1Department of Agricultural Engineerig, Assam Agricultural University, Jorhat
2Department of Horticulture, Assam Agricultural University, Jorhat
Water Technology Centre, I.A.R.I., New Delhi-110012
The experiments were conducted on old alluvial sandy loam soils of Jorhat, Assam, India during November to February for 3 consecutive years (2003–04 to 2005–06) to evaluate the economic feasibility of growing broccoli crop under drip irrigation with black plastic mulch. Actual evapo-transpiration for broccoli crop was estimated by modified penman method and net daily irrigation requirement was estimated after deducting the effective rainfall. The estimated irrigation requirement was supplied by 21 h−1 emitter for four plants by aligning the laterals in the middle two rows. The average seasonal water requirement was estimated to be 46.96 mm, which corresponds to 1.13 to 1.661 per day for four plants The yield of broccoli crop under 25 µm thick black plastic film was studied using 3 levels of drip irrigation which applied 100% (FID), 80% (0.8 FID) and 60% (0.6 FID) of the estimated irrigation requirement. Furrow irrigation treatment was used for comparison and the results showed 64 to 124% yield increase due to drip irrigation. Among the different drip irrigation levels 100% of irrigation requirement met through drip (FID) showed highest yield. The treatments with plastic mulch showed 20–67 to 26.43% higher yield over non-mulched treatments. Highest net seasonal income of US$ 2335 was observed for the treatment where 100% of net volume of water was met with drip irrigation and plants were mulched with black plastic mulch (FID+PM). However best return on investment i.e. benefit to cost ratio was observed to be highest for the treatment FID. The study revealed that drip irrigation can play a positive role in increasing productivity of broccoli, a new crop for the region.
