An article written for Farming Futures looking at practical options for reducing greenhouse gas emissions from farms.
Profitable and sustainable farming is the ultimate aim of any farm business. Minimising the environmental impact of production by reducing emissions and adapting to climate change, while at the same time achieving the increases in production that are needed to feed a growing population presents a massive challenge to the industry (and is not something that I am going to try and solve in this blog!). However being proactive and looking at your farm business is a great place to start. Having an idea of where the main areas of emissions are on-farm and developing strategies to reduce them makes good business sense in terms of improved efficiency but also moving forward may provide an advantage in terms of marketing produce to consumers who are more and more concerned by climate change.
So where do you start? Below are ten options that will reduce greenhouse gas emissions but will also increase efficiency and ultimately profitability.
Maintain a good soil structure
Soil underpins the entire farming system. A healthy well-managed soil that accumulates organic matter will sequester carbon, be productive and increase productivity, a win, win, win situation. Maintaining a good soil structure by avoiding grazing or travelling on wet soils and
minimising compaction will enable better crop growth. Building your soil organic matter content will increase not just the carbon sequestration potential, but also the water holding capacity and structural stability of the soil. Every hectare of land that raises its soil organic matter levels by just 0.1% will sequester 8.9 tonnes of CO₂ per year.
Use cover crops
Cover crops are crops primarily grown to provide ground cover rather than leaving bare soils. Their use through the winter months to protect the soil will prevent nutrient losses through nitrate leaching, and the loss of soil particles and sediment (including phosphate) through run off and erosion. This loss of nutrients and soil can have an adverse effect not just on water quality and diffuse pollution, but this release of nitrates from the soil will increase nitrous oxide emissions (300 times more potent a GHG than Carbon dioxide). Cover crops have many positive benefits to the farming system, and if they are ploughed in, they can increase the soil organic matter content of the soil (sequestering more carbon
Nutrient management planning
Improved nutrient management has a significant and cost effective role in profitable farming systems. By planning nutrient applications (either by fertiliser or organic manures), it is possible not just to minimise GHG emissions (especially nitrous oxide) but also reduce the levels of diffuse water pollution and improve profitability. The main goal of nutrient management planning is to match applied nutrient supply to crop requirements taking into account soil
conditions (including soil pH). There are various nutrient management planning tools that are available to help with the planning process.
Timing of fertiliser and slurry applications
Following on from planning fertiliser and manure applications, applying them at the right time is the crucial next step. Ensuring that they are applied at times when they can be taken up by the actively growing crop will ensure that the nitrate is not sitting in the soil risking leaching or being released as nitrous oxide. Urea applications are more prone to the loss of ammonia in windy weather as the moving air increases ammonia volatilisation from the soil. However it is more suitable as an early spring fertiliser as it is less susceptible to GHG
emissions from high soil moisture levels.
Use clover and other legumes as fertility builders
The use of clover and other legumes as a nitrogen source is something that has been practiced by organic farmers for centuries. However due to rising costs of Nitrogen fertiliser and the negative associated environmental impacts of its production and use, it is becoming an increasingly attractive proposition to all farmers. Benefits of using legumes and clover include an improvement in soil structure and soil microbiology as well as a method to tackle weed, pest and disease control.
There is emerging evidence that the fewer number of passes across the field, and the less disturbance of the soil with each pass, the
lower the GHG emissions are from the soil. The reduction in emissions occurs primarily as a result of the effects of cultivation on soil organic matter. When the soil is cultivated, it allows oxygen to enter the soil which stimulates the soil microbes and oxidises the organic
matter, which then emits carbon dioxide. Reducing the frequency and intensity of cultivations results in less organic matter being oxidised and allows for higher levels of carbon sequestration in the soil.
Efficient livestock systems
The most significant emissions associated with livestock are methane originating from enteric fermentation and nitrous oxide from manure
management. In terms of methane reduction the current advice is to work on improving the efficiency of milk or meat production through improved feed efficiency, which will benefit profit as well as reduce emissions per unit of production. Paying attention to herd (or flock) health,
welfare and fertility as well as manure storage and handling will optimise production and have associated reduction in emissions.
Maximise biomass on farm
Much of the biomass that commonly occurs on UK farms such as hedges, woodland and permanent pasture is already sequestering carbon at very
significant levels. With careful management, this can be improved to maximise the rate at which carbon sequestration occurs. As an added bonus,
more biomass often equates to better habitat for wildlife, particularly insects and birds.
Do an energy audit
There are some simple steps that you can take to reduce energy use on-farm, and ensure that your business is running efficiently. The most important step is measuring the energy you use. Identification of the main areas of energy usage on-farm and assessment of their performance is the next logical step. Prioritise no cost and low cost options first before looking at more longer time (and potentially
more costly options).
Consider installing renewable energy
Generating renewable energy is a good way to insulate our farms against rising costs, as well as ensuring a secure supply of energy. Installing renewable energy on-farm is another way to harness the productive power of the land, which we as farmers and growers appreciate more than most. FCCT has a range of tools including a Carbon Calculator and lots more info on these and other methods to reduce greenhouse gas emissions. For more information please visit the website.