Journal of Tropical Soils (Jan 2010)
Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method
Abstract
Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil ColumnMethod (Sulakhudin, A Syukur, D Shiddieq and T Yuwono): In coastal sandy soil, mainly nitrogen losses due toleaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, andhumic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated ureawith humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare twokinds sources of humic substances (cow manure and peat) which mixed with calcium as coated urea on transformation,vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5%and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHM)and humic-calcium from peat (UCHP) increased the N total and available N in the soil and decreased leaching loss ofN from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium onincubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHMranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between21.44% and 23.25%, whereas for urea (control) reached 29.48%. Leaching losses of mineral N were lower when ureacoated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM isbetter than UCHP in decreasing N leached from coastal sandy soil
