Vol. 12, Issue 10 (2023)

Onion cultivation, being a valuable cash crop in India, covers approximately 8.05 lakh hectares and is steadily expanding. In the state of Madhya Pradesh alone, onion cultivation spans about 1.8 lakh hectares. The primary objective of this research is to examine the combined impact of deficit irrigation, fertigation, and mulching in drip-irrigated onion fields. This study aims to calculate parameters like water conservation percentage, water productivity, fertigation efficiency, onion yield, and the economic viability of different treatment strategies.

The field trial was conducted using a drip irrigation system with six main treatments (T₁ to T₆) and three sub-treatments (F1 to F3). The results revealed variations in the number of leaves, plant height, bulb diameter, canopy temperature, onion yield, water conservation, and water productivity. Specifically, the range for these parameters fell within the following values: 5-13 leaves, 19.5-68 cm plant height, 3.1-7.9 cm bulb diameter, 29-45 °C canopy temperature, and 14.0-18.9 tons per hectare onion yield. The maximum water conservation of 574 mm was observed in T₁, while water productivity ranged from 3.03 to 6.00 kg/m3.

In summary, deficit irrigation and fertigation levels significantly influenced the number of leaves, plant height, bulb diameter, and onion yield. The highest yield was achieved in T₄ (18.9 tons/ha), with water savings of 104 mm in T₃. The Benefit-Cost Ratio (BCR) in the study was notably affected by the level of deficit irrigation and the cost of mulching. The straw mulch treatment consistently yielded the highest BCR under all treatments, ranging from 1.67 to 1.19. Meanwhile, the crop without mulch treatment in all main treatments yielded a BCR ranging from 1.63 to 1.08. In conclusion, farmers can achieve better yields and economic profitability by adopting 80% deficit irrigation and 75% fertigation levels.