【作者】 田德龙；

【导师】 史海滨；

【作者基本信息】 内蒙古农业大学 ， 农业水土工程， 2011， 博士

【摘要】 我国有盐渍化土地约2700万hm2,其中约670万hm2分布于农田之中。我国国民经济的发展以农业为基础,水资源又十分紧缺,农业中节水和盐渍化土壤的防治及利用问题被提到很高的地位;开发利用肥力较低特别是盐渍化土地已成为解决人口粮食需求与农业可持续发展的重要途径之一。内蒙古河套灌区土壤母质含盐,地下水位较高,存在着严重的次生盐渍化的潜在威胁。土壤是农业生存和发展的重要载体,水、肥是农业发展和农业生产效率提高的两大关键因素。目前有关水肥耦合效应机理国内外许多学者进行了大量卓有成效的研究,然而,研究主要集中在非盐渍化地区。特别在节水条件下,作物生长在盐分胁迫的环境中,水肥耦合机制就更加复杂。因此,开展盐渍化土壤水肥耦合机理研究,制定节水灌溉条件下的水-盐-肥耦合管理模式是西北盐渍化地区亟待解决的关键问题。本文以河套灌区主要经济作物油料向日葵为研究对象,采用盆栽试验与田间试验相结合的方法,以土壤、水利、植物生理学、农业及气象等多学科交叉理论为研究手段,对盐分胁迫下油料向日葵水肥耦合响应机理展开研究。主要研究内容如下:1通过对盆栽和田间试验资料的分析,定量描述了不同水、肥、盐条件下,向日葵株高、茎粗、叶面积、干物质累积量、光合速率、蒸腾速率、气孔导度、水分利用效率、叶水势等生理生态因子以及生物量、产量的响应规律。提出了适应不同盐渍化程度土壤的水肥管理阈值及指标体系。2以Jensen模型和BP人工神经网络模型为基础,建立了适用于不同含盐程度土壤油料向日葵的水-肥-盐产量模型。定量揭示了不同水肥处理下水盐及NO3-N动态变化规律。定量揭示了不同含盐土壤、不同水肥处理下各生育期内向日葵植株各器官氮素分配累积变化规律。3适用于模拟河套灌区水肥条件下油料向日葵的根区水质模型(RZWQM)能较好的模拟不同水肥处理下土壤含水率、NO3-N、生物量等指标。盆栽试验研究结果表明,向日葵苗期影响因素顺序为:盐分>水分>氮肥,现蕾期~花期为:水分>盐分>氮肥。EC值0.2~1.0ms/cm的含盐土壤上土壤含水量在70%θfc左右,施N量在337.5(kg/hm2)左右最佳,并且可以减缓盐分对向日葵的胁迫。土壤EC值在0.1~0.45ms/cm范围内,水肥盐之间表现出一定的线性关系,超出这一范围水肥盐表现出非线性关系。田间对比试验结果表明,适宜的肥量(N 225kg/hm2,P 150kg/hm2)可以缓解水盐的胁迫,影响因素效应顺序:轻度水分>磷>氮,中度水分>氮>磷;水和氮、水和磷、磷和氮交互作用为正效应,影响效应顺序为:轻度氮和磷>磷和水>氮和水,中度氮和磷>氮和水>磷和水。优化水肥方案为施氮肥量225 kg/hm2,施磷量为150 kg/hm2,灌水量为626~1088m3/hm2左右。水肥盐产量模型具有一定价值可指导当地农业生产,RZWQM模型可应用于油料向日葵水肥效应的模拟。研究结果可初步揭示盐渍化土壤水肥耦合效应响应机理,为灌区可持续发展提高农田水肥利用效率、开发盐渍化土壤提供一定的理论科学依据。更多还原

【Abstract】 China’s economic development is based on agriculture while the water resources is quite scarces. Water saving , salinization control and utilization in agticulture is mentioned to high position . Development and utilization of the lower fertility land especially the salinization has become one of the important ways to solve population demand for food and agricultural sustainable development. In western China ,the HeTao irrigation area belongs to drought,cold and desert region also with less rainfall.The inter-regional,inter-annual and inter-seasonal distribution is uneven and its variation changes great.The soil evaporation is strong and the shortage of water resource increases day by day.There exsites serious potential theate to secondary salinization when soil parent material contains salt and groundwater level is higher. Soil is an important carrier of agticulture survival and development.Water and fertilizer are the two key factors to the agriculture development and the improvement of agriculture efficiency.Nodays,many domestic and foreign scholars have carried out extensive fruitful studies on coupling of water and fertilizer whears they are mainly focus on the area which is not salinization.Especially in water-saving conditions,crop grow in salt stress environment then the coupling of water and fertilizer mechanism becomes more complicated. Therefore, study on mechanism of salinization coupling of water and fertilizer , the key problem to be solved urgently in northwest salinization region was to made the water- fertilizer - salt coupling management mode which under the condition of saving water,This paper choose the main economic crops-oil sunflower of Hetao irrigation as the study target,using the pot esperiment in combinition with the field test method , appling pedology,water conservancy, plant physiology, agricultural and meteorological etc multi-subject theory and so making research on oil-sunflower copling of water and fertilizer which under the condition of salt stess.1.Though analyzing the pot and field experient meterials,it quantitatively describe the influence regularity about the height, stem diameter, photosynthetic rate, transpiration rate, stomatal conductance, leaf RWC etc physiological and ecological factors , biomass and yield of sunflower which in different water,fertilizer and salt conditions.It presented the water-fertilizer management thresholds and index system which adapting to different level of salinization . 2. With Jensen model and BP artificial neural network model based. finally set up the water-fertilizer-salt production model that suite for different saline soil of oil-sunflwer.This paper reveals dynamic change regulation of water-salt and NO3-N beyond different water-fertilizer treatment.It also disscusses the different growth period variation of nitrogen distribution and accumulation of sunflower’s each organ which under the condition of different saline soil and different water-fertilizer process.3. RZWQM model can better simulate treatment various soil moisture content, NO3 - N, biomass ect index Under different waterPot experiment research results show that sunflower seedling influence factors orde:salty>water > nitrogen, now bolls ~ flowering :water > salty > nitrogen.EC value 0.2 ~ 1.0 ms/cm containing salt on soil moisture in the soil was about 70%θfc, N 337.5 kg / hm2 or so best, and may slow the intimidation of sunflower salty. Soil EC value 0.1 ~ 0.45 ms/cm, Between salt water and fertilizer, shows certain linear relationship, Beyond the scope of nonlinear relationships showed。Comparative test showed that the optimum amount of fertilizer (N 225kg/hm2, P 150kg/hm2) can ease the stress of water and salt, the orders of the effect were“water> P> N”in light and“water> N> P”in moderate. There was positive effect in the interactions of water, nitrogen and water. The orders of effect were“nitrogen and phosphorus> phosphorus and water> nitrogen and water”in light and“nitrogen and phosphorus> nitrogen and water> phosphorus and water”in moderate. The optimize applications of fertilizer and water were N 225 kg/hm2, P 150 kg/hm2 and water 1088m3/hm2.Salt water and fertilizer production model has certain value in guiding agricultural production, RZWQM model can be applied to simulate the Sunflower.The results of research reveal the theory of solinization coupling of water and fertilizer preliminarily.It also provide theoretical scientific basis for sustainable development of irrigation areas,raising the farmland utilizing fficiency and developing the salinization agricultural production.更多还原