[Magnesium in the fertilizers secures the feed [crops] quality]

abonos npk acidification chaulage deficiencia de oligoelementos encalado engrais npk exigence des plantes farmyard manure feed crops fumier liming magnesio magnesium necesidades de las plantas noruega norway npk fertilizers nutritive value plant requirements plantas forrajeras trace element deficiencies valeur nutritive valor nutritivo