Author
CHERUBIN, MAURICIO - Universidad De Sao Paulo | |
Karlen, Douglas | |
FRANCO, ANDRE - Colorado State University | |
CERRI, CARLOS - Universidad De Sao Paulo | |
TORMENA, CASSIO - University Of Maringa | |
CERRI, CARLOS - Universidad De Sao Paulo |
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/20/2015 Publication Date: 2/25/2016 Citation: Cherubin, M.R., Karlen, D.L., Franco, A.L.C., Cerri, C.E.P., Tormena, C.A., Cerri, C.C. 2016. A Soil Management Assessment Framework (SMAF) evaluation of Brazilian sugarcane expansion on soil quality. Soil Science Society of America Journal. 80:215-226. https://doi.org/10.2136/sssaj2015.09.0328. Interpretive Summary: Maintaining or improving soil quality/health (SQ) is essential for achieving sustainable agricultural systems that will meet global food, feed, fiber and fuel demands. This study was conducted to determine if the Soil Management Assessment Framework (SMAF) could detect SQ changes in response to land use change (LUC) from native Cerado vegetation, to pasture, to sugarcane production. Soils under native vegetation were functioning at 87% of their potential capacity, while degraded pasture soils were functioning at only 70% of their capacity. Conversion from pasture to sugarcane improved SQ, primarily because of improved soil fertility, but compaction was increased due to excessive machinery traffic. This information will be useful to farmers, land managers, conservationists, and soil scientists who are striving to define appropriate soil quality/health indicators in areas of sugarcane expansion in Brazil. Technical Abstract: The Soil Management Assessment Framework (SMAF) was developed to evaluate impacts of land use and management practices on soil quality (SQ), but its suitability for Brazilian tropical soils was unknown. We hypothesized that SMAF would be sensitive enough to detect SQ changes associated to sugarcane (Saccharum officinarum) expansion for ethanol production. Field studies were carried out at three sites across the central-southern region of Brazil, aiming to quantify impacts of a land use change (LUC) sequence [i.e., native vegetation (NV) – pasture (PA) – sugarcane (SC)] on SQ. The assessment included eight indicators that were measured and statistically analyzed for each site within the 0-10, 10-20 and 20-30 cm depth increments. Soil indicators were individually scored using SMAF curves developed for American soils and integrated into an overall Soil Quality Index (SQI) and in its chemical, physical and biological sectors. SMAF scores were correlated with other approaches to assess SQ changes, such as soil organic carbon (SOC) stocks and Visual Evaluation of Soil Structure (VESS) evaluations. Our findings showed that the SMAF was an efficient tool for assessing LUC effects on SQ of Brazilian tropical soils. The SMAF scoring curves developed using robust algorithms assigned satisfactory scores for the soil chemical, physical and biological indicators included in this study. Overall SQI scores values were significantly correlated with SOC stocks and VESS scores. Long-term LUC from NV to extensive PA promoted significant decreases in soil chemical, physical and biological indicators. Overall SQI (0-30 cm) suggested that NV soils were functioning at 87% their potential capacity, while PA soils were functioning at 70%. Conversions of PA to SC induced slight improvements on SQ, primarily because of improved soil fertility. Overall, SC soils are functioning at 74% of their potential capacity. Based on this study, management strategies are suggested to improve SQ and the sustainability of SC production in Brazil. |