Biochar improves fertility of a clay soil in the brazilian savannah: short term effects and impact on rice yield

Resumo

The objective of this study was to report single season effects of wood biochar (char) application coupled with N fer- tilization on soil chemical properties, aerobic rice growth and grain yield in a clayey Rhodic Ferralsol in the Brazilian Savannah. Char application effected an increase in soil pH, K, Ca, Mg, CEC, Mn and nitrate while decreasing Al content and potential acidity of soils. No distinct effect of char application on grain yield of aerobic rice was observed. We believe that soil properties impacted by char application were inconsequential for rice yields because neither wa- ter, low pH, nor the availability of K or P were limiting factors for rice production. Rate of char above 16 Mg ha −1 reduced leaf area index and total shoot dry matter by 72 days after sowing. The number of panicles infected by rice blast decreased with increasing char rate. Increased dry matter beyond the remobilization capacity of the crop, and high number of panicles infected by rice blast were the likely cause of the lower grain yield observed when more than 60 kg N ha −1 was applied. The optimal rate of N was 46 kg ha −1 and resulted in a rice grain yield above 3 Mg ha −1 .

Descrição

Palavras-chave

Aerobic system, Oryza sativa, Carbonised biomass, Ferralsol, Nitrogen, Oxisol

Citação

CARVALHO, Márcia T. de Melo; MADARI, Beáta E.; BASTIAANS, Lammert; OORT VAN, Pepijn A. J.; HEINEMANN, Alexandre B.; SILVA, Mellissa A. S. da; MAIA, Aline de Holanda Nunes; MEINKE, Holger. Biochar improves fertility of a clay soil in the brazilian savannah: short term effects and impact on rice yield. Journal of Agriculture and Rural Development in the Tropics and Subtropics, Witzenhausen, v. 114, n. 2, p. 101-107, 2013.