Variable rate nitrogen fertiliser test pays off for Cust farmer

Investing in a handheld nitrogen tester and using variable rate nitrogen fertiliser has proved a winner for Cust farmer Roscoe Taggart.

Taggart is participating in a project, which examines how the next generation of farmers use innovative approaches to improve their farming practices.

Waimakariri Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the Ministry for Primary Industries (MPI) for the project, with support from MPI's Sustainable Food and Fibre Futures fund along with Environment Canterbury, Ballance, and DairyNZ.

Taggart managed to significantly reduce the amount of fertiliser he applied to his family's 730-hectare arable and sheep operation, which resulted in cost savings and environmental benefits.

The cost savings of applying variable rate nitrogen fertiliser, compared to a traditional blanket approach, were "astronomical," Taggart said.

He grid-sampled his paddocks and then determined the exact amount of fertiliser required for each block via nitrogen sensors attached to the roof of his tractor.

Taggart said he spread triple super for his phosphate and potash for his potassium as a base fertiliser.

"Where in the past we would have gone with a blanket approach we have been able to save a huge amount on fert this season by using variable rate.

Cust farmer Roscoe Taggart is using a handheld nitrogen tester in conjunction with nitrogen sensors to apply the right amount of fertiliser which results in cost savings and environmental benefits. Photo / Supplied

"I think it's incredibly worthwhile to invest in variable rate technology and it feels wrong now to put a blanket application across a paddock when I know how much variability there is within a single paddock."

Taggart went a step further to hone his precision techniques when applying fertiliser by purchasing a handheld nitrogen tester which he used to fine-tune applications throughout the growing season.

Within ten minutes of the test, the nitrogen level of the plant was provided, and Taggart and his team could then put this figure into the N sensor.

This provided a starting point for the variable rate spreading of nitrogen.

"I have just purchased a Yara N-Tester which we will use to test ryegrass, cereals, and brassicas, to make sure we have the correct levels of nitrates.

"It is simple to use and allows us to find out what the N levels are and to see if we need to apply a little bit more or a bit less fertiliser.

Taggart hoped that, when the tester was combined with the N sensors on the tractor, he would be able to be even more precise.

"When it comes to managing the cost of inputs, I really believe that precision technology will help us to stay viable when looking ahead with rising costs and increasing environmental regulation.

"Anything that enables us to do more with less is better for our bottom line and for the environment."

Crop sampling with the hand-held nitrogen tester will start in late August or early September and Taggart said this would help to determine which elements were required by the plants while avoiding a blanket application approach.

"We will get a good idea of where the crops are sitting early in the season and if there is anything missing, we can address that early on."

This season Taggart would continue with the same crops; however, he was considering trialling a regen paddock and comparing this to a conventional farming paddock to work out if there was a financial benefit to this type of farming.

"I want to have the two paddocks side by side and do a gross margin on both, so I have real data to show how they compare," he said.

"I am a huge fan of on-farm comparisons and giving things a go because until you try something you never truly know if it works."