DPI special projects agronomist, Mike Keys, highlights the pros and cons of different machinery sowing tynes and points during a perennial pastures training day at Bungendore.

Perennial pastures have become very expensive to establish, so new sowings must establish well and enable graziers to run at least 12 dry sheep equivalents per hectare.

According to Michael Keys, NSW Department of Primary Industries (DPI) special projects agronomist at Queanbeyan, it takes around 12 years to cover costs at current interest rates, based on a sowing cost of $230 a hectare and gross margins of $25/dse.

"Liming is not included in this sowing cost," Mr Keys said.

"This data was produced using current costs for seed, fertiliser and contract spraying and sowing rates, to allow for labour, machinery cost and depreciation, for the Southern and Central Tablelands."

NSW DPI agronomists and technical staff recently presented the results at a training day for 25 people at Bungendore.

They visited the site where, 20 years previously, a large scale comparison of direct drilling versus conventional ploughed seedbeds and six different types of pasture seeders was conducted.

"The comparisons showed that direct drill sowing was just as successful as conventional sowing into a ploughed seedbed," Mr Keys said.

"However, complete weed control and accurate seed placement was essential no matter which method was used."

Except when using the single disc seeder, all seeders (including several different tyne configurations with narrow, direct drill pasture points and a triple disc) were able to successfully establish perennial grasses in the direct drill blocks.

The work showed heavy grazing was not able to provide good weed control and on heavily grazed blocks, few perennial grasses established.

Using a cash flow development budget developed by NSW DPI agricultural economist, Fiona Scott, the cost of pasture establishment and the influence of various stocking rates were discussed.

"The spreadsheet showed that unless stocking rates can be increased by five to six dse/ha, it is unlikely that the real cost of sowing can be re-couped," MR Keys said.

"If lime was required, costing an extra $180/ha at 2.5 t/ha, it takes an extra five to seven years to recoup the cost."

There are several clear implications from which the DPI staff draw advice:

• Only sow new perennial pastures in paddocks that have high production potential, i.e., good soils, topography and aspect
• Only sow new perennial pastures where you have the livestock numbers and enterprises to capitalise on the extra pasture production
• Choose species that have a proven record for both production and persistence (eg., sub clover and phalaris are very hard to beat in the Central and Southern Tablelands)
• Make sure you allow sufficient funds each year to maintain soil fertility and to purchase the extra stock required to use the higher production of the new pasture
• Do not sow introduced pastures on highly acidic soils where liming is required - instead use acid tolerant, modified native pastures instead
• Use lime to preserve soil pH on hay paddocks with highly fertile soils where product removal lowers surface soil pH
• Do not ignore the productive potential, especially during winter, of well fertilised annual grass/sub clover pastures
• Run a cash flow development budget before you commit to sowing a new perennial grass pasture.

The training day demonstrated that sown perennial pastures need to persist and remain productive for 15 years or more.

The other factor to ensure value for money is that they are used by a high value enterprise such as prime lambs or vealers that require high quality pasture.

Contact Mike Keys, Queanbeyan (02) 6297 1861, mike.keys@dpi.nsw.gov.au