Optimal Irrigation Schedule Of Furrow Irrigation With Plastic Film Mulch Ridge For Processing Tomato In Zhangye

Under Zhangye climatic condition and furrow irrigation with plastic film mulch ridge cultivation, it was studied that the effect on soil moisture, water consumptive use rules, biology character, yield, quality and water use efficiency of processing tomato under different treatments of irrigation schedule after transplant. At the same time, the water production functions were also obtained. And on this basis the optimal irrigation schedule was calculated.The results were as following:(1) The soil moisture increased when the irrigation norm increases. But the soil moisture in 20-80cm soil layer from surface were affected significantly by irrigation norm. There was not significant difference between treatments on the soil moisture in 0-20cm soil layer. The soil moisture in 80-100cm layer generally keeped a constant value.(2) The water consumption intensity change of processing tomato in all growth period was one peak curve. The water consumption intensity in flowering and fruiting stage was maximum by 5.72mm·d^-1, but in the later fruiting period it was minimal by 2.29mm·d^-1.(3) The increasement of irrigation norm prolonged the growth period of processing tomato. It will postpone growth stage by 2 to 6 days. This increased the disposal tomato number and then decreased the yield.(4) The irrigation norm have a significant effect on the height, stem diameter, leaf number, virgation of processing tomato. Apart from the seedling stage, a significant difference of this index existed among treatments.(5) The yield of processing tomato increased as the irrigation norm increases, but the increase range became more and more smaller. When the irrigation norm exceeded 3899.945m3·hm-2, the yield increasement becomed very limited. It belonged to the stage of yield decreasing returns. This showed that to just increase the irrigation norm will make little effect on yield. To obtain a higer yield, other agricultural measures must be persuited.(6) The tomato number and weight of individual plant increased when the irrigation norm increase. But when the irrigation norm was higher, they would not increase but decrease. The irrigation norm did not make significant difference on the vertical diameter, horizon diameter and weight of individual tomato. Both the deteriorated tomato number and deteriorated tomato rate increased with the irrigation norms increases. The max deteriorated rate was up to 12.1%.(7) The irrigation norm has a significant effect on water use efficiency of processing tomato. The Water Use Efficiency(WUE) of treatmentâ… (T1)is the highest, the value was 24.42kg·m^-3, but owing to the yield of treatmentâ… is the lowest. As it saved water, the economic income simultaneously decreased. So it is an unreasonable irrigation schedule. Treatmentâ…¤(CK) is full irrigation treatment. Although the yield is the highest, the consumptive use is the biggest too. So compared other treatments the WUE is lower. So it is also an unfeasible irrigation schedule. With an angle of yield and WUE, the treatmentâ…£is most optimal choice.(8) There was an apparent parabola curve realation between the irrigation norms and yield. The co-relative coefficient is 0.976. But a line relation existed between the water consumptive use and yield. The co-relative coefficient is 0.9998. The water sensitive coefficient of flowering and fruiting period in both Blank model and Jensen model are 0.8340 and 0.6938 respectively. They showed same crucial water sensitive growth stage. The change rule of both models was also same in the processing tomato growth stage. Namely the flowering and fruiting stage>fruiting stage>later fruiting stage>seedling stage.(9) On the basis of present irrigation schedule, this research optimized the irrigation schedule using dynamic method with Matlab software. In the past, the method in solving dynamic problem in irrigation schedule formulation generally was to run computer program in Qbasic, Basic or other language. But to solve dynamic optimization problem with Matlab software was a new attempt. The optimazed results showed that when the irrigaitn norm keep constant, the max yield increasement was up to 4567.35kg·hm^-2, income increased 1461.52yuan·hm^-2.(10) After comparing the five irrigation schedules carefully, this research recommended that treatmentâ…£was most optimal irrigation schedule. The irrirgation norm was 4650m³Â·hm^-2, it have 6 irrigation times in all growth stage. That is the first irrigating (1050m³Â·hm^-2, May 10), the second (950 m³Â·hm^-2, May 28), the third (570m³Â·hm^-2, June 16), the fouth (600m3·hm^-2, July 2), the fifth (790m³Â·hm^-2, July 23) and the sixth (790m³Â·hm^-2, Aug 12). The predictable yield was 107941.72kg·hm^-2.