Crop Water Requirement And Physiological And Ecological Effects In Intercropping Patterns In Hetao Irrigation District In Inner Mongolia

With the development of science and technology and the improvement of rational use degree of natural resource, the scale of the single planting structure is continually down while the index of intercropping and multiple cropping is continually up. Intercropping as the traditional experience of farmers in China and a stimulation in agriculture possess the advantages of taking full advantage of the growing season, improving light and ventilation conditions, Improving energy efficiency and side-line advantage. Serious lack of the water resources had become the importance factor that will influence the development of society, economy and environment. Therefore, it is necessary meaningful to study the radiation interception and utilization by intercropping canopies, the soil evaporation, plant transpiration, and root water uptake dynamics in intercropping systems for optimizing components, improving management and rising resources use efficiency and output of intercropping systems.Through field experiment in 2009-2010, the crop water requirement of three kinds of crop in two main mode of wheat intercropping maize and wheat intercropping oil sunflower, and its physiological environment were studied. Comprehensive single and double values crop coefficients of two interplanting modes and corresponding crop water requirement were experimentally studied and quantitatively analyzed. And by comparing different treatment of soil moisture, soil temperature, leaf water content, light response curve, photosynthetic rate, transpiration rate, stomatal conductance, the intercellular co2 concentration, leaf area index, chlorophyll value, the following results were analyzed.1. Through the comparison the different methods, Irmark– Allen fitting method is confirm to be suitable to alternative Penman-Monteith method which need parameters to calculate the ET0 in Hetao irrigation upstream. The result is smaller and the daily relative error value is 0.98%;ET value of a single value crop coefficients is smaller one of double value in Dengkou experiment station, while ET value of a double value crop coefficients is more close to measured results( F=0.702) and a single value crop coefficients with large difference(F=1.279) , validating the applicability of a double value provided by the research in Hetao irrigation. 2. There are twice comprehensive water-demand peak for the crops in intercropping mode in the whole birth period. The results of comprehensive crop coefficients in symbiotic stage calculated by single value method is higher than one by double value, while one of single crop in independent growth stage is higher than one by single value. Comprehensive ET of a single crop in independent growth stage varies slightly, while one of two crops in symbiotic growth stage varies bigger. Comprehensive ET of wheat intercropping maize with no plastic mulch is 750.38mm and of wheat intercropping maize with plastic mulch is 765.97mm, of wheat intercropping oil sunflower is 661.98mm. The daily evapotranspiration of the same crop in interplanting mode will be impacted by the different interplanting crops, changing with irrigation level; while one varies slightly in moderate sedimentation and sufficient irrigation conditions.3. The biological yield of the wheat intercropping maize with no plastic mulch takes slight advantage, and wheat and maize hold sway above the flux. Intercropping crops which experience a certain degree of moisture deficit and compensate moisture timely can improve economic coefficient. The biological yield of oil sunflower in interplanting mode is relatively high, reaching 10018 ~ 15091kg/hm2, but not seen in the local use. Therefore, processing bio-feedingstuff, fertilizer is recommended to bring certain economic benefits.4. The physiological and fertility index of edge lines and middle lines of three crops in intercropping mode are comparatively studied, and line effect and drought resistance relations in intercropping mode are put forward. The changes of soil water and soil temperature of different crops and corresponding middle lines under the same horizontal section in intercropping model are comparatively studied, and the understand to the water requirement law of two kinds of crops in intercropping model are proposed. It can achieve certain water-saving effect to increase plant middle lines proportion of wheat intercropping oil sunflower in full irrigation and mild sedimentation condition and reduce them if slight drought.5. According to the change rule of the surface geotemperature with temperatures, The decision factors above 0.95 of the model is obtained and the feasibility is stronger. Daily change law of soil temperature in different depth in key fertility stages of three crops in intercropping mode are studied, and sine curve of corresponding geothermal of crops is obtained. By research, corresponding crop water requirement and integrated crop water requirement of three kinds of crop were obtained, and the effect of water consumption law and the physiological and ecology were revealed.It can guide reasonable irrigation and provide some scientific theory evidences for studying mechanism of water-saving irrigation.