Fertiliser secures feedbase

In just eight years, the stocking rate at Rose Grange Pastoral Company's ‘Trawalla’ property has more than doubled.

Manager Jim Gaylard credits this growth in production to the enterprise’s approach to applying and managing fertiliser.

“The initial years of management under Rose Grange ownership were a shock to the system at Trawalla,” he said.

“Inputs increased and the property just came to life. In the past eight years we have simply been building on that production potential and you can see it by the sustained growth in dry sheep equivalents (DSE).”

Mapping trends

Trawalla has focused on mapping soil fertility trends over time, dividing the property across both the cropping and livestock enterprises into four management sections, with each management section soil tested every four years and treated accordingly.

“The cost of production for spreading fertiliser works out to be about $58/ha/year (for the period of 2014–2021),” Jim said.

“It’s hard to put a dollar value on return on investment from fertiliser use, but you can put it this way, when I came to Trawalla the stocking rate was 12 DSE/ha, it’s now 26 DSE/ha. That’s fertiliser.

“Obviously, there are other factors like better suited sown pasture species and things like that, but you could put a lot of that down to simply soil fertility.”

Jim has observed how often the first thing producers sacrifice in a tough year is soil fertility.

However, under Rose Grange owner Jock Richmond, it’s a different story.

“Jock, myself, all of his managers and everybody that works for him, would be totally on the other leg and say, well, that’s the first thing we’re going to put out; we’re going to maintain that fertility and we’ll sacrifice putting a fence up or something else,” Jim said.

“There’ll be other things that you could sacrifice before fertiliser and I think, by doing that and maintaining the soil fertility, it gives us a big advantage.”

Don’t compromise fertility

For Jock, even the high input prices producers faced in 2022 didn’t erode this commitment to soil fertility.

“I could have reconsidered fertiliser applications given current prices, but I know our cost of production and our returns, and it was still worth it,” Jock said.

“You just can’t cut out one of your biggest production drivers.”

Nitrogen is vital

In addition to phosphorus, potassium and sulfur, nitrogen (N) has a prominent role in the fertiliser program at Trawalla.

The philosophy is that maintenance applications of urea, used on highperforming perennial pastures, will increase the rate of return of fertiliser.

In autumn, N is used in the form of 100kg DAP per hectare for new sowings, with some strategic use of urea on other paddocks.

In late winter, N is used on selected paddocks to boost growth in highly productive perennial pastures, and in some of the annual pastures that will be cut for hay and silage.

“Our urea application on better pastures is a post-lambing application, spread at about the time we’re lamb marking, at a rate of 100kg/ha,” Jim said.

“Post-lambing, mobs are boxed to increase grazing intensity. This also allows us to rest paddocks that have been fertilised and focus grazing pressure on the country that’s going to go into crop.

“This way we maximise utilisation of feed on those lesser performing paddocks, knowing that we’re going to spray them out in early spring. It also lets the better country respond to the fertiliser and grow some bulk.”

The approach is that paddocks are rested until feed on offer reaches 1,500kg DM/ha, at which point stock return to graze.

“If the spring is on our side, and it looks like we’ve over-committed in areas, there’s no reason why another 100kg/ha of urea can’t go out,” Jim said.

“This is purely opportunistic on prioritised pastures.

“For instance, if we spread urea over 1,500ha, we wouldn’t go over that whole area a second time, but we might do 500ha again.

“It would be a smaller pocket of country that we know we could get going, such as a younger, newly established pasture with vigour.”

When it comes to selecting paddocks for opportunistic nitrogen application, Jim said it has to give “bang for your buck”.

“There’s not much point spreading fertiliser and then the season cuts out; you have to get a return.”

Learning from experience

“We’re all about fertiliser but not about wasting it. I think that Rose Grange’s approach has been influenced by the dairy operation in Colac (another of the Rose Grange properties); it’s been an eye opener with how much and how frequently they spread urea on their pastures,” Jim said.

Although responses have not been quantified with yield cuts, the visual response to nitrogen is clearly positive.

“We had a phalaris paddock that was split with a laneway – one side got urea and the other didn’t. I estimate we would have grown an extra 1,200–1,800kg DM/ha on the side that had urea spread.”

Seasonal action plan

• Find more soil resources at mla.com.au/healthy-soils
• Find seasonally relevant management tips and tools at mla.com.au/seasonal-hubs
• Read more case studies and access practical resources at MLA’s feedbase hub mla.com.au/feedbase-hub