Studies on the nitrification inhibitor, dicyandiamide (DCD), for increasing the efficiency of nitrogen applied to rice

Abstract

SummaryA field experiment, made during the rainy seasons oof 1982 and 1983 at the Indian Agricultural Research Institute, New Delhi, studied the effects of blending urea with dicyandiamide (DCD) on the yield and yield components of rice. DCD-blended urea was as effective as neem-cake-coated urea in respect of yield components as well as grain and straw yield of rice and when all the nitrogen was applied 10 days after transplanting both the materials produced significantly more grain and straw than prilled urea. Urea super granules (USG) were superior to DCD-blended, as well as neem-coated, urea.

Relative Efficiency of Prilled Urea, Urea Super Granules, Sulphur Coated Urea and Nitrification Inhibitor N‐Serve Blended Urea for Direct Seeded Rice

“…Also in upland direct-seeded rice cultivation the soil is subjected to alternate flooding and drainage and nitrates formed during conditions of oxidation are lost on submergence due to denitrification (PRASAD and RAJALE 1972). Under such conditions nitrifica-tion inhibitors such as N-Serve or DCD (SHARMA and PRASAD 1980a, PRAKASARAO and PRASAD 1980, SINGH and PRASAD 1985KARA and PRASAD 1986) are reported to increase the efficiency of prilled urea applied to rice. Nitrification inhibiting properties of neem cake, an indigenous material in India, have been reported (REDDY andPRASAD 1975, THOMAS andPRASAD 1983) and neem cake coated urea has been reported to be superior to prilled urea (REDDY and PRASAD 1977, SINGH et al 1980, SINGH and PRASAD 1985, SUDHAKARA and PRASAD 1986.…”

Influence of moisture regime on inhibition of nitrification by DCD

“…Furthermore nitrogen in DCD is completely recovered as mineral N (Vilsmeier, 1980). Effectiveness of DCD as a nitrification inhibitor has been reported (Amberger, 1981;Chen and Lu, 1985;Singh and Prasad, 1985;Prakasa Rao and Puttanna, 1987;Norman et al, 1988). However, no reports are available on the effect of field capacity vis-a`-vis submerged moisture regimes on the inhibition of nitrification by DCD and therefore the present study was taken up.…”