| In 21 century, the short of water resources has been main factor to affect the development of economic and society. The seventy percent of gross Water is used to irrigate agriculture, so how to saving water and develop saving agriculture has been main attack direction for developing agriculture of world. SPAC theory (Soil-Plant-Atmosphere Continuum, That is SPAC) is to research moving disciplinarian of water in continuum system between plant and its vegetal environment and in order to save water of plant. Since 1960s', SPAC theory has been rapidly developed in theory and application.At present, SPAC theory mainly researches the water moving law in soil-plant-atmosphere continuum in northwest arid area, China, but the water mutative law in each part of SPA continuum has not been systemically and exploringly research.Recent years, it is easy for seasonal drought to happen in south hill region of Si Chuan part, so the water mutative law in soil and plant and atmosphere is researched systemically by SPAC theory, and the innovative results have been obtained for carrying out saving water agriculture in hill region.Firstly, soil aspect, the non- balanced time series model for forecasting soil aquiferous capacity is built up by stochastic theory, and the BP network model is set up by MATLAB artificial neural network tool, the forecasting result is very good. Secondly, plant aspect, the day-to-day reference evapotranspiration (1999-2003) of hill region in Si Chuan middle part has been calculated by Penman formula and its changed law has been analyzed. The day change law of estival maize stem-liquid has been discussed, and the relation between maize stem-liquid and sun radiation has been built up. The partial least-squares regression model is built up to forecast crop leaf water potential of estival maize.Thirdly, atmosphere aspect, the low water age has been forecasting by R/S method of fractal theory in Si Chuan middle region. The chaotic behavior of agriculture meteorologic factors (average temperature, max temperature, min temperature, temperature of the earth's surface, evaporators, precipitation, relative humidity, sunlight time) time series (a period of ten days) is investigated using the phase-space reconstruction technique, and the delay time and relation dimension and min embedding dimension and Lyapunov exponent and Kolmogrov entropy is calculated. The atmosphere water potential is calculated by surveyed data, and the day change law of atmosphere water potential and the relation between it and sun radiation has been discussed.Fourthly, the paddy water production function (Stewart model) has been built up by field examination data; the sensitivity coefficient during the whole growing season is discussed, in the end, through the object-function of paddy water production function, the non-sufficient irrigation system is optimized by Genetic Algorithm (GA).In a word, on base of researching the change law of water in soil and plant and atmosphere, the paddy water production function and its non sufficient irrigation system have been ascertained in Si Chuan middle hill region, the application of SPAC theory has been probed into in this region, it provides scientific gist for Si Chuan middle hill region to carry out saving water agriculture. |
PDF Full Text Request