Effect Of Yield And Water Use Efficiency Under Bio-carbon Base Fertilizer And Regulated Deficit Irrigation For Peanut

Under the condition of sliding rain shelter,the interaction effects of the biochar-based fertilizer and regulated deficit irrigation on the yield and water use efficiency of peanut were analyzed by setting different application levels of biochar-based fertilizer and regulated deficit irrigation.Providing scientific basis for the wide application of biochar-based fertilizers in agriculture.The test results obtained of this study are as follows:?1?Application of biochar-based fertilizer could promote peanut growth.The height of peanut plant showed a"S"type increase over time during the whole growth period.The highest plant height was treated with 1 500 kg·hm^-2?B₂?biochar-based fertilizer without water deficit?70%field capacity,W₃?,and compared to the non-fertilizer treatment?B₀W₁?increased under severe depletion conditions 64%?2016?and 23.42%?2017?.?2?Applying 750 kg·hm^-2?B₁?or 1 500 kg·hm^-2(B₂)biochar-based fertilizer,the net photosynthetic rate and stomatal conductance were significantly increased compared with the non-fertilizer?B₀?treatment.They were increased by 16.98%and 12.96%?2016?and 8.05%and 24.44%?2017?,respectively.Under the condition of regulated deficit irrigation,the photosynthetic rate of peanut could be inhibited under severe depletion?45⁵0%field capacity,W₁?and slight depletion?55⁶0%field capacity,W₂?.The net photosynthetic rate was decreased by 9.31%and 7.52%?2016?,14.87%and 8.99%?2017?,respectively,compared to treatment without water deficit?W₃?;water deficit treatment could reduce the stomatal conductance,and thus affected the photosynthesis and transpiration of peanut leaves.?3?Applying biochar-based fertilizer could increase soil nitrate nitrogen content,which was increased by 34.00%,27.33%,10.00%?2016?and 52.34%,50.78%,41.41%?2017?,respectively,compared to no fertilizer treatment.At the same time,regulated deficit irrigation could increase soil nitrate content by 51.55%and 31.32%?2016?,18.24%and 5.85%?2017?,respectively.The total nitrogen content of the biochar-based fertilizer application 750 kg·hm^-2and 1 500 kg·hm^-22 was increased significantly.The biochar-based fertilizer was applied at a rate of 750 kg·hm^-22 without water deficitgot the highest total nitrogen content in peanut plants,3.17 g·pot^-11 and 3.65 g·pot^-1,respectively.The characteristics of nitrogen content of peanut plant organs were as follows:pod>leaf>stem>root.?4?Biochar-based fertilizers could increase peanut production to varying degrees.In the two years,peanut yield was highest when applied with 750 kg·hm^-22 biochar-based fertilizer?B₁W₃?without depletion,and the yield was increased by 45.1%?2016?and 34.34%?2017?,respectively.There was no significant difference between B₂W₁ and B₁W₃.At the same time,the application of 750 kg·hm^-22 or 1 500 kg·hm^-22 biochar-based fertilizer could improve the quality indicators of peanuts,such as protein?increased by 1.97%?,crude fat?increased by4.98%?and oleic acid?increased by 1.63%?etc.which in turn can improve the quality of peanuts.?5?Appropriate amount of biochar-based fertilizer could increase the transpiration water consumption of peanuts.Regulated deficit irrigation could reduce the transpiration water consumption of peanuts.Biochar-based fertilizer?B₁W₃?applied at a maximum yield of750 kg·hm^-22 without water depletion during the entire growth period.The water consumption of B₁W₃ treatment was the highest during the whole growth period.Compared with treatment without fertilizer and depletion?B₀W₃?,the water consumption of peanuts in 2016 and 2017was increased by 7.20%and 15.06%,respectively.Appropriate amounts of biochar-based fertilizers could increase the water use efficiency of peanuts,and modulating deficit irrigation could also improve the water use efficiency of peanuts.In the two-year experiment,the treatment with the highest water use efficiency was that with biochar-based fertilizer 1 500kg·hm^-22 under severe depletion conditions?B₂W₁?,which were 2.04 kg·m^-33 and 2.185 kg·m^-3,respectively.Compared to the treatment without water deficit,the treatment of biochar-based fertilizer?B₁W₃?with 750 kg·hm^-22 was significantly increased by 15.25%and 32.66%,respectively.In summary,the application of biochar-based fertilizer was beneficial to the growth of peanuts,increased the accumulation of dry matter and total nitrogen in peanuts,and also eliminated the negative effects of regulated deficit irrigation to achieve water-saving and production stability of peanuts.Therefore,under the conditions of this experiment,considering the yield and water use efficiency comprehensively,the best recommended combination is the application of 1500 kg·hm^-22 biochar-based fertilizer,and the lower limit of soil water content at the flowering stage is 45⁵0%of the field water holding rate.