Effect of straw mulching and irrigation on physiological activities, yield of maize (Zea mays L.) and soil physical properties under available soil moisture depletion conditions in Mollisols

A field experiment was conducted during winter season of 2016-17 and 2017-18 to evaluate the effect of residue mulch and irrigation on the physiological response and yield of maize and soil physical properties at G. B. Pant University of Agriculture and Technology, Pantnagar. The experiment was laid-out in split-plot design which includes three irrigation scheduling in main plots and four residue mulch practices in sub plots. Soil temperature at 15 cm enhanced by 0.6-9.8 0C under mulch and by 0.7-1.2 0C with irrigation at 20% DASM over other irrigation levels. Mulch significantly decreased bulk density by 1.43-3.59% while increased saturated hydraulic conductivity by 3.8-41.0% and mean weight diameter by 6.0-20.0%. Irrigation at less depletion of available soil moisture favoured soil physical properties. Mulch and increase in irrigation frequency tended to increase in relative water content and transpiration rate while decreased leaf diffusive resistance. No noticeable differences in leaf temperature were observed under mulch and irrigation. Green gram straw mulch and irrigation given at 20% DASM produced 2.6-14.2 % and 1.3-9.2% higher grain yield, respectively. Combined application of green gram straw mulch @ 5 t ha-1 along with irrigation at 20% DASM was found most beneficial for maintaining favourable soil environment and can be recommended for obtaining higher maize yield in Mollisols