The ‘C’ Word – Carbon! What’s it all about?

As someone interested in pastoral grass-based farming, you will already know that nitrogen is one of the most important nutrients for grass growth. However, did you know it is also important to include a carbon source in a foliar application of nitrogen? In this post, we will explore the reasons why a carbon source is necessary and how different charged particles play a role in combining with soil and capturing carbon.

Carbon is life! – to not put to finer point on it.

Carbon is often associated with negative environmental outcomes. However, it is a critical component of soil organic matter, which provides a range of benefits such as increased soil fertility, improved water retention, and reduced erosion. Carbon is also important for sequestering atmospheric carbon dioxide, a greenhouse gas contributing to climate change. By adding a C source to a foliar application of nitrogen, we can help build soil organic matter and reduce our carbon footprint.

Positive and negative, + and -, for a greener footprint.

Now let’s consider the differently charged particles that are important for combining with soil and capturing carbon. Cations, or positively charged particles, are attracted to negatively charged soil particles and can help to stabilize organic matter. Some examples of cations that are important for soil health include calcium, magnesium, and potassium. Anions, or negatively charged particles, are important for promoting plant growth and can help to improve nutrient availability. Examples of anions that are important for grass growth include nitrate, phosphate, and sulfate.

Nitrogen, as a fertiliser is the most productive growth nutrient plants require. However, it is negatively charged. As the soil is negatively charged, when N is applied you have two negative charges repelling each other. Think of two magnets, try pushing them together, yet all they want to do is to repel each other. This is how Nitrogen particles can behave in the soil. This negative charge leads to nitrogen being more easily leached and lost into the soil and atmosphere. With the addition of a carbon source, carbon is positively charged, at a rate of 10 to 20% of the nitrogen source the carbon is attracted to and binds to the nitrogen particles creating a molecule that binds with soil and is more easily used by the plant. This particle is then far less likely to leach and create environmental damage.

When it comes to carbon sequestration, there are two types of carbon that can be stored in the soil: labile and recalcitrant. Labile carbon is easily decomposed by microbes and is therefore more likely to be released into the atmosphere as carbon dioxide. Recalcitrant carbon, on the other hand, is more resistant to decomposition and can be stored in the soil for longer periods of time. Adding a C source that is high in recalcitrant carbon, such as biochar, humates, fish fert, or molasses, can help to build soil organic matter and promote long-term carbon storage.

Including a C source in a foliar application of nitrogen is important for building soil organic matter and reducing our carbon footprint. Not only that the dry matter growth results in numerous studies show that pastoral farmers can expect a 10-14% increase compared to urea application alone. This is a significant amount to any farmer. Understanding the role of differently charged particles in soil health and carbon sequestration can help us to make informed decisions about the types of amendments we use in our farming systems. By taking a holistic approach to soil health, we can promote sustainable agriculture and contribute to a healthier planet for future generations.

What Nutrient Products are Carbon Sources?

There are several types of C sources that can be included in a foliar spray to provide benefits not just for nitrogen use, but also for the soil microbiome. Here are some examples:

1. Humates: Humates are a type of humic acid that can be extracted from organic matter such as peat, lignite, and leonardite. They are high in recalcitrant carbon, which means they are resistant to decomposition and can be stored in the soil for long periods of time. Humates can help to improve soil structure, increase nutrient uptake by plants, and stimulate the growth of beneficial soil microorganisms such as mycorrhizal fungi and nitrogen-fixing bacteria.
2. Fish Fertilizer: Fish fertilizer is made from the byproducts of the fishing industry, such as fish bones and scraps. It is a rich source of nutrients such as nitrogen, phosphorus, and potassium, as well as trace minerals like calcium, magnesium, and iron. Fish fertilizer also contains amino acids, which are organic compounds that are essential for plant growth and can help to stimulate the growth of beneficial soil microorganisms.
3. Molasses: Molasses is a byproduct of sugar production and is high in sugars, which are a source of energy for soil microorganisms. When added to a foliar spray, molasses can help to stimulate the growth of beneficial bacteria and fungi, which can improve soil health and nutrient cycling. Molasses also contains minerals such as calcium, magnesium, and potassium, which can help to improve soil fertility.

All of these carbon sources can help to improve soil health and provide a nutrient source for the soil microbiome. By promoting the growth of beneficial microorganisms, these carbon sources can help to improve soil structure, increase nutrient uptake by plants, and promote long-term carbon sequestration in the soil. In addition, by providing a diverse range of nutrients to the soil, these carbon sources can help to reduce the need for synthetic fertilizers, which can have negative impacts on soil health and the environment. Overall, incorporating these types of carbon sources into a foliar spray can be an effective way to promote sustainable agriculture and support the health of our planet.

The use of carbon sources such as humates, fish fertilizer, and molasses in foliar sprays can provide a range of benefits for farmers looking to promote sustainable agriculture and improve soil health without reducing their outputs. By incorporating these products into their farming systems, farmers can increase nutrient uptake by plants, improve soil structure, and stimulate the growth of beneficial soil microorganisms.