Agricultural Composting

In ground composting saves time and money.

In-ground composting is a biological farming method that involves spreading manure, as many growers already do, and then applying Petrik Evergreen or Bxd biology as a spray before light incorporation. The incorporation assists in the composting but is also required for the survival of the biological components which will not persist on the soil’s surface. Significant results have been achieved with manure rates as low as 2t/ha.

The process creates similar compounds to those in compost. The ultimate objective is humus creation which is what provides most of the benefits to the crop, although the N, P and K in the manure help with this as well. The same practice can be applied to a Green Manure crop, although most growers do not have the water required to grow these.

Commonly, applications are incorporated with a Kelly chain but we have also sprayed in front of the planter and “tickled the biology in” with the tines of the planter. In ground composting is used in many crops from banana and papaya to sorghum and wheat. The process, also known as sheet composting, has been approved by the Biological Farmers of Australia - organic producers are not permitted to use raw manure. Substantial savings in time and money compared to conventional composting are achieved through the handling of the manure to make compost which is usually around a six week job. Many growers also buy in straw to add to the manure to balance the C:N ratio. By in-ground composting we use the carbon in the fields. When conventionally windrow composting the pile will usually need to be turned approximately 10 times through the composting process which requires equipment and a compost turner to do properly. On top of this you end up with slightly more than half of the volume you started with. Raw manure is usually available for approximately $20-$30 per tonne, and compost generally retails for $150/tonne. Both will incur transport and spreading costs.

Where windrow composting is used Total Grower Services also has a specific Petrik biology to work in those temperatures and carbon levels. Windrow composting is usually required for crops where food safety requirements prevent the use of raw manure, such as lettuce, or where the aim is to decompose elements such as weed seeds first. Compost is also useful in place of manure for specific crop stages where the nitrogen release from raw manure is undesirable. In-ground composting is a preferred option - you get more of the N, P and K and carbon to the soil, as you do not lose volume through composting. The soil, if seeded with the correct biology, will still produce humic and fulvic acids from the manure which will become humus. These humic compounds produced by in-ground composting will be those required by your native biology to allow it to proliferate. Most of these core biology systems are still in soils however they are restricted by the lack of humus. When we talk about carbon loss from soils we often do not consider the real problem which is humus loss.