They could then be destroyed either by plowing under or burning.
The farmer secures the humus by plowing under stubble and sod, and occasional green crops.
It may be prepared, beginning a year or two ahead by growing and plowing under well fertilized green manure crops.
Pruning off badly infected twigs and plowing under scabby leaves are good sanitary measures.
It furnishes more green food for plowing under than the medium red; hence, it is, on the whole, a better improver of the soil.
Then moisture is better conserved by plowing under the crop early and a better physical condition of the soil secured.
By plowing under the rye crop you do not increase the amount of nitrogen, the most important element of fertility in the soil.
The second year's crop is obtained by the simple method of plowing under the plants in the fall.