Soil Management Plans – they may sound like another piece of pointless paperwork, but they can benefit outdoor pig producers. Sarah Trickett reports
Field design can have a huge impact not only on the day-to-day management of outdoor pig units, but also in preventing potential problems from occurring. And with environmental pressure increasing, particularly with relation to outdoor pigs, all producers should be thinking about producing a Soil Management Plan (SMP).
But while SMPs may sound like additional paperwork, it is something producers should be doing to demonstrate good practice, explained BPEX environmental programme manager, Nigel Penlington at a recent Grand Designs workshop, Tidworth, Hampshire.
“SMPs aren’t as time-consuming as farmers may think. The plan basically assesses the risks of surface runoff and soil erosion and describes how the soil will be managed to ensure good structure and to maintain the infiltration of rainwater,” he said.
During a 15-minute exercise, producers were tasked with completing a theoretical soil management plan, to demonstrate how easy it is. Mr Penlington said it was also a simple way to “cover your backs”. “When you have assessed the risk and designed the layout accordingly and have written it down, it can avoid potential problems that may put government payments to landlords in jeopardy,” he said.
When producers were asked whether they had encountered environmental problems, several admitted they had. These ranged from runoff when ground was covered in snow, runoff which caused water on the road and footpaths, and problems with drainage around the feed face. All of these issues had been rectified by different methods, whether installing ditches, grass runoff strips at the bottom of slopes, or additional drainage around permanent feed sites.
Knowing the soil type is crucial in preventing such environmental problems, said Mr Penlington. “Soil type influences how water moves through the land. For example, water in a clay soil will move laterally, whereas in a sandy soil it will move vertically.”
And finding out your soil type is simple. “When you take a sample of soil and wet it slightly, if you run it through your fingers and it feels gritty then it is a sandy soil, when it feels silky and like talcum powder then it is a silty soil and when it has a buttery texture it is a clay soil.”
Another good technique for establishing soil types in a field is to look on Google Earth, said Mr Penlington. “Google Earth is a great tool, as you can quite often see what the soil type is by looking at the colour of the land and crops being grown.”
As well as soil type, Mr Penlington stressed the importance of highlighting the erosion risk, which includes soil texture, slope and annual rainfall.
“Organic matter content and soil structure are two important points to consider, as sandy soils for example, are structureless and are more prone to erosion. Also the degree of slope is important, as when a slope is unbroken the water velocity will be higher. And the shape of the slope can make a big difference, as a concave slope will be more likely to channel water and erode more quickly compared to a convex slope,” he added.
Only once a management plan is drawn up should producers really start thinking about planning the layout. “Pigs can often be kept on land that isn’t ideal, which means careful management is needed. The ideal site is gently sloping, free-draining land,” he explained.
Several factors can help prevent soil erosion such as providing ground cover, assessing feed areas, tracks and vehicles, and providing buffer zones.
Providing ground cover such as grass can help improve soil and can be easily incorporated in to the rotation, said Mr Penlington. Most producers attending did enter on to paddocks with grass although stubble was also quite common.
Ringing noses was also raised by BPEX knowledge transfer manager Helen Thoday who asked the audience how beneficial is was. Although most said it wasn’t, some producers did find it helped prevent paddock damage. “In some instances nose rings can protect ground cover, but it does have a welfare concern,” she said.
The feed face is also an area that can influence field conditions, added Ms Thoday. “In paddocks, the most commonly used area is the feed and water area. Although it is up to the individual farm, it is often argued that square paddocks offer better land use compared to radials because pressure on land is spread out. In any case, spreading the feed length out as far as possible is the best way to reduce pressure and prevent damage.”
Tracks used to access fields for feeding are also vulnerable to soil damage and erosion, explained Mr Penlington. “There are things that can be done to reduce damage such as designing tracks wide enough so the same area isn’t constantly used. Looking at different tyres and tyre pressure should also be considered, for example, the wider the tyre the more area the pressure is spread over.”
And levelling tracks with a grader rather than renovating with discs can also be better. “Levelling ruts with a grader means you are not digging down so far and disturbing the soil structure further down.”