Effect of season, soil and land use pattern on soil N-mineralization, Ammonification and Nitrification: A study in Arunachal Pradesh, Eastern Himalaya

Net N-mineralization, ammonification and nitrification as influenced by climatic factors, soil characteristics and land use patterns were studied soils of two different land use patterns prevalent in East Siang district, Arunachal Pradesh. Ammonification and nitrification rate varies significantly (p<0.001) between the land use pattern and seasons. The greater amount of N-mineralization was recorded during the rainy season in both the land use patterns while during the spring season (Paddy AES) and rainy season (Homegarden). Ammonification rate is positively correlated with soil pH, SOC, NH₄-N and NO₃-N. Conversely, nitrification rate is negatively correlated to ammonium and nitrate concentration which suggests that available nitrogen concentration was not saturated in these agricultural systems. Lesser nitrification rate compared to the ammonification rate would be helpful in conserving the soil nitrogen.