Complete: Factory estimates of K in beet tissue water for monitoring the potassium status of soils

Timescale: 2005 - 2006

Project Lead: Unknown

Project Sponsor: BBRO and British Sugar

Project Summary

The project used beet and soil sampled by British Sugar staff from individual fields prior to the 2005-06 processing campaign to validate the use of factory tarehouse estimates of potassium concentrations in beet tissue-water to characterise the K status of the soil.

Main Objectives

Current general recommendations for potassium fertilizer use derive from experiments done 30-40 years ago which established the premise that sugar beet require a minimum of concentration of 120 -180 mg of exchangeable K per kg of topsoil (equivalent to an ADAS Soil K Index of 2-) to achieve maximum yields of sugar. The recently completed 6-year series of BBRO funded experiments by British Sugar plc and Rothamsted Research on plots at Rothamsted with a wide range of long-established differences in exchangeable soil K has confirmed that these concentrations of exchangeable soil K are still adequate for the much higher yielding crops that are now being grown.

Latest Report

Final Report 2005

Outcomes / Key Message For Growers And Industry

Except for a minority of cases, the Soil K Index rankings of over 260 fields from the Allscott, Bury, Newark, Wissington and York factory areas based on K concentrations in beet tissue water agreed well with those based a soil analysis.