Organic Amendment and Fertilizer Effect on Soil Chemical Properties and Yield of Maize (Zea mays L.) in Rainfed Condition

Indonesia contributes 2 % of maize (Zea mays L.) production on the global scale, making it the sixth largest producer in the world. Maize is grown mainly (89 %) in rainfed areas. In agriculture management, rainfed areas have problems, such as lack of water and nutrient availability. This study aims to identify the role of organic amendments and NPK fertilizer in rainfed land management. The research was conducted in Karanganyar regency, Central Java, Indonesia, with an average temperature of 30 - 31 °C, relative humidity of 86 %, and rainfall around 2100 mm year-1. The experiment was carried out during May - August (dry season). The experiment consisted of 5 treatments: (i) control (CO); (ii) compost fertilizer (CF); (iii) straw mulch (MC); (iv) legume cover crop (CC), and (v) NPK fertilizer (AF), and was arranged in a randomized complete block design with 4 replicates. The results showed compost and mulch can increase soil organic carbon (62 and 9.8 %, respectively), organic matter (62 and 9.8 %, respectively), plant height, cob weight, and biomass (30 and 18 %, respectively). On the other hand, legume cover crops have an adverse effect on the growth and yield of maize, due to nutrient competition between them. NPK fertilizer treatment has the highest value for growth and yield of corn crop, at 179.6 cm and 83.4 g, respectively, followed by compost, mulch, control, and legume cover crop, because NPK fertilizer can supply all nutrients, which are easy for the plants to absorb. Treatment compost 20 t.ha-1 can give the same result as NPK fertilizer 15-15-15 200 kg.ha-1 in plant growth and production.