Effects of interaction between nitrogen application and planting density on growth and nitrogen utilization efficiency of peanutOA

Peanuts,as important leguminous and oil-producing crops,play a significant role in ensuring the safety of edible oil production and facilitating economic trade.Nevertheless,the appropriate density and fertilizer application rate for cultivating peanuts remain unclear.To explore the effects of the appropriate nitrogen fertilizer(N)application rate and planting density on the growth and development of peanuts,a two-year experiment was carried out from 2022 to 2023.Three N fertilizer levels(0 kg·hm^(-2) for NO,120 kg·hm^(-2) for N120,180 kg·hm^(-2) for N180)and three planting densities(255,000 plants·hm^(-2) for D1,300,000 plants-hm 2 for D2,345,000plants-hm^(-2) for D3)were used to systematically study the effects on peanuts.The results showed that under the same N application level,the morphological indices,per-plant and population dry matter accumulation,leaf photosynthetic performance,as well as N accumulation,utilization,and metabolic capacity of peanut all showed the trend of D2>D1>D3 across different planting densities.At the same density level,the growth and development of peanut under N120 and N180 were superior to those under NO.N120-D2 significantly enhanced the leaf area index(LAI)of peanuts,the population dry matter accumulation was significantly increased by13.99%and 15.15%in the N120-D2 compared to the N180-D2 at the stage of pod-filling stage.The net photosynthetic rate(Pn)of the N120-D2 was elevated.The N accumulation of leaves increased by 6.91%and11.49%,14.57%and 20.97%compared with N120-D1,N120-D3,N metabolizing enzyme activities were also enhanced.In terms of yield,N120-D2 also realized 11.57%and 7.94%increase compared with N180-D2,and yield was higher in 2023 than in 2022.Thereby,N x D interaction can enhance the N efficiency and influence the photosynthetic capacity,and further improve crop yield.