Rice husk ash as corrective of soil acidity

• Main Authors: Gláucia Oliveira Islabão, Ledemar Carlos Vahl, Luís Carlos Timm, Donald Luiz Paul, Aline Hernandez Kath
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Ciência do Solo 2014-06-01
• Series: Revista Brasileira de Ciência do Solo
• Subjects: correção de acidez; poder de neutralização; poder relativo de neutralização total
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000300025&lng=en&tlng=en

Rice husk ash (RHA) is a by-product from the burning of rice husk that can have favorable effects on the soil in terms of acidity correction. The objectives of this study were to determine the effective calcium carbonate equivalent (ECC) of RHA under field conditions, and establish technical criteria as a basis for estimating the overall ECC of RHA. The 12 treatments of the experiment consisted of 10 RHA dosages (0, 10, 20, 30, 40, 60, 80, 100, 120, and 140 Mg ha-1) and two references, one of which was an absolute control (AC) and the other a plot limed and fertilized according to official recommendations (recommended fertilization - RF). The soil was sampled twice (15 and 210 days after incorporating RHA), in the layers 0.00-0.10 and 0.10-0.20 m, to determine the pH(H2O) and base saturation (V%). The ECC and neutralizing value (NV) of RHA were also determined. The results showed that RHA neutralizes soil acidity, in a faster reaction than conventional limestone, despite a low ECC (around 3 %).