Three Steps To Improve Your Soil: Digest-It for Effluent in action

Acknowledgements:
David Wright, Irish Farmers Journal.
Gill Gallagher, Devenish Nutrition.

  • Lakeland Dairies, Devinish Nutrition, and Thomson & Joseph established a soil improvement program across three monitor farms in 2013
  • The program aims to address the physical, chemical and biological requirements of the soil as a means of improving production. BioAg’s Digest-it for Effluent is being used to address the biological aspect
  • One participant has increased dry matter production by 20.5% and milk from forage by 8.3%

Biological

The biological component of the program involves the addition of BioAg Digest-it for Effluent added to the slurry produced on farm, with the aim of improving nutrient availability and reducing ammonia losses.

Digest-it for Effluent is a liquid biological composting product containing aerobic bacteria, enzymes and nutrients designed to aerobically digest slurry.

Thomson & Joseph import the product into Britain and Ireland for distribution via Denenish and Lakeland.

A total of 20 litres of product treats 100,000 gallons of slurry and costs around GBP200 plus VAT.

Trials at the Devenish research farm in Dowth, Co Meath, suggest that there is a payback of 3:1 when using the product.

When evaluated on pig slurry, treated slurry resulted in a 36% increase in grass dry matter yield, when compared with untreated slurry.

In a trial using dairy cattle slurry, the yield benefit was 23%.

The response is mainly due to the product breaking down the ammonia in slurry into microbial nitrogen, which is a more long-term source of nitrogen to the plant.

Farmers who use the product also maintain that there is less smell (due to the reduced ammonia) and the slurry is easier to mix.

Physical & Chemical

The physical and chemical dimensions to the program involve implementing a range of on farm strategies:

  • With recent studies suggesting that poor soil structure can lead to a reduction in grass growth by up to 40%, the program incorporated strategies to reduce soil compaction, including minimising machinery use where possible (especially on wet fields), reducing “overwintering” livestock in fields, and reducing the grazing of low plant density forage crops late in the season.
  • In addressing the chemical properties of their paddocks, the first step was to correct soils with a pH below 6, or phosphorus or potassium indexes below 2. Regular soil analysis ensures nutrient deficiencies are identified and corrected.
  • Referring to recent studies on the calcium to magnesium balance, the program participants are conscious that where magnesium levels are too high, the availability and uptake of other nutrients can be impeded. Gypsum was used to rectify this imbalance, with the addition of calcium also acting to improve soil structure and drainage.