A common objection to fall plowing is that the ground is so dry in the fall that it does not plow up well, and that the great dry clods of earth do much to injure the physical condition of the soil. It is very doubtful if such an objection is generally valid, especially if the soil is so cropped as to leave a fair margin of moisture in the soil at harvest time. The atmospheric agencies will usually break down the clods, and the physical result of the treatment will be beneficial. Undoubtedly, the fall plowing of dry land is somewhat difficult, but the good results more than pay the farmer for his trouble. Late fall plowing, after the fall rains have softened the land, is preferable to spring plowing. If for any reason the farmer feels that he must practice spring plowing, he should do it as early as possible in the spring. Of course, it is inadvisable to plow the soil when it is so wet as to injure its tilth seriously, but as soon as that danger period has passed, the plow should be placed in the ground. The moisture in the soil will thereby be conserved, and whatever water may fall during the spring months will be conserved also. This is of especial importance in the Great Plains region and in any district where the precipitation comes in the spring and winter months. Likewise, after fall plowing, the land must be well stirred in the early spring with the disk harrow or a similar implement, to enable the spring rains to enter the soil easily and to prevent the evaporation of the water already stored. Where the rainfall is quite abundant and the plowed land has been beaten down by the frequent rains, the land should be plowed again in the spring. Where such conditions do not exist, the treatment of the soil with the disk and harrow in the spring is usually sufficient. In recent dry-farm experience it has been fairly completely demonstrated that, providing the soil is well stored with water, crops will mature even if no rain falls during the growing season. Naturally, under most circumstances, any rains that may fall on a well-prepared soil during the season of crop growth will tend to increase the crop yield, but some profitable yield is assured, in spite of the season, if the soil is well stored with water at seed time. This is an important principle in the system of dry-farming. CHAPTER VIII REGULATING THE EVAPORATION