Amending inorganic fertilizers with rice straw compost to improve soil nutrients availability, nutrients uptake, and dry matter production of maize (Zea mays L.) cultivated on a tropical acid soil

This study was carried out to assess the effect of amending inorganic fertilizers with rice straw (RS) compost in improving the soil nutrients availability, nutrient uptake, and dry matter production of maize cultivated on a tropical acid soil. A pot trial was conducted for 60 days and maize (F1 hybrid sweet corn 801 variety) was used as a test crop. Rice straw compost was applied at rates of 5 t ha(-1), 10 t ha(-1), 15 t ha(-1) and 20 t ha(-1), respectively. Treatments of amending inorganic fertilizers with RS compost were found to increase soil total N, available P, and exchangeable K at the end of the pot experiment. This was possible because it increases the nutrients availability in the tropical acid soil by reducing NH3, H2PO-, and K+ loss through volatilisation, leaching and denitrification. The soil pH and the soil EC also significantly increased with the presence of RS compost. Dry weight of maize plants (leaf and stem) and higher N, P, and K uptake in leaf, stem, and root of maize were observed under treatments amended with RS compost. An application rate of 15-20 t ha(-1) of RS compost together with 130 kg ha(-1) urea, 200 kg ha(-1) Christmas Island rock phosphate, and 67 kg ha(-1) muriate of potash are recommended to improve the soil NPK contents and growth of Zea mays in acidic soil.