The Biochar Effect On Organic Matter Cycling in A Degraded Tropical Soil.

If 6 billion people will require adequate food in the future, sustainable agriculture is the challenge for the new millennium. Biochar (BC) may retain nutrients and influence soil organic carbon (SOC) levels making it a potentially important tool. The SOC mineralization rates were monitored in mixtures of a degraded tropical soil containing 35% BC with organic matter additions equivalent to 0, 10, 40, 70 and 100 t ha^-1 (SB, SM-10, SBMO40, SBMO-70, SBMO-100); plus a treatment of just soil without OM or BC (S).  Thirty day mineralization rates were evaluated on soil removed at 0, 80, 160, 240 end 320 days from study pots kept in a greenhouse. The BC promoted fast initial soil mineralization, decreasing gradually until stabilize at 160 incubation days, with total mineralization rate in the period for S, SB, SM-10, SBMO40, SBMO-70, SBMO-100, equal to 135, 1630, 1970, 2084, 1911 and 2153 mg C g-1 of  mixture, respectively. The OM additions did not result in statistically different results due to high BC addition and its high mineralization.