First, there is a natural tendency, under the somewhat moist conditions of spring, for the soil to settle compactly and thus to restore the numerous capillary connections with the lower soil layers through which water escapes.  Careful watch should therefore be kept upon the soil surface, and whenever the mulch is not loose, the disk or harrow should be run over the land.

Secondly, every rain of spring or summer tends to establish connections with the store of moisture in the soil.  In fact, late spring and summer rains are often a disadvantage on dry-farms, which by cultural treatment have been made to contain a large store of moisture.  It has been shown repeatedly that light rains draw moisture very quickly from soil layers many feet below the surface.  The rainless summer is not feared by the dry-farmer whose soils are fertile and rich in moisture.  It is imperative that at the very earliest moment after a spring or summer rain the topsoil be well stirred to prevent evaporation.  It thus happens that in sections of frequent summer rains, as in the Great Plains area, the farmer has to harrow his land many times in succession, but the increased crop yields invariably justify the added expenditure of effort.

Thirdly, on the summer-fallowed ground weeds start vigorously in the spring and draw upon the soil-moisture, if allowed to grow, fully as heavily as a crop of wheat or corn.  The dry-farmer must not allow a weed upon his land.  Cultivation must he so continuous as to make weeds an impossibility.  The belief that the elements added to the soil by weeds offset the loss of soil-moisture is wholly erroneous.  The growth of weeds on a fallow dry-farm is more dangerous than the packed uncared-for topsoil.  Many implements have been devised for the easy killing of weeds, but none appear to be better than the plow and the disk which are found on every farm. (See Chapter XV.)

When crops are growing on the land, thorough summer cultivation is somewhat more difficult, but must be practiced for the greatest certainty of crop yields.  Potatoes, corn, and similar crops may be cultivated with comparative ease, by the use of ordinary cultivators.  With wheat and the other small grains, generally, the damage done to the crop by harrowing late in the season is too great, and reliance is therefore placed on the shading power of the plants to prevent undue evaporation.  However, until the wheat and other grains are ten to twelve inches high, it is perfectly safe to harrow them.  The teeth should be set backward to diminish the tearing up of the plants, and the implement weighted enough to break the soil crust thoroughly.  This practice has been fully tried out over the larger part of the dry-farm territory and found satisfactory.