Metody oceny stanu odzywienia roslin uprawnych azotem

Different methods used to evaluate the nutrition status of crops are described in the paper. Actually two groups of methods are distinguished: visual and chemical ones. The last ones include direct and indirect methods. Until now direct methods have had a dominant position. However, actually indirect methods become more and more popular mainly owing to their non-desfructive character and quick results they give. SPAD test based on measuring of chlorophyll contents is a good example of such a method.