Effect Of Water And Nitrogen Coupling On Water Consumption And Growth Characteristics Of Tomato Processing By Degradable Mulch Covered By Drip Irrigation

Object:In order to develop water-saving and fertilizer saving agriculture,solve the problem of residual mulch,promote the practical application of degradable mulch,and ensure the sustainable development of agriculture in oasis irrigation area.In this paper,the effect of water and nitrogen coupling on water consumption and physiological growth characteristics of tomato processed by drip irrigation with degradable mulch mulching was carried out.According to crop indexes,the degradable mulch suitable for drip irrigation under inner membrane in Xinjiang region was evaluated by using mathematical analysis method,and the suitable amount of water and nitrogen under degradable mulch mulching in the region was comprehensively evaluated.The results provide a theoretical basis for the optimization of suitable degradable mulch types and water and nitrogen management of drip irrigation processing tomato.Methods:Through the field plot experiment,the tomato variety"heniz1015"was selected as the test material.In 2019 and 2020,three factors including the type of degradable plastic mulch,irrigation quota and nitrogen application rate were set up,Five kinds of plastic mulch treatments（PE,BM1,WM1,BM2,WM2）with different materials,colors and functions and the control group（bare land）were set,three irrigation quotas（W1:3600m³/hm²,W2:4200m³/hm²,W3:4800m³/hm²）and three nitrogen application levels（N1:200kg/hm²,N2:250kg/hm²,N3:290kg/hm²）were set for complete combination design.There were 45 treatments with 3 replicates for each treatment.Results:（1）Different plastic mulch treatments have significant effects on the soil moisture content and ground temperature of processing tomatoes by drip irrigation（P<0.05）.It can be seen from the average water content of different soil layers in two years that the average soil water content in the 0～60cm soil layer treated by the degradable membrane is 1.69%～4.17%lower than that of the PE treatment,and the order of water retention effect is BM2>BM1>WM1>WM2.Plastic mulch can significantly increase soil moisture by 1.5%～3%,and degradable plastic mulch can increase soil moisture by 0.5%～1.5%（P<0.05）.The average temperature of 5-20cm soil in the seedling stage of the degradable mulch treatment was2.04～3.52℃lower than that of PE treatment（P<0.05）,and 2.03～3.52℃higher than that of CK（P<0.05）.During the whole growth period,the average ground temperature of the film-coated treatment was higher than that of the control group（bare ground）by 0.71～1.89℃,and the order of heat preservation effect was:PE>BM2>BM1>WM2>WM1,among them,the water retention and heat preservation ability of PE mulch is better than other degradable mulches,and the water retention and heat preservation effect of black mulch is better than that of white mulch.（2）Different plastic mulching treatments and water-nitrogen coupling have significant effects on the physiological growth indexes of processing tomato by drip irrigation（P<0.05）.The plant height,stem thickness,leaf area index（LAI）,photosynthetic index,and fluorescence parameters of tomato treated by drip irrigation for two years have the same performance.The overall performance is BM2>BM1>PE>WM2>WM1>CK,indicating that a suitable degradable film cover can make the plant height,stem thickness,LAI,P_n,T_r,G_s,C_i,F_v/F_m,F_v/F₀,q P,ΦPSⅡ,Y（NO）,NPQ of each growth period of the drip irrigation processing tomato can be maintained at a high level.The physiological and growth indicators showed a trend of first increasing and then gradually decreasing with the increase of irrigation amount and nitrogen application rate.All indicators and parameters reached the highest level during the fruit expansion stage,and the W2N2 treatment reached the highest level.（3）Different plastic film treatments and water-nitrogen coupling effects have significant effects on the yield,quality,WUE,Production-to-investment ratio,irrigation water utilization rate,partial productivity of nitrogen fertilizer,and the production of processing tomato by drip irrigation（P<0.05）.The indicators of processed tomatoes in 2020 are slightly better than those in 2019,the fruit yield of each mulching treatment was 13.26%～26.59%higher than that of CK treatment（P<0.05）,and the average total yield of black degradable mulch treatment was 2.56%～5.48%higher than that of white degradable mulch treatment（P<0.05）,the quality indicators,WUE,and production investment of degradable membrane treatment are0.56%～3.85%,-1.16%～6.63%,-2.78%～9.44%higher than PE treatment（P<0.05）.The yield and quality of processed tomatoes increased first and then decreased with the increase in water and nitrogen usage（N2>N3>N1）.The highest level of each index appeared in W2N2 treatment,and the highest level of yield exceeded the lowest level by 10.59%.Irrigation factors did not have a significant effect on the partial productivity of nitrogen fertilizer,and nitrogen application factors did not have a significant effect on irrigation water use efficiency（P>0.05）.（4）The effect of water-nitrogen coupling on the total water consumption,dry matter accumulation and nitrogen distribution of tomato processed by degradable mulch drip irrigation during the whole growth period reached a significant level（P<0.05）.The soil moisture content of each treatment during the whole growth period increases with the increase of the irrigation quota.With the extension of the growth period,the water consumption of processed tomatoes presents a trend of first increasing and then decreasing.the water consumption of processing tomatoes shows a trend of increasing first and then decreasing with the extension of the growth period.The water consumption in the fruit expansion period reached the highest243.5 mm,in which the water consumption modulus and water consumption intensity had similar laws with water consumption.The change trend of dry matter accumulation is:fruit>stem>leaf,the ratio of nitrogen in stems,leaves,and fruits at the mature stage is about 1.75:1:7.9,and the fruit expansion stage has a significant impact on the nitrogen accumulation and distribution of drip irrigation processing tomatoes（P<0.05）.Conclusions:Based on the principal component analysis and correlation analysis,the comprehensive evaluation of soil temperature,soil moisture content,P_n,F_v/F_m,yield,TSS,VC,SSC,TA,WUE and the ratio of production to investment were carried out,the results show that the black degradation mulch（BM2treatment）has better economic effect.At the same time,the plant height,P_n,F_v/F_m yield,irrigation water use efficiency,nitrogen partial productivity,TSS and VC were comprehensively evaluated,and the optimal water and nitrogen treatment W2N2（irrigation amount is 4200m³/hm²,nitrogen application amount is 250kg/hm²）was obtained.Multiple regression method was used to construct the binary quadratic equation of each evaluation index and the amount of water and nitrogen.Using the normalization method,the reasonable acceptable range was defined as≥85%acceptable area.Comprehensive evaluation shows that the suitable irrigation interval for drip irrigation processing tomatoes in the Wuyi farm area with special climate and geographical environment is 4017-4443m³/hm²,and the nitrogen application interval is 230-267kg/hm².