Xiapu Gai, Hongyuan Wang, Ya Yang, Huiyuan Sun, Bo Yang, Shuxia Wu, Qiang Zhang, Xingwang Ma, Degang Zhao, Hongbin Liu
{"title":"Effects of fallow and chemical fertilizer applications on soil carbon and nitrogen pools in North China Plain: Medium-term and long-term trends","authors":"Xiapu Gai, Hongyuan Wang, Ya Yang, Huiyuan Sun, Bo Yang, Shuxia Wu, Qiang Zhang, Xingwang Ma, Degang Zhao, Hongbin Liu","doi":"10.1016/j.still.2025.106450","DOIUrl":null,"url":null,"abstract":"Improving soil fertility is pressingly needed for national and global sustainable development. Land fallow has been considered an important measure to alleviate the degradation of soil fertility. However, it remains unclear regarding how fallow affects soil organic carbon (SOC) and total nitrogen (TN) pools. Therefore, our objective was to assess the effects of fallow on SOC and TN pools along the 0–200 cm soil profile, and to further clarify whether its long-term effects are consistent with medium-term effects. Through a comparative field study on a fluvo-aquic soil, we evaluated both medium (11 years 1991–2001) and long-term (27 years 1991–2016) effects of two land management practices on SOC and TN pools, soil biogeochemical properties and microbial communities. The practices were: (1) natural fallow and (2) chemical N, phosphorus (P) and potassium (K) fertilizers (NPK treatment). Results showed that for the medium-term experiment, SOC and TN pools along the 0–200 cm soil profile in the fallow treatment were 10.9 %-98.9 % and 11.4 %-91.8 %, respectively, of that in NPK. For the long-term experiment, however, the SOC pools in the fallow were 1.1–1.6 times that of NPK, and for TN correspondingly 1.1–1.2 times in the 0–60 cm soil layer but only 16.4 %-75.3 % in the 60–200 cm layer. Furthermore, fallow resulted in lower microbial biomass C (MBC), N mineralization and potential nitrification rate than NPK did. Fallow increased the relative abundance of <ce:italic>Proteobacteria</ce:italic> but decreased that of <ce:italic>Chloroflexi</ce:italic> and <ce:italic>Nitrospirae</ce:italic>. These results imply that the lower microbial activity especially the reduction of nitrification processes may have contributed to the greater soil C and N sequestration of fallow with the time prolonged. In conclusion, medium-term fallow will inhibit the increase of soil C and N storage, although it can improve soil C and N storage in the long term in North China Plain.","PeriodicalId":501007,"journal":{"name":"Soil and Tillage Research","volume":"29 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Soil and Tillage Research","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1016/j.still.2025.106450","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Improving soil fertility is pressingly needed for national and global sustainable development. Land fallow has been considered an important measure to alleviate the degradation of soil fertility. However, it remains unclear regarding how fallow affects soil organic carbon (SOC) and total nitrogen (TN) pools. Therefore, our objective was to assess the effects of fallow on SOC and TN pools along the 0–200 cm soil profile, and to further clarify whether its long-term effects are consistent with medium-term effects. Through a comparative field study on a fluvo-aquic soil, we evaluated both medium (11 years 1991–2001) and long-term (27 years 1991–2016) effects of two land management practices on SOC and TN pools, soil biogeochemical properties and microbial communities. The practices were: (1) natural fallow and (2) chemical N, phosphorus (P) and potassium (K) fertilizers (NPK treatment). Results showed that for the medium-term experiment, SOC and TN pools along the 0–200 cm soil profile in the fallow treatment were 10.9 %-98.9 % and 11.4 %-91.8 %, respectively, of that in NPK. For the long-term experiment, however, the SOC pools in the fallow were 1.1–1.6 times that of NPK, and for TN correspondingly 1.1–1.2 times in the 0–60 cm soil layer but only 16.4 %-75.3 % in the 60–200 cm layer. Furthermore, fallow resulted in lower microbial biomass C (MBC), N mineralization and potential nitrification rate than NPK did. Fallow increased the relative abundance of Proteobacteria but decreased that of Chloroflexi and Nitrospirae. These results imply that the lower microbial activity especially the reduction of nitrification processes may have contributed to the greater soil C and N sequestration of fallow with the time prolonged. In conclusion, medium-term fallow will inhibit the increase of soil C and N storage, although it can improve soil C and N storage in the long term in North China Plain.