Test slurry for invisible value

20 May 2020

Using a slurry testing kit and flow meter can save producers up to £265 per hectare in fertiliser costs. 

So says Tramspread’s Terry Baker, who stresses that if producers don’t know the nutrient value of their slurry, and the rate it is being spread at, then the financial savings and crop benefits are guess work.

Plant-available nitrogen

A nitrogen meter, such as the Agros Nova Mk3, can test slurry and manure for plant- available nitrogen (N) in just five minutes. “These kits only cost £425 and offer producers a lab-test-accurate reading of kilogrammes of plant-available N per cubic metre,” says Mr Baker.

Nutrient value

“Once they’re aware of the nutrient value, producers can begin to calculate the volume of slurry required for the crop and use a flow meter to spread it accurately.”

The Tramspread Isobus flow meter package is one of the most accurate methods of measuring slurry application. It connects a flow meter to the tractor’s GPS and can be used to adjust the application rate from the cab.

Accurate report

“Combining field maps, choosing the application rate and recording the amount of slurry applied will give the operator an accurate report of the amount of slurry applied per hectare,” explains Mr Baker.

“When this technology is coupled with accurately tested slurry, it also offers producers a way to measure the cost benefit of slurry application to the farm.”

Savings available

The data in AHDB’s RB209 nutrient management guide helps to illustrate the savings available by testing slurry and applying it accurately. Calculating the available nitrogen, phosphate and potash (N, P and K) of slurry can save significant sums of money.

ADAS soil scientist John Williams has used the RB209 guide to equate this to between £215 and £265 per hectare, based on a season’s application of 95m3/ha of cattle slurry, according to Mr Baker.

Undervalued resource

“Slurry is one of the most undervalued resources that producer have,” he adds. “If stored and tested and applied carefully, with close attention to nutrient value, slurry offers significant savings and environmental benefits.”