Reaction rate and residual effect of rice husk ash in soil acidity parameters
The rice husk ash has as one of the main uses their incorporation in agriculture, however, their residual effect in soil is still unknown. This investigation aimed to evaluate the reaction rate and residual effect of rice husk ash in soils acidity parameters. To this end, a field experiment was conducted with five treatments: four rice husk ash dosages 0, 30, 60 and 120 t.ha-1 and one treatment with recommended soil lime and fertilizer where five soil samples were collected in the layers 0,00 –0,10 m and 0,10 –0,20 m to the 15, 211, 400, 517 and 804 days after ash incorporation. Chemical attributes were determined: soil pH (pH), soil base, exchangeable cation values (Ca, Mg, K and Na) and cation exchange capacity (CEC) at pH 7. Results showed that reaction rate of rice husk ash is faster when compared to liming. As greater was rice husk ash dosage applied in soil higher is the residual effect in pH. And, as corrective of soil acidity, the residual effect of rice husk ash is just the required time to occur the natural process of reacidification and leaching of basic cations.