In this Valtra blog, we take a look at a common problem farmers may encounter – soil compaction. We ask why avoiding soil compaction is so important, the agronomical impacts of compacted soil, the benefits of looking after soil structure, and how you can improve your overall soil health.
What is soil compaction?
Soil compaction happens when the small particles of soil get pushed together reducing the amount of space or pores between them. This can happen relatively quickly, for example when heavy machinery is driven over the soil, or slowly over time when lighter machinery is driven over the soil repeatedly.
The negative impacts of soil compaction.
When soil becomes compacted, the smaller gaps between soil particles hold less air. This makes it more difficult for water to pass through the soil, leading to drainage and aeration problems. Poorly draining or waterlogged soils can quickly restrict a plant’s ability to absorb the nutrients, gasses, and water they need to thrive. In dry conditions, soil compaction reduces the amount of rain that penetrates the soil, exacerbating drought and reducing yields.
The lack of oxygen in the soil causes anaerobic conditions where the normal balance of saprophytic and mycorrhizal fungi is upset. Saprophytic fungi help break down organic matter in the soil, while mycorrhizal fungi help plants absorb nutrients like phosphorous and nitrogen. Plants may also display symptoms of iron deficiency chlorosis. As plants get weaker in these conditions they are more susceptible to pests and diseases. Research varies on how much soil compaction reduces yields, but some experts claim yields can decrease by as much as 55%
A related problem to soil compaction is smearing. Soil smearing can happen when the soil is worked during wet conditions. Ploughing and turning wet soil can result in the implement smoothing over the surface of the soil, closing up the small pores or air gaps. Tractor wheels can also slip in these conditions, causing similar issues.
How to avoid soil compaction
As the old saying goes, ‘prevention is better than cure'. A few practices and solutions you can adopt can make a huge difference. No-till and conservation tillage reduce the amount of stress on soil but are not suitable in all situations. Applying one simple logic can greatly help you reduce soil compaction – put less pressure on the soil.
1. Drive less over the soil
Every time you drive over the soil you are going to compact it. That is a fact. You can limit this damage by choosing solutions that allow you to get more done in fewer passes. Valtra Section Control with Multiboom allows you to control individual sections of up to three booms at once to apply exactly the right amount of product or seed to the right area of the field. For example, when seeding, you can apply both seed and fertilizer at the same time using both front and rear-mounted implements. This avoids having to drive over the field twice, meaning less compaction, and saving you time as well!
2. Limit the area of soil that is compacted
By minimising the area of soil that you drive on in your fields, you can reduce the overall amount of soil that is compacted. By setting up precise waylines and then strictly keeping to them, the remaining field will not be driven over at all. Valtra Guide automatically steers the tractor along pre-defined waylines. High accuracy and minimal wayline drift mean that with Valtra Guide you can keep to the same waylines from one application to the next, and from one season to the next. With the Wayline Assistant feature, it is easy to set up waylines and even create field boundaries from mapped areas. Watch the video below to find out more about Wayline Assistant.
3. Avoid soil smearing and excess compaction when turning
Soil compaction and smearing can often happen at the headland when turning your tractor. It is not always possible to avoid working the soil when it is less than 100% dry. Therefore, it is very important to make efficient turning patters to minimise wheel turning when the tractor is not moving, and reduce the overall distance driven over the soil. Together with Auto U-Pilot and Valtra Guide, SmartTurn makes the field driving experience fully automated. With SmartTurn you can choose from predefined turning patterns and ensure consistent and efficient turning, eliminating manual turning errors.
4. Spreading the load
Large farms and farming contractors that use heavier, high horsepower tractors cannot always avoid placing heavy loads on the soil. However, spreading the weight of your tractor over a wider surface area will reduce the load. One way to achieve this is by lowering tyre pressure slightly when on the field. Manually changing the tyre pressure on your tractor can be laborious and time-consuming. Luckily, Valtra Unlimited Studio can fit an intelligent Central Tyre Inflation System to your tractor. Currently, this is available for new N and T Series tractors. The system allows users to adjust tyre pressures automatically via SmartTouch to slightly increase the surface area of the tyre that is in contact with the soil. As well as improving grip, this also spreads the load, reducing soil compaction.
Intelligent and effective ways to reduce soil compaction
The only way to eliminate soil compaction is not to drive on the soil. Practices such as no-till-, and conservation tillage agriculture can greatly reduce the amount of stress placed on the soil. There are also many technical solutions that can reduce soil compaction and improve yields. Valtra Guide automatically keeps to waylines, while SmartTurn reduces soil stress at the headland. Valtra Unlimited Studio’s CTIS is a useful and adaptive tool for larger, high horsepower tractors. If you are interested in how Valtra solutions can help you protect the health of your soil to maximise yields, speak to your local Valtra dealer.