RESPONSE OF DIRECT-SEEDED RICE (ORYZA-SATIVA) TO LEVELS OF NITROGEN AND IRRIGATION IN CALCAREOUS SOIL

A 2-year experiment was conducted with direct-seeded rice (Oryza sativ e L.) at Pusa with 4 levels of irrigation (3, 5, 7 days drying after d isappearance of 7 cm ponded irrigation water and a rainfed control) al ong with 4 N levels (0, 40, 80 and 120 kg/ha). Rice field can be dried even up to 7 days after disappearance of irrigation water with a grai n yield of 19.13-21.29 q/ha and net return of Rs 2,648-3,014//ha again st similar yields at 3 or 5 days drying. However, rainfed control show ed a significant decrease in grain yield compared with the other dryin g periods. Response to N was recorded up to 80 kg N/ha, with a rice yi eld of 22.19-23.70 q/ha compared with 24.10-25.28 q/ha at 120 kg N/ha, both being at par with each other. Water-production function and grow th characters were also significantly decreased due to rainfed control and lower levels of N in most of the cases.