Effects of Liming, Urea and NPK Fertilizers on Availability and Movement of Mineral Nitrogen in Peat Soils under Aerobic and Anaerobic Condition

摘要

In this study, effects of lime (CaCO3) and fertilizers (Urea and NPK 15:15:15) onavailability and movement of ammonium-N (NH4+-N) and nitrate-N (NO3- -N) in peatsoils under aerobic and anaerobic condition were studied. Treatments used were: T0(Control), T1 (NPK only), T2 (Urea only), T3 (Urea + NPK), T4 (Lime only), T5 (Lime+ NPK), T6 (Lime + Urea) and T7 (Lime + Urea + NPK). Results showed thattreatment applied with NPK only, combination of urea and NPK, liming with NPK, andliming with both urea and NPK had produce observable amount of NO3- -N in aerobiccondition, indicating that application of NPK was able to enhance nitrification.Consequently, treatment with a combination of urea and NPK, and lime with urea givethe highest total concentration of NH4+-N produced throughout the weeks underaerobic and anaerobic condition, respectively, suggesting that highest concentration ofNH4+-N is able to be produced in both conditions as long as there is an existence ofurea in the treatment, with either liming or NPK application. For mineral soilunderlying peat, there was NH4+-N deposition observed which ranged from 4.2% up to50.43% showing that there is a nutrient movement in peat water throughout its profileeven though the water table is fixed at certain depth in a closed system. From this study,it can be concluded that combination of urea and NPK demonstrate a steady pattern ofNH4+-N and NO3- -N release under aerobic condition whereas combination of ureaand lime works better under anaerobic condition for NH4+-N release.