Studies on Nitrogen Forms as Affected by Long-Term Manuring and Fertilization in Vertisols

Studies on continuous use of manures and fertilizers for more than 8 years indicate that a very small portion of the total N remains in mineralised form, while organic N fractions predominated in all the treatments. Insoluble humin-N and amino acid-N dominated amongst the various N fractions. Addition of FYM had pronounced influence in increasing total and organic N content and green manuring yielded greater amount of readily available nitrogen (NO₃-N) as compared to other treatments.