Boost summer crops with effluent

By Dairy News

AS WE head into summer, many dairy farmers are keenly focused on growing as much fodder as possible to prepare for the possibility that current conditions will affect feed availability and pricing for the year ahead.

A sound strategy is to utilise dairy effluent to boost summer crop yields.

Dairy effluent contains water that will help crops grow and nutrients worth thousands of dollars, equivalent to several tonnes of single super phosphate, urea and potash.

Additional fodder yields can fill part of the summer feed deficit, replacing expensive hay and other bought-in supplements.

Another benefit of using this resource now is emptying the effluent pond in preparation for next winter.

Applying effluent to seedlings or crops prior to germination is not recommended as the high potassium (potash) and salt content can burn seedlings.

However, four to eight weeks after germination, an application of effluent can give a significant boost to overall crop yields.

Research has shown that for every 25 mm of liquid effluent applied you can expect increases of one to two tonnes DM/ha, with some yield increases as high as four tonnes DM/ha. This is consistent across a range of different summer forage crops including turnips, chicory, forage rape and millet.

Important tips to keep in mind when applying effluent:

  • Ideally, test the effluent before application. Nutrient levels vary from pond to pond and year to year. The effluent application rate should be based on nitrogen and potassium content of the effluent and crop requirements.
  • If you have sown a single graze crop such as turnips, then apply the entire effluent application in one go at around six to eight weeks after sowing, when the plants are in their rapid growth phase. If using a travelling irrigator, wait until turnips are established to minimise bulb damage.
  • If you have sown a regrowth crop such as forage rape or pasja, then split the effluent application and apply half about three to four weeks before the first grazing and the remaining immediately after this grazing.
  • Effluent contains large amounts of nitrogen, so care should be taken to avoid nitrate poisoning. Crops shouldn’t be grazed for at least three weeks following effluent application. This will also reduce the risk from pathogens that could be in the effluent.
  • Young cattle (under 12 months of age) shouldn’t have access to effluent-treated areas.
  • Adjust your fertiliser program as appropriate to account for the nutrients in the effluent applied.

Agriculture Victoria can assist you with developing an effluent use plan for your farm. This includes a visit by a dairy extension officer to conduct a stocktake of the effluent available for use.

Effluent will be sampled and options identified to effectively use effluent on your farm to save on fertiliser while keeping nutrients on-farm.

For more information on effluent use plans, phone Helen Chenoweth at Agriculture Victoria in Warrnambool on (03) 5561 9906 or Rachael Campbell at Agriculture Victoria in Ballarat on (03) 5336 6868.

For more information about Agriculture Victoria support for dairy farmers preparing for dry seasonal conditions, phone Alex Goudy on (03) 5561 9935 or visit: