As the global human population continues to rise, more land will need to be committed to agricultural production to meet a likely rise in demand for food, says Dr William Stiles from the Institute of Biological, Environmental and Rural Sciences (IBERS) at Aberystwyth University.
This has the potential to increase the conversion of land which has not been previously used for agriculture, or to intensify agricultural activities on land already used for food production. Farmland habitat, referred to as the agroecosystem, is perhaps the most important environment in the UK in terms of wildlife and biodiversity, as this is the primary land use type covering nearly 75% of the country. In recent times this environment has been associated with biodiversity loss and with reductions in presence of wildlife as a consequence of post-war agricultural intensification.
What drives biodiversity at the farm scale?
Specific factors governing different landscapes, such as topography, may inform which system is most appropriate or feasible in a given situation, but overall this can best be achieved where the amount of land set-aside for wildlife is increased. Excluding portions of land from production around the margins of fields will promote wildlife by increasing food and habitat opportunities and by limiting exposure to fertiliser and pesticide applications. The amount of land which can be spared will depend on field and farm size, but even a one metre strip between hedge and crop has been shown to benefit wildlife. Alternatively, a strip of habitat can be created across the middle of a field, which will provide habitat for small mammals and invertebrates (usually a double ploughed ridge sown with native tussock grasses). These are often referred to as ‘beetle banks’ and should be approximately 2-3 metres wide for best effect. Tree and hedgerow planting, to create woody vegetation patches, will also benefit wildlife and can have additional beneficial effects from stock management and ecosystem service perspectives.
Can increasing wildlife populations benefit farm management?
Agri-environment schemes in the UK have actively promoted the introduction of farm management approaches which benefit our native flora and fauna. Wildlife-friendly farming strategies can support wildlife that is considered beneficial in an agricultural context, such as those which engage in pollination or as natural enemies of crop pests. This in turn may have positive influences on agricultural production. One recent field based study compared different amounts of land removed from production for the purpose of wildlife habitat creation. Measured yield was demonstrated to increase for the studied crops of wheat, beans and oil seed rape, in fields with up to 8% of land set aside. When compared with control fields (with no wildlife habitat patches), the overall yield was comparable, which indicated that the benefits derived from the wildlife friendly approaches, in terms of increased yield, compensated for any loss incurred from taking portions of land out of production. This effect is due to improvements in the delivery of natural services provided by wildlife and from the fact that the land sacrificed could be considered less productive or lower yielding (for instance, at field edges where there is increased compaction, competition from trees and hedgerows for light and water, and greater stress from pest species). It is also expected that time will be needed for populations of some wildlife species to recover from current low levels. Thus, whilst some benefits may be observable in the short term, it could be expected that as populations will continue to improve, then beneficial influences on yield and ecosystem service delivery, will continue to strengthen.
Other studies have demonstrated increased yield in grassland as a result of increasing plant diversity by sowing species rich seed mixtures. In an experiment considering gradients of plant species richness and management intensity, higher diversity was shown to be more effective in increasing productivity than higher management intensity and low-input high-diversity fields had similar productivity to high-input low-diversity management regimes. Whilst overall costs associated with restoration would need further consideration, and some thought should also be given to field and soil preparation as soil nutrient status is likely to dictate the success of sowing species rich mixtures, this demonstrates the potential for increasing habitat availability whilst reducing environmental impact and cost of production to the farmer, by reducing fertiliser input requirements.
So what are the benefits?
Any benefits associated with the enhancement of wildlife will need to be weighed against the cost of such approaches in the context of farm management. These could include land lost from production, or the cost of any upkeep or maintenance of set-aside or wild areas. However, evidence to date suggests that providing habitat and food for wildlife on farms, may have positive effects on potential production yield, as well as improving the potential for ecosystem service delivery. In the long term, such actions may become even more important due to current rates of environmental change, which are likely to add additional pressure to this already pressurised ecosystem. By changing approaches to farming to conserve biodiversity by providing for wildlife, it may be possible to enhance the potential for resilience in the agroecosystem, helping to future-proof it against expected shifts in climate.
Credit to: https://www.farminguk.com/News/Farming-Connect-The-importance-of-biodiversity-and-wildlife-on-farmland_46046.html