Plastic film and straw mulch effects on maize yield and water use efficiency under different irrigation levels in Punjab, Pakistan

This two-year field experiment was conducted to assess the effects of irrigation and mulches on yield and water use efficiency (WUE) of maize. Treatments involved three irrigation levels (I ₁ = 60% field capacity, I ₂ = 80% field capacity and I3 = 100% field capacity) and two mulches (M ₁ = plastic film and M ₂ = rice straw). No-mulch was regarded as control. Grain yield of maize was increased as the irrigation levels were increased and yield (6.2 Mg ha ^-1 in both years) in 100% field capacity irrigation level was the highest. Plastic film mulching produced the highest grain yield (5.7 Mg ha ^-1 in 2014 and 5.6 Mg ha ^-1 in 2015) of maize. Mulching decreased total water use in maize from 553 mm in no-mulch to 485.8 mm in plastic film. The WUE in plastic film were 10.2 and 11.4 kg ha ^-1 mm ^-1 in 2014 and 2015 respectively. Straw mulch significantly increased soil organic matter (0.57 to 0.87%) and active carbon (286 to 353 mg kg ^-1 ) with a decrease in soil bulk density (1.42 to 1.37 g cm ^-3 ) in surface and sub-surface soil layers. Effects of plastic film mulching were more pronounced in improving yield and WUE of maize while straw mulch was more effective in improving soil organic matter and active carbon. In conclusion, mulching improved the soil organic matter and moisture retention with decrease in bulk density and ultimately improved the yield and WUE of maize and net income.