Soil-plant water dynamics, yield, quality and profitability of spring sweet corn under variable irrigation scheduling, crop establishment and moisture conservation practices

Spring sweet corn as a short duration cash crop is gaining popularity in northern India owing to increasing demand in urban and peri-urban regions. Under hot dry climate and minimal rainfall, irrigation is the major yield contributing factor for attaining superior quality cobs and higher economic returns. The study aimed at examining the effect of irrigation scheduling (I) (IW/CPE 1.0, 1.2, 1.4), sowing methods (S) (flat and furrow) and moisture conservation practices (M) (no-residue, rice straw mulch 6.0 t ha⁻¹ and rice straw biochar 3.0 t ha⁻¹) on spring sown sweet corn yield, quality, profitability and water use efficiency in the Tarai region (sandy loam soil texture) of Uttarakhand, India. The experiment was conducted in split factorial design (Main I x S, Sub M) with 18 treatment combinations and three replications. Results indicated that the combination IW/CPE 1.4 +furrow+mulch being at par with IW/CPE 1.4 +furrow+biochar were superior in terms of dehusked cob yield which was ~42% higher over IW/CPE 1.0 +flat+control. Application of biochar 6 t ha⁻¹ and straw mulch 3 t ha⁻¹ increased dehusked cob yield of sweet corn by ~6–9% over control (no-residue) during both years. Among irrigation schedules, IW/CPE 1.0 obtained highest irrigation water use efficiency (IWUE) followed by IW/CPE 1.2. Mulch and biochar being on par recorded 7–10% higher IWUE over no-residue control. Likewise, furrow sowing increased IWUE by 39–44% over flat method with ~25% higher water savings. Average soil moisture content under mulch and biochar was 25% and 12% higher respectively over no-residue. Maximum net returns was obtained under the combination IW/CPE 1.4 +furrow+mulch (1672 USD ha⁻¹) which was 69% higher over IW/CPE 1.0 +flat+no-residue. Sweet corn quality parameters viz., total soluble solids and non-reducing sugar was significantly higher under IW/CPE 1.0 and 1.2 in comparison to 1.4, as well as under furrow sowing over flat sowing. Therefore, although maximum yield and profitability of sweet corn was obtained under irrigation schedule IW/CPE 1.4, the treatment combination of IW/CPE 1.2 with furrow sowing and mulch/biochar application may be adopted for attaining superior quality parameters and improved water use efficiency of sweet corn.