We’re putting more and more synthetic fertilisers into our land and simultaneously asking more from our productivity and outputs. Something has to give and is that organic matter? The thing that is unseen and slowly going away without us even realising?
How many years will it be until SOS has another meaning of, Save Our Soils? If we keep using synthetic fertilisation schemes year after year, our plant yield can drop. This may be a direct correlation to the drop in organic matter and carbon content in soils.
In the past, compost-based solutions have been provided and sold to horticulture and viticulture industries as a replacement or competitor to synthetic fertilisers. These commercial fertilisers primarily help with weed suppression and moisture retention. They can also typically contain small amounts of specific nutrients based on what growers are looking for. But looking back at these statistics, there is a need to reconsider the vast value and long-term benefits of compost.
Compost: the all-around fertiliser and soil conditioner
Compost helps with weed suppression and moisture retention. Looking at the natural nutrients compost holds, it can be considered an all-around fertiliser and soil conditioner. Most composts naturally contain a range of macro and micronutrients including calcium, magnesium, boron, nitrogen, phosphorous, iron, copper, manganese, and potassium. But more so, the incredible, true value and long-term benefits of compost applied to soils are seen over a two to three year period.
There’s an opportunity to change our mindsets on creating healthy soils for our plants to a long-term investment, rather than the need to see instant results and outcomes typically looked for in business.
“Will Bakx, a soil scientist for Sonoma Compost in Petaluma, CA, produces high-quality compost from urban yard trimmings. Many vineyard managers who apply compost and mulch after harvest are finding these products to be useful components of their vineyard floor management program. While some vineyard managers purchase these soil amendments, others make their own compost from grape pomace (grape marc). Either way, compost, and mulch are products that result from recycling materials that might otherwise be wasted. Growers and researchers alike are discovering the benefits of these recycled soil amendments.” – Christy Porter, California Integrated Waste Management Board from ‘Compost and Mulch – Investing in vineyard health’
Long-term benefits of compost to build up your organic matter & carbon content in soils
There are immediate benefits seen within a year or growing season from the application of compost and carbon media; like better fruit or plant yield, increased moisture in the soil, and less under-vine weed control. However, after years and years of pillaging soil, the carbon content has deteriorated quite drastically.
When the carbon or organic matter in soils deteriorates, it loses the ability to stay healthy and support positive microorganisms and fungi such as mycorrhizal to support the plant’s root structure. It also helps to extract nutrients from synthetic and organic fertilisers.
It’s fair to say, globally we’ve neglected the need for carbon content in soils. So with this in mind, it will take a number of years to rebuild this sustainably, in growing environments.
How to repurpose waste to increase your organic matter?
There are other options to build your carbon and organic matter contents in your soils including the use of biochar. This may be effective for small-scale plantings and orchards but the cost can become excessive in large-scale projects. Biochar will have an effect on soil health and carbon although does not add nutrients, weed suppression, or moisture retention benefits.
Repurposing grape marc and other fruit marc or processing wastes from the horticultural sector back to the soils can also assist and it is a very low cost to do so. Grape marc can be difficult to spread because the waste doesn’t flow easily by spreading. But if other media are blended with it such as aged sawdust or viticulture bark fines, they can improve the media and make it spreadable. There’s a chance of seed dispersal but usually, the biggest challenge is council regulation permits because of minimal storage timeframes. However, this blending and applying process can be done to regulation by working with a partner like Wholesale Landscapes.
Other horticultural wastes such as rejected fruit also have the benefit of being low-cost but with spreadability challenges. Inputs like hop vine waste can make a very good and nutritious compost with great structure and the ability to assist the soil. Adding sawdust or other carbon such as aged bark fines to this waste will help create a consistent flowing product that can easily be applied.
Changing this mindset and investing in soil health will aid in a sustainable future for New Zealand growing environments. We’re continually investing in and learning new ways to repurpose natural residues for the health of the soil and for a better environment overall. If you want to join the conversation and learn more about what we’re doing to better the environment as a company, please get in contact.
