Although there are several ways to revitalize nutrient deficient soils into producing turf, one of the cheapest and more effective solutions comes from using compost as a soil amendment. Different varieties of soil types could benefit from using these biosolids. Clay soils, for example, can have improved structure with reduced surface crusting and compaction as well as enhanced drainage when amended with compost material. Sandy soils can benefit from composts by retaining water and nutrients longer and increasing microbial activity. The added nutrients that compost provides will promote faster turf growth, improve its density and color, and increases rooting with less need for fertilizer and irrigation. The advantage to using compost is that it promotes better and more natural turf compared to the same amount of topsoil.
Compost can come from many sources and have different characteristics depending on the waste material used and how it is made. In selecting the right compost for turf management, it would be necessary to investigate the various types of compost to determine which type can be best used. Biosolids from wastewater treatment plants would produce the best characteristics in quality compost because of its high nutrient content, lower carbon ratio, and the correct balance of pH and moisture to improve turf soil. High organic matter improves soil physical properties including moisture holding capacity, aggregation, porosity and tilth.
Here are a few things to consider when looking for the ideal compost material:
When inspecting its appearance, it should resemble dark topsoil and have no presence of large stones, pieces of wood, glass, or other undesirable objects. Quality compost should have an ‘earthy’ aroma and not have any foul odors emanating from it which could be the result of ammonia or sulfur. Offensive odors may suggest an ‘immature’ compost that has not been fully processed and should therefore not be used.
Presence of Weed Seeds
Another thing to watch out for when evaluating compost is the presence of weed seeds. If the material was thoroughly composted, there should be no viable seeds present. Weed seeds can happen if the compost is not processed properly or if it is stored outdoors for too long. Too much weed seeds in the compost would completely ruin an entire batch and become unusable for turf application.
When it comes to moisture content, it has been found that a moisture level of around 30-50% is ideal for compost handling, surface application and soil incorporation. Wet composts (>60%) would tend to clump and not spread evenly on the surface resulting in poor mixing. Dry compost (<20%) are easier to apply but tend to produce excessive dust. This dust can be easily swept away by wind and can cause health issue when inhaled or exposed to the eyes. It would also take more effort to incorporate this into the soil.
Carbon to Nitrogen Ratio
Another factor to consider is the carbon to nitrogen ratio (C:N) The ideal number should be 30:1 because a higher carbon content would produce more microorganisms that can deplete nutrient stores in the soil making it unsuitable for turf use.
These are just a few of the guidelines that can help with identifying the best compost for use in restoring turf vegetation. Other factors such as nutrient levels, pH, and the presence of soluble salts and metals should provide ancillary information to help zero in on the ideal compost.
If you are a farmer in the Niagara Region and are interested in considering biosolids as a potential application to your fields, please call us on 1 (877) 479-1388. There is no cost for us to apply to the MOE or to spread biosolids on your field. These costs are covered by the Region of Niagara.