| Rice controlling irrigation techniques in NingXia are studied and the model of controlling irrigation on saline land is defined in this paper. Based on the achievements in crop water-salt production function research internal and external, water-salt model suited to saline conductions is fixed.According to the on-the-spot experimental data,the quantify of water requiring and the laws of water offering-requiring, water production rate and the variety of physiology and eco-quota of rice on condition of controlling irrigation on saline land. Experimental data on salt content changing, soil moisture, rice evapotranspiration, stomata resistance, canopy intercepting photosynthetically useful radiation are systematically analyzed by using advanced instruments and devices: pootable photosynthesis determination system (CI -301), crop canopy image analysis metre (CI -100) and MP4 .The results show that all the quotes of rice controlling irrigation are better than others rice irrigation ways,and water-saving is 71%(compared with basin irrigation),yield is 9615kg/hm2, irrigation water production rate is 1.75kg/m3.Water-saving,high yield ,canopy lighted structure and yield forms are all considered and analyzed all-sidely ,after comparing .appropriate controlling irrigation model and water-salt changing in different growth periods of rice on saline land are defined quanlitively, which offers the basis for the popularization of controlling irrigation techniques on saline land.Finally, the best scheme of rice on saline land is fixed by using dynamic programming model,and the results are more reasonable compared to real experiment data.The research achievements in this paper are useful for perfecting the theory of water-saving irrigation of rice on saline land and applying controlling irrigation techniques to saline land more widely. |
