Soil health refers to the status of a whole set of soil physical, biological and chemical indicators which affect a soil’s capacity to function as a living ecosystem that supports crops, animals and ultimately humans for present and future generations.
Can I build soil health on my farm and hand it on in better condition than I got it?
To a 20cm depth, one hectare of soil weighs approximately 2,400t. So the answer is yes, but it takes time and is done by building practices that improve soil health into your system over your career as a farmer and steward of the land.
Just as soil health is built incrementally over a career, many of the benefits are reaped over the long-term. Adding organic manures to soil is an excellent way you can build soil health.
What are the key components of soil health?
There are three pillars of soil health; the physical, the biological and the chemical (Figure 1).
Only by focusing on all three can the reward of top yields and healthy soil be achieved in the long term. To highlight the benefits of manures, I will describe an example of how manure can positively affect each of the three pillars of soil health.
How can manures improve my soil physical health?
Soil physical health is concerned with how the sand, silt and clay fractions come together to maintain good soil structure.
This is important, because it affects what happens soil structure and aeration when soils get wet or machines travel over them.
They can help here because addition of manures as part of a system over the long term will build soil organic matter levels.
This organic matter provides energy for soil microbes which secrete organic polymers. These polymers will coat silt and sand particles, allowing them to bind into water stable packets, which can better support machine traffic. The effect of organic matter on soil structure and aeration on wetting can be seen in Figure 2.
Figure 2: Effect of organic matter on soil structure after wetting.
How can manures improve soil biological health?
In a spoon of healthy soil, there can be more life than all the humans that have ever lived on earth.
Just like us, this soil biological and microbiological life needs to be fed to function.
Keeping a living growing commodity or cover crop on the land throughout the year and adding manure are two of the best ways to provide the carbon-rich energy compounds that soil life needs.
Figure 3: Effect of organic manure (OM) addition on earthworm abundance.
As an example, Figure 3 shows how soils which have received organic manures have much greater earthworm abundance than soils not receiving manure.
How can manures improve a soil’s chemical health?
The nitrogen (N), phosphorus (P) and potassium (K) content of organic manures are often used to estimate their value. However the physical and biological benefits of manures also have a value. Manures can be a cost-effective way to build soil chemical fertility.
Bear in mind that nutrient variability can be high, so make sure you get an analysis – it’s worth it. You wouldn’t spread bagged fertiliser without a label, why do it with manure?
Manure has a benefit over bagged mineral fertiliser, in that it contains more than just N, P and K. Figure 4 shows that a 22m3/ha application of cattle slurry delivers significant amounts of other nutrients.
Figure 4: What is in an example 22m3/ha application of slurry including carbon (C)?
The most striking is the amount of carbon, which far exceeds all the other nutrients. While not all of the carbon will be retained in the long term, research has shown that where manure is added as part of a system, about 14% of the carbon is retained long term.
Talk to your Teagasc adviser about making manure part of your tillage system. Including manure in your system can help to build a healthy soil that will pay you dividends in the long term as well as the short term.
You will also have the satisfaction, in time, of handing the land and soil on to the next generation in better condition than you received it.
Read more
Crops & Spreaders event offers something for everyone
Soil health refers to the status of a whole set of soil physical, biological and chemical indicators which affect a soil’s capacity to function as a living ecosystem that supports crops, animals and ultimately humans for present and future generations.
Can I build soil health on my farm and hand it on in better condition than I got it?
To a 20cm depth, one hectare of soil weighs approximately 2,400t. So the answer is yes, but it takes time and is done by building practices that improve soil health into your system over your career as a farmer and steward of the land.
Just as soil health is built incrementally over a career, many of the benefits are reaped over the long-term. Adding organic manures to soil is an excellent way you can build soil health.
What are the key components of soil health?
There are three pillars of soil health; the physical, the biological and the chemical (Figure 1).
Only by focusing on all three can the reward of top yields and healthy soil be achieved in the long term. To highlight the benefits of manures, I will describe an example of how manure can positively affect each of the three pillars of soil health.
How can manures improve my soil physical health?
Soil physical health is concerned with how the sand, silt and clay fractions come together to maintain good soil structure.
This is important, because it affects what happens soil structure and aeration when soils get wet or machines travel over them.
They can help here because addition of manures as part of a system over the long term will build soil organic matter levels.
This organic matter provides energy for soil microbes which secrete organic polymers. These polymers will coat silt and sand particles, allowing them to bind into water stable packets, which can better support machine traffic. The effect of organic matter on soil structure and aeration on wetting can be seen in Figure 2.
Figure 2: Effect of organic matter on soil structure after wetting.
How can manures improve soil biological health?
In a spoon of healthy soil, there can be more life than all the humans that have ever lived on earth.
Just like us, this soil biological and microbiological life needs to be fed to function.
Keeping a living growing commodity or cover crop on the land throughout the year and adding manure are two of the best ways to provide the carbon-rich energy compounds that soil life needs.
Figure 3: Effect of organic manure (OM) addition on earthworm abundance.
As an example, Figure 3 shows how soils which have received organic manures have much greater earthworm abundance than soils not receiving manure.
How can manures improve a soil’s chemical health?
The nitrogen (N), phosphorus (P) and potassium (K) content of organic manures are often used to estimate their value. However the physical and biological benefits of manures also have a value. Manures can be a cost-effective way to build soil chemical fertility.
Bear in mind that nutrient variability can be high, so make sure you get an analysis – it’s worth it. You wouldn’t spread bagged fertiliser without a label, why do it with manure?
Manure has a benefit over bagged mineral fertiliser, in that it contains more than just N, P and K. Figure 4 shows that a 22m3/ha application of cattle slurry delivers significant amounts of other nutrients.
Figure 4: What is in an example 22m3/ha application of slurry including carbon (C)?
The most striking is the amount of carbon, which far exceeds all the other nutrients. While not all of the carbon will be retained in the long term, research has shown that where manure is added as part of a system, about 14% of the carbon is retained long term.
Talk to your Teagasc adviser about making manure part of your tillage system. Including manure in your system can help to build a healthy soil that will pay you dividends in the long term as well as the short term.
You will also have the satisfaction, in time, of handing the land and soil on to the next generation in better condition than you received it.
Read more
Crops & Spreaders event offers something for everyone
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