Soil and plant testing and analysis as a basis of fertilizer recommendations

General principles of plant nutrition don't furnish the concrete information, necessary for practical treatments in a given situation. Thus, the questions arise which parameters must be considered an how can they be determined. This leads to consider the concepts of nutrients diagnosis, as well as the methodology and the corresponding equipment and instrumentation, for putting it into practice. The question may arise whether plant or soil analysis should be used for diagnosis crop nutrient requirements and making fertilizer recommendations.Both methods may be complementary, not competitive and the laboratories should be in the possibility to carry out both types analysis. It is recommendable to start soil analysis prior to plant testing.There are many possibilities and methods for testing soil chemical and nutrient properties. It is indeed highly recommended to agree on a minimum of uniformity of methodology.