Drip irrigation and fertigation effects on corm yield, water-and fertilizer-use efficiency and economics in elephant foot yam (Amorphophallus paeoniifolius)

A field experiment was conducted during 3 consecutive years (2009–11) at Dumuduma, Bhubaneshwar, Odisha, to study the effect of drip irrigation and fertigation levels on corm yield, water-and fertilizer-use efficiency as well as economics in elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]. The experiment laid out in a split-plot design with 3 replications, consisted of 3 drip irrigation levels, viz. I₁, 60% cumulative pan evaporation (CPE); I₂, 80% CPE and I₃, 100% CPE, in main plots and 3 fertigation levels, viz. F₁, N-K₂O @ 80–80 kg/ha; F₂, N-K₂O @ 100–100 kg/ha and F₃, N-K₂O @ 120–120 kg/ha in subplots. A control treatment (flood irrigation and soil application of N-P₂O₅-K₂O @ 100-60-100 kg/ha) was also included for comparison. Soil application of PO₂o₅@ 60 kg/ha was done in all the fertigation treatments and farmyard manure @ 10 t/ha was applied to all the treatments during the last ploughing and incorporated into the soil. Higher corm length, diameter and yield/plant were recorded with drip irrigation at 100% CPE with fertigation of N-K₂O @ 120–120 kg/ha. The highest corm yield (37.0 t/ha) was obtained due to drip irrigation at 100% CPE and fertigation of N-K₂O @ 120–120 kg/ha. However, the maximum water-use efficiency (WUE) was recorded with drip irrigation at 80% CPE and fertigation of N-K₂O @ 120–120 kg/ha. This treatment resulted in optimum corm yield (35.7 t/ha) with net saving of 4, 341, 000 litres (434.1 mm) of water/ha of land/season, net income of 154 × 10³ /ha and net profit 701/mm of water applied.