The Science 10

EFB Mulching, Cause for a Rethink?

The answer lies in the C:N ratio.

Carbon/nitrogen ratios are a general guide to help determine the point at which compost should be applied to the field. The ideal C/N ratio is about 30:1. Process One is formulated to process high ratios and speedily bring down that number. Materials too high in carbon make composting inefficient, takes longer to decompose. This is why EFB at roughly 50:1 C/N ratio takes much longer to be of benefit to the Oil Palms in the field. The negative effect may be that they rob the nitrogen from the ground while decaying before actually providing nutrients to the palm!

As the oil palm biomass and effluent is broken down to simpler forms of proteins and carbohydrates, it becomes more available to a wider array of bacterial species that will carry it to a further stage of decomposition.

Carbohydrates (starches and sugars) break down in a fairly rapid process to simple sugars, organic acids, and carbon dioxide that are released in the soil. When proteins decompose, they readily break down into peptides, amino acids, and then to available ammonium compounds and atmospheric nitrogen. Finally, species of "nitrifying" bacteria change the ammonium compounds to nitrates, in which form they are available to the Oil Palm.

At this stage of decomposition, the materials are near to becoming finished compost, with the exception of a few substances that still resists breakdown. Through complex biochemical processes, these substances form humus.

Process One microorganisms, like any other living things, need both carbon from the carbohydrates, and forms of nitrogen from the proteins in the compost substrate. In order to thrive and reproduce, all microbes must have access to a supply of the elements of which their cells are made. The principal nutrients for bacteria, actinomycetes, and fungi are carbon (C), nitrogen (N), phosphorus (P), and potassium (K). Trace elements are needed in minute quantities.

These chemicals in the organic compound are not in their pure form, and certainly not all in the same form at the same time. For example, at any given moment, nitrogen may be found in the form of nitrates and nitrites, in ammonium compounds, in the complex molecules of undigested or partly digested cellulose, and in the complex protein of microorganism protoplasm.

There are many stages of breakdown and many combinations of elements. Microorganisms can make use of nitrogen and other elements only when they occur in specific forms and ratios to one another.