Efficiency of nitrogen carriers in calcareous soil under hybrid rice-wheat -green gram cropping system: a step towards Nutrient Expert® based 4R Stewardship plant nutrition approach
The carriers or the sources of added nitrogenous fertilizers play an important role in regulating N transformations, changing N loss patterns, and influencing NUE. Thus, there is ample opportunity to improve yields of hybrid rice-wheat system through the use of right nitrogen sources. Nutrient Expert (NE) decision support system based on principles of site specific nutrient management (SSNM), offers solutions for providing field specific fertilizer recommendations to improve yield and economics of rice-wheat growing farmers in the region. Recently some N sources has been introduced in the market such as neem-coated urea, sulfur coated urea, etc. Thus, for improvement in efficiency of Nutrient Expert recommendations based on locally available N sources by the farmers, a field experiment was initiated during kharif-2016 in hybrid rice-wheat-green gram cropping system at experimental farm of DRPCAU, Pusa.
IPNI-2016-IND-542
2017 Annual Interpretive Summary
Nitrogen (N) fertilizers play an important role in regulating N transformations, changing N loss patterns, and influencing N use efficiency (NUE) in crop production. There is ample opportunity to improve the productivity and economics of hybrid rice-wheat cropping system through the application of right N sources under the different agro-ecological regions of India. The Nutrient Expert® (NE) fertilizer decision support tool, based on the concept of 4R Nutrient Stewardship and principles of site-specific nutrient management (SSNM), offers solutions for providing field-specific fertilizer recommendations to improve yield and economics of rice-wheat growing farmers in the region. Recently several N sources have been introduced in the market such as neem-coated urea, sulfur-coated urea, and others. Thus, for determination of right source of N under varied climatic regions, NE-based fertilizer recommendations with locally available N sources were tested in a field experiment in hybrid rice-wheat-green gram cropping system at the experimental farm of DRPCAU, Pusa, Bihar. The study was initiated in Kharif 2016 and has continued.
The treatments included application of N, phosphorus (P) and potassium (K) fertilizers in all the of research plots based on the NE recommendations for maize and wheat. The different sources of N fertilizer included prilled urea, neem-coated urea, ammonium sulfate, calcium nitrate, diammonium phosphate, sulfur-coated prilled urea, and sulfur with neem-coated urea. The effect of the sources was compared within treatments as well as with N omission plots. The study reported highest rice equivalent yield resulted from fertilization with sulfur-coated prilled urea (11.5 t/ha), followed by calcium nitrate (11.3 t/ha), compared to the other treatments. The lowest cropping system yield was observed when sulfur and neem-coated urea was used as a N source. The study will be continued for three years to understand the trend and impact of different sources.