不同灌水条件下分层施肥对土壤养分垂直分布与小麦根系生长和功能的影响OA北大核心CSTPCD

[Objective]In order to explore the effects of fertilization on soil nutrients and wheat(Triticum aestivum L.)root growth,and to shape a good root architecture,so as to provide a theoretical basis for scientific fertilization and high-yield and high-efficiency production of wheat field.[Method]The experiment was conducted in Yuanyang Scientific and Educational Park of Henan Agricultural University from 2021 to 2023.The pool planting positioning experiment is adopted.And three fertilization treatments(F0:no fertilization;F1:shallow application of N,P,K fertilizer;F2:1/3 shallow application plus 2/3 deep application of N,P,K fertilizer)and three irrigation treatments(W1:prior to sowing irrigation;W2:prior to sowing irrigation plus irrigation at jointing stage;W3:prior to sowing irrigation plus irrigations both at jointing and anthesis).A total of 9 treatment combinations were used to determine concentration dynamics of soil nutrients and root morphological and physiological traits at different soil layers within 0-100 cm.[Result]Under different irrigation frequencies,the concentrations of available N,P,K nutrients were relatively high in top soil layer and decreased with the soil depth.In the soil layer of 0-60 cm,the trend of concentrations of available N,P,K nutrients under different treatments was as F2＞F1＞F0.Especially,the nutrient concentrations were significantly increased in 20-40 cm soil layer in layered application treatment(F2).Compared with those in shallow application(F1),the concentrations of nitrate nitrogen,ammonium nitrogen,available phosphorus,and available potassium increased by 16.03％,7.67％,8.82％,and 6.32％under F2 under different irrigation frequencies from anthesis to maturity,respectively.Also,under F2 treatments,the concentrations of both nitrate nitrogen and total nitrogen increased in 80-100 cm soil layer,and irrigation enhanced the treating effects.The distribution of available potassium concentration in 0-100 cm soil layer exhibited an S-shaped curve,and K concentration increased at maturity stage suggesting the phenomenon of potassium excretion.The wheat roots were mainly located in the 0-40 cm soil layer.Morphological & quantitative traits and physiological function of roots were significantly improved under F2 in the 20-40 cm soil layer:compared with those under F1,the root length density,root surface area density,root volume ratio,root dry weight density,root vigor,and root physiological potential were increased by 38.42％,16.93％,25.65％,43.07％,33.12％,and 31.10％,respectively.The correlation analysis showed that concentrations of available N,P,K nutrients in 0-20 cm soil layer were significantly positively correlated with root morphological & quantitative traits(P＜0.01).Root physiological potential in 0-60 cm soil layer was significantly positively correlated with soil nitrate nitrogen,ammonium nitrogen,available phosphorus,and available potassium,respectively.[Conclusion]The layered N,P,K fertilization combined with key irrigations at three stages achieved a high degree of coordination between root configuration,growth,physiological functions,and appropriate distribution of available N,P,K nutrients,and enhanced the root biomass in 20-40 cm soil layer,indicating more absorptions of nitrogen,phosphorus,and potassium from the soil and a higher grain yield.