Nutrient Leaching in a Colombian Savanna Oxisol Amended with Biochar
- Julie Majorad,
- Marco Rondonbe,
- Diego Molinabf,
- Susan J. Rihac and
- Johannes Lehmann *a
- a Dep. of Crop and Soil Sciences, Cornell Univ., Ithaca, NY 14853
d current address: Faculty of Agricultural and Environmental Sciences, McGill Univ., 21,1111 Lakeshore, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada
b Centro Internacional de Agricultura Tropical (CIAT), A.A. 6713 Cali, Colombia
e current address: International Development Research Centre, Ottawa, ON K1G 3H9, Canada
f current address: Centro de Investigaciones en Palma de Aceite, cra 42 # 33-07 Villavicencio, Colombia. Assigned to Associate Editor James Ippolito
c Dep. of Earth and Atmospheric Sciences, Cornell Univ., Ithaca, NY 14853
Nutrient leaching in highly weathered tropical soils often poses a challenge for crop production. We investigated the effects of applying 20 t ha−1 biochar (BC) to a Colombian savanna Oxisol on soil hydrology and nutrient leaching in field experiments. Measurements were made over the third and fourth years after a single BC application. Nutrient contents in the soil solution were measured under one maize and one soybean crop each year that were routinely fertilized with mineral fertilizers. Leaching by unsaturated water flux was calculated using soil solution sampled with suction cup lysimeters and water flux estimates generated by the model HYDRUS 1-D. No significant difference (p > 0.05) was observed in surface-saturated hydraulic conductivity or soil water retention curves, resulting in no relevant changes in water percolation after BC additions in the studied soils. However, due to differences in soil solution concentrations, leaching of inorganic N, Ca, Mg, and K measured up to a depth of 0.6 m increased (p < 0.05), whereas P leaching decreased, and leaching of all nutrients (except P) at a depth of 1.2 m was significantly reduced with BC application. Changes in leaching at 2.0 m depth with BC additions were about one order of magnitude lower than at other depths, except for P. Biochar applications increased soil solution concentrations and downward movement of nutrients in the root zone and decreased leaching of Ca, Mg, and Sr at 1.2 m, possibly by a combination of retention and crop nutrient uptake.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.