Micronutrients in Swedish cereals – Impact on yield and soil‐crop interactions

A sufficient supply of micronutrients is essential to develop a high crop yield. Although micronutrients are just as important as macronutrients, they have received much less attention in both research and practical farming. A majority of Swedish crop production is carried out with large application of macronutrients but without any input of micronutrients. The guidelines used for micronutrients fertilization in cereals are based on experiments carried out about 60 years ago and since then much has changed. Crop yields are much higher today, with other varieties and larger inputs of macronutrients (NPK). There has also been a differentiation between animal farms with large application of manure and farms with no input of organic fertilizers. There is a need to further investigate the status of different micronutrients in cereals grown in Sweden today, what impact they have on yield and how different soil characteristics and cultivation measurements influence the crop supply. An important task is to identify hidden deficiency in cereals, i.e. what concentration levels of the different micronutrients in crop that causes a decrease in yield without any visible deficiency symptoms. In the project there will also be an evaluation of grain analyses as a way of detecting hidden deficiency in cereals. The project will be based on analysis and evaluation of existing data within the monitoring program of Swedish agricultural soils, complementary analysis of archived soil and grain samples from different field experiments as well as two pot experiments. The outcome of the PhD project aims to contribute to the development of updated guidelines for micronutrients in Swedish cereals.