Organic matter II. Consequences of its accumulation

The accumulation of organic matter occurs because the rate of mineralisation is slower than the rate of organic matter formation.

The organic matter of our sports surfaces is the result of the sum of mowing debris, stems and roots of grasses plus the contribution of invertebrates, insects and small dead animals.

The basic structures consist of cellulose, tannin, cutin and lignin plus other proteins, lipids and sugars.

An important qualitative characteristic to take into account is the C/N ratio, i.e. the ratio of carbon to carbon dioxide. Nitrogen total. The microbial communities need relationships in the 8 environment for their optimal functioning and mineralisation of organic matter.

An important negative consequence of this is its accumulation on the surface of the soil profileThe percentage of macropores (pores with a diameter of aerationd>0.08mm) due to clogging of these and decreasing the saturated hydraulic conductivity. On the other hand, this clogging causes oxygen deprivation stress, one of the reasons that lead to the "Summer Bentgrass Decline. These situations tend to occur in cool-climate turf in the summer, when part of the root system dies. This increase in organic matter can lead to clogging of the macropores, resulting in a lower rate of oxygen diffusion, stressing the roots, which are unable to absorb water as respiration and the energy required for this process is reduced.

From more than 4% of organic matter accumulation in the first 5 cms of the soil profile, we have to pay attention to possible stress situations, due to low oxygen content and low saturated hydraulic conductivity. Recall that 1% by weight is equivalent to 5% by volume. Therefore, the work of sand proofing to dilute these quantities. In addition, heat transfer increases with increasing VWC and therefore the thermal stress.

Other consequences of accumulation include scalding, greens soft, footprints, deep bites, etc.

On the other hand, the positive aspects are the increase of the cation exchange capacity and the decrease of pH.