EFFECT OF LIME NITROGEN ON THE EFFICIENCY OF UREA AND OTHER AMMONIUM NITROGEN FERTILIZERS

Five pot experiments were conducted with wheat and rice in a net house to study the effect of lime nitrogen (LN, contains about 55% calcium cyanamide) amendment rates on the efficiency of urea, the recovery ure a-N-15, the efficiency of the three nitrogen fertilizers (NF), on the efficiency of urea in the three soils, and on NO3- -N leaching from a flooded soil. A rate of LN-N of 5-8% of applied fertilizer N increased the recovery of labeled urea-N by 9.42%. The effect of LN on the effi ciency of NF was urea > ammonium sulfate > ammonium chloride. Under fl ooded conditions, LN decreased NO, formation and leaching. Responses o f several crops to LN amended fertilizers were also studied in field e xperiments. At equal NPK applications, the efficiency of basal applica tions to rice, wheat, corn, potatoes, soybean, peanut, grapes, peaches , melon and watermelon were better with LN than without. Efficiency wi th a basal fertilizer for rice or wheat with LN were the same as with the same fertilizer without LN applied in split applications.