Farmers need to associate sustainability with much more than the environment and remember that much of what can be good for the environment can also be good for your pocket.
When we talk about sustainability on farms, we have to think about the economics and the environment and many of the solutions to farm sustainability lie in our soils.
Soils are the engine room of farms. They have the power to grow high-yielding crops, hold nutrients which we would otherwise have to pay for and store carbon, which takes greenhouse gases out of the atmosphere and could be an income stream in the future.
Here are five tips for improving soil health and, in turn, your farm’s sustainability. It should be noted that, like anything in life, sometimes we have to make an initial investment for that soil to improve and this investment will hopefully pay off in the long run.
1 Take a soil sample
The first place to start with your soil is to take a soil sample and find out if it is high or low in different nutrients and soil pH. Start with phosphorus (P), potassium (K) and pH. Once you get them right, you can move on to some of the elements we need in smaller amounts, but which are still very important, such as manganese and magnesium.
Fertiliser prices are high at present so where P and K need to be increased look into using slurry, farmyard manure and chicken litter.
2 Develop a nutrient management plan
Improving soil health and structure takes time, so a plan is needed. Applying a buildup level of P one year and not the next, when you are in index 1 for P, will not suffice. A clear plan needs to be made on what the soil needs.
All farms should have a nutrient management plan. If you don’t, work with your adviser to formulate one and take into account all sources of nutrients on the farm or possible sources which can be imported on to the farm.
This will require some paperwork, but will pay off in the long run.
3 Plant crops that supply their own nitrogen
Taking some fertiliser out of the mix will significantly reduce costs. For tillage farmers, protein crops will not require artificial nitrogen to be applied and can reduce input costs, while these crops also benefit soil structure and leave residues behind which will help to increase soil organic matter content.
On grassland, clover is now an essential part of the sward. To allow that clover to thrive, nitrogen rates need to be reduced. Teagasc research has shown that where clover content of the sward reaches 20%, farms can reduce their nitrogen use to 150kg N/ha and produce almost the same amount of grass (13.4t DM/ha) as someone applying 250kg N/ha (producing 13.5t DM/ha) at the same stocking rate of 2.74 cows/ha. This is a massive saving and can reduce the amount of nitrogen being lost to the air and to water, which is extremely important.
For those planting multispecies swards, it is important to limit clover content of the swards to 40%; over this level the clover may contribute to nitrate leaching.
4 Build organic matter
Building soil organic matter is essential to improve nutrient availability from the soil and to improve the soil’s health and structure.
It will also be essential in the future as carbon storage becomes increasingly popular and building carbon in the soil, which is directly linked to soil organic matter build-up, could bring in another income. However, it is a slow process.
The application of organic manures such as slurry and farmyard manure can help in organic matter buildup, as well as compost and digestate. Chopping straw and returning it to the soil is also a great way of returning plant material to the soil.
Reducing tillage levels can also help as the organic matter being added to the soil is being kept in the same layer, which should be biologically active.
5 Add diversity to improve soil structure and soil and plant health
Diversity is important in many parts of life. We all need diversity in our diet to make sure we get the right vitamins, minerals, enough fibre and energy.
Soils also need diversity. Different root lengths of plants allow more food to be availed of deeper into the soil. These roots can also help to tackle compaction. Shorter roots can help to make the soil crumbly.
A variation of plants also results in different food availability for insects and brings diversity to the microorganisms in the soil, which can help to improve soil health and grow better crops.
In grassland this might be a multispecies sward. Diverse cover crops can be planted on tillage land and there can also be benefits to combi-cropping or even mixing varieties to prevent the spread of disease in tillage crops and reduce pesticide use.
Planting clover with grass or peas with barley can result in less artificial nitrogen being spread as these plants fix nitrogen from the air.