Studies on Release of Different Nitrogen Forms Specifically NO_3~- , NH_4~+, Available N and Fertility Status in Soil Relating to Soil Fertility Ratings in Maize (Zea mays L.) Cultivation

摘要

Nitrogen is the most important mineral nutrient for crop production, and its adequate supply in the soil in different forms which roots can take up is essential for high yields. The field experiment was conducted on a Vertisol at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad under rainfed condition. The experiment was laid out in randomized block design (RBD) with three replications to study for different forms N and soil fertility status in maize cultivation with different fertility ratings. Treatment T_8 recorded highest ammonical-N, nitrate-N and available N content compare with other treatments. Treatment 5 (T_5) recorded lowest ammonical and nitrate - N content and treatment 6 was recorded low available N content in soil. The available N, P and K was recorded in content of 258.67 kg/ha, 24.50 kg/ha and 367.33 kg/ha, respectively in treatment T_8. From this study it was found that simultaneous application of nitrogen and potassium resulted in the highest amount of ammonium fixation from the added nitrogen.