156-13 Physical Fractionation of Organic Matter and Management Impacts of Tropical Soils.

Poster Number 1325

See more from this Division: SSSA Division: Soil Fertility & Plant Nutrition
See more from this Session: Ph.D. Graduate Student Poster Competition

Monday, November 16, 2015
Minneapolis Convention Center, Exhibit Hall BC

Moniki Campos Janegitz, Crop Science, Sao Paulo State University, Botucatu, SP, BRAZIL, Ciro Antonio Rosolem, C.P. 237, University of Sao Paulo, Botucatu, SP, BRAZIL, Gustavo Henrique de Menezes Bacco, Sao Paulo State University, Botucatu, Brazil and Camila Grassmann, Crop Science, São Paulo State University, Botucatu, Brazil
Poster Presentation
  • poster-ASA-2015-UNESP-Moniki-Janegitz.pdf (512.1 kB)
  • Abstract:
    Physical fractionation of organic matter and management impacts of Tropical soils

    Moniki Campos Janegitz; Ciro Antonio Rosolem, Gustavo Henrique de Menezes Bacco, Camila Grassmann,

    São Paulo State University, College of Agricultural Sciences, C.P.237, Botucatu,

    AL 18603-970, Brazil

    The increase of soil organic matter (SOM) improves the Cation exchange capacity (CEC) of tropical weathered soils. Moreover, the soil acidity amelioration is required to achieve high yields in these soils. The application of lime may increase SOM with time by improving cation chemical bonds with soil colloids. Soil C fraction may also be affected by different cropping systems. Our objectives were to evaluate the C and soil physical changes under practices as tillage and acidity remediation. The experiment was carried out in an oxisol in Botucatu, São Paulo, Brazil in two fields (no till and conventional systems). The treatments were: control, lime, silicate, gypsum + lime and gypsum + silicate. Limestone, silicate and gypsum rates were calculated to raise soil base saturation to 70%. The initial soil pH was 3.7. The soil samples from both areas were taken one year after treatment applications at depths from 0 to 40 cm, and we examined cation exchange capacity, organic matter and soil porosity. The quantity of total carbon also was analyzed, including carbon particulate and carbon associated minerals (CAM), which were obtained by physical fractionation. The results suggest that C-loss depends on soil management system. The SOM amount caused modification on CEC and carbon physical fractionation. The limestone, silicate and gypsum treatments increased the CEC in soil when compared to control. The silicate used increased labile soil C and C contents in the particulate fraction. Lime + gypsum results in increased soil stable C, and soil physical properties were also influenced in that treatment. 

    Acknowledgement: Capes e FAPESP – Proc 2012/09550-0

    See more from this Division: SSSA Division: Soil Fertility & Plant Nutrition
    See more from this Session: Ph.D. Graduate Student Poster Competition