Long-term Fertilizer Application Alters Acidification Rate and Acid-Neutralizing Capacity in Corn and Soybean Rotational/Continuous Cropping Systems of Mollisol Field
In this study,to explore the effects of different cropping systems and fertilization practices on acidification indexes and acid buffering mechanisms in black soil,based on the Northeast Dryland Black Soil Fertility Monitoring Long-term Positioning Experiment Station,soil acidification rate(SAR)and soil acid-neutralizing capacity(ANC)under following seven treatments were investigated:continuous soybean with chemical fertilizer(CS),continuous corn with chemical fertilizer(CC),and corn-soybean rotation treatments including both corn and soybean with chemical fertilizer(CCF SCF),corn with chemical fertilizer plus straw return while soybean without chemical fertilizer but plus straw return(CCR SNOR),corn with chemical fertilizer while soybean without chemical fertilizer(CCF SNOF),corn with chemical fertilizer while soybean with 1/2 chemical fertilizer(CCF S1/2CF),corn with chemical fertilizer while soybean with dairy manure(CCF SDM).Soil ANC and acid-buffering capacity(ABC)at pH 5.0 and pH 4.5 were further calculated by using quadratic curve fitting model as references.The results showed that the change of SAR ranged from-0.019--0.097 ΔpH/a compared to the background pH after 9-and 10-year experimentation.Changes of SAR were lowest under CCF SDM in both two years(-0.021 and-0.019 ΔpH/a).Moreover,soil ANCpH5.0 in 9th year was 1.11-1.77 times compared with in 10th year under CCF SCF,CCR SNOR,CCF SNOF,CCF S1/2CF,and CCF SDM.The trends of ANCpH4.5 was consistent with ANCpH5.0.Variation partitioning analysis showed that soil organic matter(SOM)and the sum of exchangeable base(SEB)were the main factors affecting the changes in soil ANC,and both explained 63.44％and 43.67％of soil ANC and ABC variations after 9 and 10 years,respectively.In conclusion,chemical fertilizer application decreased soil ANC and accelerated soil acidification,while organic fertilizer application increased soil ANC by increasing SOM and SEB.
Black soilSoil acidification rate(SAR)Acid titration curveSoil acid-neutralizing capacity(ANC)
国家科技期刊平台
NSTL
万方数据
