DPI technical assistant Brad Welsh inspected crops in the trial plot at Tamworth in February

Summer crop trials at Tamworth and Moree during the past two years have shown that viable alternatives to sorghum are available.

However, NSW Department of Primary Industries (DPI) economist at Tamworth, Fiona Scott, said budgeting for likely yields and profitability, particularly relative commodity prices, was a critical element in crop selection.

The 2005-06 trials at Moree and Tamworth included seven crop species: sorghum, sunflower, soybean, maize, mungbean, cowpea and sesame.

Three varieties of each crop type were sown where possible. Sites were sown during early December 2005.

DPI district agronomist at Tamworth, Loretta Serafin, said the varieties were primarily selected based on their maturity, to encompass a quick, medium and long season variety. However, this was not possible for all crops.

The 2006-07 trial at Tamworth was sown on November 13, 2006 and included six crop types: sorghum, sunflower, mungbean, cowpea, maize and sesame. The sesame plots failed to establish due to a cold snap following planting. Gross margin per hectare results by variety were calculated for each trial.

Commodity (on-farm) prices used were average crop prices for northern NSW during the past seven years (2000-2007).

They included Banjo (blackeye) cowpeas $800 per tonne, Red Caloona cowpeas $700/t, maize $240/t, mungbeans (processing grade) $550/t, sesame $900/t, sorghum $190/t, soybeans $375/t, mono-unsaturated sunflowers $550/t and poly-unsaturated sunflowers $490/t.

Ms Scott said seasonally the relative prices of the different commodities could vary considerably. The prices also assumed that commodities met quality requirements.

Variable costs applied were in-crop only; using commercial retail prices for seed, fertiliser and any post-sowing preemergent weed control or in-crop herbicide or insecticide, plus commercial contract harvest rates and research levies.

No estimates were included for consultant’s fees, interest, cartage, grading, bagging or drying, silo storage or wages.

The table shows a summary of results across varieties and locations and years. Not all varieties were trialled in each year and some failed at one location.

Ms Serafin said the differences between varieties indicated that varietal choice was important. Varieties should be sown within their sowing window for optimum performance.

Sunflowers, maize and experimental mungbean line ATF3944 were competitive with sorghum.

Sesame and soybean gross margins were relatively poor due to low yields. Soybean was prone to damage from feral pests and insects under dryland conditions at Moree. Dryland soybean varieties used there require a longer season and more rainfall than these regions usually receive.

Sesame is a relatively new crop but the yield at Moree in 2005-06 of 0.95t/ha showed this crop has potential as a future alternative summer crop.

Relative yield performance can be matched to gross margins to develop an indicative profitability for the range of available crop options.

Based on yield ranges from the trials and given the crop prices used above, a comparison of gross margins can be estimated (see graph).

Applying the sorghum yields across the Tamworth and Moree sites (low 2.1 t/ha, average 4 tonnes/ha, high 5.4 t/ha), and using the average commodity prices and similar costs to those used to evaluate the trials, the most profitable alternatives appear to be mungbeans and sunflowers (both mono-unsaturated and poly-unsaturated).

These relationships may change significantly due to changes in relative commodity prices.

Guideline gross margin budgets for summer crops are on the NSW DPI website.

Contact Fiona Scott and Loretta Serafin, (02) 6763 1100, Stephanie Belfield, (02) 6750 6300.