YIELD AND VALUE. 



The yield of hay varies according to the fertihty of the soil upon 

 which it is raised, whether it is grown on rich lowlands or on the 

 drier and more sterile uplands. In the Gulf States cowpeas will 

 probably give an average yield of 2 to 3 tons per acre, while 4 to 6 

 tons are not uncommon. Farther north the average will range from 

 li tons in Ohio to 2^ tons in Arkansas, Missouri, and Tennessee. As 

 with other crops, the time of planting, the character of the soil and 

 of the cultivation, and the amount of rainfall have much to do with 

 the yield. Along the Gulf it is one of the best hay crops. North of 

 the latitude of the Ohio River it is chiefly valuable as an addition to 

 the list of drought-resistant, summer-soiling crops and as a crop that 

 will yield a considerable amount of forage on soil too sterile to grow 

 red clover. The commercial value runs from $G to $20 per ton, being- 

 governed by the relative abundance of other grades of hay and fod- 

 der. Its feeding value is equal to that of the best red clover, and 

 the hay ranks high in palatability and digestibility, 



FERTILIZERS. 



It has been found that, as a rule, it does not pay to use high-grade 

 commercial fertilizers on cowpeas; this, however, depends largely 

 on the soil and on what crop is to follow this green manurial one. 

 It is usually unprofitable to fertilize with expensive nitrogen, in the 

 form either of nitrate of soda or of guano, and even the organic 

 nitrogen of cotton-seed meal does not act upon this crop as rapidly 

 as upon cotton and the cereals. The nitrogen of the fertilizers seems 

 not to influence the percentage of protein in the crop, and the general 

 opinion of agriculturists in the South is that it does not cause a 

 sufficient increase in yield of vines to pay the cost. At the Delaware 

 Station 160 pounds of muriate of potash per acre doubled the yield of 

 vines, and superphosphate produced no effect. At the Georgia Sta- 

 tion combinations of superphosphate and potash gave the best results, 

 but later exjDeriments there indicated that large amounts of potash 

 are unprofitable, and that superphosphate at the rate of from 200 to 

 400 pounds per acre gave better results. Superphosphates are very 

 much preferable to untreated rock phosphate. The latter can be sold 

 at very much lower rates, and it remains to be seen whether it would 

 not be a profitable method to apply the soft phosphate to the cowpeas 

 for the benefit of the succeeding crop in the rotation, for it has been 

 found that the insoluble phosphoric acid of the untreated rock becomes 

 changed to forms available as plant food in the presence of large 

 amounts of decaying vegetable matter in the soil. If it is found that 

 this process can be relied upon, then the cowpea will have another 



