pressed around the seed and the topsoil afterwards stirred to prevent evaporation.  This permits of a much more rapid and complete germination.  The drill, the advantages of which were taught two hundred years ago by Jethro Tull, is one of the most valuable implements of modern agriculture.  On dry-farms it is indispensable.  The dry-farmer should make a careful study of the drills on the market and choose such as comply with the principles of the successful prosecution of dry-farming.  Drill culture is the only method of sowing that can be permitted if uniform success is desired.

The care of the crop

Excepting the special treatment for soil-moisture conservation, dry-farm crops should receive the treatment usually given crops growing under humid conditions.  The light rains that frequently fall in autumn sometimes form a crust on the top of the soil, which hinders the proper germination and growth of the fall-sown crop.  It may be necessary, therefore, for the farmer to go over the land in the fall with a disk or more preferably with a corrugated roller.

Ordinarily, however, after fall sowing there is no further need of treatment until the following spring.  The spring treatment is of considerably more importance, for when the warmth of spring and early summer begins to make itself felt, a crust forms over many kinds of dry-farm soils.  This is especially true where the soil is of the distinctively arid kind and poor in organic matter.  Such a crust should be broken early in order to give the young plants a chance to develop freely.  This may be accomplished, as above stated, by the use of a disk, corrugated roller, or ordinary smoothing harrow.

When the young grain is well under way, it may be found to be too thick.  If so, the crop may be thinned by going over the field with a good irontooth harrow with the teeth so set as to tear out a portion of the plants.  This treatment may enable the remaining plants to mature with the limited amount of moisture in the soil.  Paradoxically, if the crop seems to be too thin in the spring, harrowing may also be of service.  In such a case the teeth should be slanted backwards and the harrowing done simply for the purpose of stirring the soil without injury to the plant, to conserve the moisture stored in the soil and to accelerate the formation of nitrates.—­The conserved moisture and added fertility will strengthen the growth and diminish the water requirements of the plants, and thus yield a larger crop.  The iron-tooth harrow is a very useful implement on the dry-farm when the crops are young.  After the plants are up so high that the harrow cannot be used on them no special care need be given them, unless indeed they are cultivated crops like corn or potatoes which, of course, as explained in previous chapters, should receive continual cultivation.

Harvesting