The condition to be met and the effect of the operation should always be given serious thought.
We have considered after-cultivation as influencing soil fertility by checking a loss of water by evaporation and weed transpiration, and this is its main influence but other benefits follow.
Keeping the surface soil loose and open benefits fertility because it directly aids the absorption of rain, favors ventilation, and has a beneficial influence over soil temperature. Indirectly through these factors it aids the work of the beneficial soil bacteria and the chemical changes in the process of preparing plant food for crop use.
CHAPTER XIX[ToC]
Farm Manures
FUNCTIONS OF MANURES AND FERTILIZERS
In Chapter II we learned that the roots of plants for their growth and development need a soil that is firm yet mellow, moist, warm, ventilated and supplied with plant food. We also learned that of the plant foods there is often not enough available nitrogen, phosphoric acid, potash and lime for the needs of the growing plants.