Laboratory incubation assessment of amending phosphate fertilizers with rice straw biochar in improving soil phosphorus availability

Phosphorus is an essential plant nutrient and plays important role in carbon uptake also provide many function and superiority. Phosphorus can promote rapid growth of plants and help in develop roots and improve water uptake by roots. Phosphorus deficiency in plants can be identify by observed the changes and abnormalities that shown by the plants. Major problem phosphorus deficiency in soil is phosphorus fixation. Phosphorus fixation is where volume of phosphorus in the soil decreases due to the presence of aluminum and irons. The objectives of this study were to
characterize the selected physic-chemical properties of soil sample and rice straw biochar, and to determine the soil phosphorus availability upon amending phosphorus fertilizer with rice straw biochar in a laboratory incubation study. An incubation study was conducted at laboratory at University Malaysia Kelantan, Jeli Campus. Rice straw biochar were used in the treatments. Treatments with mixture of rice straw biochar showed significantly increase in soil pH for 30 days, 60 days and 90 days. Besides, significant reduction of exchangeable acidity, aluminum and iron in the soils compared to treatments with chemical fertilizer and soil only. Furthermore, there also significant increase in phosphorus availability in treatments amended with rice straw biochar for 30 days of incubation. This was due to reduction of soil exchangeable acidity, aluminum and iron concentration, thus increase the phosphorus availability in
the soil. As a conclusion, biochar derived from rice straw can be used to improve phosphorus availability in acid soils by reducing the soil phosphorus fixation.