Seedbed management, transplanting methods and irrigation regimes influence the growth, productivity and economics of summer rice (Oryza sativa L.)

Abstract

A field experiment was conducted during the rabi (winter) seasons of 2017–2018 and 2018–2019 at the Central Research Farm under Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, to study the effects of planting techniques, irrigation regimes, and nursery bed management on the growth, yield, nutrient dynamics, water productivity, and economics of summer rice (cv. Shatabdi) production. The experiment was performed in a strip-split plot design with twelve treatment combinations, which were replicated three times. The design consisted of two types of transplanted rice establishment methods (viz., puddled transplanted rice (PTR) and nonpuddled transplanted rice (NPTR)) allocated to the main plot, three irrigation regimes (three-day intervals; six-day intervals; nine-day intervals) allocated to the subplot, and two nursery bed management practices (conventional seedbed and improved seedbed) allocated to the subplot. Higher growth attributes, such as plant height, tiller count, biomass, and LAI, were found under nonpuddled conditions at the time of harvesting. Similarly, a three-day irrigation interval and improved seedlings led to better growth traits. The yield attributes and yield varied nonsignificantly among the crop establishment methods. However, the lowest irrigation intervals accounted for 53.78% and 43.02% greater grain yield than did the nine-day intervals in two consecutive years, respectively, and produced statistically similar yields with six-day intervals. The percentage of seedlings transplanted from improved seedbeds was 4.01 and 4.13% greater than that from conventional seedlings. A similar trend was observed for both input and irrigation water productivity, except that the nine-day irrigation interval resulted in significantly greater water productivity than did the other intervals. The treatment consisted of nonpuddled transplanted rice along with six six-day irrigation intervals and improved seedbed management, resulting in the highest net return and benefit:cost ratio due to the low production cost. Thus, it can be concluded that transplanting seedlings into nonpuddled soil from an improved seedbed with intermittent irrigation might be the most judicious and recommended in terms of productivity as well as profitability for summer rice production.