Comparative Study of Drip Irrigated Dry Direct Seeded Rice and Conventionally Flooded Transplanted Rice Productions

A field experiment was conducted to compare the growth, yield and water use in drip-irrigated aerobic rice and conventionally flooded transplanted rice. The experimental design was split-plot design with 3 varieties in the main plot and 2 levels of irrigation (1.0 Epan& 1.5 Epan) in combination with 2 doses of N (100 & 125% of recommended dose of fertilizers) in the sub-plot and replicated thrice. An observation trial with these 3 varieties under transplanted conditions with 100 & 125% N was taken up. The experiment was conducted during Kharif, 2022 & 2023 at College Farm, College of Agriculture, Rajendranangar, Hyderabad, Telangana, India. In each variety, the best-performing irrigation level was found at 100% N & 125% N. Best-performing treatments under dry direct-seeded (DDSR) conditions was compared with conventionally flooded transplanted rice (CFTPR) with the same variety and same dose of N for growth parameters, yield attributes & yield as well as water productivity using a one-sample t-test. A significantly higher root length was observed in direct-seeded rice compared to transplanted rice in all the 3 varieties; while panicle weight did not differ with establishment methods @ 5% level of significance. Number of unfilled grains & chaffy grain% was low in direct-seeded rice of DRR Dhan-42, while it did not differ statistically for JGL-24423 at 100% N. For KNM-1638, transplanted rice recorded a significantly lower number of unfilled grains & chaffy grain percentage at both 100 & 125%N. DDSR & CFTPR recorded comparable grain yields in DRR Dhan-42 @ 100 (P = 0.22) & 125% N (P = 0.07) & in JGL-24423 @ 100% N (P = 0.18). For KNM-1638, higher grain yield was reported in transplanted rice over dry direct-seeded rice at both 100 (P = 0.01) & 125% N (P = 0.01). A significantly higher harvest index was reported by transplanted rice @ 100% N in KNM-1638 (P = 0.02), whereas it did not differ statistically for JGL-24423 & DRR Dhan-42. Drip irrigated direct-seeded rice recorded 2-2.4 times higher water productivity & 2- 3 times lower water use compared to conventionally flooded transplanted rice. There is a 57-68% saving in irrigation water in DDSR over CFTPR. It can be concluded that drip irrigated dry direct-seeded rice saves a hefty amount of irrigation water without compromising yield depending on the variety. For saving irrigation water without compensating yield, drip irrigated dry direct seeding of paddy is recommended with 100% N in JGL-24423 & DRR Dhan-42.