| 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. |
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