Can compost increase the moisture retention capacity of soils?

MRA Consulting Group

Farmers are always looking for ways to increase soil water moisture while minimising water use.

MRA, supported by the NSW Department of Planning Industry and Environment, is promoting the benefits of compost in agricultural systems through some innovative approaches.

This approach is looking at using compost blends as a way to improve the soil’s moisture retention capacity.

Project Background

Compost has many benefits as a soil amendment in agriculture. It is understood to increase nutrient cycling, improve soil structure, improve soil water holding capacity, buffer pH and increase biological activity. This project seeks to demonstrate and quantify the impact that compost applications have on soil water.

Soil moisture

Extreme droughts are becoming more prevalent under a changing and extreme climate. Varying environmental conditions make it increasingly harder to manage soil growing properties in agriculture. If soil could retain moisture for longer periods, the irrigation demands for vegetable growers can be reduced. Thus, improving water saving practices and reducing economic overheads of farming systems.

Aim

This project aimed to increase the awareness of the benefits of compost for soil-water management among vegetable farmers in the Sydney region. Field days were held as part of the project, centering around promoting and extending the outcomes of the on-farm demonstration, showcasing state of the art soil monitoring equipment and recording the impact of compost on soil water. This work built on previous NSW Government investments in this topic, and region, and sought to expand the use of composts in vegetable production in the Sydney Basin.

Outcomes

This project utilised the Greater Sydney Local Land Services (GS LLS) site, Demonstration River Farm in Richmond, to conduct compost trials, with particular focus on the impact of compost on soil water content. The trials were conducted over two growing seasons, winter 2019 and summer 2020, and results were presented in June 2020, via a live, on-line webinar.

Soil moisture was monitored on plots of different rates of compost using some readily available and affordable technology supplied by Agnov8, that records daily soil moisture levels at 15-minute intervals. The trial demonstrated that growing a crop in compost rich soils increases the soil moisture content, delivering optimal growing conditions and therefore, a reduced demand for irrigation.

Farm walks were held in August to demonstrate firsthand to local and regional vegetable growers how the trial was set up and included some preliminary results on crop yield and plant health.

This project has raised awareness to local and regional vegetable farmers about compost’s impact on soil water retention by communicating and demonstrating the growing and potentially economic benefits of using compost.

This builds on previous NSW Government investments in this topic and region and seeks to expand the use of composts in vegetable production in the Sydney Basin.

Webinar

To learn more or register your interest in any similar workshops or webinars, email info@mraconsulting.com.au or go to http://www.mraconsulting.com.au

The project was funded by the NSW Department of Planning, Industry and Environment through the Waste Less, Recycle More (WLRM) Organics Market Development program.

As always, we welcome your feedback on this, or any other topic on ‘The Tipping Point’.