Study On Water & Heat Transfer Model And High Efficient Water Using Techniques Of Summer Corn Straw Mulching In Hebei Province

Hebei province is one of the most serious water scarcity provinces. Water resources scarcity seriously restricts national economy. Furthermore Hebei province is the grain and cotton production base of our country. Water resources scarcity aggravated the conflict of all water using sections. The result was that the agricultural irrigation water was cut down and the foodstuff yield was impacted. This puts forward a new challenge to traditional irrigation. Not only getting high yield in per irrigation area, but also getting the most economic benefit. The efficient method of getting the most economic benefit is deficient irrigation. It can save the irrigation water, improve using efficiency of irrigation water and get the aim of highly efficient water using under high crop yield.Supported by State Science & Technology Project on Food Production Enhance, the experiment was designed to study water and heat transmission mechanism, relation between water and yield and high water using techniques. Two factors were considered in the experiment such as straw mulching quantity and irrigation times. The quantity of straw mulching had four levels of 150% mulching, 100% mulching, 50% mulching and non -mulching. Trend line method and square difference method was used to analyze the experimental data, the results shows that a straw mulching quantity has close relation with corn yield and its compared factor. The more straw mulching quantity, the higher corn yield. The yield of maximum straw mulching quantity got up to 693.22kg/hm~2, which was 33.36% higher than that of non straw mulching. The author also found that straw mulching could improve water using efficient obviously through analyzing water using efficient. The water using efficient of maximum straw mulching quantity got 2.97kg/m~3. which was 45.58% higher than that of non straw mulching.A canopy temperature model, plant root water uptake model, coupled movement of water and heat model of summer corn were built respectively in Soil Plant Atmosphere Continuum which based on the soil water dynamics theory and deficient irrigation theory. Some model parameters were also obtained through experiments, limit difference was used to disperse models and models were solved by computer program such as MATLAB, CURXPT, et al. the results of model satisfy with the experimental data. The result indicates that corn intakes mainly soil water between 0 and 80cm and the heat between 0 and 15cm in corn growth. The model reflected the principle of water and heat movement under different straw mulching quantity and irrigation times in summer corn growth. The resultwas fitted to the experimental data. At last, corn evaporation in straw mulching was calculated and the high efficient water using techniques were put forward which was available in Hebei province. The study indicates that the effect of summer corn water saving and yield increasing is obvious evident which is theoretical base of crop high yield under the water saving condition.The experimental study of summer corn water and heat transport and high efficient water using under straw mulching does not only reveal the principle of water and heat transport under straw mulching, but also analyze the relation among straw mulching, corn yield and its compared factor. The study results are the theoretical base to establish a technique system on summer corn high yield high efficient water using. The research results have significant application value to improve food yield and relaxed the tension of water resources.