Impact of the application of tannic acid and procyanidins on the nitrogen use efficiency and N2O emissions during rape growth period
It is important for the green and sustainable development of agriculture to improve the nutrient use efficiency of farmland ecosystem and reduce soil N2O emission.In this study,the effects of plant extracts such as procyanidins and tannic acid were investigated on plant biomass,N2O emission and nitrogen use efficiency in pot experiments of rape grown in northern China calcareous soil.A total of five treatments were designed including UR(UR),UR+low procyanidins(PC1),UR+high procyanidins(PC2),UR+low tannic acid(TA1)and UR+high tannic acid(TA2).The results showed that procyanidins and tannic acid treatments increased the rape yield by 7.9%-17.9%and nitrogen content by 10.3%-23.2%compared to the UR.Procyanidins and tannic acid treatments significantly inhibited the content of inorganic nitrogen such as NO2- and NO3- in the soil.Procyanidins and tannic acid treatments significantly reduced N2O emission during the growth period of rape.The reduction of N2O affected by the procyanidins was 28.1%-33%,and was 32.9%-41.5%by the tannic acid treatments.The nitrogen use efficiency of rape was increased by 5.0%-9.7%.In summary,the application of procyanidins and tannic acid in calcareous soil not only significantly reduced N2O emissions,but also helped to improve the yield and nitrogen use efficiency of rape.This study provided a novel idea for the simultaneously realization of the green recycling of plant extracts such as procyanidins and tannic acid together with the N2O emission reduction in calcareous farmland soil in northern China.
procyanidinstannic acidnitrous oxideinorganic fertilizernitrogen use efficiency