Yield and water productivity of rice as influenced by responsive drip irrigation, alternate wetting and drying versus conventional flooding under silty loam soil texture

Resumo

Rice is a semi-aquatic crop, thus demands waterlogged condition in root zone, hence farmers generally puddle the land before transplanting to control deep drainage losses, which is destructive to the soil physical, chemical and biological health. Addressing these issues, this research study evaluated the yield and water productivity (WP) benefits of rice (PK 1121) for the un-puddled alternate wetting and drying (AWD) and responsive drip irrigation (RDI) against the conventional flooding (CF) with puddling, as control during 2021, using randomized complete block design with three replicates. The results indicated significantly less (p ≤ 0.05) irrigation application (76% < CF) but with larger (18%) yield trade-off for the RDI treatment. Although, the AWD treatment showed comparatively less water saving (32% < CF) but resulted relatively higher yield (4% > CF). Nevertheless, the WP of RDI was significantly higher (249% > CF) but reduction in irrigation application was the main contributor. In contrast, both higher yield and reduced irrigation contributed to the higher WP (52% > CF) of AWD treatment. The study shows the prospects of increased WP by AWD at convenience and less cost, than the RDI system for PK 1121 rice variety. However, increasing the water release capacity of RDI or using drought tolerant variety may increase the WP of rice under RDI system at no yield trade-off, which may be instrumental for growing rice without puddling in the water scarce areas of the country.