An ongoing Innovative Farmers field lab is looking into the impact of mob grazing on soil, biodiversity and animal health. Six dairy farmers have teamed up with researchers for the trial to see if tall grass grazing practices can work for dairy herds. The group are currently on a variety of different pastures - from rye grass to permanent pasture and herbal leys.
Last week, in a collaborative session with FABulous Farmers, the group heard from Siobhan Griffin from Next Level Grazing. Siobhan started farming in 1989 in New York State and now lives in New Zealand where she farms 4200 ewes on 400 hectares. Through Next Level Grazing, Siobhan works with pastoral farmers and equips them with the knowledge to heal the land and build carbon in the soil. Over the two-hour workshop, Siobhan shared the highs and lows of her farming journey, as well as how to build soil organic matter and have a more resilient grazing operation.
Siobhan’s tips for a more resilient grazing system:
1. Promote biodiversity to drought-proof your farm
For the first ten years of farming, Siobhan was only planting perennial rye grass and white clover. She shared that, “sometimes we would get 30°C in the summer and only 5ml of rain in a month and the rye grass would turn brown. We noticed that the deep-rooted plants, like dandelion and red clover, did much better under those conditions.”
Studies have shown that diversity can make farms more productive. Your land productivity increases as you build your topsoil. Having a greater diversity of deep-rooted plants that help build soil organic matter enables you to build more topsoil and have greater productivity. Deeper-rooted plants are more drought tolerant as they pull water up from deep layers in the soil and store it in their tissue, enabling plants to continue growing during periods of drought.
2. Increase your use of perennial plants
Growing annuals results in soil disturbance from persistent use of chemicals or tilling. While Siobhan grew annuals for years on her farm, she noticed that the soil carbon level did not rise. Annuals pump more liquid carbon down into the soil when they first start growing, but once they start making seed and reach senescence, they stop feeding the soil consistently. Siobhan said, “we took annuals out of our programme and it was at that point that our soil organic matter started to lift. You can increase soil carbon in your soil’s deeper layers by encouraging deep-rooted perennial pastures.
3. Optimise pasture recover period
When grass isn’t actively growing it slows its liquid carbon pathway that is feeding the soil. Having overly long rest/recovery periods of pasture will result overall in slower grass growth.
Siobhan advises to avoid plants getting to the stage where their leaves are turning yellow and starting to die as it reduces their ability to harvest solar energy as the sward has stopped growing. Additionally, it slows nutrient cycling. Optimal recovery helps you grow pasture faster per unit of input; getting optimal recovery for the plants that you want to see more of should be a part of your grazing plan and will lead to more growth of other high-quality plants. Siobhan commented that “it’s not about the height [of the plant], it’s about the physiological recovery of the plants that you’re monitoring because they are the ones you want to see more of.”
4. Plan for unpredictable weather
- Supplement in spring to give your pastures more of a chance of recovery before you start grazing them.
- Plan in deferred pasture through flash grazing, keeping more area in the round and taking off less supplement. The lower you take your pasture, the slower your pasture grows so supplement at times when your grass growth is slow. Even though it costs money to buy-in supplement food, in the long-run you’ll need less winter supplement because you’ve grown more pasture during summer months.
- Lift slowly from where you’re at: If you’re already on diverse leys, you’re already several steps ahead. The first step is trying to achieve the three-leaf stage on your pasture - especially in the summer. Keeping an eye on the leaf stage within your pasture enables you to see if a paddock is ready to be grazed. you grow one tonne more kg’s per hectare per year with no added inputs. If you manage your time correctly then you will need less inputs and will grow more.
Source: https://www.dairynz.co.nz/feed/pasture/assessing-and-allocating-pasture/leaf-stage/
The benefits of holistic grazing: Raindance Farm, Middlefield, New York State (2008-2015)
Siobhan previously farmed on silt loam soils at Raindance Farm in New York State; the farm went organic in 1997 and started holistic planned grazing in 2007. These changes allowed Siobhan to achieve a 3% increase in soil organic matter over six years, consistently high milk production and enabled her to get a higher grass-fed premium for her meat. For Siobhan “the important thing isn’t the [soil organic matter] number, the important thing is the change in soil carbon – it allowed our pastures to be more resilient in the summer.”
A list of other benefits:
- She maintained organic milk production at 5,600 litres.
- Soil Organic Matter increased from 6% to 9% in six years.
- Fewer pests in the garden and orchard.
- There was 88% less lameness - dairy cows only need a 17% protein diet but when we’re managing for perennial rye grass and white clover, their diet can be more around 24-27% protein. This higher protein diet can result in the animal having excess urea and needing to excrete more nitrogen - this can raise the milk urea nitrogen (MUN) level and lead to lameness. It can also cause off-flavours in meat and milk. Siobhan eliminated these issues with the introduction of mob grazing, more diverse pastures and grazing her stock for optimal recovery periods.
- They became 99% mastitis free with organic management.
- Saw big increase in ground nesting birds –which anecdotally resulted in fewer caterpillars in their apple harvest.
