The volume weight of the organic matter in the plough layer of peat lands cultivated by different methods

The investigation is a report of the results from determinations of the volume weight of the organic matter in the plough layer of cultivated peat lands. They are believed to justify the following conclusions. As a consequence of continued cultivation through several decades, the volume weight of the organic matter in the plough layer increases. Owing to the fact that cultivation also adds plant residues and root substance to the soil of the plough layer, this increase cannot be positively attributed to the favourable effect of the cultivation measures on the humification of the peat alone, though this effect is certainly thought to be at least partially responsible. The increase of the volume weight is also thought to be one of the reasons why peat lands in the course of continued cultivation gradually evolve a closer resemblance to humus soil. The cultivation methods influence the change in volume weight of the organic matter. Fertilizing, liming and addition of mineral soil for soil improvement usually produce an increase in the volume weight.