Chemical control of nitrification under rice in the Central Rainlands of the Sudan

Abstract

2-amino-4-chloro-6-methyl pyrimidine "AM" was used as a selective inhibitor of nitrifying organisms to prevent denitrification losses. Zero, 6, and 12 kg/ha of the chemical, 43 and 86 kg/ha urea-N or their equivalents were used in vitro and in vivo experiments. In the in vitro experiment, clear and significant inhibition lasted for 6 weeks. In both the pot and field experiments inhibition lasted shorter and only insignificant increases in yield and yield components were attained. The value of this chemical for rice under the soil and climatic conditions of the Central Rainlands seems to be small, though it seems promising for lighter (leaching) soils.