Translations:Benutzer:Arian/Klett-Mini-Test/990/en

The cover crops shift the ratio of cereal to broad-leaved crops in favour of the latter. The deep-rooting crops with the greatest root mass — lucerne followed by clover — outweigh the proportion of mostly shallow-rooting root crops with their limited root mass. The cereal crops occupy the middle position in both respects. Leaving aside the contribution of cover crops and organic manuring, the humus balance over the twelve years may be assessed as slightly positive. Soil cultivation, principally in spring and autumn, exerts a negative influence on it. The suspension of this cultivation during one quarter of the twelve years through the growing of field fodder crops mitigates the humus loss, as does the moderate deep-working in autumn and early winter by plough, cultivator, disc plough, and the like. Compensating for losses, or indeed a gradual settling towards a lastingly higher level of humus content, is then the task of the humus-donating cover crops — but above all of manuring with farmyard manure and composts.