Farming: Future proofing the farm – 20 ways farmers can reduce contaminant loss
08 Nov 2018
There are four areas of contaminant loss that farmers are busy addressing:
Interesting to note why these contaminant losses are a problem:
At one level it seems obvious that farmers would rather retain nitrogen, phosphorus and soil on their farms because this is what they need to carry on farming. If a farmer or gardener is working with natural ingredients, two of them being the basic food requirement for grass and plants (nitrogen and phosphorus) and the soil itself, the farmer or gardener doesn’t want to send their assets down the nearest river to the sea. It is expensive and time-consuming to replace.
On another level, some of the prevention measures are expensive, it may be easier to get the replacement nitrogen and phosphorus out of a truck and the landscape may make it hard to keep hold of the soil. In the past, the easy way out has predominated.
There is broad agreement on the changes farmers need to make and the first of these is to undertake a planning exercise. A Land and Environment Plan, to be precise. This is to understand the pros and cons of each farm, because every farm is different. The job is to identify the environmental resources on the farm and to understand the risks to the environment, that is, to other people down-stream.
There are plenty of tool-kits available to farmers to help them with this and plenty of support from the farmer organisations.
What should come out of the Land and Environment Plan is an attempt to match land use with the capability of that land.
For instance, flat land is generally of low risk of loss of phosphorus and soil (comes mainly from sheep and beef), but a high risk from the loss of nitrogen (which comes mainly from diary).
Steep land has a high risk of loss of phosphorus and soil and a low risk of the loss of nitrogen.
Soil types have a big influence on how easily contaminants are lost too, as you can imagine.
Here are some of the things farmers are doing to reduce contaminant loss:
- Doing a nutrient budget using the most recent version of OVERSEER©, New Zealand software that helps farmers improve nutrient use on farms. From a dollars perspective, this is rated as a net financial gain for the farmer compared to the costs of implementing it (dollar positive).
- Using soil testing, avoiding the unnecessary application of phosphorus for a big dollar positive gain.
- Reducing the number of old female cattle for a decent reduction in all three loss groups and a decent dollar positive gain. Male cattle disperse urine more widely. Less concentration means less leaching. Less live-weight on the farm over winter benefits soil health and reduces soil loss.
- Finishing off cattle rather than wintering them over for another winter to benefit soil health and reduce soil loss.
- Matching stock management to land capability – keep heavy animals off the hills. Requires contour fencing for greatest benefit.
- Grazing wetter paddocks early in winter for a decent dollar positive gain.
- Strip grazing towards waterways rather than away from them to reduce run-off.
- Planting popular, willow or other trees on southern faces that get wet or are erodible while still providing some grazing, to prevent soil and phosphorus loss from erosion. Potential for drought fodder depending upon species of tree used. Provide shade and shelter for animals.
- Rotating herds of animals more often onto fresh pasture when wet weather hits for a decent dollar positive gain. Good reduction of loss of phosphorus, soil and micro-organisms from this practice.
- Planting forest on southern hill faces for long-term investment. Expensive up front.
- Managing hotspots from tracks and yards by shaping the land and help prevent the loss of phosphorus, soil and micro-organisms for good dollar positive gain. Direct stockyard run-off onto paddocks rather than water-ways.
- Fencing and planting out dams, wet and boggy areas and waterways to keep animals away from water. Reduce animal losses, reduce contaminant loss and protect stream life. Piping water to troughs rather than giving animals direct access to natural sources. Planting around dams to cool water in summer but don’t plant on dam wall. All adds capital value to the farm.
- Planting shade trees away from areas of high surface water run-off.
- Moving water troughs and gateways away from areas of high surface water flow. Great benefit on steeper land.
- Putting in culverts and bridges at regular stock crossings.
- Building sediment traps or bunds to slow water flows and filter sediment. For more on bunds, see here. Expensive but can be very effective.
- Reducing soil cultivation by adopting strip tillage or direct drilling of seed into the soil. Can make a big impact on the reduction of phosphorus and soil.
- Cultivating along contours rather than up and down the slope where slope is greater than 3o.
- Avoiding cropping on steep land.
- Actively managing grazing of winter crops. Graze from top to bottom of the paddock contour. Avoiding leaving stock on during wet periods, for long periods or in concentrated areas. Big dollar gains possible from this practice and good reductions in contaminant losses possible.
See the full document here (great site).
Risk of Contaminant Loss on Different Landscapes
From Environmental Opportunities, Making regulation work for New Zealand sheep and beef farmers, Rabobank Agribusiness Report Special Edition/2015, by Blake Holgate.
Acting on the farm to reduce contaminant loss is not really an option any more, it is the expected business practice that is slowly but surely becoming a bottom line for farmers. Farmers shouldn’t feel threatened by these sorts of developments. Every sector of society has or are under-going similar sorts of changes just to stay in business. Change is endemic.
Money spent now on farms to reduce contaminant loss is a great investment for the future.
Keep asking great questions …
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