水氮互作对固定道垄作春小麦生长、产量和水氮利用的影响

发布时间：2018-06-10 14:10

本文选题：固定道垄作沟灌 + 春小麦　；参考：《甘肃农业大学》2016年博士论文

【摘要】：水、氮是制约甘肃河西灌区春小麦生长发育的两个因子。随着农业水资源的日益亏缺和盲目增施氮肥造成面源污染范围的扩大,引进并推广新的节水耕作方式及氮肥减量化是实现小麦高产高效的关键途径,对实现河西灌区农业的可持续发展意义非凡。为此本试验采用固定道垄作栽培,通过2015年春小麦不同水氮处理田间试验,以低水1200(W1)、中水2400(W2)、高水3600 m3·hm-2(W3)为主处理,0(N0)、低氮90(N1)、中氮180(N2)、高氮270 kg·hm-2(N3)为副处理,采用裂区设计,对不同水氮处理下春小麦地上部与根系生长、产量、耗水规律、土壤剖面硝态氮分布、植株氮素积累及转运规律进行了研究,以提高春小麦籽粒产量、水分利用效率和氮肥利用率为目标,确定了水、氮优化投入量,以期实现小麦高产高效。主要研究结果如下:1、水氮互作显著影响小麦生长。适宜的水氮供应量对小麦叶面积指数、籽粒干物质累积及分配存在显著的互作优势,水氮供应量过高或者过低,互作优势减弱。相同施氮量下,干物质、叶绿素SPAD值、光合速率、蒸腾速率及气孔导度随灌水量增加而增大(W3W2W1),旗叶叶片胞间CO2随灌水量增加而增大(W1W2W3),籽粒干物质分配比例随灌水量增加先增加后减小(W2W3W1)。小麦生长对施氮量的响应取决于灌水量。W1处理下,SPAD值随施氮量增加表现为先增大后减小(N2N3N1N0),W2处理下,拔节至灌浆期,SPAD值随施氮量增加先增加后不变(N2、N3N1N0),成熟期SPAD值随施氮量增加而增加(N3N2N1N0);W3处理下,SPAD值随施氮量增加而增大(N3N2N1N0)。W1、W2处理下随施氮量增加光合速率、蒸腾速率及气孔导度均先增大后减小(N2N3N1N0),W3处理下光合速率、蒸腾速率及气孔导度随着施氮量的增加而增加(N3N2N1N0)。各处理旗叶叶片胞间CO2随着施氮量的增加而减少。灌水与施氮均能增加小麦营养器官的干物质,W2N2处理籽粒干物质分配比例最高。2、灌水量及施氮量在一定阈值,水、氮对春小麦根系生长(根干重密度、根长密度、根表面积及根系活力)呈正效应,过高水氮投入量对春小麦根系生长呈报酬递减效应。施氮与灌水显著影响根系生长,表现为灌水氮肥水氮互作。根系特征参数随灌水量的增加先增加后减小(W2W3W1),根系特征参数对氮肥的响应取决于灌水量,W1处理下,根系特征参数N1处理下最大;W2处理下,根系特征参数N2处理下最大;W3处理下,根系特征参数N3处理下最大,适宜增加灌水量与施肥量(W2N2)有益于根系特征参数(根干重密度、根长密度、根表面积及根系活力)的提高;85%以上的小麦根系分布于0~40 cm土层,90%以上的根干重密度与85%以上的根长密度集中在0~40cm土层,W2N2处理能增加40~60cm小麦根系分布比例、提高根系活力、显著提高春小麦根长密度及根表面积边行优势,促进根系对下层及侧向水分和养分的截获和吸收;小麦根长密度垂直分布满足以e为底数的指数函数y=Ae-Bx;通过对小麦根系特征参数的主成分分析表明,以W2N2处理促根效果最好。3、灌水量及施氮量对小麦籽粒氮素积累具有互作效应,适宜的施氮量及灌水量对小麦籽粒氮素积累量呈正效应,过量灌水、施氮对小麦籽粒氮素积累量呈负效应。W2N2处理能够增加小麦花前氮素转运量及花后氮素同化量,提高小麦籽粒氮素的分配比例,进而可以获得较高的籽粒氮素积累量、氮素收获指数及氮肥利用率。春小麦收获土壤硝态氮含量的垂直分布在表层(0~20cm)最高,随土层深度的增加先减少后增加再减少。随施氮量增加各土层硝态氮含量及累积量均有所增加,随着灌水量的增加0~120cm土层硝态氮含量及累积量减小,其中0~80cm土层硝态氮含量及累积量随着灌水量增加而减小,80~120cm土层硝态氮含量及累积量随着灌水量的增加而增加。4、相同施氮量下,小麦籽粒产量随着灌水量的增加而先增加后不变(W3、W2W1),W3与W2处理差异不显著;W1处理下,春小麦籽粒产量随施氮量增加先增加后减小(N2N1N3N0),W2处理下,籽粒产量随施氮量增加先增加后不变(N3、N2N1N0),W3处理下,籽粒产量随施氮量增加先增加后减小(N2N3N1N0)。籽粒产量边行及次边行的边行优势随灌水量、施氮量的增加先增加后减小,W2N2处理下,小麦单株籽粒产量边行及次边行的边行优势最大。W2N2处理下水分利用效率最高(13.71kg.hm-2.mm-1);产量与0~20 cm土层根长密度、根系活力呈显著抛物线回归关系,与20~60 cm土层根长密度、根系活力呈显著线性正回归关系,与60~80 cm土层根长密度、根系活力无相关性。产量与0~40 cm土层根干重密度呈显著抛物线回归关系,与40~60 cm土层根干重密度呈显著线性正回归关系,与60~80 cm土层根干重密度无相关性。从节约水资源、降低过量施氮所造成的环境污染、提高作物产量和水氮利用效率等方面考虑,固定道垄作栽培下,施肥量与灌水量控制在N2(180 kg·hm-2)与W2(2400 m3·hm-2)条件下有利于促进春小麦籽粒干物质及氮素累积与分配、春小麦根系生长,减小0~120cm土层硝态氮含量及累积量,进而提高春小麦籽粒产量及水氮利用效率,是河西灌区固定道垄作栽培春小麦适宜的水氮组合。
[Abstract]:Water and nitrogen are two factors restricting the growth and development of spring wheat in the Western irrigated area of Gansu. With the increasing shortage of agricultural water resources and the expansion of nitrogen fertilizer, the introduction and extension of new ways of saving water and reduction of nitrogen fertilizer are the key ways to achieve high yield and high efficiency of wheat, and the sustainable agriculture in Hexi irrigation area can be realized. In this experiment, the fixed ridge culture was used in this experiment. Through the field experiment of different water and nitrogen treatment in spring wheat in 2015, the experiment was carried out in 2015, with low water 1200 (W1), water 2400 (W2), high water 3600 m3. Hm-2 (W3), 0 (N0), low nitrogen 90 (N1), medium nitrogen 180 (N2), high nitrogen 270 kg hm-2 (N3) as a side treatment, under different water and nitrogen treatment. The growth, yield, water consumption law, distribution of nitrate nitrogen in soil profile, nitrogen accumulation and transport of plant were studied to improve the grain yield, water use efficiency and nitrogen utilization rate of spring wheat, and the optimal input of water and nitrogen was determined to achieve high yield and high efficiency of wheat. The main results are as follows: 1, The water and nitrogen interaction significantly affected the growth of wheat. The suitable water and nitrogen supply had significant mutual advantage on wheat leaf area index, dry matter accumulation and distribution of grain. The supply of water and nitrogen was too high or too low, and the mutual advantage weakened. The dry matter, chlorophyll SPAD value, photosynthesis rate, transpiration rate and stomatal conductance increased with the amount of irrigation. Adding and increasing (W3W2W1), the intercellular CO2 of flag leaves increased with the increase of irrigation amount (W1W2W3). The proportion of dry matter distribution of grain increased first and then decreased with the increase of irrigation water (W2W3W1). The response of wheat growth to nitrogen application depends on the irrigation amount.W1 treatment, SPAD value increases with nitrogen application and then decreases (N2N3N1N0), W2 treatment, jointing to jointing. During the filling period, the SPAD value increased with the increase of nitrogen application (N2, N3N1N0), and the SPAD value at maturity increased with the increase of nitrogen application (N3N2N1N0). Under W3 treatment, SPAD value increased with the increase of nitrogen application (N3N2N1N0).W1, W2 treatment increased photosynthetic rate with nitrogen application, the transpiration rate and stomatal conductance increased first and then decreased (N2N3N1N0), W3 treatment under photosynthesis. The rate, transpiration rate and stomatal conductance increased with the increase of nitrogen application (N3N2N1N0). The intercellular CO2 of the leaves of the flag leaves decreased with the increase of nitrogen application. The irrigation and nitrogen application could increase the dry matter of the wheat vegetative organs. The proportion of dry matter distribution in the W2N2 treatment was the highest.2, the irrigation amount and the amount of nitrogen applied to a certain threshold, and the water and nitrogen were small to spring. The root growth (root dry weight density, root length density, root surface area and root activity) was positive effect. High water and nitrogen input decreased the growth of root growth in spring wheat. Nitrogen application and irrigation significantly affected root growth, showing the interaction of water and nitrogen with irrigation nitrogen. The root characteristic parameter increased first and then decreased (W2W3W1), root system, and root system. The response of characteristic parameters to nitrogen fertilizer depends on the amount of irrigation. Under the treatment of W1, root characteristic parameters N1 treatment is the largest; under the W2 treatment, the root characteristic parameter N2 treatment is the largest. Under W3 treatment, the root characteristic parameter N3 treatment is the largest, suitable for increasing irrigation quantity and fertilizer amount (W2N2) is beneficial to root characteristic parameters (root dry density density, root surface density, root surface) More than 85% of wheat roots were distributed in 0~40 cm soil layer, more than 90% of root dry weight density and over 85% root length density were concentrated in 0~40cm soil layer. W2N2 treatment could increase root distribution ratio of 40~60cm wheat, increase root activity, increase root length density and root surface area edge of spring wheat, and promote root system. The intercepting and absorption of the lower and lateral water and nutrients; the vertical distribution of the wheat root long density satisfies the exponential function y=Ae-Bx with the E as the base, and the principal component analysis of the characteristic parameters of the wheat root indicates that the root effect of the wheat root is best.3, the irrigation amount and the amount of nitrogen have mutual effect on the nitrogen accumulation of the wheat seed, and the suitable amount of nitrogen application. And the amount of irrigation has a positive effect on nitrogen accumulation in wheat grain. Excessive irrigation, nitrogen application to wheat grain nitrogen accumulation is negative effect.W2N2 treatment can increase the nitrogen transport and nitrogen assimilation amount before flower, and increase the nitrogen distribution ratio of wheat grain, and then get higher grain nitrogen accumulation and nitrogen harvest index. The vertical distribution of nitrate nitrogen content in the harvested soil of spring wheat was the highest in the surface layer (0~20cm), which decreased first and then decreased with the increase of soil depth. With the increase of nitrogen application, the nitrate content and accumulation of the soil layer increased, with the increase of the amount of irrigation, the nitrate content and accumulation of 0~120cm soil layer decreased, of which 0~80cm The nitrate content and accumulation of soil layer decreased with the increase of irrigation. The content and accumulation of nitrate nitrogen and accumulation in 80~120cm soil layer increased.4 with the increase of irrigation amount. Under the same amount of nitrogen application, the grain yield of wheat increased first and then remained unchanged (W3, W2W1), and the difference between W3 and W2 treatment was not significant; under W1 treatment, the grain yield of spring wheat followed by W1 treatment. The amount of nitrogen increased first and then decreased (N2N1N3N0). Under the W2 treatment, the grain yield increased first and then remained unchanged (N3, N2N1N0). Under the W3 treatment, the grain yield increased first and then decreased with the nitrogen application (N2N3N1N0). The edge row and secondary line advantages of grain yield increased with the irrigation water, and the nitrogen application increased first and then decreased, while the W2N2 treatment was smaller. The water use efficiency was highest (13.71kg.hm-2.mm-1) under the maximum.W2N2 treatment of the grain yield and the edge row of grain yield. The yield and the root length density of 0~20 cm soil layer, root activity showed a significant parabolic regression relationship, and the root length density of 20~60 cm soil layer, root vigor showed a significant linear regression relationship with the root length density of 60~80 cm soil layer. There was no correlation between root activity and root dry density of 0~40 cm soil layer, which showed a significant linear regression relationship with the root dry weight of the soil layer. There was a significant linear regression relationship with the dry weight density of the root of 40~60 cm soil layer. There was no correlation with the dry weight density of 60~80 cm soil root. In terms of rate and so on, under the fixed ridge cultivation, under the conditions of N2 (180 kg. Hm-2) and W2 (2400 m3. Hm-2), the accumulation and distribution of dry matter and nitrogen in spring wheat grains, the growth of spring wheat roots, the decrease of nitrate nitrogen content and accumulation in the 0~120cm soil layer, and the increase of grain yield and water nitrogen benefit in spring wheat are also considered. The efficiency is a suitable combination of water and nitrogen for spring wheat cultivation in Hexi irrigation area.
【学位授予单位】：甘肃农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S512.12

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