+----------------------------+ PLOT 9. | Muriate of Potash 8 lbs. | | Acid Phosphate 16 " | +----------------------------+ +----------------------------+ PLOT 10. | Nitrate of Soda 8 lbs. | | Acid Phosphate 16 " | | Muriate of Potash 8 " | +----------------------------+ If the amount of fertilizer is too small to distribute evenly over the plot, mix it thoroughly with a few quarts of dry earth or sand to give it more bulk and then apply it. In the use of fertilizers it should always be remembered that small crops are not always due to lack of plant food, but may be caused by an absence of the other conditions necessary for root growth and development. The soil may not be sufficiently moist to properly supply the plants with water. Too much water may check ventilation. Poor tillage may check root development. Unless the physical conditions are right the possible effects of additional plant food in the form of fertilizers are greatly diminished. The farmer who gets the largest return from fertilizers is the one who gives greatest attention to the physical properties of the soil. He makes use of organic matter and is very thorough in his methods of tillage. Every farmer should apply to his State Experiment Station for bulletins on the subject of fertilizers. CHAPTER XXIV THE ROTATION OF CROPS SYSTEMS OF CROPPING There are two methods or systems of cropping the soil: The One Crop System, or the continuous cropping of the soil year after year with one kind of crop. The Rotation of Crops or the selection of a given number of different crops and growing them in regular order. The purpose of this chapter is to inquire into the effect of these two systems of cropping: On the soil conditions necessary for the best growth and development of the crops. On the market value of the crops. On the increase of or the protection from injurious diseases and insects. On the distribution of labor throughout the year. On the caring for farm stock. On the providing for home supplies. This inquiry and the conclusion will be based on the following facts learned in the foregoing chapters. Plant roots need for their growth and development (see Chapter II): A mellow yet firm soil. A moist soil. A ventilated soil. A warm soil. A soil supplied with plant food. Decaying organic matter or humus is one of the most important ingredients of our soils. Because: It greatly influences soil texture and therefore the conditions necessary for root growth. Its presence or absence greatly influences the attitude of soils toward water, the most important factor in plant growth. Its presence helps light, sandy soils to hold more water and to better pump water from below, while it helps close, heavy soils to better take in the water which falls on their surface. Its absence causes an opposite state of affairs.