The Effect of Neem (Azadirachta indica) Coated Urea Fertilizer against NH4+ and NO3- Concentration in Clay Loam Soil Texture

Abstract

The study aims to determine the level NH₄⁺ and NO₃^- in the soil with clay loam texture with addition neem coated urea fertilizer. This study was conducted in Experimental Farm of Biology Faculty of Mathematic and Natural Science Makassar State University and Laboratory of Assessment Institute for Agriculture Technology in Maros. This research was an experimental study using a Completely Randomized Design (CDR) with five treatments are control, urea, neem (2,5%) coated urea, neem (5%) coated urea and DCD (5%) coated urea with three replicates. Analysis of NH₄⁺ and NO₃^- levels in this study using colourimetric method. Results obtained by the levels of NH₄⁺ and NO₃^- produced after applied of nitrification inhibitor materials coated urea fertilizer as indicated by concentration of NH₄⁺ and NO₃^- produced in soil. Neem (5%) coated urea as a nitrification inhibitor showed the best effect in increasing levels of NH₄⁺ in the soil, while DCD (5%) coated urea were the best inhibitor in reducing levels of NO₃^- in the soil.