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Technical notes

Potassium and nitrogen interactions in crops

March 2012

by A E Johnston and G F J Milford, Rothamsted Research, Harpenden, Hertfordshire AL5 2JG Introduction Interactions between nutrients – their importance in crop nutrition The importance of potash for crops Crop response to nitrogen at two levels of exchangeable potassium in soil Crop response to nitrogen on soils with a range of exchangeable potassium levels […]

Assessing soil fertility; the importance of soil analysis and its interpretation

October 2011

by Johnny Johnston, Lawes Trust Senior Fellow, Rothamsted Research, Harpenden, AL5 2JQ, UK Introduction Soil fertility Soil analysis and soil nutrient status The Base Cation Saturation Ratio (BCSR) system Issues about the BCSR system Accuracy of the determination of cation ratios in many UK soils Method of presenting the data for the base cations The ratio […]

Fertilisers and Hypomagnesaemia: An Historic Exaggeration?

December 2004

by Professor Gordon Hemingway Glasgow University Veterinary School, Bearsden, Glasgow G61 1QH, UK 1. Introduction. It is widely held that clinical hypomagnesaemia in dairy cows when transferred to unsupplemented spring grazing is associated with high levels of fertiliser nitrogen (N) and especially with large combined amounts of fertiliser nitrogen and potassium (K). This is mainly […]