Höstveteetablering : inverkan av sådjup och aggregatstorleksfördelning på uppkomst och skottutveckling

Abstract: Winter wheat is a very important crop, but despite this its yield in Sweden has remained the same since 1990. Several studies have been conducted pertaining the optimal conditions for the establishment of spring cereals. However, there is very few studies that have taken place on the favorable conditions for the establishment of winter wheat. The aim of this work was to investigate the effects of sowing depth and seedbed properties, especially aggregate size, on the emergence and shoot development of winter wheat. The work has examined the conditions for the winter wheat establishment in Mälardalen. The study had two parts, a farmer survey and a field trial. Farmers' survey was conducted on 16 fields to study how winter wheat was established. The farmers' survey also compared two tillage systems, ploughing and non-inversion surface cultivation. The field trial was designed to compare the different sowing depth under the same conditions and was conducted in Säby, Uppsala. The field trial compared the sowing depths 2 cm, 4 cm and 6 cm. In both the farming survey and field trial, investigations were conducted on the seed bed quality, plant emergence, and number of shoots, sowing depth and winter hardness. In the field trial, crop yield was determined. The results of the study showed that if all other conditions are similar, a shallower sowing depth led to faster emergence compared to a deeper sowing. The proportions of different aggregate size have no effect on plant emergence. Earlier studies indicates, however, that a certain large aggregates in the surface have a positive effect for protecting against the harsh winter climate and the risk for siltation. A rapid emergence means that the plant is able to develop a higher number of shoots. A high number of shoots is the factor that gives the best winter hardness. The main factor for quick emergence and shoot formation is the time of sowing. The fields that were sown earlier had the fastest emergence speed and developed the highest number of shoots. The results of this study did not demonstrate any significant differences between ploughing and non-inversion surface cultivation.