旱区膜下滴灌棉田间作条件下土壤水盐肥迁移机制及作物生长研究

发布时间：2018-03-11 04:13

本文选题：膜下滴灌　切入点：间作　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：新疆地区水资源极度匮乏,常年膜下滴灌导致可耕地面临次生盐碱化的危害,造成单位面积耕地产量下降,作物减产,水分利用效率降低。因此,本文在新疆早区膜下滴灌棉田间作盐生植物和经济作物绿豆条件下,通过盆栽试验和大田试验探讨间作条件下土壤水盐肥迁移特性、作物耗水规律,以及zuowu生长响应机制。主要研究结果如下:(1)通过盆栽试验模拟棉田间作条件下作物根系交叉的试验条件,探讨棉田间作苜蓿条件下与棉花根系交叉对土壤水盐迁移及棉花生长的影响,结果表明:与棉花单作相比,间作苜蓿条件下的各处理土壤剖面含盐量显著降低,脱盐效果较好,水分利用效率提高,棉花产量增加。在间作条件下,与间作苜蓿根区无隔挡处理相比,塑料布和纱布隔挡条件下棉花生长较好,产量增加,生育期内作物耗水量减小,水分利用效率提高。(2)棉田间作不同盐生植物对土壤水盐迁移机制及棉花生长的影响研究表明:与棉花单作相比,间作苜蓿和碱蓬可显著增加膜间间0-40cm 土层水分含量及生育期内耗水量,减少膜间和膜内土壤水分深层渗漏;间作碱蓬可显著降低膜间0-60cm 土层含盐量,间作苜蓿可显著减小0-20cm和40-60cm 土层的含盐量,20-40cm上层处于积盐状态,间作碱蓬的脱盐效果好于于间作苜蓿。棉花单作处理的根密度可生长至40cm 土层深度处,而间作碱蓬处理的根重密度只能达到30cm深度处,且与棉花单作相比,间作碱蓬处理的膜间和膜内0-20cm 土层的根重密度显著较大,但在20-40cm 土层中相反;同时,通过三年的间作试验,间作碱蓬和苜蓿可促进棉花生长,增加棉花产量,提高水分利用效率。(3)棉田间作经济作物绿豆条件下不同施氮量对土壤水盐肥迁移及棉花生长的影响研究表明:间作绿豆条件下,施氮量对土壤水分分布及作物耗水量的影响不大,但随着施氮量的增加,土壤盐分和全氮含量主要在20040cm 土层累积,有机碳主要在0-30cm 土层累积,且施氮量过大会造成氮素流失.当施氮量为390kg/hm2时,可较好的供给间作条件下棉花和绿豆的生长需求,促进作物生长,增加作物产量,提升水分利用效率和氮速率用效率。Logistic生长模型可较好的模拟间作条件下不同施氮量对棉花和绿豆生长过程,施氮量为390kg/hm2时棉花生物量的累积速率及绿豆的生长速率最大,有助于棉花和绿豆的生长发育。
[Abstract]:The water resources are extremely scarce in Xinjiang, and the drip irrigation under mulch causes the arable land to face the harm of secondary salinization, which results in the decrease of cultivated land yield per unit area, the decrease of crop yield and the decrease of water use efficiency. In this paper, the characteristics of soil water, salt and fertilizer migration and crop water consumption were studied by pot experiment and field experiment under the condition of intercropping halophyte and mung bean in cotton field under drip irrigation in early area of Xinjiang. The main results are as follows: 1) the experiment conditions of crop root crossing under cotton intercropping were simulated by pot experiment. The effects of intercropping of alfalfa and cotton roots on soil water and salt migration and cotton growth under cotton intercropping were studied. The results showed that the salt content in soil profiles of intercropping alfalfa was significantly lower than that in cotton monoculture, and the desalination effect was better. Compared with the intercropping alfalfa root area, the cotton grew better under the condition of plastic cloth and gauze, the yield increased, and the water consumption of crops decreased during the growing period under the condition of higher water use efficiency and higher cotton yield. The effects of different halophytes on soil water and salt migration mechanism and cotton growth in cotton field were studied. Intercropping alfalfa and Suaeda salsa could significantly increase the water content in 0-40cm soil layer and water consumption during the growing period, and decrease the deep leakage of soil water in the intermembrane and intramembrane soil layers, while the salsa intercropping could significantly reduce the salt content in 0-60cm soil layer. Intercropping alfalfa can significantly reduce the salt content of 0-20cm and 40-60cm soil layer and the upper layer is in a salt accumulation state. The desalination effect of intercropping Suaeda salsa is better than that of intercropping alfalfa. The root density of cotton monoculture can grow to the depth of 40cm soil layer, and the desalination effect of intercropping Suaeda salsa is better than that of intercropping alfalfa. The root weight density of intercropping Suaeda salsa was only 30 cm deep. Compared with cotton monoculture, the root weight density of intercropping Suaeda salsa treated by intercropping Suaeda salsa was significantly higher than that of cotton monoculture, but the root weight density of intercropping Suaeda salsa was higher than that of cotton monoculture, but the root weight density was opposite in 20-40cm soil layer. Intercropping Suaeda salsa and alfalfa can promote cotton growth and increase cotton yield. The effects of different nitrogen application rates on soil water, salt and fertilizer transfer and cotton growth under the condition of intercropping mung bean in cotton field showed that: under the condition of intercropping mung bean, the effect of nitrogen application on soil water, salt and fertilizer transfer and cotton growth was studied. Nitrogen application had little effect on soil water distribution and crop water consumption, but with the increase of nitrogen application amount, soil salt and total nitrogen content mainly accumulated in 20040cm soil layer, and organic carbon mainly accumulated in 0-30cm soil layer. When the amount of nitrogen applied was 390 kg / hm ~ 2, the growth demand of cotton and mung bean could be improved under the condition of intercropping, which could promote crop growth and increase crop yield. Logistic growth model could simulate the growth process of cotton and mung bean with different nitrogen application rates under intercropping conditions. The biomass accumulation rate of cotton and the growth rate of mung bean were the highest when the nitrogen application rate was 390 kg / hm ~ 2. Helps cotton and mung bean grow and develop.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S562

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