不同灌水处理条件下蓄水坑灌苹果树根系分布与土壤水分动态研究

发布时间：2019-06-10 05:06

【摘要】：随着社会经济发展与人们生活水平提高,苹果在人们生活中的重要性逐渐显现,苹果营养丰富,是人们生活的不可或缺的食品之一,由此,苹果也成为我国农业种植结构的重要组成部分之一。但由于干旱问题的存在,严重影响了苹果的产量和品质。蓄水坑灌法是一种解决北方干旱问题的中深层立体果林灌溉新方法。进行不同灌水处理,调控适宜的土壤水分是蓄水坑灌苹果高产与高质的基础。为此,论文采取田间试验和理论分析与模拟相结合的研究方法,以地面灌溉(DM)为对照,设置三个灌水处理(土壤壤含水率控制在田持的50%-80%(W1)、60%-90%(W2)、70%-100%(W3)),对蓄水坑灌条件下苹果树根系分布与土壤水分动态进行研究,主要研究结果如下:1、蓄水坑灌不同灌水处理灌前土壤含水率分布规律一致,均为随着深度的增大而增大,各处理灌前土壤含水率关系为W1W2W3。灌后蓄水坑灌土壤含水率以蓄水坑为中心呈椭球状分布,距坑中心越远,土壤含水率越小。不同处理灌后土壤含水率分布范围和含水率值不同,各处理的大小关系为W1W2W3。不同灌水处理下的蓄水坑灌果园土壤水分一维、二维和三维分布模型均符合指数模型。地面灌溉后含水率集中于土壤表层,而蓄水坑灌后主要集中于30-120cm中深层土壤,蓄水坑灌法更具有节水、保水优势。在任意深度位置处,不同处理下的土壤含水率均随时间呈现相同的变化趋势,三种处理下的各层含水率随时间变化的均值大小表现为:W3W2W1。三种处理下的根区土体的平均含水量随时间呈现锯齿状的波动趋势,三者的数值大小表现为:w3w2w1,并且不同处理间的差异达到极显著水平。2、蓄水坑灌果树全生育期需水量及需水强度均随灌水量增加而增加,不同处理需水量及需水强度大小关系为w1w2w3;不同灌水处理下的苹果树需水量和作物系数随时间均呈现抛物线形的变化,不同处理作物系数关系为w1w2w3;不同灌水处理下的苹果树茎流随时间均呈现先逐渐增大,然后逐渐减小的变化趋势,不同处理下的茎流量大小关系表现为:w3w2w1;不同灌水处理下的果园棵间蒸发量呈现先逐渐增大后减小的变化趋势,而棵间蒸发占作物需水量的比例呈现相反的变化趋势。3、不同灌水处理条件下蓄水坑灌苹果树根长密度、根表面积密度、根重密度、根系含水率和根系活力垂向分布规律一致,均为随着深度的增大呈先增大后减小的变化趋势。不同灌水处理不同生育期,根长密度、根表面积密度、根重密度、根系含水率和根系活力分布范围不同,根长密度、根表面积密度和根系含水率分布的深度范围为w3w2w1,根重密度的深度范围为w2w3w1,根系活力不同生育期深度分布范围不同,在春梢旺长期和盛花期表现为w2w3w1,在幼果期、膨大期和成熟期表现为w3w2w1。不同灌水处理不同生育期,根长密度、根表面积密度、根重密度、根系含水率和根系活力垂向最大值出现位置关系为w3w2w1。建立了不同灌水处理条件下蓄水坑灌根长密度、根表面积密度、根重密度、根系含水率和根系活力垂向分布模型和时空动态变化模型。蓄水坑灌w2处理的根长密度、根表面积密度、根重密度、根系含水率和根系活力均大于地面灌溉dm处理,w2处理的根长密度、根表面积密度、根重密度、根系活力分别是地面灌溉dm处理的1.14、1.15、1.21、1.01和1.18倍。4、不同灌水处理对蓄水坑灌苹果树产量和品质有明显影响,单株苹果产量、果形指数、硬脆度和可溶性固体关系为W3W2W1,可滴定酸关系为W3W1W2,糖酸比关系为W2W3W1。综合比较平均根系活力、果形指数、果实硬度、可溶性固体、可滴定酸、糖酸比和水分生产率,采用主成分分析法得出不同灌水的综合排名为W2DMW1W3,即蓄水坑灌适宜的灌水处理为W2。5、基于最小二乘支持向量机,建立了以土壤初始贮水量或土壤初始含水率、预测起始时间、预测时段长度、时段内灌水量、时段内降雨量、参考作物需水量ET0和处理编号为输入,以蓄水坑灌果园根区2m厚土层土壤贮水量或分层含水率为输出的LSSVM-WSP-1土壤贮水量和LSSVM-WSP-10分层土壤含水率预测模型,提出了加速差分进化算法求解模型中的超参数,并采用田间实测数据对模型进行验证,结果表明模型具有较高精度,可用于蓄水坑灌果园贮水量和分层土壤含水率的预测。
[Abstract]:With the development of social economy and the improvement of people's living standard, the importance of apple in people's life is becoming more and more important, and the nutrition of apple is one of the indispensable food of people's life. But as a result of the drought, the yield and quality of the apple are seriously affected. The water storage pit irrigation method is a new method to solve the problem of northern drought. Different irrigation treatments can be carried out, and the appropriate soil water is the basis of the high yield and high quality of the water storage pit. In this paper, the method of field experiment and theoretical analysis and simulation is adopted to control the water content of soil in the field of 50% -80% (W1),60%-90% (W2) and 70% -100% (W3)). The main results of the study on the distribution of the root system and soil moisture of the apple tree under the condition of water storage pit irrigation are as follows:1. The distribution of water content in the soil before and after different irrigation treatments in the water storage pit is consistent with the increase of the depth, and the water content of the soil before each treatment is W1W2W3. The water content of the soil in the water storage pit of the water storage pit is distributed at the center of the water storage pit, and the further the distance from the center of the pit is, the smaller the water content of the soil. The distribution range and water content of the soil after different treatment were different, and the size of each treatment was W1W2W3. The model of one-dimensional, two-dimensional and three-dimensional distribution of soil water in the water storage pit under different irrigation treatments is in accordance with the exponential model. The water content after surface irrigation is concentrated on the soil surface layer, and the water storage pit is mainly concentrated in the deep soil of 30-120cm, and the water storage pit irrigation method has the advantages of water saving and water retention. In any depth position, the water content of the soil under different treatments is the same as the time, and the mean size of the water content of each layer under the three treatments is as follows: W3W2W1. The average water content of the soil in the root area under the three treatments showed a sawtooth wave tendency with the time, the numerical values of the three treatments were: w3w2w1, and the difference between the different treatments reached a very significant level. the water demand and the water demand intensity of the whole growth period of the water storage pit irrigation tree are increased with the increase of the irrigation quantity, the water demand of different treatment and the water demand intensity are the w1w2w3, and the water demand and the crop coefficient of the apple trees under different irrigation treatments are in a parabolic shape along with the time, The relationship between the different treatment crop coefficients was w1w2w3; the stem flow of the apple trees under different irrigation treatments was gradually increased with the time, then gradually decreased, and the relationship between the stem flow and the size under different treatments was: w3w2w1; The evaporation capacity of the orchard under different irrigation treatments was gradually increased and the change trend was decreased, while the ratio of evaporation to the water demand of the crops was the opposite trend. The water content of the root system and the vertical distribution of the root activity of the root system are consistent, and the variation trend of the reduction after the increase of the depth increases. the depth range of the root length density, the root surface area density and the root system water content distribution is w3w2w1, and the depth range of the root weight density is w2w3w1, The root activity was different in different growth stages, and w2w3w1 was expressed in the long-term and blooming period of the spring-tip and w3w2w1 at the stage of the young fruit, the expansion period and the mature period. The relationship between the root length density, the root surface area density, the root weight density, the root system water content and the vertical maximum value of the root activity was w3w2w1. The model of root area density, root surface area density, root weight density, root system water content and root activity vertical distribution model and space-time dynamic change model were established under different irrigation treatment conditions. the root length density, the root surface area density, the root weight density, the root system water content and the root activity of the root surface area density, the root surface area density, the root weight density and the root activity of the water storage pit irrigation w2 treatment are more than 1.14, 1.15, 1.21, 1.01 and 1.18 times of the surface irrigation dm treatment, The effects of different irrigation treatments on the yield and quality of the apple tree in the water storage pit were significantly affected. The apple yield, the fruit shape index, the hard and the soluble solid relation of the single plant were W3W2W1, the titratable acid relationship was W3W1W2, and the ratio of the acid to sugar was W2W3W1. The average root activity, the fruit shape index, the fruit hardness, the soluble solid, the titratable acid, the sugar and sugar ratio and the water productivity were compared, and the main component analysis method was used to obtain the comprehensive ranking of different irrigation of W2DMW1W3, that is, the appropriate irrigation treatment for the water storage pit was W2DMW1W3. based on the least-square support vector machine, the initial water content of the soil or the initial water content of the soil, the predicted starting time, the length of the prediction period, the amount of irrigation water during the time period, the rainfall in the time period, the ET0 and the processing number of the reference crop water requirement are input, In this paper, the model of soil moisture content of LSSVM-WSP-1 and LSSVM-WSP-10 soil water content prediction model, which is the output of the soil storage volume or the stratified water content of the 2m-thick soil layer in the root area of the water storage pit, is put forward, and the super-parameter in the model of the accelerated differential evolution algorithm is proposed, and the field measurement data is used to verify the model. The results show that the model has high precision and can be used for predicting the water content of the water storage and the water content of the layered soil in the water storage pit.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S661.1

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