A Dynamic Model Of Growth For Rapeseed Multiple Cropping After Wheat Harvesting In The Northwest Of China

Natural resources such as light, heat and water can be utilized scientifically, the hazards of windblown sand by the uncovered surface of earth can be reduced, the natural ecological condition and promote the sustainable development of the agriculture and animal husbandry can be improved, it has important significance to plant rape in the tow-months free time after harvesting wheat in the Northwest of China.In the paper a dynamic simulation mode has been set up that can use the routine meteorological materials to simulate production process of the feeding rape, the production potential of the light-warm of the rape in the Northwest theoretically has been discussed, the rules varying with the area and time about the output of the rape stem and leaf and offer the theoretical foundation for the area of planting rape have been analyzed , the period of seeding and make the measures for proper culturing and managing have been optimize. The following conclusions were thus obtained.1. According to the climatic conditions in the Northwest and the characteristic of the growth of feeding rape, the simulating model have been set up about the course of nutrition growth, dry material accumulation and the output predicting. At the same time a convenient and practical computer program have been compiled.2. A method has been put forward that used routine meteorological materials as plant growing simulation model to input parameter, and a way to solved the problems that using the total amount of the solar radiation in one day to simulate the day change of the solar radiation and also using the day temperature on average was used in this thesis, daily highest temperature, daily minimum temperature to simulate daily changing of the temperature.3. Through field experimentation and theoretical simulation, meteorological ecological characteristics of the cabbage type double-low rape (low erucic acid, low glucosinolate) have been analyzed, and the curve about light-photosynthesis and the formula about the relationship of the respiration and temperature, as well as the physiologic and ecologic parameter about light saturation point and compensate point ofthe rape and the most suitable, the lowest and the highest temperature of the rape growth have been got.4. Through simulating analyzing the different seeding period of the rape in northwest areas, the increasing laws of the dry material and the fresh weight of the feeding rape have been calculated on four typical areas such as Lanzhou, Xining, Urumchi and Yinchuan, and the theoretical output have been analyzed, the latest suitable sowing time for different areas have been made sure of.5. The material production process and the ultimate output under the different sowing density have been analyzing by using the simulating model, the scheme about optimizing the seeding quantity and the planting density has been put forward.6. Through simulating the output of the rape stem-leaf in the four-regional, comparing the output potentiality of all parts, the theoretical foundation for the area of planting rape has been offered.