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Rational potassium manuring for arable cropping systems
Author(s) -
Johnston A Edward,
Goulding Keith W T
Publication year - 1988
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740460102
Subject(s) - arable land , crop rotation , crop , soil water , cropping , agronomy , environmental science , productivity , potassium , mathematics , agroforestry , agricultural engineering , chemistry , biology , agriculture , ecology , soil science , economics , engineering , macroeconomics , organic chemistry
Interest in potassium (K) manuring has decreased in recent years because applying K leads to no environmental problems, few soils are K deficient and K is cheaper than N. However, fresh K optimises yields, especiatly with high‐yielding crops and through its interaction with N, and K residues benefit crops in a way that often cannot be offset by fresh K. To achieve a rational basis for K manuring, the various sources of K and demands for K by the crop must be considered and used, together with soil and crop analyses, to predict K fertiliser requirements. K should be applied annually, perhaps as an NK compound, on light‐textured soils. On heavier soils it can be applied at any convenient point in a rotation, probably just before the most K‐sensitive crop is grown. Applications should match or slightly exceed crop requirements. There is little to gain from omitting K and every reason, both economic and agronomic, to include it. Such a rational policy will provide due reward in current crop yields and quality and in future soil productivity.