The effects of tillage on seed-soil contact and seedling establishment

Abstract

Abstract An increase in seed-soil contact is a key objective of field tillage operations, as it can improve the maintenance of water supply for germination under varying environmental conditions and improve establishment. However, the effects of management techniques on the microstructure of the soil, and especially on the region immediately surrounding the seed, have not yet been extensively studied. Using X-ray computed tomography (CT) to quantify the 3D soil microstructure, we revealed high variability in the seed-soil contact under varying field conditions. Tillage operation had a significant effect on seed-soil contact (as measured by image analysis) with loamy sand soil ranging from 15 % (minimum tillage) to 30 % (maximum tillage) compared to 5% (ploughed and syncro) to 15 % (ploughed) in silty clay loam soil. However, differences in seedbed porosity did not lead to significant differences in seed-soil contact and subsequent establishment. Intensive farming did not necessarily result in ideal seedbed conditions or high precision with respect to sowing. As such, it appears that farmers are only able to minimally impact seed-soil contact via tillage operations.