Evaluation of Root Zone Behavior and Cucumber Yield under Different Mulch Materials and Irrigation Schedules under Tunnel Farming

Water plays a crucial role in better agricultural production. The situation of irrigation water in Pakistan is getting worse day by day. New sowing techniques for high-value agriculture are the only solution to increasing water and crop productivity. Drip irrigation coupled with mulch in tunnel farming can be an effective tool for better agricultural production. Therefore, this study was designed to check the impact of different mulch materials coupled with various irrigation schedules on cucumber yield and its root zone behavior. Three types of mulch, i.e., black, transparent, and wheat straw, each under two different levels of deficit irrigation (DI) of 20% DI and 40% DI, were compared with farmer practice as a control. The experiment was conducted at a farmer's field and laid out under a randomized complete block design. The effect of treatments was checked on the number of leaves per plant, plant height, number of fruits per plant, fruit weight per plant, and crop yield. Moreover, the effect of treatments was checked on the crop root zone. The Hydrus-1D model was calibrated to successfully simulate soil moisture in the root zone. The study's results revealed that among all treatments, the total yield of the cucumber was higher under 20% DI than 40%. The treatment T3 (transparent mulch + 20% DI) had a maximum yield of 47.31 tons/ha, whereas the minimum yield of 31.86 tons/ha was obtained under control. There was little difference between the yield of black plastic mulch and wheat straw mulch. Maximum root length was found in the case of black mulch with 20% DI (86.9 cm), and the maximum diameter of the root zone canopy was observed under wheat straw mulch. Hydrus-1D proved its ability and was recommended for simulating root zone moisture, with the lowest value of R2 = 0.894. It was concluded that cucumber production with 20% DI is viable for drip irrigation with mulch applications.