-1 to 200 kg P2O5 HA-1, the accumulation of deep nitrate nitrogen decreased from 196 to 134 kg N HA-1 in 2011; in 2012, it was reduced to 55.9 from 134 kg N, but no accumulation in 2013. In order to effectively prevent nitrate leaching, In order to prevent its deep accumulation, the application of local phosphate fertilizer should not be lower than 100 kg P2O5 ha-1.. In the dryland agricultural production of the Loess Plateau, according to the law of nutrient requirement under different precipitation conditions, the amount of nitrogen and phosphorus fertilizer is determined, and the crop yield and soil culture are increased by combining the regulation of the soil nitrate nitrogen residue and the summer idle period in the harvest period. Fertilizer and environmental friendliness are of great significance.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S512.11
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本文编号：2071045