Gizachew Tarekegn Getahun
Sammanfattning av doktoranduppgiften
Improvement of the upper subsoil through loosening and structure stabilisation using crop residues or lime
Subsoil can limit crop growth, yield and quality of crops by being compacted, saline, acidic, nutrient deficient or low in soil organic matter. Improvement of subsoils through loosening is expensive and its effect may not last, as soils can re-compact. Therefore, combining loosening with other binding or flocculating agent may be relevant. In this PhD project subsoil loosening and incorporation of crop residues to achieve structure stabilization is to be tested both in a field and lysimeter study. The addition of lime to subsoil will be investigated in the laboratory through incubation experiments. The dynamics of aggregate formation and stability will be studied in all three experimental approaches and crop performance will be tested in the field and lysimeter study. Using different experimental scales help to identify variables controlling processes and to establish mechanistic relationships between structural changes and impacting factors. The project is assumed to provide essential information about the possibility and limitation to improve physical conditions in the subsoil and the impact on crop performance.