Cropping soil moisture in uncharted territory

Agriculture Victoria grains agronomist Dale Boyd said moisture levels had been building early.

Summer storms in the second half of January, followed by good rains in March and well above average rainfall in April had laid the groundwork.

"We're seeing very wet conditions from central Victoria, moving right across the northeast," he said.

"What we've received in May has made it quite wet and had great infiltration down to depth in those central Victorian and northeast areas.

"The Wimmera is still tracking good but certainly doesn't have the deeper soil moisture levels that the eastern part of the state has got."

There was still quite a lot of variability in the Wimmera.

"They've got a whole range over in the Wimmera from still being at around 10 per cent [soil moisture] working their way up to about 50pc, so there's still plenty of capacity there to take on more water and deep soil moisture that can still build up," Mr Boyd said.

Wimmera-based AGRIvision Consultants general manager Kent Wooding said his clients were adopting a steady-as-she-goes approach the the conditions.

"We're not changing plans based around [the good soil moisture], we're not changing plans based around market information either because things can change dramatically," he said.

"But what we are doing is ensuring growers are ready to capitalise should this season continue to be positive.

That meant getting the timing of sowing, weed control and application of nitrogen right.

"And then it means understanding your soil nitrogen levels, and optimising your nitrogen based on the current yield expectations," Mr Wooding said.

"So I think it's understanding moisture, it's understanding yield expectations and then understanding that return on value with nitrogen."

Agriculture Victoria soil moisture probes show northeastern Victoria, however, is already quite wet.

"This is probably uncharted territory for the monitoring program to have a full profile in some of these districts so early in the season and yet to hit winter," Mr Boyd said.

"Probably even an average winter on a full profile now will make some low-lying areas too wet with some yield implications with water logging.

"But free draining soils and higher areas should be able to grow through those and, when we get to spring, should be sitting on good yield potentials and good deep soil moisture levels to draw upon."

AdvancedAg agronomist Gus van Tilborg confirmed there were wet conditions northeast of Shepparton in particular as well as anywhere paddocks had been irrigated throughout autumn.

He said rain this weekend could leave some paddocks left unsown.

"Most farmers are working towards the end of the sowing program but if they've still got a bit to go, some paddocks will be certainly too wet and with the days getting shorter and cooler, they're not going to dry out very quickly," Mr van Tilborg said.

Mostly though, the impact was not on a broad scale, with farmers generally opting to work around wet portions of paddocks.

Among the benefits of soil moisture probes, Mr Boyd said, was a better understanding of moisture deep in the profile to inform sowing decisions.

"Up until a few years ago when we got some good runs on the board with the moisture probe network, deep soil moisture was really an unknown," he said.

"You can't dig post holes everywhere.

"And because it's being logged every hour, we can now compare seasons right back going back to 2011, and that gives us some good insights."

Mr Boyd said farmers could combine the soil moisture data with tools like Yield Prophet.

"Yield Prophet willo incorporate the seasonal outlook and crop development and also have a nutrient budget in there to come up with potential crop yields," he said.

"You've certainly got good confidence in the way the seasons progressing if you've got a model indicating one thing and you've got an actual measurement also indicating the same thing."

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