Innovative Land Arrangement in Combination with Irrigation Methods Improves the Crop and Water Productivity of Rice (<i>Oryza sativa</i> L.) Grown with Okra (<i>Abelmoschus esculentus</i> L.) under Raised and Sunken Bed Systems

Abstract

The underground water and water storage reservoirs are rapidly depleting due to nominal recharging by the rainfalls making water a scarce resource for irrigation resulting in poor crop growth and production. Irrigation water application should focus on the proficient use of each drop of water. Water productivity (WP) in agriculture can be improved through crop diversification, proper land and water management techniques. Considering this, a field investigation was carried out during 2013–2014 and 2014–2015 to study the crop response of rice (Oryza sativa L.) + okra (Abelmoschus esculentus L.) system to land configurations and irrigation regimes. Three raised-sunken beds (RSB) having width (m) ratios of 1:3, 2:3, 3:3 and two irrigation schedules viz. continuous standing water (CSW) of 5 ± 2 cm depth and alternate wetting and drying (AWD) at 3 ± 1 days interval for rice in sunken bed were tested. Rice yield was more (4.36 and 4.89 Mg ha−1) under CSW irrigation than AWD irrespective of raised bed width. The highest okra yield was noted by 14.09 and 15.43 Mg ha−1 with AWD in 1:3 RSB systems, whereas the lowest yield was recorded in CSW 1:3 RSB systems. Rice equivalent yield (REY) was found as the maximum in AWD than CSW irrespective of raised and sunken bed configurations. The AWD in 3:3 RSB systems exhibited the highest WP of 1.02 and 1.01 kg m−3 during the first and second year of study, respectively. Wider RSB system of land configuration ratio of 3:3 saved about 40–45% of irrigation water. Such information will help in the planning of an innovative intercropping system of summer rice + okra in the field by changing the land configuration to the raised bed and sunken bed with the AWD irrigation system.

Keywords

• raised-sunken bed
• irrigation
• yield
• water productivity