A Sprayable Biodegradable Polymer Membrane (SBPM) technology: Effect of band width and application rate on water conservation and seedling emergence

With a rapidly growing global population, increased agricultural productivity is required to achieve future food security. Efficient use of water and other agricultural inputs such as nutrients and pesticides must underpin agronomic practices to improve crop establishment and increase crop yields. A glasshouse study was conducted to explore the potential of a newly developed sprayable biodegradable polymer membrane (SBPM) applied in bands to reduce soil evaporation and increase soil temperature, thus improving germination, emergence and crop establishment. The aims were two-fold: (i) to evaluate the effectiveness of the SBPM in reducing seedbed water loss and its effect on seedling emergence; and (ii) to determine an effective band width (100 vs 150 mm) and application rate of SBPM to conserve seedbed water. Our study demonstrated that a high application rate (1 kg m-2) is effective at reducing soil water loss, but it reduces crop emergence (cotton, sunflower, sorghum, mung bean, carrot, capsicum and rockmelon). All three SBPM application rates (1, 0.5 and 0.25 kg m-2) showed increased soil water content compared to the control plot (bare soil surface). The applied bands, 100 and 150 mm width, limit evaporation and increased soil water potential and temperature compared to the control, however with no significant differences between the two treatments. Crop emergence was proportional to the application rate and decreased with increasing application rate (i.e., control < 0.25 kg m-2 < 0.5 kg m-2 < 1 kg m-2). The SBPM suppressed weed growth similar to conventional mulch film and was most effective at 0.5 kg m-2 and 150 mm width. Future research should focus on the field SBPM application management with an emphasis on crop emergence zones, biodegradability and comparing its effectiveness with other conventional mulches.