Optimized boll-loading capacity of cotton root system increases seedcotton yield under wheat-cotton straw return with appropriate nitrogen fertilization  

作　　者：Zhitao Liu Wen Jin Qin Wang Wei Hu Binglin Chen Yali Meng Haishui Yang Zhiguo Zhou 

机构地区：[1]College of Agriculture,Nanjing Agricultural University,Nanjing 210095,Jiangsu,China [2]Agronomy College,Shandong Agricultural University,Tai’an 271018,Shandong,China

出　　处：《The Crop Journal》2025年第2期576-586,共11页作物学报(英文版)

基　　金：supported by the Jiangsu Agricultural Science and Technology Innovation Fund(CX(22)2015);the Fundamental Research Funds for the Central Universities(XUEKEN2022008);the Innovation Center for Modern Crop Production Cosponsored by Province and Ministry(CIC-MCP);the Cotton Industry Technology Research System of Shandong Province(SDAIT-03).

摘　　要：Long-term straw return with appropriate nitrogen(N)fertilization increases seedcotton yield and fiber quality,and the root system plays an important role in cotton production.However,under straw return and N fertilization,the relationship between the cotton boll-loading capacity of the root system and seedcotton yield remains unclear.In this study,a ten years of long-term field experiment was conducted in a wheat-cotton rotation system.The effects of straw treatments(straw return and straw removal)and N rates(N0,N75,N150 and N300 representing 0,75,150 and 300 kg N ha^(-1),respectively)on cotton root activity,boll-loading capacity of the root system and their relationship to seedcotton yield from 2019 to 2022 were quantified.The results showed that straw return with an appropriate N fertilization of N150 increased root biomass,the rate and components of root-bleeding sap,as well as boll-loading capacity of the root system and seedcotton yield,but decreased the ratio of root to shoot biomass.Furthermore,the root-bleeding sap rate reached the maximum at 30 d post anthesis(DPA)during the peak boll setting stage.However,the contents of nitrate-N,free amino acids and soluble sugar in root-bleeding sap decreased from 10 DPA.Notably,in 2021 and at 30 DPA,the highest contents of nitrate-N(4.8μg mL^(-1))and free amino acids(8.3μg mL^(-1)),as well as soluble sugar(3.4μg mL^(-1))were observed at N150 under straw return.The increase in seedcotton yield is positively correlated to the soluble sugar content.Straw return significantly increased the boll-loading capacity of the root system,which first increased but then decreased with the increase in N fertilization.Under straw return with N150,the maximum seecotton yield(3455-4544 kg ha^(-1))was recorded,and the largest boll loading(49-54 boll 100 g^(-1))and boll capacity(242-292 g 100 g^(-1))of root system at the boll opening stage were observed.Therefore,straw return with appropriate N fertilization improved root activity and the boll-loading capacity of the root system,the

关 键 词：Wheat-cotton straw return Nitrogen fertilization Seedcotton yield Root-bleeding sap Boll-loading capacity of the root system 

分 类 号：S562[农业科学—作物学]