ProBio-FarmAid Field Trial: Observations and Conclusions

The trial product was received in pre-packed 450 gram soluble plastic bags and application to the effluent pond via the main dairy shed waste drain was simple and effective. Effluent testing by WaterCare Services, Auckland, showed significant enhancement of the Potassium and Sulfur fractions in the treated effluent compared with the untreated control. Physical observation of both the treated and control ponds by the farm staff and the writer showed a reduction of odour from the treated pond.

Soil sampling of paddocks before and after effluent application on both farms was carried out by Stuart Lumley of ‘Altum’ a subsidiary company of Balance Agri-Nutrients Ltd, Hamilton. Soil testing of the sam­ples was performed by Hill Laboratories Ltd. Hamilton. Effluent, both treated and untreated, was applied to designated paddocks on the same day at the same rate of application (13 mls) well within the local body allowable application rate. Grass growth after seven and fourteen days was measured on both paddocks by using a calibrated plate meter. It was observed that the treated effluent paddock achieved an average growth rate of 95 Kg/dry matter/day, compared to the control paddock average growth rate of 68 Kg/dry matter/day.

Soil sample analysis of both treated and control paddocks showed that Nitrate-N + Nitrite-N* in the treated effluent paddock was nearly four times as great as the untreated paddock (42 mg/Kg dry wt. as opposed to 11.2 mg/Kg dry wt.).

The analysis of the treated and untreated effluent before application showed virtually the same amount of total Nitrogen (as N ) in both samples. Therefore, it can be assumed that Nitrogen in the treated effluent has been modified and is more readily taken up by the pasture which results in improved grass production. See copies of Analysis Certificates attached.

Both farmers involved in the trial were impressed with the increased grass production achieved by the treat­ed effluent paddock and the ease with which the product can be applied to the effluent pond. The reduction in the odours given off the treated effluent whilst not important to grass production was noted as beneficial to the overall environment of the dairy operation. I would like to express my thanks to both Messrs Houghton and Bradstreet for their excellent co-operation in conducting the trial.

George Mitchell

Mitchell Partners
7th May 2012

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