Abstract

A pot experiment was conducted to investigate the morphological, physiological and biochemical straw mulch-induced response of soybean under water-deficit conditions. Soybean (Glycine max L. Merrill) variety “Xidou 7” was treated with varying quantity of wheat straw mulch viz: (control (no straw mulch), 3750, 7500, 11000 and 14750 kg/ha) under water-deficit conditions. The experimental results indicate that the varying quantity of straw mulch significantly improved the plant growth in terms of plant height, leaf area, number of leaves/plant and stem diameter. Mulch treatment also significantly enhanced the photosynthesis (P_N), intercellular CO₂ concentration (Ci), transpiration rate (E) and stomatal conductance (gs) over the control. The gas exchange parameters were improved depending on the quantity of wheat straw mulch; significantly highP_N and E was observed in the treatment where wheat straw was applied at the rate of 11000 kg/ha. Wheat straw mulch treatments led to noticeable reduction in malondialdehyde (MDA) contents, which protected the drought stressed soybean plants from membrane damage. Furthermore, the free proline contents linearly increased with increase in straw mulch quantity. It is evident that wheat straw mulch can considerably modulate growth, photosynthetic and physio-biochemical attributes of soybean under drought. The research will effectively solve seasonal drought problem and can provide technical assistance for sustainable agriculture development.

Key words: Soybean, growth, water-deficit, wheat straw mulch.