Optimization and evaluation of water saving irrigation system for green pepper in solar greenhouse

【作者】 孙健；

【导师】 王铁良； 李波；

【作者基本信息】 沈阳农业大学 ， 农业水土工程， 2015， 博士

【摘要】 蔬菜作为人们每日必不可少的食材,为满足人们对新鲜蔬菜需求,特别是在春冬季节对反季节新鲜蔬菜的大量需求,近年来在我国很多地区都已经出现了规模庞大的日光温室群,日光温室的迅速发展,在给蔬菜种植户带来了丰厚收入的同时,也缓解了北方地区对蔬菜的需求压力。然而蔬菜是需水量较大的作物,因日光温室中土壤耕层无法直接利用自然降雨,只能依靠人为灌溉来进行补充水分,在当前种植户普遍粗放的灌溉模式下,温室蔬菜的灌溉水量要比裸地蔬菜大的多,这不仅造成了水资源的浪费,而且会导致日光温室内环境的恶化,从而导致病虫害发生和作物品质产量的下降。在当前水资源日益紧缺的大背景下,制定一种适宜的温室蔬菜节水灌溉制度,提高日光温室中的水分利用效率,就显得尤为重要。青椒作为人们生活中最常见的蔬菜,种植区域十分广泛,种植面积非常大,本文以青椒为研究对象,在沈阳农业大学水利学院综合试验基地的节能日光温室中进行试验研究,青椒品种为35-619,于2012年9月中旬开始。试验采用桶栽的方式,灌溉方式采用目前最为流行的滴灌,试验共设13个处理,其中一个为充水对照处理,每个处理3次重复。试验将青椒的生育期划分为苗期、开花着果期、结果盛期、结果后期4个阶段。通过对不同土壤水分状况下温室青椒产量、品质及水分利用效率进行了系统的观察研究,并应用灰色关联分析、动态规划法、遗传算法、自由搜索算法等方法对温室青椒的水分敏感时期及敏感指数,对温室青椒各生育期最适宜土壤含水率范围、青椒各生育期最适宜灌水量及其灌溉制度优化进行了系统的研究。主要研究结论如下：(1)基于试验实测数据,对不同水分处理对青椒产量、VC含量及水分利用效率的影响进行了分析,得出了合理的水分分配对青椒产量、VC含量及水分利用效率的提高有显著的影响。利用线性和非线性的相关分析方法找出了青椒产量及品质对水分最为敏感和主要敏感的时期,得出了青椒的产量及品质与青椒各生育期灌水量的关联程度,青椒产量与各生育期灌水量关联度从大到小依次为：开花着果期、结果盛期、苗期、结果后期；青椒Vc含量与各生育期灌水量关联度从大到小依次为：结果盛期、苗期、开花着果期、结果后期。可以看出在不同的水分处理条件下青椒果实品质和产量与开花结果期、结果盛期的灌水量关系密切,为日光温室青椒水分生产函数的建立及各生育期灌水量的优化提供了理论基础。(2)建立了温室青椒水分生产函数,基于2012年实测数据资料,选用了大家所熟知的加法模型中的Sudar模型、Blank模型、Singh模型和乘法模型中的Jensen模型、Rao模型,采用SPSS软件分别对5种模型进行求解,得出了5个模型的敏感指数,并对结果进行了检验及比较分析,最终结果表明,Jensen模型在描述温室青椒水量与产量方面更合理准确。基于确定的温室青椒水分生产函数,利用2013年实测数据对温室青椒水分生产函数Jensen模型的适应性进行了检验,结果显示产量预测相对误差较小,平均误差约10\%。(3)在日光温室滴灌条件下,基于遗传算法以青椒水分生产函数为目标函数,以灌水量和青椒各生育阶段末的土壤储水量为决策变量,对土壤储水量进行优化,得出了青椒各生育期最适宜的土壤含水率范围分别为：苗期为62.5\%-99.5\%、开花着果期为72.5\%-99.9\%、结果盛期为62.5\%-65\%、结果后期为72.5\%。基于2012年、2013年实测数据对该优化结果进行验证讨论,得到符合上述土壤含水率范围的水分胁迫试验处理均为各自年度实测数据产量及水分利用率最高,从结果可以看出基于遗传算法对温室青椒适宜土壤含水率范围优化是比较符合实际的,为温室青椒各生育阶段灌水量的确定提供了理论基础。(4)分别采用动态规划法、遗传算法及自由搜索算法对青椒各生育期的灌水量进行了优化,得出了基于动态规划格点法温室青椒生育期内灌溉水量以285mm为最佳,其对应苗期、开花着果期、结果盛期、结果后期的灌水量分别为30mm、60mm、105mm、 90mm;基于动态规划逐次渐近法温室青椒生育期内作物灌溉水量以240mm为最佳,其对应苗期、开花着果期、结果盛期、结果后期的灌水量分别为30mm、45mm、90mm、75mm；基于遗传算法温室青椒生育期内灌溉水量以285mm为最佳,其对应苗期、开花着果期、结果盛期、结果后期的灌水量分别为27mm、7mm、109.5mm、70.5mm;基于自由搜索法温室青椒生育期内灌溉水量以270mm为最佳,其对应苗期、开花着果期、结果盛期、结果后期的灌水量分别为23mm、65mm、100mm、82mm。(5)对3种优化算法结果进行的对比分析结果表明：动态规划逐次渐近法的灌溉水量最小,为240mm,自由搜索法的相对产量最大,为0.9608,遗传算法与动态规划格点法的最佳灌水量相同,均为285mm。(6)确定温室青椒全生育期的灌水量为285mm,最终得出温室青椒的灌溉制度为：灌溉定额为285mm,苗期的灌水量为30mm、开花着果期的灌水量为90mm、结果盛期的灌水量为105mm、结果后期的灌水量为60mm,灌水定额为15mm,苗期灌水2次,开花着果期灌水6次、结果盛期灌水7次、结果后期灌水4次。

【Abstract】 Vegetables as the essential food supplies in people’s daily life, meet the needs of the fresh vegetables for people, especially the need for out-of-season in spring and winter. In recent years, a great amount of regions in China have appeared large groups of heliogreenhouses, and with the rapid development of it, the incomes of vegetable-growing household has been increased, meanwhile, the pressure of the need for vegetables in the north has been relieved. However, the vegetable is the crop which needs great deal of water, and because the surface soil in the greenhouse can not make use of natural rainfall directly, it could only complement the water by artificial irrigation. Under this general extensive irrigation mode, the water amount of irrigation in greenhouse is far more than that in nudation. It not only cause the waste of water resource, but deterioration of the environment in greenhouse as well, which lead to the pests and diseases and quality reduction of the crop. Under the background of scarce water resources, making a proper irrigation program of saving water and improving water use efficiency for the vegetables in the greenhouse becomes particularly important.This experiment was taken in energy-saving solar greenhouse in the test base which is in the College of Water Conservancy in Shenyang Agricultural University. The experimental material is green pepper, and the variety is 35-619. It was carried out since the mid-September, 2012. It adopted the pot cultivation, and set 13 processings, one of which was for water filling contrast and each of those processings was repeated 3 times. The duration period of green pepper is divided into four stages:seedling stage, flowering stage, prime fruiting stage and later fruiting stage. With the field trial and theoretical analysis, this research shows systematic study on water sensitive stage and index of green pepper, the proper soil water content and the most suitable amount of water for irrigation of each duration period of the greenhouse pepper. The main conclusions are as follows:(1)Based on the experimental data in 2012 and 2013, the effects of different water treatments on pepper yield,VC content and water use efficiency were analyzed.obtain reasonable allocation of water has a significant impact on the pepper yield,VC content and water use efficiency.By using linear and nonlinear methods to find out the yield and quality of pepper is the most and basic sensitive period of moisture,and get the degree of association between the fruit quality and production and irrigation amount in different growth period. The degree of association between production of green pepper and water amount period from large to small is, flowering stage, prime fruiting stage, seedling stage and later fruiting stage. And the degree of association between VC content of green pepper and water amount period from large to small is, prime fruiting stage, seedling stage, flowering stage and later fruiting stage.Known from the results, under different conditions of water treatment, the fruit quality and production of green pepper have close relation with flowering stage and later fruiting stage, which provide the theoretical foundation for the establishment of water production function of green pepper in the green house and optimization of the water amount in different stage of duration.(2)According to the real situation in the experimental base, combining the former research and choose three classical additive models:Sudar, Blank and Singh as well as multiplicative model:Jensen and Rao. And use SPSS software to solve 5 models severally according to the experimental data in 2012. Then get sensitive index of 5 models, and test the results and analyses comparatively. The result shows that Jensen model describe the water and production amount more accurate. Based on certain water production function of greenhouse pepper, and adopt experimental data in 2013 to examine water production function model of greenhouse pepper; the result shows that error of the productive predication is very tiny, and the average of the error ids about 10\%.(3)See the water production function as the objective function; the irrigation amount and each soil water storage amount of the pepper’s last growth stage as decision variable, use the genetic algorithm to optimize the amount of soil water storage and get the most proper ranges: seedling stage:62.5\%-99.5\%; flowering stage:72.5\%-99.9\%; prime fruiting stage: 62.5\%-65\%; later fruiting stage:72.5\%. It was examined based on the experimental data, drawing conclusion that water stress experiment that meet range of that soil moisture content is annual amount of production of experimental data and Water Use Efficiency is the highest. From the result, to optimize the range of soil water storage rate with genetic algorithm is practical, which provide the theoretical basis of irrigation program of greenhouse pepper.(4)Use dynamic programming method, genetic algorithm and free search algorithm optimize the irrigation program of greenhouse pepper, the most proper water amount of irrigation of the dynamic programming point method is the most proper:285mm; and correspondingly, the water amount of irrigation in seedling stage, flowering stage, prime fruiting stage and later fruiting stage is 30mm,60mm,105mm and 90mm. And amount of irrigation with the dynamic programming method is the most proper:240mm. The water amount of irrigation of those stages is 30mm,45mm,90mm and 75mm. The most proper water amount of irrigation which based on the genetic algorithm is 285mm, and amount of irrigation of those stages is 27mm,78mm,109.5mm and 70.5mm. The most proper water amount of irrigation based on free search method is 270mm, and the water amount of irrigation of those stages is 23mm,65mm,100mm and 82mm.(5)Use dynamic programming method, genetic algorithm and free search algorithm optimize the irrigation program of greenhouse pepper, and compare three optimization algorithms and it turns out that the amount of irrigation with the dynamic programming method is the minimum:240mm; while the amount of production of free search algorithm is maximum:0.9608. The best proper amount of irrigation water that comes from genetic algorithm and dynamic programming lattice method is 285mm.(6) Confirm that irrigation program of greenhouse pepper is 285mm, and the irrigation amount of sidling stage, flowering stage, prime fruiting stage and later fruiting stage are as follows:30mm,90mm,105mm and 60mm. The irrigation regime of green pepper is that the water applied was 285 mm for the whole growth period,irrigation water per time is 15mm;Among them:2 times of irrigation at seedling stage,6 times of irrigation at flowering and fruiting stage,7 times of irrigation at grandly fruiting stage,4 times of irrigation at late fruiting stage.

【关键词】 日光温室； 青椒； 水分生产函数； 土壤含水率； 灌溉制度；
【Key words】 greenhouse； green pepper； water production function； soil moisture content； irrigation regime；