By transferring O2 and CO2 between the earth's pores and the atmosphere, the process of soil aeration provides air supply underneath. It helps prevent crops from going without oxygen and lowers dangerous carbon dioxide levels in the subterranean air if they go too high.

The actual depth of the subsoil will differ from farm to farm, but it is obvious that it is significantly deeper than the working depth of the majority of traditional tillage techniques. Most conventional tillage techniques, which concentrate on the upper soil layers, are unable to penetrate this layer of soil, which gradually compacts over time and restricts the root growth of pastures and crops, resulting in reduced yields. The more vigorous root growth allows roots to grow to deeper levels, making the pasture and crop more resilient to summer dry’s and winter wet periods.

 'Understanding Subsoil Aerators: What Are They?'

Many become confused between ‘Aerators’ & ‘Subsoil Aerators’ believing they do the same job but in fact they do not.

‘Aerator’ is a term commonly used to describe a spike roller type of aerator which perforates the ground with holes to allow air, water and nutrients to penetrate into the grassroots (often using concrete weights to penetrate the ground).

Given that the weight of the average 120hp tractor that’s commonly found on NZ farms is around 5,000kg (compare that to a golf cart weighing 400-500kg) or the total weight of a 15-member rugby team of 1,500kg compared to the 305,000kg weight of the average 610 head NZ dairy herd it’s pretty obvious you’re going to be dealing with a whole different level of compaction issues in an agricultural situation than your local council has at the bowling green or golf course. 500kg of dairy cows v rugby players and 120hp tractors v electric golf carts, the much greater weight and compressive force from livestock and heavy machinery is going to create compaction issues much deeper into lower soil layers. As in, the compaction is going to reach down into the Subsoil layers which are 300mm and below.

Subsoil Aeration is the method of aerating that actually reaches deep into the subsoil! The prime difference between these two styles of aerators is a Subsoil Aerator uses shanks/legs that penetrate down into those lower layers, with a foot that provides a lift as the subsoil aerator runs through the ground. This upward-lifting effect creates fractures in the soil, making it more permeable thereby removing compaction & making the soil looser.

'The Role of Subsoil Aerators in Boosting Crop Health'

What part does soil aeration play in the wellbeing of roots?

To breathe and release energy from the glucose-oxygen reaction for their requirements, plant roots need air oxygen. Poorly aerated soils prevent roots from breathing properly, depriving them of oxygen, which causes them to wither. The plant eventually dies because roots are needed to receive nutrients and water. Aeration has effects on soil that go beyond crop development. Aerobic earth-dwelling bacteria and adequate oxidation require soil aeration.

Soil compaction prevents the flow of nutrients & water to the roots of your grass & crops, leading onto lower dry matter in pasture & lower yields in crops. Subsoiling works by lifting the soil & fracturing the structure to create a looser & more 'aerated' soil that allows nutrients to flow & roots to grow.

• Eliminates Compaction: By aerating soils you remove compaction damage from pugging & machinery traffic. Aeration is particularly important in high traffic areas such as water troughs, gateways & feed out areas where compaction levels are higher than the rest of the paddock. Aerated soils enable more vigorous & deeper root growth for healthier crops & plants.

• Deeper Root Structure: Soil compaction seriously hampers root growth & the depth to which roots can grow, by sub soiling the ground is broken up to provide conditions for easier root growth, this results in more vigorous & deeper root structures that take up more nutrients & provide greater resilience in dry spells & other weather events, enabling pastures & crops to 'hold on' for longer.

• Greater fertiliser uptake: When soils are compacted or do not have sufficient permeability, fertiliser is wasted. This is due to it not absorbing into the ground & simply vaporising or washing off the surface & not into it. When soil is aerated & permeable the fertiliser absorbs into the soil & is more readily taken up by the roots.

• Greater Soil Porosity: Greater porosity of soils means the level of oxygen is increased as it flows more freely in permeable ground, this speeds up plant growth as more oxygen becomes available at root level. On the other hand compacted soils decrease oxygen levels & increases the amount of carbon dioxide in the ground, this causes an eventual slow down in growth.

• Increase in pasture growth: This is the reason why farmers aerate soils! The combined factors of subsoil aeration have been proven to increase pasture dry matter yield by 28% in the right conditions, increasing growth, production and profits.