The Farming Social Hub - a voice for the farming community

Making the case for fertiliser

Sticking up for the fall guy: why fertiliser still has a big role in farming

There has been a lot of discussion among various farming and environmental groups about decreasing or ceasing the use of artificial input – fertilisers, insecticides and pesticides – in a bid to lessen agricultural impact upon the natural world and the environment.

However, more than ever, farmers are being asked to farm land efficiently and, in a world where black grass, virus yellows, septoria are all too virulent, farmers currently need something stronger in their tool box than a hoe and good luck.

That is the opinion of Amy Vickers, a fertiliser trader at ADM Agriculture, an international grain, seed and fertiliser company. “We shouldn’t be looking to remove fertiliser from the farmer’s toolbox but rather looking for ways to help them use it in a sustainable way,” she said during an informative interview with the Farming Social Hub. (Episode 22).

Amy has been involved in the fertiliser industry for more than 11 years and during that time, she has developed an impressive depth of knowledge, using the latest research to understand how farmers on a variety of soil types need to adopt different practices to get the most from their land.

“The bottom line is – if the soil isn’t healthy, with good properties, then you won’t have a successful business,” she says. However, she makes the additional point: “Good soil management means the total supply of nutrients in the soil, from all sources, must meet but not exceed the crop’s demand. If a nutrient is missing, then plan growth is hindered.”

Soil knowledge is key

Over the course of the past decade, Amy has seen the emphasis change, both from the suppliers’ and the buyers’ viewpoint. “As an industry we are seeking ways to improve the environment both environmentally and economically. Historically, we have had a tendency to stick to certain types of fertiliser because that was the way it was always done. But when we soil tested, particularly with grasslands, it proved that a more tailored approach to soil nutrition was needed. On the arable farms, there is usually an agronomist involved so they are already looking at a tailored approach.”

Experts in the field will have a good knowledge of soil properties across the UK. Texture is one property that will determine what fertiliser is needed. Structure is also important for root development while, in turn, the percentage of organic matter in the soil will determine the structure. Soil overlying different rock types such chalk or sandstone, will impact the pH scale. These are all things that experts working in the fertiliser industry will have in-depth knowledge about and Amy feels that their expertise should be taken onto the farms more regularly.

Cover crops – not the whole story

Cover crops have been the source of much debate of late, particularly with the expected release of information about agri-environmental schemes such as ELMS. On the plus side, Amy says cover crops will enhance the health of the soil through organic matter, micro-organisms and the prevention of soil erosion and weed invasion.

“That all sounds great but there is no guarantee the soils will then be productive. It is difficult to calculate a specific monetary value and be convinced there will be good return. I’ve also seen studies that suggest cover crops can both conserve soil moisture but also transpire soil moisture, and that comes down to knowing the soil type and properties.”

Amy makes the additional point that for cover crops to have maximum benefit they would need to be tilled back into the soil. In regenerative farming, no-till is the preferred option, making this a difficult circle to complete.

Adding further confusion into the mix, Amy says that for carbon to be successfully stored in the soil for any length of time, nitrogen is needed in the process. Generally this involves the use of nitrogen to convert the carbon into organic matter, either through nitrogen-fixing legumes or fertiliser. Only some of the nitrogen would be captured, a lot would escape into the atmosphere or waterways, where it becomes a problem in its own right.

“I am all for anything that might mitigate climate change but we do need to have more knowledge, which will come with time and practice. And the realisation that there is no one-size fits all.”

Renewable nutrient source from poultry manure

Nitrogen, phosphorus, potassium and sulphur are the main elements in crop fertilisers. But, as Amy mentioned earlier, it is the total supply of minerals that must be attended to. If one mineral is deficient then plant growth is inhibited. Trace elements are needed as much as the main four elements.

Micronutrients can be added at blending plants, but there are two main products on the market that contain essential trace elements – FibrePhos and P-Grow are two PK fertilisers of totally organic origin. These consist mainly of potash and phosphate but with sulphur, magnesium, sodium and calcium and other trace elements added. It is derived from the incineration of deep litter poultry manure. It is used for fuel for electricity power stations and the ash from the process is the by-product. It is a renewable nutrient source that reduces the use of scarce resources.

So how far down the regenerative farming route does Amy think we can go and still produce enough food to feed the population?

“The pressure is on fertiliser when it comes down to reducing impact on the environment but we can’t remove them completely. There has been lot of talk about sustainable farming models. To achieve this it seems to be important to increase land, reduce stock and therefore reduce staff. Could this be a problem in the future. There is no point in reducing our agricultural footprint to help the environment if we then have to import far more food.

“In terms of fertiliser, mineral and organic matter, it is necessary to have both to provide a sustainable farming landscape.

“We need to get our narrative sorted. Fertiliser has been jumped on but actually what we need to do is to continue research and development to make it a more sustainable product.”