Effect Of Regulated Deficit Irrigation And Different Amount Of Deeply Buried Straw On The Yield And Quality Of Tomato In Greenhouse

The application of straw returning technology not only eliminates the environmental problems caused by straw burning,but also effectively improves soil structure and promotes microbial activity,crop root growth as well as greenhouse gas emissions.Under the condition of water stress,there is not enough research on the deeply volume of corn straw in the northern energy-saving solar greenhouse,and there is no reasonable management system suitable for tomato in greenhouse cultivation in Liaoning Province.Under the condition of tomato in greenhouse,the 2cm segmental corn straw was deeply buried in a concentrated way,setting up no straw S₀ treatment,a small amount of deeply buried straw S₁ treatment?1.5×10⁴kg/ha?,a middle amount of deeply buried straw S₂ treatment?3×10⁴kg/ha?and a large amount of deeply buried straw S₃ treatment?4.5×10⁴ kg/ha?.Drip irrigation under membrane was used.In the full growth period of tomato,using field water capacity??_F?as the upper limit of irrigation,4 different drip irrigation thresholds were designed for low drip irrigation thresholds W₁?50%?_F?,medium drip irrigation thresholds W₂?60%?_F?,higher drip irrigation thresholds W₃?70%?_F?,and high drip irrigation thresholds W₄?80%?_F?.The effects of the amount of deeply buried straw and drip irrigation thresholds on growth index,yield and quality index and water use efficiency of tomato in greenhouse were studied.The amount of deeply buried straw and the drip irrigation thresholds for tomato in greenhouse growing in northern area were explored.It provides a reference for the production of fruits and vegetables in greenhouse.The results of the study show that:?1?When the drip irrigation thresholds is 70%of field water capacity,it is conducive to the growth of tomato plant height and stem diameter.Compared with W₁?27.84cm²?irrigation level,the area of tomato leaves in W₂,W₃ and W₄ treatments irrigation levels are increased by 8.01%,34.66%and 39.19%respectively.A small amount of deeply buried straw?1.5×10⁴kg/ha?is used to inhibit tomato plant height,stem diameter and leaf area growth.Increasing the amount of deeply buried straw?more than3×10⁴kg/ha?can promote tomato plant growth.?2?Moderate water deficit is beneficial to the increase of tomato yield.When the drip irrigation thresholds is 70%of the field water capacity,tomato has high production,and tomato yield is increased by36.51%compared with that of W₁ treatment.Compared with no straw,deeply buried straw can improve the total yield of tomato.When the straw amount is 3×10⁴kg/ha,tomato yield will increase significantly,reaching to 9.50%.When the drip irrigation thresholds is 60%of field water capacity,it is beneficial to the accumulation of vitamin C and organic acid in tomato.A medium amount of deeply buried straw?3×10⁴kg/ha?can improve the content of vitamin C,organic acid and reducing sugar of tomato.The average weight of single fruit contributes the most to total tomato yield,and has a significant and direct effect on the total tomato yield?P<0.01?,while the growth index of tomato?especially plant height and leaf area?has no significant and direct effect on the total yield,as well as the quality of tomato.?3?Drip irrigation thresholds can effectively reduce the tomato irrigation amount and improve water use efficiency.Increasing the amount of deeply buried straw has no significant effect on the amount of tomato irrigation,but can effectively improve the yield of tomato,so as to improve the water use efficiency.The water use efficiency of deeply buried straw of a medium amount?3×10⁴kg/ha?is 27.93kg/m³,significantly increased by 6.56%compared with no straw level.?4?Considering the yield and quality of tomato,irrigation water use efficiency and other indexes,a comprehensive evaluation of tomato under different drip irrigation thresholds and different amount of deeply buried straw is carried out based on entropy TOPSIS model.It is concluded that the lower limit of irrigation is 60%of field water capacity,and the 3×10⁴kg/ha amount of deeply buried segmental corn straw is more conducive to tomato in greenhouse cultivation in northern area,so as to achieve the purpose of saving water,high yield and high quality.