镁肥用量对花生养分吸收和光合特性的影响OA北大核心CSTPCD

[Objective]The aim of this study was to explore the impact of an appropriate amount of magnesium(Mg)fertilizer on nutrient absorption and photosynthetic characteristics of peanuts for high yield and high efficiency,so as to provide the theoretical support for peanut high yield and high efficiency.[Method]Field experiments were carried out from 2021 to 2022 to study the effects of four MgSO4 dosages(0,20,40,60 kg·hm-2,referred to as T1,T2,T3,T4)on the growth and development,yield and nutrient absorption,photosynthetic characteristics,photosynthetic rate-limiting enzymes,and antioxidant enzymes of peanuts.[Result]The rational application of Mg showed a significant effect on peanut plant height,with the maximum value observed at 40 kg·hm-2 in different periods.The flower needle stage showed a significant effect of Mg on branching,with an average increase of 8.8％than that under T1.The treatments with Mg application had 3.5％-15.1％higher dry matter accumulation than that under Tl.The yields,pods per plant,100-pod weight,and 100-kernel weight significantly increased within the ranges of 7.6％-15.5％,2.4％-18.1％,1.5％-11.1％,and 3.5％-10.9％,respectively,reaching the maximum value under T3.At the maturity stage,the nutrient absorption of different treatments as follows:nitrogen(197.3,206.8,217.9,and 204.8 kg·hm-2),phosphorus(37.1,40.1,42.3,and 39.4 kg.hm-2),potassium(75.6,79.7,81.1,and 78.5 kg·hm-2),calcium(38.5,45.4,46.8,and 42.3 kg·hm-2),and Mg(20.9,25.4,26.6,and 23.6 kg·hm-2).The nutrient absorption reached the maximum under T3,which were 10.4％,14.0％,7.3％,21.6％,and 27.3％higher than under T1,respectively.Reasonable application of Mg increased the SPAD,net photosynthetic rate,activity of rubisco enzyme,and antioxidant enzymes in peanut leaves.The SPAD value reached the maximum under T3 in each growth stage.At the pod-setting stage,the changes in Pn,Gs,Tr,and Ci due to Mg application were within the ranges of 2.7％-10.3％,-3.7％-15.8％,-6.6％-5.9％,and-8.2％--3.0％,respectively.The activities of Rubisco,SOD,and CAT increased by 2.7％-9.1％,0.6％-5.3％,and 2.1％-7.3％,respectively,while the PRO decreased by 3.3％-10.3％.[Conclusion]Rational application of Mg fertilizer promoted peanut growth,increased nutrient absorption and yield,improved photosynthetic characteristics,and delayed leaf senescence.The recommended Mg application rate in soils with exchangeable Mg of 243 mg·kg-1 was 40 kg·hm-2.