Feeding the soil is the process of adding organic matter to improve its nutrient value, water retention and structure. Organic matter comes in many forms, from home-made compost to well-rotted manure (horse and pig and pelleted chicken manure are popular for feeding garden soils). You can also grow green manures, which you sow on bare patches of earth and then dig into the soil before they flower.
Organic matter is also available in the form of slow-release fertilisers or blood, fish and bone. Organic liquid fertilisers can work to feed the soil but they are mostly taken up immediately by plant roots, therefore giving little back to the soil. Lastly, the ‘chop and drop’ system of mulching soil with chopped up leaves or grass clippings can also work well, offering a natural, slow-release solution to dry, weedy, nutrient-poor soils.
Why feed the soil?
Feeding the soil increases nutrients and water retention, and improves soil structure. While feeding the soil every couple of years will keep your garden looking good and your ornamental plants growing and flowering well, feeding the soil is much more important in the vegetable patch. After all, your plants are only as healthy as the soil they’re growing in – it makes sense to ensure the fruit and veg you eat are growing in the healthiest soil possible.
More on composting and feeding the soil:
We outline five benefits of feeding your soil with organic matter, below.
Improve the soil structure
Bulky materials like home-made garden compost, well rotted manure or leaf mould break down and release nutrients slowly. As they break down they’re eaten by earthworms and other detritivores, which move through the soil, creating drainage channels. Bulky materials can therefore lighten heavy soils, helping them to drain more easily. On lighter, sandy soils, organic matter helps increase water retention, as the matter is naturally more water retentive than the soil itself. So-called ‘sticky’ manures, like pig manures, are particularly useful on very sandy soils.
Increase soil nutrient levels
When you add artificial fertilisers to soil you add soluble nutrients, which are washed away if not immediately absorbed by the plants. By adding organic matter, which breaks down over time, you add nutrients that stay in the soil and are absorbed more slowly. All organic matter has nutrients such as nitrogen, phosphorous and potassium, plus trace elements such as magnesium, copper and manganese. As earthworms take organic matter into the soil to eat it, they create their own manure. Bacteria, fungi and other micro organisms get to work on the matter as well, which aids the uptake of soil nutrients by plant roots.
Be more eco-friendly
Artificial fertilisers come with a high carbon and environmental footprint. They’re made with raw materials such as ammonia and phosphate rock. The mining of phosphate rock can cause severe environmental damage, including loss of biodiversity, while the process of converting the raw materials into useable fertiliser involves the use of petrol or natural gas.
What’s more, if not absorbed by the plants, artificial fertilisers can be washed away by rains, eventually winding up in rivers. The increase in nitrogen to rivers can cause algal blooms, which can smother and kill all forms of other life in the water, including fish.
Adding organic matter will help you to avoid all of these pitfalls.
While some forms of organic matter can be expensive to buy, home-made compost is free. You don’t need a compost bin – simply pile compost into a corner of the garden and harvest the compost once a year to add to your garden. Other types of mulch, for example grass and leaf clippings, also cost little, if anything, to produce. Green manures such as phacelia cost as little as a packet of seed. What’s more, your local stables might sell manure for as little as a pound a bag, or even give it away for free. Compare this to synthetic fertilisers, which need applying as regularly as every fortnight.
Improve the biodiversity of your garden
A garden rich in wildlife comes with free pollination and pest control services. It’s also nicer for us – who doesn’t love seeing birds, bees and butterflies in the garden?
A compost heap is the perfect spot for a nesting bumblebee, hungry frog or sleeping hedgehog. Bulky organic matter such as home-made compost, leaf mould or well-rotted manure, creates further habitats for beetles, worms, centipedes and other invertebrates on the ground, while it breaks down. This increase in abundance of soil invertebrates means there’s more food for animals further up the food chain, including birds and hedgehogs, making your garden alive with food and nesting opportunities for a wealth of wild species.