Soil preservation is one of your main concerns. To limit the impact of agricultural vehicle passage, a judicious choice of tyre together with the right tyre pressure adjustment are indispensable.
But it is also very important to use…. tyres that are in good condition and that are not too worn.
The use of worn tyres effectively has the same consequences on soil compaction as the use of tyres with badly adapted inflation pressure (in particular overinflated tyres), that is to say increased compaction of your land. Yet this compaction is a decisive factor in terms of your soil’s potential. Worn lugs increase tyre slippage and decrease grip, which has a worse effect on the soil structure than if you were using new tyres.
The earth is a living environment in which many gas and fluid exchanges take place. These exchanges are possible due to porosity and cracks between soil particles. The abundance of these cracks and slits enables good soil aeration (renewal of gasses) and as such a good oxygenation of the seedlings.
A plant’s roots capture part of this oxygen. If there is not enough oxygen, their activity is first reduced then their development is completely blocked (no new roots and no further growth). If the oxygen content is really very low, the roots will die. Compacted soil therefore reduces the depth of the root system and limits the plant’s nutrition potential. Soil aeration also plays an essential role during the germinating stage (providing oxygen after sowing).
Microfauna such as worms, in particular anecic earthworms and certain insects, are also affected. Yet worms play a crucial role in soil aeration due to their tunnelling activity and by creating cracks.
The cracks in the soil not only contain gases, but also water. Large porosities (including tunnels formed by living organisms in the soil) allow the water to infiltrate deep into the soil, thus avoiding asphyxiation of the roots. When the soil is compacted, the water tends to flow laterally in the soil or remain on the surface. The result is that less water is stored at depth. Yet this water, that serves as a reserve is vital during dry periods.
In addition, the stagnation of the water in the ruts can encourage the emergence of diseases caused by fungi in particular.
As the water cannot flow deep down, the soil is wetter on the surface and warms up more slowly in the spring, which slows down crop growth. Temperature is effectively an important factor. A plant develops when the outside temperature is above its base temperature, which is specific to each plant species (0°C for wheat, 6°C for corn, for example). The higher the average daily temperatures over the crop cycle the more the plant develops, leading to a potentially better yield.
A higher temperature in spring may also allow you to harvest earlier, which is to say in conditions that are likely to be drier and better for avoiding soil compaction.
As for the smaller porosities, they retain the water by surface tension right next to the roots. The water dissolves the mineral elements of the soil (including phosphorous and potassium which are not very mobile in the ground) and solubilises the gases, allowing them to be absorbed more easily by the plant.
The reduced number of porosities linked to the use of worn tyres reduces the capillary upwelling of water to the surface during dry periods. The plants are therefore less irrigated, less nourished and more sensitive to dry periods without precipitation.
Bridgestone-agriculture Blog is written and administered by tractor tyre experts who are available to provide you with advice on agricultural tyres. They will help you to maximise your productivity with information on all things relating to tyres: inexpensive tractor tyres, technical data for agricultural tyres, solutions for avoiding soil compaction, sprayer tyre pressure, why and how to ballast your tractor tyres, when to use dual-wheels, the mechanical causes for abnormal wear, discounted agricultural tyres, etc...
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