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Design and sprinkler irrigation experiment of controllable fertilizer applicator based on plunger pump and single chip microcomputer |
ZHU Mei, GU Jialin*, CHU Chenggui, LI Xiaole, ZHU Dequan |
School of Engineering, Anhui Agricultural University, Hefei, Anhui 230036, China |
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Abstract In order to realize the accurate flow and no head loss of the integrated fertilization equipment, a high precision controllable fertilizer applicator based on plunger pump and single chip microcomputer was designed. The fertilization uniformity experiments of sprinkler irrigation and drip irrigation systems with six flow gradients under constant flow mode was carried out. Under the ratios of water and fertilizer of 1∶10, different working conditions of total flow rate of two kinds of sprinklers were designed. The stabilizing effect of the constant water-fertilizer application with that of inconstant one on the fertilizer concentration in the branch tube of integrative water and fertilizer was compared. The result show that when the flow rates of the fertilizer are 100 L/h, 200 L/h, 400 L/h, 600 L/h, 800 L/h and 1 000 L/h under the constant-current mode, the coefficient of unifor-mity CU of sprinkler is 99.33%-99.71%, and the coefficient of variation CV is 0.35%-0.75%. CU and CV are positively and negatively correlated with the flow rate of fertilizer applicator. The conductivity equivocation EC_- of sprinkling fertilizer has a significant positive correlation with the total average conductivity of fertilizer liquid sprayed and the flow rate of the fertilizer applicator. In the constant water fertilizer ratio mode, the fertilizer concentration in the pipeline of the experimental group tends to be stable at 160 s, and the deviation rate between the conductivity value and the target value is less than 4%, respectively. The experiment of constant flow mode of fertilizer applicator show that the variation coefficient of fertilizer uniformity under large flow is only 50% of that under small flow. It is an effective way to achieve variable fertilization with high uniformity for the sprinkler system of integrative water and fertilizer by changing the flow rate of the fertilizer applicator. The experiment shows that the constant-current mode can effectively reduce the external influence on the fertilizer concentration in the branch tube.
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Received: 24 October 2020
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