Nitrogen Mineralization of Four Andisol Soil Depths which is Cultivating Organic and Conventional in Ciwidey and Cisarua.

Abstract

Conventional agricultural system uses pesticide and organic fertilizer excessively that cause nutrient accumulation in waters and ground water that can pollute environment. Nitrogen is one of essential nutrient with low availability in the ground. Nitrogen is dynamic nutrient and easy to change. Therefore it needs to obtain information about nitrogen mineralization degrees especially NH4+ and NO3- in some depths of Andisol soil which is developed for cultivating organic and conventional in Ciwidey and Cisarua. The soil samples were taken from 0-25, 25-50, 50-75, and 75-100 cm depths at Ciwidey (Bukit Organik) and Cisarua (Permata Hati dan Bina Sarana Bakti). Drilling was done in each embankment of four points which were chosen randomly of each cultivating area. Soil samples of four points were mixed to homogenous. NH4+ and NO3- contents of the soil were analyzed using KCl and CaCl2 spectrophotometric methods. Based on the results, there was a difference of nitrogen mineralization (content of NH4+ and NO3-) in the some depths of Andisol soil which is developed for cultivating organic and conventional at Permata Hati, Bukit Organik, and Bina Sarana Bakti. Nitrogen mineralization of NH4+ in the soil of organic cultivating is slower than conventional cultivating.