SOILS AND FERTILIZERS 433 



layers might be added straw, leaves, mold, or other litter, adding 

 100 pounds ground phosphate rock to each ton of material useot. 

 Be sure to wet all thoroughly. When the compost heap is com- 

 pleted, cover it about 4 inches deep with good loam or with forest 

 mold. 



When applying 2 tons per acre or less, the best results can be 

 obtained by putting the compost in the furrow and bedding out on 

 it. Be careful not to bury too deep, especially on clay soils. When 

 using more than 2 tons per acre it is better to scatter broadcast. 



Bearing in mind the supplemental value of the cowpea, it is 

 safe to say that by using compost at least 50 per cent can be added 

 to the productiveness of the average 100-acre farm, and that simply 

 at the cost of a few tons of acid phosphate and a little labor. With 

 the barnyard manure and with the cowpea at his service to save 

 and gather nitrogen for him, the average farmer is simply wasting 

 his money when he continues to buy nitrogen in commercial fer- 

 tilizer when he could easily produce all that his land needs upon his 

 farm. In some States cotton seed is used in addition to the acid 

 phosphates. The seed should be made thoroughly wet before ap- 

 plying to the compost. 



When Manure Should Be Applied. It is the prevailing opin- 

 ion of chemists as well as practical men that where it is practicable 

 it is best to apply manure and urine to the soil in the freshest pos- 

 sible condition. The fertilizing constituents of well-rotted manure, 

 as already explained, are more quickly available to plants, and the 

 manure itself is less bulky and easier to distribute. On the other 

 hand, fresh manure mixed with the soil readily undergoes a fer- 

 mentation which not only increases the availability of its own fer- 

 tilizing constituents, but also assists in rendering soluble the hitherto 

 insoluble fertilizing constituents of the soil. In fact, even with 

 special precautions to prevent injurious fermentation under the 

 feet of the animals and in the heap, the greatest return is likely to 

 be gotten from manure applied in the fresh condition. 



The form in which manure should be applied (whether fresh 

 or rotted) is determined largely by the soil on which it is to be used. 

 If improvement of the mechanical condition is the main object 

 sought, the best results will be obtained by applying the fresh man- 

 ure to the heavy clay soils and the well-rotted manure to the light 

 soils. If, however, uie prompt action of the fertilizing constituents 

 of the manure is desired, light soils, in a favorable season, are likely 

 to utilize coarse manure to better advantage than heavy soils. De- 

 composition takes place slowly in heavy soils and the constituents 

 of the fresh manure become available very slowly. In light soils, 

 on the other hand, unless the season is dry, the conditions are such 

 that the manure decomposes readily, and the fertilizing constitu- 

 ents are probably rendered available as fast as the plant needs them. 

 There is also considerable danger on this class of soils that some of 

 the soluble constituents will be carried away in the drainage if well- 

 rotted manure is applied. For this reason such manure should be 



