At a time when there's a spotlight on the dairy industry's impact on waterways, Southland dairy farmer Dylan Ditchfield is working on changes that are showing great potential for improvements on-farm and for water quality.
Dylan had Environment Southland land sustainability officer Karl Erikson develop a Focus Activity Farm Plan for his Glenlapa property. In the plan, Karl suggested a sequence crop because of the particularly well-draining soils on Dylan's winter grazing blocks. These soils are a high risk for nitrogen losses to streams and groundwater. "We weren't sure if the climate and weather in the area would make this a viable option, so we were keen to find out," Karl says.
Sequence cropping refers to growing crops on the same field in the same year, one crop being sown after the harvest of the other.
Karl, who has a passion for keeping up with the latest farm systems research, was inspired by a presentation on sequence cropping at a farm field day. It was put forward as an answer to the question: How can nitrogen leaching from winter grazing crop paddocks be reduced?
"Results of that study on a farm in Canterbury show that nitrogen leaching can be reduced by 25-30% by planting a sequential crop of oats immediately after harvesting kale, when compared to traditional kale cropping practices," Karl says.
Typical winter grazing practice on a dairy farm would see cows on paddocks from June until around the end of August. Paddocks are often then left bare until they dry in October/November, when they're re-sown with swedes or returned to pasture.
"The paddocks left for two months have a lot of dung and fertiliser on them, which can be moved easily with some heavy rain and lead to overland flow, causing problems for water quality," he says.
