Trees and pasture productivity are rarely discussed in the same conversation, but farmers who think of trees as either shading out grass growth or taking away valuable grazing land are missing out on vital pasture productivity potential.
The last couple of decades in farming has been led by the ‘green revolution’ and solutions that are sold in big white bags or plastic drums. As a Farm advisor working with leading soil scientists and training with the world’s most productive farmers, I can confidently say that the next revolution in agriculture is going to be a biological one.
This shift in mindset for many landowners feels like they are having to unlearn more than learn something new. But those who manage to embrace regenerative agriculture can expect better returns, increased productivity and reduced input costs.
Managing your farm as a ‘whole’ rather than a series of parts is where the big idea starts. Here’s four ways in which trees are an important part of a functional ‘whole’ farm.
1) Improved water infiltration. One key element of any productive landscape is how well the land slows and holds water. Forage plants need a good supply of water to be at their most productive. Saturated land, however, leads to dead plants and bare soil; perfect conditions for rush and moss to move in. A healthy water cycle is when raindrops hit tall foliage, then are absorbed in decaying litter and spongy carbon rich soils. A variety of plant root architecture helps infiltrate water to many soil layers ensuring water is held for times of drought. Roots help prevent surface saturation which leads to water traveling across the surface carrying precious top soil with it. Deep roots from trees and hedges can reach far into pastures helping this process and ensuring optimal aeration of your soils. (1)
2) Massive mineral uplift. Healthy plants need forty two essential nutrients to be at their most productive and disease resistant. Some of these come from soluble minerals in the soil and are absorbed through plant roots then are released back to the soil surface through decaying plant matter and animal excretions. Rain washes these nutrients downwards, so deep roots are essential for catching leaching minerals before they become out of reach or pass into streams. In a conventionally grazed pasture the grass foliage is often too short to reach these bountiful nutrients (which is one of the many reasons we recommend Holistic planned grazing.) Trees can offer an enormous nutrient uplift. Their roots tap into the deepest of soil layers and bump up against the minerals in the rock itself. The nutrients are shifted upwards into their leaves and then once a year they release these mini mineral parcels to the ground, fertilising your pasture for free.
3) Microbial superhighways. Recent soils science is ‘blowing the minds’ of many land management experts. Plants can absorb soluble – plant available – nutrients from the soil but these can be limited depending on your soil type and climate. The real potential for pasture productivity – that doesn’t come from an expensive bag – is in the so called ‘microbial bridge.’ In healthy soil, small microbes dissolve and absorb minerals, that are not in a form that plants can absorb, from rock and other pathways. Plants can access these by passing some of the food they make through photosynthesis into the soil in the form of a microbe attracting exudates. This mixture of sugar, carbohydrate and protein attracts these bacteria and fungi close to the root. If the pasture is diverse enough to support predatory microbes the plant root activity will attract those too. The bigger guys eat the littler guys, conveniently excreting the nutrients held in the prey’s tiny biomass in a handy plant available form right at the plant root. In a complex pasture or diverse woodland, the fungi start to build superhighways through tiny root like filaments. These ‘super roots’ not only have a greater ability to absorb nutrients, but can pass the goodies back and forth between plants and trees depending on who needs what! Talk about the ‘world wood web!’ By having woodland at the edges of your pasture and hedges or individual trees within it, you can increase the mycorrhizal fungi in your soils benefiting the forage plants growing in your pasture. (2)
4) Livestock medicine cabinets. Plants all need nutrients to thrive; everything higher up the food chain accesses these nutrients through eating plants or animals that have in turn eaten plants. The more nutrient dense the plants the healthier everyone in the food chain. Most UK modern farmed pastures have a poorly microbial bridge. When grasses are ‘fed’ artificial fertiliser they get lazy and don’t pump out liquid carbon exudates to attract symbiotic microbes. UK grasslands also tends to be grazed short which severely limits how much ‘natural’ soluble food the short root of the plant can take up. This has led to mass mineral deficiency in our livestock, and a booming agri-supply business! It’s common now to see a mineral tub in most livestock fields and medical intervention by farmers treating the symptoms of a poor diet seems to have reached an all-time high. If you see cattle in a reseeded pasture surrounded by a hedge, I’ll bet you some will be browsing the hedge. The deep roots and effective microbial interaction means their foliage is rich in everything the livestock’s’ bodies are screaming for. Different native plants contain phytochemicals which are essentially natural and powerful medicines. Native and more traditional breeds of domestic animals have an inherent knowledge of what their bodies need to solve health issues – they just can’t find it in a rye grass and clover sward! Modern plant breeding focuses on increasing protein or efficiency when grown with Nitrogen, instead of animal health, soil health or microbial interplay. (3)
Balance in nature is key, and a complex and diverse habitat has been shown to be more robust and resilient. When you see ‘plagues’ or extinctions, it is often because complexity has been reduced. Perhaps you have one plant that supports one or two insects, who in turn are eaten by one or two birds or predatory insects. If the predatory birds and insects have no habitat and die, the insects lower down will thrive, possibly out stripping their food supply and becoming a pest. Trees, woodlands and hedges offer homes to thousands of invertebrates, mammals and birds. This added complexity helps avoid livestock bothering insect booms, accelerates pollination, and helps balance out problem parasites.
A more complex pasture of native deep-rooted plants, grazed in a holistic plan, coupled with a landscape that includes forage hedges, individual trees and woodlands could significantly reduce your costs and increase your productivity and profitability. There are many more ways in which trees and hedges offer value on farmland and it is saddening to see the fast decline of these underrepresented assets.
I hope this article has helped you look at trees in a new light, we need to protect our woodlands and hedgerows not just for natures sake but, for the sake of truly sustainable food resilience too.
Please feel free to share or link to this article if you liked it. Thanks Caroline