Soil fertility and plant nutrition research under field conditions: Basic principles and methodology

In the agricultural science, soil fertility and plant nutrition have played an important role during the 20th century in increasing crop yields. In the 21st century, importance of this field is still expanding due to the limitations of natural resources (land and water), sustainable agriculture, and concern about environmental pollution. In this context, increasing crop yields will be associated with rational use of chemical fertilizers, increasing use of organic sources of nutrients, recycling of plant available nutrients, and exploiting genetic potential of crop species or cultivars within species in efficient use of nutrients. Hence, in the future, increasing crop yields will be a challenge for agricultural and soil scientists. Conducting fertilizer field trials for adequate sources, methods, rates, timing of application along with crop species or genotypes within species, under different agroecological regions are necessary to generate data and their use for achieving maximum economic crop yields. The objective of this article is to present basic concepts and discuss methodology of soil fertility and plant nutrition research under field conditions.