In these days machinery has made so many wonderful changes in the management of crops that the farmer who sticks to the old farming customs has no chance of making more than a living. When the country was new, it was the practice to farm one section until it was exhausted, and then to move to fresh soil. The farmer was saved the bother of cultivating, as virgin soil needed practically only to be planted to bring forth a good harvest. But conditions have changed and the virgin soil left today is not important in the farming possibilities. Therefore, we have had to look for other means of getting crops and making every inch of land do its share. We no longer allow land to lie fallow that it may rest and renew itself. We renew it by fertilizing and by rotation of crops. Crop rotation is very valuable because it is a saving of fertilizer and labor, and keeps the soil in good condition. This has been proved by experiments made without manure, depending entirely upon rotation for fertilizing, which gave excellent results. There are probably a dozen or more good reasons for the value of crop rotation which have not yet been discovered and formulated, but the following are well known: Some crops tend to correct the faults of others. It has been proved that the continuous growing of one crop injures the soil in some respect, and the crop falls off both in quantity and quality. Rotation tends to overcome this difficulty. Then, too, this rotation works out and evens up the inequalities of the soil, partly through the different treatment required by the different crops. Different plants draw different portions of food from the soil and at different times. By rotation these heavy drafts on the plant food do not come at the same times, and the seasons get a chance to even up the inequalities. Different plant food gets mixed into the soil, so that the roots can feed on it, by the decay of the parts left in the ground or which are plowed under. But the greatest benefit comes from the nitrogen compounds through growing plants, such as cowpeas, crimson clover, etc.; these “leguminous” plants have little knots or tubers on their roots with the mysterious power of gathering the free nitrogen out of the soil or air, and turning it back again to the soil in condition to be used by other plants. Now nitrogen is the hardest to keep and the most expensive of all the plant foods that the farmer has to buy, and to get this nitrogen is sometimes the only reason he has for buying chemical fertilizers. This shows the importance of leguminous crops to the farm. They supply this nitrogen at almost no cost, or at a profit. Some plants have more power than others to use the contents of the subsoil, and may draw less on the upper soil, and further, by their decay may add richness to the earth. Most legumes have this power to take nourishment from the subsoil.