摘要
Biochar application can alleviate the adverse effects of saline-alkali stress on crops.However,the long-term effects of one-off biochar application on soil physicochemical properties,salt concentration,nutrient availability,soil enzyme activities,and rice yield under highly saline-alkali paddy soils remain unclear.Here,a 6-year paddy field study was conducted in a saline-alkali paddy field using two nitrogen application levels(0 and 225 kg ha−1)and four biochar application rates[0(T0),1.5%(T1.5),3.0%(T3.0),and 4.5%(T4.5)biochar,w/w].The results showed that compared with T0,the bulk density(BD)under T1.5,T3.0,and T4.5 treatments significantly decreased by 11.21%,16.33%,and 25.57%,while total porosity(Tp)and saturated hydraulic conductivity(Ks)increased by 19.15-27.34%and 3217.78-5539.83%,respectively.Biochar consistently improved soil macro-aggregates,mean weight diameter(MWD),and the percentage of water-stable aggregates(PWSA)over the years.Additionally,one-off application of biochar continuously reduced the soil Na+concentration,Na+/K+ratio,Na+/Ca2+ratio,saturated paste extract(ECe),exchangeable sodium percentage(ESP),and sodium adsorption ratio(SARe).However,it reduced the pH in 2021 and 2022 only.It enhanced the concentration of K+,Ca2+,Mg2+,and cation exchange capacity(CEC)over the 6-year study,indicating its longer-term positive impact.Furthermore,the one-off biochar application,especially under high application rate treatments(T3.0 and T4.5),significantly and continuously improved nutrient availability and soil enzyme activities.However,alkali-hydrolysable nitrogen(AN)decreased in the initial year of biochar application.The grain yield of T1.5,T3.0,and T4.5 surpassed that of T0 by 116.38%,141.24%,and 145.20%,respectively.Notably,the rice yield reached its peak with the treatment of 3.0%(w/w)in all 6 years of study period.These findings offered new perspectives on repairing and improving soil quality and production ability of highly saline-alkali paddy soils.
出处
《Biochar》
CSCD
2024年第1期709-730,共22页
生物炭(英文)
基金
funded by the National Natural Science Foundation of China(No.32071951)
the Natural Science Foundation of Jilin Province(No.20230101258JC)
the Chinese Scholarship Council(No.202008220050).
