Want higher protein? Here are some tips

Steve Jefferies

Profitable wheat growing is increasingly linked to producing higher protein grain. This season, for instance, the Australian Wheat Board has added a further bonus of $5 a tonne for ASW wheat at 10 per cent protein or better — the bonus being over and above normal protein differentials.

So how can you achieve higher protein levels?

Steve Jefferies is a senior research officer with the South Australia Research and Development Institute and heads the SA Field Crop Evaluation Program. The program is financially assisted by growers through the GRDC. Here are his views on protein.

Ground Cover: Many growers are making decisions now on what seed to keep for 1994-95. What are the implications as far as protein is concerned?

Mr Jefferies: Well, one thing they should not do is change varieties because of some perceived difference in protein performance. The protein difference between one variety and another grown under identical conditions is very small. With Spear and Machete, for example, there will be less than 0.5 per cent difference in protein with Machete on average being the higher.

Ground Cover: So where do the differences arise?

Mr Jefferies: Proteins can vary substantially between soil types and rotations. Even between the sandhill and flats in the same paddock there could be a difference of three per cent. So protein is a reflection of soil fertility and environment rather than varieties.

Ground Cover: Is it possible to breed a variety with a capacity to produce higher protein than another?

Mr Jefferies: Breeding is possible for small gains in protein but the farmer can make greater gains by adjusting his management system to achieve a higher protein. Growers should be using the protein information which they get regularly. It's an excellent retrospective measure of the nutrition status of the crop harvested.

Ground Cover: And the season?

Mr Jefferies: And the season. Over time the farmer can get a good idea of the relative fertility of a paddock from his protein results and he can adjust his management to try and lift protein and yield. On numerous occasions I have known growers to throw out a particular variety because it has achieved similar yields to another, but lower protein. If there was better soil nutrition then the lower protein variety might have improved in protein and produced greater yields.

Ground Cover: So farmers should look at soil nutrition and management before discarding a variety?

Mr Jefferies: That's dead right. If a crop of Spear had 10 per cent protein and Machete eight per cent, you don't say Machete was worse. It says you should have done a lot better with your management of that Machete crop particularly since it is eligible for the higher-priced Australian hard classification.

Ground Cover: So where does yield come into this question?

Mr Jefferies: Breeders are developing varieties with higher yield potential but to achieve higher yields it often requires good management and things like protein can tell you whether you are on the right track.

Our work with nitrogen consistently shows that where the grain protein was below 10 per cent, large economic yield responses to nitrogen fertiliser usually occurred. Whereas where the protein was above 10 per cent, yield responses to applied nitrogen were less predictable.

If Farmer X is averaging say between nine and 10 per cent protein in his wheat, this is telling him he should lift his game either with his rotations or fertiliser practices because he is not achieving the yield and now he is not going to have the potential to tap into that new AWB premium — and he is producing a product which is difficult to sell in the world market.

Ground Cover: How much can a farmer blame the season for a poor protein result?

Mr Jefferies: There is no doubt the environment is important but the nutrition of the paddock is more so. Early seeding and good spring conditions usually result in lower protein. If you get a dry. hot spring the protein will go up but if the nutrition is high the protein will go up by more.

Durum growers are all too aware of the importance of achieving high protein. They are planning their management and rotations around the durum crop and some are putting over 100 units of nitrogen on annually to get their protein over 13 per cent. That's where the maximum premium is.

Ground Cover: What are the marketing implications?

Mr Jefferies: The wheat industry will be relying on farmers to produce a quality product. In turn, it will be important for the market to pay for quality and for good market signals to be sent to the growers.