Farms tackle effluent issues

MyFarm syndicates are taking a proactive approach to effluent management and investing heavily to mitigate problems and lessen their environmental footprint.

In Southland seven of the syndicates managed by MyFarm have upgraded their effluent storage capacity and application systems in the past two years at an average capital investment of around $100,000 per farm.

MyFarm supervisor Grant Payton says new larger effluent storage ponds give a minimum of 60 days storage, allowing more flexible management over wet periods. On many farms the effluent discharge area has also been extended - up to 100ha on the larger properties, which in turn has a positive impact on farm fertiliser budgets.

AgResearch figures indicate K-line irrigation improves retention of nutrients by 20-40kg/N/ha/yr; 30-60kg potassium/ha/yr and 2-4kg phosphate/ha/yr delivering an average saving of $4250 per year for a 700 cow farm.

“The greater the area the less total capital fertiliser that is required due to the levels of nutrients such as potash and nitrogen being applied via effluent application. Systems with solid separation will also allow for the solids to be applied to poorer performing areas of the farm and/or new crop ground in spring again reducing fertiliser expenditure.”

Grant says equity managers and sharemilkers are adapting well to the new technology and report on the positive benefits additional storage provides in busy periods such as spring.

“The extra storage is allowing farm management to place greater focus on animal welfare and pasture management until conditions allow for the application of effl uent in mid to late spring.”

To achieve this also requires a conscious effort at the end of the season to ensure all pond levels are at their lowest heading into winter which is the focus at this time of year for on farm management.

Construction of a 60-day storage pond and extended discharge area was completed at Edendale Pastoral just before the start of this season. Sharemilker, Eli Gibbs says he was thankful for the additional capacity early season, which meant not having to irrigate at all until conditions dried up in October.

Adjusting to the management of K-line pod irrigators is taking time, but he says it’s worthwhile when you consider the effluent irrigation now covers approximately 75 of Edendale’s 220hectares.

“Those paddocks haven’t had any fertiliser on them this season and they’ve been keeping up with the rest of the farm so far and sometimes going ahead.”

Meanwhile Grant Payton says the effluent management developments have strengthened AGInvest’s relationships with Environment Southland, Fonterra, consultants and contractors.

MyFarm continues to closely monitor development of effluent technology and regulations. Recent council and Fonterra feedback indicates it may soon be possible to introduce systems that reduce overall dairy shed water use by up to 20% through recirculation of waste water washing down yards. This is currently being reviewed by Fonterra and the NZ Food Safety Authority and if agreed will be a considerable benefit  to all dairy farms in reducing their environmental footprint.

Grant says all the new effluent systems built in the past two years could easily be adapted to capture this potential benefit, making these farms even more sustainable.