| The structure of the small-scale Sprinkler Irrigation Systems is composed of power machine pump,pipeline and nozzle.Due to the flexible configuration of the nozzle,the sprinkler unit is easy to move,so it has strong adaptability,can adapt to a variety of crops,soil,irrigation plots,and can also adapt to various land scales.Irrigation occasions have gained more applications in agricultural production in China.However,light and small sprinkler irrigation units will face many limitations in practical applications,and structural optimization and multi-functional expansion of light and small sprinkler irrigation units are required.At the same time,in order to better realize the integration of sprinkler irrigation water and fertilizer,it is necessary to study the water and fertilizer distribution and uniformity of light and small sprinkler irrigation units.The main research contents and results are summarized as follows:(1)Structural optimization of light and small sprinkler irrigation units and research on various irrigation modes.(1)Improvement of the nozzle fixing device.The key components of the outdoor workbench of the sprinkler irrigation unit are designed.A four-antenna type nozzle fixing device is proposed to make the nozzle fixed more reliable,more convenient to move,and more adaptable to local terrain.(2)Research on various irrigation modes.In the practical application,the irrigation demand in the two modes of spray drip irrigation is difficult to apply at the same time.A U-shaped modular multi-function drip irrigation system is proposed,which can realize the independent irrigation of sprinkler irrigation and drip irrigation at the same time.Irrigation,fertilization and drainage.(2)Study on the influence of working pressure and working pressure difference on the water distribution and sprinkler uniformity of the light and small sprinkler irrigation unit.The indoor sprinkler test bench was set up to simulate the working pressure difference of the sprinkler head.The uniformity coefficient C_u and the uniformity coefficient D_u were selected as the evaluation indexes.Five kinds of adjacent 10PY nozzles were set under different working pressures(0.22 MPa,0.25 MPa,0.28 MPa).The working pressure difference of the nozzle(0 MPa,0.01 MPa,0.02 MPa,0.03 MPa,0.04 MPa)was tested to study the influence of the working pressure of the nozzle and the working pressure difference of the adjacent nozzle on the water distribution and sprinkling uniformity of the sprinkler.The test results show that compared with the sprinkling uniformity coefficient C_u,the distribution uniformity coefficient D_u can reflect the influence of the adjacent working pressure difference on the low irrigation area,and is more suitable for the occasions of more attention to irrigation quality and individual crop differences.(3)Study on the effect of fertilization concentration on the distribution and uniformity of water and fertilizer.At the working pressure of 0.22 MPa,five fertilization concentrations(20 g/L,35 g/L,50 g/L,65 g/L,80 g/L)were selected for sprinkler fertilization experiments.The results showed that the effect of fertilization concentration on the uniformity coefficient of spray irrigation and the uniformity coefficient of C_u was different.With the increase of fertilizer concentration,D_u and C_u did not show monotonous change trend and the change trend was inconsistent.The uniformity coefficient of fertilizer spray irrigation and the uniformity coefficient of irrigation and irrigation were not sensitive to the change of fertilization concentration.From the whole,the uniformity coefficient of fertilizer distribution and the uniform distribution coefficient of fertilizer application showed a downward trend with the increase of fertilization concentration,and the local variation trend was similar..The concentration of spraying fertilizer in the sprinkler irrigation area is not evenly distributed.The test results show that the uniformity of fertilization is better than the uniformity of fertilizer.(4)Study on the effect of proportion of fertilizer in proportional fertilization pump on the distribution and uniformity of water and fertilizer.Five fertilization ratios(0.4%,0.8%,1.2%,1.6%,2.0%)were tested at a working pressure of 0.25 MPa.The test results show that different fertilizer ratios have different effects on the uniformity of fertilizer spray irrigation and the uniformity of fertilization.When the proportion of fertilizer absorption changed,the uniformity of fertilizer spray irrigation and the uniformity of fertilizer application showed disproportion.The uniformity coefficient of fertilizer application and the uniformity coefficient of fertilizer irrigation had similar changes,but they were different in some intervals.(5)Study on the influence of nozzle working pressure on water and fertilizer distribution and water and fertilizer uniformity.Under the ratio of absorption of 1.2%,three sets of nozzle working pressures(0.22 MPa,0.25 MPa,0.28 MPa)were selected for sprinkler fertilization test.The study found that pressure is still the biggest factor affecting the uniformity of fertilizer,and the effect of fertilizer concentration can not be ignored.When the working pressure of the nozzle is 0.28MPa,the uniformity of the fertilizer is the best.When the working pressure of the nozzle is 0.22MPa,the uniformity of the fertilizer is the worst.When the working fluid has the greatest influence on the uniformity coefficient of the irrigation,the working pressure of the nozzle is 0.28MPa,and the working pressure is 0.25MPa.The fertilizer solution has the least influence on the uniformity of irrigation.The effect of pressure on the uniformity of fertilizer application is similar to the effect of pressure on the uniformity of fertilizer spray irrigation. |
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