The effect of a nitrification inhibitor on the concentration of nitrate in plants

Abstract

Calcium nitrate, or ammonium sulphate without or with 1% of the nitrification inhibitor 2-chloro-6 (trichloromethyl) pyridine were applied in the spring to winter wheat growing on clay- and sandyloam soils; 50 or 100 lb N/acre was applied on the clay-loam and 75 or 150 lb N/acre on the sandyloam. On permanent grassland ammonium nitrate or ammonium sulphate without or with 1 or 2% of inhibitor were broadcast to supply 100 or 200 lb N/acre. Winter wheat was sampled 32 days, and grass 68 days after applying fertilizers. Ammonium sulphate increased nitrate in the wheat on the clayloam soil but significantly less with than without the inhibitor. On the sandy-loam, wheat given ammonium sulphate with and without the inhibitor contained similar amounts of nitrate-N. The double amount of ammonium sulphate without inhibitor increased the nitrate content of grass most, and the nitrate content decreased with increasing amount of inhibitor.