Effect of nano urea foliar application on urea reduction, rice productivity and economic feasibility

Nano urea technology is gaining importance mainly due to improvement in crop yields besides reducing environmental issues. It is essential to study the effect of foliar application of nano urea on reduction of conventional urea, growth, grain productivity and net profit of rice. A field experiment was carried out at ADAC & RI, TNAU, Tiruchirappalli during Rabi, 2023. The treatments consisted of three levels of nitrogen (100, 75 and 50 %), nano urea (0.4 %) foliar application in twice (Active Tillering (AI) and Panicle Initiation (PI) stages) and thrice (AT, PI and Flowering stages) combined with 75 and 50 % N and control. Rice variety TRY 5 was used. The results showed that 100 % N application as conventional urea registered significantly increased growth, grain productivity (5200 kg/ha) of rice over lower levels of N and control. However, it was statistically comparable with 75 % N + nano urea (0.4 %) foliar application either two times (AT and PI stages) or three times (AT, PI and Flowering stages). Reducing 25 % N and substituting with nano urea spray twice or thrice showed comparable results with 100 % N. Nano urea spray either two or three times were comparable with each other, indicated that two sprays were sufficient. Economics of nitrogen application found that higher BCR (2.62) was obtained with application of conventional urea at 100 % N over other treatments. 75 % N application in soil + nano urea foliar application twice (AT and PI stages) and thrice (AT, PI and flowering period) gave similar BCR of 2.41.