The resin technology, developed by Unibest International, has been used for more than a decade for environmental monitoring. In agricultural applications now coming to market, the ion-exchange resin adsorbs nutrients only in forms available for plant uptake. To test a field’s nutrient availability status, the resin capsule – about the size of a cherry tomato – is mixed with a small amount of soil and distilled water in a jar, then analyzed by a laboratory five days later.

Unibest recently announced that WinField, the Land O’Lakes agronomy company, will be the technology’s exclusive distributor in the U.S. agriculture market. The resin capsules – sold under WinField’s Nutrivision Resin Capsule Technology and Unibest’s Ag Manager brands – will be available through participating WinField retailers and other providers beginning in 2014, according to Josh Krenz, WinField director of plant nutrition.

The capsules can detect more than a dozen nutrients, including nitrate and ammonium nitrogen, phosphorus, potassium, boron, iron, manganese and zinc. WinField, which has tested the resin technology for over three years, will provide potassium results in 2014. More nutrients will follow in 2015 after additional calibration research.

 “Of the 180,000 tissue samples we have taken on various crops over the past five years, potassium is one of the leading deficient nutrients,” Krenz says. “We see a great need for expanding knowledge about potassium deficiencies.”

The list price for an Ag Manager test kit is $50. Pricing for Nutrivision is available from Winfield dealers. For information, visit or