Raised bed with modified furrow system and supplemental irrigation for sustainable dryland agriculture in Alfisols of semi-arid India

Aim: To develop an improved rainwater harvesting technique for field crops in drylands, and to study its efficacy to promote moisture conservation, mitigate soil erosion, in order to enhance crop productivity and water use efficiency. Methodology: This experiment was laid out in a strip-plot design with soil and water conservation (SWC) treatments and supplemental irrigation during 2021 to 2023 with maize -pigeonpea crop rotation. The SWC treatments were: M1- Raised bed with modified furrow system (RBMF); M2- RBMF with coir pith compost; M3- RBMF with farmyard manure; M4- RBMF with tank silt and M5- Control (without raised bed/ Farmers practice). The irrigation treatments were: I0-No irrigation (NI); I1-With supplemental irrigation using sub-surface (10 cm) drip (SSDI) and I2-With supplemental irrigation using surface drip (SDI) in three replications. Maize and pigeonpea was taken up in alternate years. The observations included soil physical and chemical properties, runoff, soil loss and grain yield. Results: During normal year, RBMF with coir pith compost or farmyard manure in the furrows increased the grain yield in maize by 17.0-18.4% and pigeonpea yield by 38.2 -54.2%, respectively.These treatments improved the soil moisture by 2-3% (dry basis) and controlled soil loss by 55 to 60%. Along with these treatments, two irrigations increased the pigeonpea yield by 80-88% whereas one irrigation in maize increased the yield by 33-35%. Among irrigations, the sub-surface drip system resulted in more crop yield and higher water use efficiency (WUE) of 3.25 to 3.40 kg ha-1 mm-1 during the period of drought year. Interpretation: RBMF along with coir pith compost or farmyard manure in the furrows had improved the soil moisture, reduced soil erosion, enhanced nutrient status of soil, crop productivity and water use efficiency considerably in the Alfisols. Key words: Alfisols, Drylands, Moisture conservation, Raised bed, Sub-surface drip, Supplemental irrigation