Design of on-site water collecting system and online pesticide premixing system for sprayer in paddy fields

Abstract. Owing to the oversize water tank of sprayer in paddy fields, the ground pressure is too heavy to avoid car trapping. Meanwhile, the rice-fish symbiosis system is a long-term development agroecosystem in south China, which maintains a steady water level in the ditch. Therefore, we could collect water locally from ditch and mix medicine online, so as to reduce the volume of water tank. On-site water collecting system and on-line pesticide premixing system for sprayer in paddy fields were designed in this paper. To meet the requirements for the cleanliness of water, a water sink with flexible system and servo-driven system was devised for on-site water collecting system. The flexible system could reduce the collision, ensure the water intake always orient the front and imitate the terrain of ditch through slightly location adjustment. In the servo-driven system, the servo cylinder could drive the water collecting device to the suitable position, according to the signals sent by the angle sensor. Then water was drawn from the sump by self-priming pump, and filtered by filter, whose cleaning device was controlled by solenoid valves. Water would be mixed with pesticides in medicine premix tank, whose amount could be precisely controlled, and pesticides of appropriate concentration would flow to the spray tank. Experimental results showed that the proposed solution could reduce the weight of the unit decrease the ground pressure and prevent car trapping while the accuracy and homogeneity of pesticide premixing was improved by applying on-line pesticide premixing system.