Working with nature
PUBLISHED: 08:11 28 March 2014 | UPDATED: 08:46 28 March 2014
Alan Beat looks at the myriad ways you can encourage biodiversity on your smallholding
Given the interdependence of all living things, including ourselves, it can be argued that we hold a shared responsibility to actively encourage biodiversity on our smallholdings, in order to safeguard a sustainable future. This need not be difficult or expensive to achieve, and may show financial benefits over the long term
Around the smallholding
Many creatures require cover in which to shelter, nest, feed or hibernate, and this can be provided simply through avoiding over-tidiness. For example, leave nettles uncut in a sunny position, as these are the food plant for caterpillars of several butterfly species, including red admiral, peacock and small tortoiseshell.
Piles of fallen leaves can be left in a corner to benefit a range of insects, small mammals and fungi. Spare some grass from mowing or grazing and allow it to grow long and tussocky, to support the huge range of invertebrates whose life cycle depends upon flowering grasses.
Of course, this approach needs to be kept in proportion! ‘Leaving it to nature’ invites domination by the most vigorous plants, which can force less competitive species into decline. So, apply a healthy dose of common sense: control invasive plants as required, but leave some untouched where they do no harm.
An extension of this approach is to deliberately set aside small pockets of land and leave nature to do the rest. A field corner that is difficult to access, or boggy, or steep, can be simply fenced off. At first the grass will grow long; then tussocks develop; other plants creep in; perhaps brambles take over; then invasive tree and shrub species like willow, ash and hawthorn appear; then a woody copse develops that shades out the bramble beneath its canopy; and so on. You can choose to intervene and manage at any point, or simply allow nature to take its course.
All it costs is a bit of fencing and, eventually, that will be compensated by the firewood harvest.
On the land
Choosing to avoid the application of artificial fertilisers and other agro-chemicals to the land is a significant move. Artificial fertilisers boost the growth of more vigorous grasses at the expense of weaker, slower-growing species. The effect, on a diverse sward, is to encourage domination by the coarse grasses that best respond to soluble nitrates. That may appear to favour maximum cropping, but it’s bad for biodiversity, and things are rarely as simple as they seem.
Suppressing clover with expensive artificial nitrogen is a very bad idea financially, because clover fixes nitrogen from the air into the soil for free! The root systems of different herbs draw nutrients from varying depths of soil and subsoil, many reaching down far deeper than grasses, increasing the range of nutrients available to livestock and providing better grazing during drought conditions.
The use of chemicals like weed killers or pesticides will nearly always have a negative impact on biodiversity, despite the ‘greenwash’ claims often made by manufacturers. A recent example has been the widespread poisoning of allotments and gardens by aminopyralids, originally sprayed on grassland to control broadleaved weeds, but which survive passage through the digestive tracts of farm livestock or horses to contaminate their manure.
Some wormers administered to livestock can similarly pass through to render their manure lethal to those organisms that break it down to release nutrients back into the soil. So avoiding the use of expensive agrochemicals is a really positive choice both for biodiversity and profitability.
Choosing not to introduce alien species is another positive decision. The environmental damage caused by introductions ranging from grey squirrels to Japanese knotweed is well documented, yet many invasive exotic plants remain widely available today at pond and garden centre outlets. Don’t buy them or introduce them, and make the effort to control any that appear on your smallholding.
In the garden
The use of chemicals in the garden has a negative impact, not only on biodiversity, but also risks affecting those who consume the food it yields. Pesticides will poison many creatures besides those targeted, so use natural methods of control instead.
Grassland can be managed in ways that specifically benefit biodiversity. Suppose permanent pasture displays a few colourful flowers such as ragged robin or meadowsweet. Positive management could be targeted at increasing the number and range of such plants, for example by changing the grazing regime from sheep to cattle, because cattle leave the sward more variable in length and generally longer, allowing plants that are grazed out by sheep to thrive instead. Another change might be to close the field for a cut of late hay in July or August, after most flowering plants have dispersed their seed. A third change might be to cease using artificial fertiliser on this field, for the reasons given above. Over several years, such management could encourage a dramatic increase in flowering plants, and in the creatures whose life cycles are associated with them.
Where there are no established wild flowers to begin with, you might choose to create a wildflower meadow from scratch. A good first step is to impoverish the soil, often achieved by removing the top few inches of turf for sale. The poorer subsoil is then seeded and left unfertilised. Ensure that seed is of local provenance, and not based on imported seed. A simple and effective way to achieve this is to obtain bales of late hay from an old-established local wildflower meadow and cart these to your new site, before cutting them open and strewing the hay loosely around. Enough seed will fall out to establish the new meadow.
Banks and hedges
It’s now widely recognised that trimming hedges annually is both expensive and detrimental to wildlife. Trimming every second or third year instead, on a planned rotation, is both cheaper and better for wildlife. Nothing could be simpler, while
the mutual benefits are clear. Even better for biodiversity is the re-introduction of hedge laying. Start by allowing regrowth without any trimming for several years until the stems are tall enough to lay in the traditional manner. Each hedge is then revisited in rotation on a regular cycle of eight to 12 years, depending on growth rates. The result is a wide variation in hedge size around the smallholding at any given time to provide maximum wildlife benefit. The environmental stewardship payments currently available should cover the cost of employing a hedge layer, or you might choose to do the work yourself and keep the money. You also gain the harvest of firewood and sticks for the garden, for home use or sale; and once the hedge is fully stock proof, you won’t need fencing any more. You could also choose to extend the habitat available by planting new hedges, or building new earth banks or stone walls as field boundaries, in place of fencing. Of course these all involve an initial investment of money and labour, but taken over a lifetime actually work out far cheaper than fencing, so can be viewed as a sound long-term investment.
Creating a pond and/or wetland can attract a broadrange of wildlife to your smallholding. Many creatures depend upon still water for at least part of their lifecycle, and so cannot exist without it. The pond surrounds are equally important, and the ideal is for shallow pond margins to blend progressively into marsh and then to damp meadow, with long grass and some scrub and tree cover all close to the water. Well-designed new ponds can become outstanding habitat within a few years, but any pond is better than none.
The significance of buildings for wildlife is often overlooked. Barns and other outbuildings can form important roosting or breeding sites for a range of creatures, from bats to barn owls, and even the farmhouse roof space may be colonised. New buildings can be planned to maximise this potential by incorporating features that encourage colonisation, while existing buildings are easily enhanced by the provision of nest boxes. Simply leaving a door or window open to provide access may be all that is required for wildlife to move in!
Action taken with the best of intentions may have unforeseen consequences, so
there are times when specialist advice should be sought before work starts. For example, before digging a pond, the site should be surveyed for plants and
invertebrates that already live there, to assess whether the proposed work will cause more harm than good. It may be better to create ponds alongside existing wet areas, thereby enhancing rather than destroying them. Approach the local wildlife trust to carry out an initial survey and advise on future management.
Hedge laying, stone walling and other landscape management may qualify for enhanced payments under the Single Farm Payment scheme, so contact your
regional office of Natural England. Work that may affect watercourses is likely to
require advice or permission from the Environment Agency. Changes of land use from agricultural to another category (for example, construction of a large pond) may require planning permission from your local authority before work starts.
An holistic approach
The best approach of all is to pursue all of the foregoing options in an holistic design to maximise biodiversity on the smallholding. You’ll spend some time and money on this, it’s true, and may sacrifice some productivity in the short term, but wildlife trusts and other conservation bodies have come to recognise the economic potential of this approach, and environmental stewardship is now actively promoted as a realistic source of additional farm income.
Positive management for wildlife has been widely shown to make good financial sense, in addition to delivering clear environmental benefits.