M2 – Irrigation efficiency in Punjab

Partner: ZEF in cooperation with UAF

 

Objective
Improving cotton irrigation towards optimization of productivity is based on a two-step approach guided by major objectives: (i) analyzing/assessing the currently practiced irrigation strategies and techniques (‘inventory analysis’), (ii) identification of approaches and development of measures to improve current irrigation strategies and techniques (‘options towards improvement’) taking into account the agricultural production system and the institutional framework in Pakistan. By applying a bottom-up approach, these investigations refer to the level of fields, farms, and areas supplied by a Distributary canal (Mungi Distributary canal in Punjab).

Current Results
The current irrigation practices in cotton irrigation were analyzed by simulations in terms of irrigation water demand and supply made available by the canal system (and potentials for conjunctive use including groundwater). Contrasting simulations on current practice versus optimized irrigation schedules reveals the potential range for improvements and supports conceiving improved irrigation strategies for mobilizing this potential. 

In the period mid-May till mid-Nov. 2017, a gross irrigation amount of 370 mm was inflow to Mungi, in addition to 184 mm of effective rainfall. An irrigation scheduling model (FAO-AquaCrop) was used to estimate the crop water demand of cotton considering daily meteo data, soil, crop features, and an irrigation supply interval of 7 days (Warabandi fixed rotation) and an irrigation amount at field level of 358 mm (based on a technical irrigation efficiency of 50% and a groundwater reuse by pumping 90% of the irrigation losses. These simulations lead to a raw cotton yield in the range of 2.2 t/ha which matches yield level in Mungi. Changing the irrigation interval from 7 to a 14-day rotation leads to 40 mm less evaporation losses.

Expected Outcome
M2 will conceive irrigation scheduling strategies and options on advanced handling of irrigation techniques enabling a higher efficiency, effectiveness, and productivity of irrigation water and salt management. Practical applicability of these strategies is enhanced by carrying out tests and refining the strategies at the Experimental Station of UAF and at Farmers’ fields (see: D1). Furthermore, in cooperation with HRW the inter-relations between technical measures for improving irrigation performance and the institutional context is considered enabling to detect most promising steps for introduction in Punjab.