Försök med olika harvar 1977-1985

Field trials with different types of harrows were carried out in cereals. In a first series types commonly used by farmers were compared on different soils ranging from sand to heavy clay. Measurements showed that there were large differences in the variance of the working depth within treatments and that improvements ought to be made. Between the types the differences in the variance of working depth and also in average yield were rather small. During the years 1980-1985 a second series of field trials in cereals with improved implements was carried out on clay soils at Ultuna. The harrows were heavier, of ten with more leveling boards, more and stronger tines and in one case with narrower sections than earlier. These improvements resulted in a finer tilth, less roughness in the seedbed bottom and in years with a dry spring and early summer also in a higher yield. Similar results were obtained with an increasing number of harrowings. Together with the Swedish Sugar Company, an experimental harrow was built for crops requiring a shallow seedbed and with great demands on the quality of the seedbed. In sugarbeets, the results of the trials were the same as mentioned for cereals. From that basic approach, the firm of Kongskilde developed the Germinator