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Alternative Fertilizers and Pasture Productivity

After 6 years of applied research a selection of alternative fertilisers are performing well in a pasture fertiliser study involving 3 properties on the southern tablelands in native perennial based pasture country deficient in phosphorus and sulphur.

The Native Pasture and Alternative Fertilizer Project located in the Binalong and Bookham area has been in operation for 6 years following its commencement in Spring 2008. The project was instigated by producers within the Binalong Landcare (sub group of Harden-Murrumburrah Landcare Group). Since its inception the project has been a collaborative effort between Binalong Landcare, NSW Department of Primary Industries and more recently South East Local Land Services. Interest in the project has been substantial given that it is one of very few in eastern Australia to have investigated with scientific rigor a range of alternative fertilizer products for use on perennial grass based pastures.

It is well recognised in the tableland grazing areas of NSW that both phosphorus and sulphur are key drivers of pasture growth. Pasture responses measured in the trial over the 6 years have largely been according to a products ability to supply available phosphorus and sulphur.

Products tested include animal manure; burnt sewage sludge; crushed rock with added phosphate; food and garden waste compost; humus compost plus lime plus soft rock phosphate and gypsum; humus compost tea extract plus molasses and liquid fish; reactive phosphate rock treated with a proprietary microbial culture, lime and gypsum; liquid foliar fertiliser containing a mix of macro and micro nutrients and microbes with a granular fertiliser containing high phosphorus.

Products are not necessarily compared at identical nutrient levels (some higher, some much lower) to superphosphate but at rates and frequency advocated by suppliers. A control (nil) treatment is also included. At the start of the study trial sites tested low in phosphorus (10 mg/kg or less Colwell) and low in sulphur (2-5 mg/kg). Soil pH ranged between (CaCl) 4.0 - 4.2 and aluminium (Al) levels were 15 - 33 percent.

A cost effectiveness comparison based on the first 5 years of the project shows that some products trialled are relatively close in performance to superphosphate based on prices for the Yass region.

Products containing lime raised soil pH and lowered aluminium as expected while other products containing no lime showed no effect on soil pH. Over the 6 year period two soil biological tests were used to monitor soil microbial status (Flourescen Diacetate Microbial Activity Test and Biomass Carbon Test). After 5 years of monitoring the soil annually in spring there was no effect of fertilizer treatment on soil microbial status according to these 2 tests. Tests from the sixth year are still undergoing statistical analysis and will be available in early spring.

A field day on 1 September 2015 in Bookham will showcase 6 years of key pasture, soil and economic results from the project. The field day will also provide the opportunity to hear from 2 key invited speakers, Dr Alan Richardson, Soil Biologist, CSIRO, Canberra who will speak on phosphorus cycling in pasture grazing systems and the importance of soil microbiology; and Dr Lewis Kahn, Agricultural Consultant, Armidale who recently completed an assessment of the efficacy and cost effectiveness of alternative soil treatments for improving the biology and productivity of soils, pasture and livestock. Dr Kahn will present a summary of the analysis of 5 alternative fertilizer/soil treatments field research projects conducted across south eastern Australia, one of which was the Native Pasture and Alternative Fertilizer project near Binalong and Bookham.

If you are interested in attending the field day please contact Michelle Borland, South East Local Land Services, Goulburn, phone 48241904 or email: michelle.borland@lls.nsw.gov.au

A report summarising the 6 years of results will be available in early December and can be obtained by contacting Fiona Leech, South East Local Land Services, Email: fiona.leech@lls.nsw.gov.au.

We gratefully acknowledge our funding providers for this project over the 6 year period including NSW DPI, NSW Office of Environment and Heritage, former Murrumbidgee Catchment Management Authority (MCMA), Local Land Services, Federal Department of Agriculture, Fisheries & Forestry (Caring for our Country Community Action Grants), Woolworths, Landcare Australia, Meat and Livestock Australia and Siebelco.

Fiona Leech
South East Local Land Services
Yass
02 6118 7701
fiona.leech@lls.nsw.gov.au