Efficiency of applying urea and UTEC carbamide on rice crops

¹ Federal Scientific Rice Centre, Krasnodar, Russia
² Kuban State Agrarian University, Krasnodar, Russia

^* Corresponding author: bondarevatatjna@mail.ru

Abstract

The high efficiency of UTEC carbamide (modified NBPT – N-(n-butyl) thiophosphoric triamide carbamide) is experimentally proven basing on analysis of the dynamics of the ammonium nitrogen content in the meadow soil of rice irrigation systems of Krasnodar region and the urease activity, the nitrogen consumption by rice plants, yield, nitrogen yield removal and its utilization from fertilizer. Different schemes of applying nitrogen fertilizer are assessed. It is shown that when applying nitrogen fertilizer at a full rate in one step, it is necessary to give preference to UTEC carbamide; with fractional UTEC application, it is advisable to apply before sowing and as top dressing in germination phase, the second UTEC carbamide fertilization is less effective than that with urea; with a 20% reduction in the UTEC carbamide application rate, a yield comparable to that under the traditional scheme and rate of urea application is formed; the greatest ecological and agrochemical effect is achieved with the following fertilization system: before sowing – ammophos 100 kg/ha (N₁₂P₅₂) + UTEC carbamide 120 kg/ha (N₅₅); 1st top dressing (germination) – UTEC carbamide 100 kg/ha (N₄₆); 2nd top dressing (tillering) – urea 80 kg/ha (N37).