Water scarcity in arid regions increases the need for technologies to improve water productivity. The integrated effects of plastic film mulching and water stress on grain maize under conventional and alternate furrow irrigation methods are still poorly understood in Sindh’s climate. Therefore, field trials were conducted at Malir farm, Sindh Agriculture University Tandojam, Pakistan, during the cropping season 2020–2021 to investigate whether mulching is practicable for grain maize production under the different furrow irrigation methods. The experiments involved two types of furrow irrigation, two water stress levels (sufficient and severe water stress), and plastic film mulching. Treatments were laid out in a randomized block design and three replications. The conventional and alternate furrow irrigation method was assigned to the main plot, while the water stress and plastic film mulching were in sub-plots. The results showed that different furrow irrigation methods significantly affected plant growth, grain yield parameters, and crop harvest index. Significant highest plant growth and grain yield of maize crop were observed with the conventional furrow irrigation (CFI) compared with the alternate furrow irrigation (AFI) method. However, grain yield and irrigation water productivity (IWP) were increased significantly by the plastic film mulching. The results revealed that sufficient water stress was more effective in sustaining grain yield and IWP than crop irrigating at several water stresses. The interaction effect of furrow irrigation and water stress, furrow irrigation, and plastic film mulching significantly impacted the IWP of grain maize. The IWP of the maize crop was significantly higher under the AFI than the CFI method if it was mulched with plastic film and irrigated at sufficient water stress level.

The most important factor impacting wheat production is water stress that occurs during the reproductive growth stage. Therefore, the plant responses and water productivity as affected by drought priming were investigated during Rabi seasons 2021 and 2022. The field trials were conducted in the research field of the Department of Irrigation and Drainage, Faculty of Agricultural Engineering, Sindh Agriculture University, Tandojam. The Hamal-BNS wheat variety was subjected to differing irrigation water regime levels (40%, 50% and 60% of soil water holding capacity, SWHC) after being subjected to drought priming, irrigation water recovery (water closure period) and drought priming. There were six treatments: (1) DPP-40 (drought priming plants at 40% of SWHC), (2) DPP-50, (3) DPP-60, (4) CTP-40 (controlled treated plants at 40% of SWHC), (5) CTP-50 and (6) CTP-60. During the experiment period, soil moisture content was significantly affected by the different treatments at various growth stages of wheat. The results indicated that winter wheat pre-exposed to drought priming attained a stress imprint that improved the subsequent deficit water levels which occurred during the later plant growth stage as demonstrated by the progress of test weight, grain yield, plant level water use efficiency and irrigation water use efficiency as well as relative yield compared to CTP-50 (control treatment). Under the irrigation water regime levels during the post-anthesis period, primed wheat plants sustained grain yield and higher relative yield than wheat plants without priming due to the better irrigation water regime for drought-primed wheat plants. Similarly, primed wheat plants consumed 18.3% less irrigation water as compared to non-primed plants, which significantly increased plant level WUE and irrigation WUE and decreased dry biomass and root development of drought-primed wheat plants. Therefore, to conserve fresh water for other field crops and increase water productivity in the Sindh province, it is recommended that drought priming is used during the early growth period of wheat plants as a successful irrigation method.

Performance assessment of infiltration models for varying soil textural classes

Sindh is in the lower reaches of the Indus River; it is most vulnerable to a variety of upstream water development challenges. The aim of this research was to determine aquifer characteristics in the command area of Tando Allahyar-II distributary within the culmination of underground water potential. The hydraulic properties of the aquifer as well as the susceptibility of the formation to tedious extraction and saltwater upcoming were recognized. Three pumping tests were performed at head, middle, and tail reaches along the selected distributary. The drawdowns were measured at head reach (5.1667 h), at middle reach (6.0 h), and at tail reach (19.667 h) of the selected distributary by performing the pumping tests. Groundwater levels were lower at the tail reach compared to those at the head and middle reaches, likely due to a higher concentration of tubewells in the lower reach. The head and middle reaches showed higher groundwater levels, possibly due to constant head conditions promoting infiltration and recharge. The pumping test versus drawdown analysis revealed that the tubewells should be run with 7-h (on) and 4-h (off) operation. Further, the tubewells at all reaches (head, middle, and tail) should be closed for a minimum of 4 h between operations. This strategy would allow safe groundwater extraction, maintain water quality, and prevent water table depletion in the study area. The hydrodynamic and hydro-salinity behaviors were scrutinized in PWMIN 5.3 (version) by means of the MODFLOW mode. The results were estimated to compare the calibration and validation simulation outcomes using measured data. The model was successfully calibrated, and the root mean square (RMS) value of the head tubewell varied between 0.024 and 0.108, whereas it speckled between 0.0166 and 0.0349 for the middle tubewell and between 0.0659 and 0.0069 for the tail tubewell. The RMS values for hydrodynamic behavior for the head, middle, and tail reaches were less than 10%. These values represent a suitable match between the observed and simulated heads when a water table depletion of 1 to 2 m was observed due to extreme pumping. However, the average relative error values, for all validated procedures, were less than 10%.