Soil, land use time, and sustainable intensification of agriculture in the Brazilian Cerrado region
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- 作者：Kleber Trabaquini ; Lênio Soares Galvão…
- 关键词：Cerrado ; Land use change ; Food security ; Soil nutrients ; Remote sensing ; Agriculture
- 刊名：Environmental Monitoring and Assessment
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：189
- 期：2
- 全文大小：
- 刊物类别：Earth and Environmental Science
- 刊物主题：Monitoring/Environmental Analysis; Environmental Management; Ecotoxicology; Atmospheric Protection/Air Quality Control/Air Pollution; Ecology;
- 出版者：Springer International Publishing
- ISSN：1573-2959
- 卷排序：189
文摘
The Brazilian Cerrado area is in rapid decline because of the expansion of modern agriculture. In this study, we used extensive field data and a 30-year chronosequence of Landsat images (1980–2010) to assess the effects of time since conversion of Cerrado into agriculture upon soil chemical attributes and soybean/corn yield in the Alto do Rio Verde watershed. We determined the rates of vegetation conversion into agriculture, the agricultural land use time since conversion, and the temporal changes in topsoil (0–20 cm soil depth) and subsurface (20–40 cm) chemical attributes of the soils. In addition, we investigated possible associations between fertilization/over-fertilization and land use history detected from the satellites. The results showed that 61.8% of the native vegetation in the Alto do Rio Verde watershed was already converted into agriculture with 31% of soils being used in agriculture for more than 30 years. While other fertilizers in cultivated soils (e.g., Ca+2, Mg+2, and P) have been compensated over time by soil management practices to keep crop yield high, large reductions in Corg (38%) and Ntot (29%) were observed in old cultivated areas. Furthermore, soybean and cornfields having more than 10 years of farming presented higher values of P and Mg+2 than the ideal levels necessary for plant development. Therefore, increased risks of over-fertilization of the soils and environmental contamination with these macronutrients were associated with soybean and cornfields having more than 10 years of farming, especially those with more than 30 years of agricultural land use.