Effects of the co-application of Chinese milk vetch and chemical fertilizer on the leaching and loss of dissolved organic carbon and nitrogen in different paddy soils
In this study,we sought to investigate the effects of the application of Chinese milk vetch on the concentrations of dissolved organic carbon(DOC)and dissolved organic nitrogen(DON)in paddy soil,and to elucidate the leaching characteristics of DOC and DON.We used three typical soils(yellow,yellow podzolic,and gray paddy soils)used to cultivate rice in a subtropical region to investigate the effects of single chemical fertilizer application(CK)and combined Chinese milk vetch and chemical fertilizer(cmv)treatment on the migration characteristics and leaching of DOC and DON in different paddy soils through field experiments.The results revealed differences among the three assessed paddy soil types with respect to the leaching characteristics of DOC and DON.The loss of DOC through leaching was found to be highest in gray paddy soil,with leaching loss under the CK treatment being 24.09%and 72.15%higher than that from the yellow podzolic and yellow paddy soils,respectively,whereas cmv treatment significantly increased by 16.53%and 40.55%,respectively.The largest loss of DON via leaching was detected in the yellow paddy soil,in which loss under the CK treatment was 18.93%and 37.01%higher than that from yellow podzolic and gray paddy soils,respectively.However,we detected no significant differences in the leaching loss of DON among the three different paddy soil types treated with cmv.Compared with the CK treatment,we detected reductions of 24.67%,14.88%,and 13.54%in the leaching loss of DON in the cmv-treated yellow,yellow podzolic,and gray paddy soils,respectively,and we found no significant differences between the two fertilization treatments in the plaster field.We also established that the leaching of DOC and DON through the soil layers of the assessed paddy fields was characterized by a delayed progression,and that the rate of DON leaching was greater than that of DOC.Grey correlation analysis revealed that organic matter was the most important factor associated with DOC leaching loss in paddy soils,whereas soil porosity was the most important factor determining the loss of DON through leaching.On the basis of our findings in this study,we established that the leaching of DON from different types of paddy soil occurs earlier than that of DOC,and that the leaching loss of DON was higher in yellow paddy soil fields,whereas the loss of DOC was higher in gray paddy soil fields.Co-application of Chinese milk vetch was found to reduce the leaching loss of DON in paddy fields,whereas the loss of DOC through leaching in low-fertility paddy soil increases under conditions of equivalent amounts of nitrogen,phosphorus,and potassium.
Chinese milk vetchpaddy soildissolved organic carbondissolved organic nitrogenleaching characteristic
万方数据
维普
