بررسی کاربرد فناوری نرخ متغیر در کشاورزی دقیق به همراه پیاده سازی سیستم آبیاری هوشمند

Feeding the farm amendments with variable rate -instead of old fashioned constant rate feeding- is the most important achievement of modern precision farming. The rate of supplying nutrients , fertilizers or water for each point of field is based on information prepared by maps or sensors. Variable Rate Technology (VRT) is implemented in different farm operations as irrigation, fertilizing , spraying and seeding. Using these technologies is depend on socio-economic conditions. Prioritizing techniques like questionnaires containing comparision criteria , their weights and feasible alternatives should be applied here to decide on implementing VRT in our agriculture systems. Carrying out this part of survey, lead us to the result that in our situation in Iran, spraying operations have the highest priority due to its wide applications and lower costs. Other applications of VRT as fertilizing, seeding and irrigation, are held in lower ranks respectively. Although, thre are some difference in point of view among farmers micro-economic considerations and government macro-economic sensitivities, which may affects the ranking results but not so much. The second part of survey focuses on VRT in irrigation; here is considered a pilot in "Homaijan" district near Sepidan of Fars province. With an area of one hectare and about 2,400 apple trees. Thre were different irrigation systems with varying costs, specifications and qualities which could be installed. Again, with the priotrizing methods, we found the rank of each irrigation system and products due to important criteria through questionnaires. The "moisture sensor based automated drip irrigation system" had the highest priority among other systems. Although there are some cost differences between products of suppliers. Studies revealed that arranging a uniform field characteristics & variables, will show a uniform needs for irrigation. This uniformation could be possible with considering the soil texture and it involves soil sampling experiments and different paths for piping to have a better control on water needs of each path. With considering an assumed soil map, an automated irrigation system designed which used the products of higher ranked suppliers. A PID controller is considered for this system and decesion point of this controller was set at 50% moisture in the depth of 60cm under surface by using moisture sensor. This described system, is the optimum one for this VRT irrigation system. KEYWORDS: Irrigation Systems, Variable Rate Technology (VRT ) , Multi criteria decision , Control Systems, Soil Analysis.

Keywords:

فناوری نرخ متغیر , آبیاری , سیستم های هوشمند , محصولات میوه ای