Precision that doesn’t have to cost the earth

The cost and sophistication of precision farming equipment is enough to make most farmers wince. But one farm manager from Oxfordshire thinks there is an easier way.

Toby Hogsbjerg, manager of two separate estates near Burford, Oxfordshire, says the opti-box from precision farming company SOYL has proved a real time and money saver.


First introduced at Lamma in 2011, it’s a small GPS-enabled touch-screen system that lets operators download field files on the move to control variable rate seeding and fertiliser application. Files can be sent to the box either from the farm office or straight from a SOYL agronomist.

The box has a Vodafone sim card that provides data transfer on the move. It connects to the mobile network using SOYL’s SOYLsync software over a secure network.

If signal is lost for any reason then the system automatically picks an average rate from surrounding cells and applies that until signal is regained.

“It’s a fool-proof system,” says Mr Hogsbjerg. “And because recommendations can be changed between fields at the touch of a button, downtime is minimal.” Things can be adjusted across the farm as well, so if we have a block of late-drilled wheat we can up the rate across the lot.”


The variable rate system relies on mapping. SOYL completes soil tests once every four years to provide an overview of soil condition and nutrient values.

The grids produced are feathered so when it comes to application, the rate doesn’t jump from block to block but instead steadily increases or decreases.

Fields are also pictured about every 10 days by satellite imagery (providing it’s not cloudy). It shows differences in crop growth, and ground tests by an agronomist “calibrate” the satellite image by providing accurate growth stages and leaf area indexes as a means of comparison. Farmers can look at the field images throughout the nitrogen season and download the pictures for comparison.


One of the biggest headaches in developing precision farming systems is the issue of compatibility. The opti-box will work with all major drill, spreader and sprayer brands through a cable connection. It can also work in conjunction with other GPS providers – converting information from SOYL to be used on other systems like TopCon or Greenstar by way of a USB stick.


The farm can use variable rate application across its entire 1,000ha of mainly limestone-laden Cotswold brash soil. SOYL mapped the fields four years ago and Mr Hogsbjerg expects soil nutrition to have improved when the land is retested next year.

“We’ve cut about 20kg/ha off our nitrogen application to wheat and barley by using fertiliser more practically and adjusting timings,” he says. “We’ve also adjusted early applications according to yield maps, which we think has made a difference.”

The farm has been applying P and K at variable rates since the fields were mapped. The system has been used to apply nitrogen across the estates this spring, and September 2011 was also Mr Hogsbjerg’s first foray into variable rate seeding of 140ha of wheat.


Yields can be boosted by between 3-7% by switching to a precision system thanks to a more targeted approach to fertiliser placement. There’s also money to be saved, particularly at current input prices.


SOYL reckons savings can be as much as £30/ha/year for targeted P and K application, and up to £45 for precise nitrogen application.

It is providing recommendations for over 1m acres in the UK. The driving force for people switching to precision fertiliser application has come from new machinery purchases. Variable rate versions are commonplace and so it cost less than £1,000 to be able to apply at a variable rate.

The box costs £995, which includes all the bits and bobs required for set-up, A further £30 a year is charged for support and updates.



• 1,000ha over two estates

•  400ha wheat (half milling)
• 280ha OSR
• 120ha barley
• 160ha linseed/stubble turnips

Machine list 
 Challenger 765C
 2 x Massey Ferguson 6480
 Ford 7810
 Chafer 4,000-litre
 Horsch 6m drill
 CTC Kverneland CTC stubble cultivator 5m
 Kuhn spreader
 Lexion Terra Trac 760, 10.5m

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