The Research On Key Technology Of Intelligence Varlable Rate Fertilization

Sustainable development of agriculture requires the use of minimum investment to maximize production, and precision agriculture provides a good way for sustainable agriculture. In this paper, the intelligent variables as the research object, which aim at variable rate fertilizer method is analyzed in small-scale and mid-scale farmers, the key mechanism and system is researched that variable rate fertilizer spreader in large-scale farming production, and built a variable rate fertilizer system based on multi nutrients in China, and some relevant tests are completed. Some experiments have analyzed that effect of variable rate fertilizer by the information of crops growing. The main research contents and conclusions are as follows:It was analyzed the automatic and semi-variable rate fertilizer system control technology in suiting to small-scale and mid-scale farming. Aim at using a single fertilizer for long-term in farming, which set up multi-nutrient variable rate fertilization system based on tractor hydraulic system by analyzing CAN bus control technology. The multi-nutrient variable rate fertilization system was constructed by utilizing several microcontroller-driven nodes including GPS system, embedded control terminal, variable rate application controller and ground speed module to act as data collection and control points along CAN bus. The paper has researched that the key technology of variable rate fertilizer machine based on crop growing state, it was analyzed the process of prescription map and data processing ways..A variable rate fertilizer system online determination was designed based on crop growing state, which achieves fertilizer variable application by crop itself growing. By calculating fertilizer amounts using the model of NFOA, some experiments have taken in our country production condition. In the way of fertilizer by tradition based on soil nutrient, yield and crop growing state, the experimental results show that the yield all increased, but yield map shown that experiment of crop growing state was production uniformity, coefficient of variation of yield decreased from12.79%to8.16%in experiment field, saving fertilizer used. Experiment of variable rate fertilizer field and traditional fertilization shown that was more benefit of economy and environment in variable rate fertilizer field, increase yield3kg/mu, and saving fertilizer2.5kg/mu.The automatic test equipment coefficient of friction has been designed, which can solve some questions that the friction coefficient of fertilizer is difficult to test, operation factors and other factors lead to lower accuracy during the testing process, and the coefficient of friction of three common fertilizer were tested in the paper, the experiments conclusion is verified that the test device performance. A theoretical analysis was conducted the motion state of granular fertilizer during moving in spinner disc and leaving. Analysis of condition that granular fertilizer can leave spinner disc, an analytical calculation the state of granular fertilizer subjected to force under inertia effect during fertilizer was moved to disc border, and a motional equation was established.Aim at variable rate fertilizer spreader, in this paper have designed the gate device of automatically adjust, the equipment of falling fertilizer which can change opening size and falling fertilizer position in disc by manual adjustment. And a special vane has designed which equipped a wing of separating fertilizer. The device can separate fertilizer of falling to vane, and some fertilizer can throw by the wing in the vane. The vane can fix in±30°, the curve equation for the wing of separating fertilizer was x2+(y-178)2=1782, the angle of fertilizer threw from leaving disc is20°, the uniformity of spreading has got a well purpose. The control system for adjusting spreader breath has designed, which has solved spreading breath difficult control during tractor accelerating and shift.The experimental results showed that fertilizer amount has linear correlation with gate opening size, the device of falling fertilizer can separate fertilizer from conveyor chain to two part that falling into disc, the coefficient of variation is10%in experiment. In experiment of disc rotation, the results showed that the rotation of disc has well multinomial relation to information of PWM, R2is0.997, rotation error is range±10rpm/min. The experiment of fertilizer uniformity shows that the uniformity is well by using wing of separating fertilizer vane. By spreading overlap test, the results shows that availability breadth coefficient of variation is14.77%, the working result can meet to production in fact, and the spreader productivity is4times than tradition variabale rate fertilizer machine by breadth of3.6metre.