Environmental and hydrological implications of innovative sprayable biodegradable polymer membrane

Project summary

Plastic mulch films are widely used in agriculture to enhance crop production by suppressing weeds, conserving soil water and increasing soil temperature. However, the majority of plastic mulch films are not biodegradable and are typically removed after each growing season. Recovery of these plastics from the soil is difficult and can affect successive crop yields while causing substantive cost to farmers and negative environmental effects. Due to increasingly stringent regulations regarding use of non-degradable plastic in agriculture they are likely to be phased out in the near future. In the past 10 years several classes of ‘biodegradable’ materials have been studied, but most of these films are reported to be relatively weak in mechanical properties, not efficiently degradable and cost prohibitive. More recently, researchers have turned their attention to sprayable biodegradable polymer coatings for use on soils due to their easy application and versatility. The main objective of the proposed collaboration is to explore the value of recently patented water based Sprayable Biodegradable Polymer Membrane (SBPM, developed by CSIRO) through field experiments and numerical modeling. First part of the research will be focused on experimental settings and data collection regarding water balance monitoring with various sensors. The second part will include hydrological model calibration based on field data and performing simulations of water and solute behaviour under sprayable mulch. These simulations will include multiple scenarios (e.g. different management systems, irrigation methods and mulch applications), thus provide information about the environmental and hydrological effects of such practices in agricultural fields. Expected results will be published in recognized scientific journal and should increase the usage of this innovative technology in agricultural production, resulting in lowering plastic pollution problems. The group will further explore global funding possibilities or EU funding agencies to conduct research under different environmental conditions in Croatia.

Reduction in cumulative soil evapouration (water loss) in pot trials usingbiodegradable PU based membranes (SBPM) sprayed onto the soil surface compared withbare soil surface treatments

Estimation of the hydrological SBPM using HYDRUS suite

www.pc-progress.com

PROJECT OBJECTIVE

The main objective is to explore the value of recently patented water based Sprayable Biodegradable Polymer Membrane (SBPM, developed by CSIRO) through field experiments and numerical modeling.

Specific objectives include:

i) Setting up a field experiment with improved SBPM in Australia;

ii) Installation of field sensors for soil water balance monitoring and a setup of soil physics laboratory in Townsville;

iii) Collecting first data from the field trial and calibration of hydrological model;

iv) Performing 2D numerical modeling for water flow and solute movement (nitrate) using HYDRUS 2D/3D suite;

v) Execution of multiple modeling scenarios which include different management techniques like furrow irrigation and drip (subsurface) irrigation;

vi) Analysis of the field and numerical results and make an assessment of SBPM from environmental and hydrological points of view;

vii) Dissemination of the results through publications in scientific journals and upcoming meetings and events and exploring the funding opportunities for further research.

References:

  • Adhikari, R., Bristow, K.L., Casey, P.S., Freischmidt, G., Hornbuckle, J.W. and B. Adhikari. 2016. Preformed and sprayable polymeric mulch film to improve agricultural water use. Agricultural Water Management 129: 1-13.

  • Filipović, V., Romić, D., Romić, M., Borošić, J., Filipović, L., Mallmann, F. J. K., Robinson, D. A. 2016. Plastic mulch and nitrogen fertigation in growing vegetables modify soil temperature, water and nitrate dynamics: Experimental results and a modeling study. Agricultural Water Management, 176, 100–110.

  • Šimůnek, J., van Genuchten M. Th., Šejna, M. 2016. Recent developments and applications of the HYDRUS computer software packages. Vadose Zone Journal, 15(8), pp. 25, doi: 10.2136/vzj2016.04.0033, 2016.

Patents:

  • Sprayable Polymer Membrane for Agriculture (CSIRO Ref. TW8842) Based on International Application No. PCT/AU2015/000334. Inventors: Bristow, K.L., Adhikari, R., Casey, P.S., Freischmidt, G., Hornbuckle, J.W.

  • Hydrophobic-Hydrophilic Switchable Polymers for Use in Agriculture (CSIRO Ref. TW8998) Pending Australian Provisional Application No. 2016901048 Inventors: Bristow, K.L., Johnston, P., Adhikari, R.

Croatian Science Foundation (CSF)

"for Unity Through Knowledge Fund - UKF Secretariat"

Ilica 24

HR-10000 Zagreb, Croatia

RESULTS

Publications:

Filipović, V., Bristow, K.L., Filipović, L., Wang, Y., Sintim, H.Y., Flury, M., Šimůnek J. Environmental Science & Technology 2020 54 (8), 4709-4711. doi: 10.1021/acs.est.0c00909

Braunack, M.V.; Adhikari, R.; Freischmidt, G.; Johnston, P.; Casey, P.S.; Wang, Y.; Bristow, K.L.; Filipović, L.; Filipović, V. Initial Experimental Experience with a Sprayable Biodegradable Polymer Membrane (SBPM) Technology in Cotton. Agronomy 2020, 10, 584. doi:10.3390/agronomy10040584

Braunack, M. V., Zaja, A., Tam, K., Filipović, L., Filipović, V., Wang, Y., & Bristow, K. L. (2020). A Sprayable Biodegradable Polymer Membrane (SBPM) technology: Effect of band width and application rate on water conservation and seedling emergence. Agricultural Water Management, 230, 105900. doi:10.1016/j.agwat.2019.105900

Braunack, M.V., Filipović, V., Adhikari, R., Freischmidt, G., Johnston, P., Casey, P.S., Wang, Y., Šimůnek, J., Filipović, L., Keith L. Bristow, K.L. (2021). Evaluation of a Sprayable Biodegradable Polymer Membrane (SBPM) Technology for soil water conservation in tomato and watermelon production systems. Agricultural Water Management 243, 106446.

Filipović, V., Gerke, H.H., Robinson, A.D, Šimunek, J., Bristow, L.K.,Clothier, E.B. (2019). Can We Improve Agricultural (Environmental) Management By Using Novel Numerical Modeling Approaches? Embracing the digital Environment, San Antonio.

Filipović, V. (2019). Crop Adaptation seminar: How can we improve agroecosystem management by combining critical zone observatories with numerical modeling? (16.08.2019. Canberra CSIRO)

Filipović, V. (2019). Science with Sushi seminar: How can we improve agricultural and environmental management by using novel numerical modelling approaches within the soil critical zone? (30.07.2019. Townsville CSIRO/James Cook University)

Filipović, L. (2019). Science with Sushi seminar: Trace metals bioavailability in soil (27.08.2019. Townsville CSIRO/James Cook University)

In preparation:

Wang, Y., Šimunek, J., Filipović, V., Bristow K.L. (2020). An analysis of polymer membrane barrier effects on the surface energy balance and soil evaporation: Does mulch technology always reduce soil evaporation? Vadose Zone Journal



Fig. a) Conceptual sketch of SBPM effect on local scale soil hydrology, (b) soil after application of the spray-on, (c) SPBM_gap plot, (d) ODP slotted plot, (e) experiment layout in the field taken during October/November 2015 at the Australian Cotton Research Institute (ACRI), Narrabri.

Fig. b) pot experiments (Exp. 1 & 2) with various seedlings and c) tray experiment (Exp. 3) with different SBPM band width and application rate at the Australian Cotton Research Institute (ACRI), Narrabri.

Fig. Soil water loss (g) over time in pots with three different application rates of SBPM (0.25 kg m-2, 0.5 kg m-2, 1 kg m-2) and control (bare soil) for (a) experiment 1 (with seedlings), (b) experiment 2 (without seedlings) and (c) with additional graph showing water loss calculated from soil moisture (water content) sensors (without seedlings, experiment 2). Bars indicate least significant difference between treatments.

Fig. A) Average (%) seedling emergence of 3 replicates per treatment for both cotton and sorghum species (n=30), with standard errors bars in experiment 3 on trays and B) example tray with emerged seedling and weeds.

SSSA Early Career Award 2019. for Prof. Vilim Filipović

SSSA Soil Science Research Award 2019. Prof. Jirka Šimunek

11th November, San Antonio, Texas, USA