Physiological and biochemical properties of wheat (Triticum aestivum L.) under different mulching and water management systems in the semi-arid region of Punjab, Pakistan

Abstract In order to meet the dietary requirements of the rising human population with diminishing water resources, there is the need to adopt techniques that optimize crop yield under reduced water conditions. Therefore, a greenhouse experiment was carried out to determine the effect of mulching and reduced irrigation on wheat production. The experiment included four mulching treatments (un-mulched, black plastic sheet mulch, wheat straw mulch and cotton sticks mulch) and two watering regimes (normal watering and partial root-zone drying irrigation (PRI) technique that involves alternate watering to only one side of root zone only) arranged in a completely randomized design. Wheat growth (leaf area index, plant height), water related parameters (leaf relative water contents (RWC), leaf turgor potential and physiological (chlorophyll contents, stomatal oscillation and photosynthetic rate) parameters and biochemical indicators were significantly higher with mulching than un-mulched for both irrigation levels. However, among the mulching treatments, the use of black plastic mulch gave the best results. Among the mulch treatments, RWC increased by 4.29%, 7.50% and 10.73% with black plastic mulch compared to wheat straw mulch, cotton stick mulch and control treatment, respectively. Between the two irrigation levels, higher wheat growth, physiological and water related parameters were found with full irrigation. Whereas leaf osmotic potential, quality traits and antioxidant enzymatic activities were higher with PRI. This study shows that, particularly with black plastic film, mulching combined with partial root zone drying can be effectively used in conserving soil water, thus increasing crop water use, photosynthetic rate, and yield.