The Research Of Lower Micro-irrigation System For Corn

Low pressure drip irrigation is new form of irrigation with water-saving energy-efficient,the current number of scholars are in-depth research, from rising to the theory test conductedin-depth inquiry, and achieved certain results, however, most of current research on thelow-pressure drip irrigation system have stayed only in the system’s own research, and do notbring good crops and irrigation systems to combine. Hydraulic performance of the system isnot yet emitter-depth study, after the integration of water and fertilizer under low pressureconditions emitter clogging problems have not given accurate conclusion. And thelow-pressure drip irrigation system has been studied is the use of ideas and pressure dripirrigation system, whether emitter hydraulic characteristics are differences in atmosphericpressure and low-pressure situation. The study of irrigation uniformity and the flowcharacteristics under low pressure conditions is not deep enough. To solve the aboveproblems, this paper is by the combination of laboratory tests and field trials, to Study thelow-pressure drip irrigation system’s hydraulic characteristics and low pressure drip irrigationsystem of corn. This paper obtained the following conclusions:1.(1) In the condition of mixing in fertilizer,4different experiments with drip irrigationemitter flow are reduced for different degree when compared with water. A dripper flow hasreduced the amount of the maximum, reducing0.011L/h (under conditions of fertilizer driptape A dripper average flow of2.6%). B dripper flow has reduced the amount of the least,reducing0.004L/h (under conditions of fertilizer drip tape B dripper average flow of1.1%),affected Significantly.(2) Drip irrigation uniformity with4kinds of fertilizer underconditions decreased when compared to water. Drip irrigation uniformity coefficient with Cdecreases maximum, reducing the0.078(C average drip tape irrigation uniformity10.3%);drip irrigation uniformity coefficient with A decreases maximum, reducing the0.05(Caverage drip tape irrigation uniformity5.4%). Different types of drip tape irrigationuniformity affected by varying degrees, drip tape C＞drip tape B＞drip tape D＞drip tapeA(A:rated pressure0.08MPa,rated discharge1.5L/h, wall thickness0.1mm; B:rated pressure0.1MPa,rated discharge3.0L/h, wall thickness0.4mm; C:rated pressure0.04MPa,rateddischarge1.0L/h, wall thickness0.095mm; D:rated pressure0.1MPa,rated discharge1.0L/h, wall thickness0.2mm).(3) Fertilizer dissolved in water for irrigation drip tape of4kinds havedifferent blockage, with the number of irrigation and drip irrigation interval increases with thedegree of blockage. The flow rate of drip tape B is reduced the maximum, reducing the0.069L/h(4stages with B average flow drip17.2%), the flow rate of drip tape B is reducedthe least, reducing the0.041L/h(4stages with B average flow drip12.1%), affectedSignificantly. the different kind of drip tape has different degree of blockage.2. In the case of clear water and other conditions remain unchanged, with the increasingin the length of drip tape laying, irrigation uniformity is reduced, with the inlet pressureincreasing, irrigation uniformity is increased. But the values do not change significantly.Laying lengths and inlet pressure have different effects on uniformity with different types ofdrip tape, the impact of laying length on irrigation uniformity is greater than the inlet pressure.Reducing capillary length or increasing inlet pressure (low pressure) can improve irrigationuniformity. The reasonable length of three kinds of drip tape is60m (3m),40m (4m),60m(3-5m).3. In the case of clear water, pressure head is the main factor of the hole flow of drip tape,each hole of the drip tape traffic shows a positive correlation with the pressure head. Thelength of drip tape has impacted on the flow hole limited, the degree of the impact of dripemitter has associated with flow pattern, has little effect on the flow pattern within the emitterclosed to full turbulence, the impact on the emitter closed to laminar flow regime is relativelysignificant. Drip tape laying drip tape length on the overall impact of the current trend hasassociated with the drip emitter flow pattern, no matter how the length of drip tape laying,drip with the flow uniformity is good. For the drip tape witch flow pattern deviates fromturbulent, when laying length is between10m to40m, the flow of drip irrigation is uniform,But when length is60m, the flow will be uneven, specific performance: the flow of near inletis more than far away from inlet, entire drip has a decreasing trend from the inlet to the end.Pressure only affects the flow of the hole,but distribution trends.4. The irrigation of corn has applied low pressure drip system, pressure have a significanteffect on economic output(P <0.05). The amount of irrigation has a significant impact on theefficiency of water. The inlet pressure and fertilization had no significant effect on theefficiency of water. Inlet pressure has a significant effect on total biomass yield(P <0.05), andthe amount of irrigation and fertilization did not affect its significantly then. From the analysisof variance, we can see the inlet pressure, irrigation and fertilizer had no significant effect onthe aboveground biomass (P>0.05). Inlet pressure, irrigation and fertilizer had no significanteffect on economic factors. Optimal configuration parameters are: Inlet pressure3m,irrigation2520m3/hm2, fertilizer684kg/hm2, the highest yield is10.63t/hm2, the average yield increase11.64%, irrigation reduced by28.6%.