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 urea-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 efficiency of NF was urea > ammonium sulfate > ammonium chloride. Under flooded conditions, LN decreased NO, formation and leaching. Responses of several crops to LN amended fertilizers were also studied in field experiments. At equal NPK applications, the efficiency of basal applications to rice, wheat, corn, potatoes, soybean, peanut, grapes, peaches, melon and watermelon were better with LN than without. Efficiency with a basal fertilizer for rice or wheat with LN were the same as with the same fertilizer without LN applied in split applications.