MAINTAINING FERTILITY OF LAND 193 



After the crop is grown, the problem of whether to 

 harvest it depends not on its cost, but on its value as feed 

 and as green manure and the additional cost of harvesting. 

 The remaining 20 acres were harvested and yielded 25 

 tons. Raking, bunching, and hauling in cost $48.31, or 

 $1.93 per ton. The hay was worth $8. It was, therefore, 

 worth $6.07 in the field. Figured at 83 per cent dry matter, 

 this would be $7.31 per ton of dry matter. Since three 

 tons of manure contain about one ton of dry matter, the 

 corresponding value of manure, after it was spread in the 

 field, would be $2.44. Whether it paid to plow this 

 clover under depended on how good use his animals 

 could make of it, and on how busy the farmer was, and 

 on the comparative benefits of manure and green manure 

 on the potato crop. It seems likely that it would pay 

 better to feed it. 



The next year (1911) on this same farm hay was worth 

 $18 per ton, or about $16 above the cost of raking, bunch- 

 ing, and hauling in. This would make the dry matter 

 cost over $19 per ton. The corresponding value of 

 manure would be over $6 per ton. Part of this clover 

 hay was fed to sheep, and part plowed under as green 

 manure. The sheep paid for the hay at this price, paid 

 for all other feed, the use of barn, horse labor, interest, 

 and all other expenses, and left 41 cents per hour as pay 

 for labor spent on them. So that in this case there was 

 a great loss from plowing under clover, not only because 

 the dry matter cost too much, but because it limited the 

 number of sheep kept. 



There are some cases in which it is best to plow under 

 a green manure crop, because it does not pay to keep ani- 

 mals to eat it, or because animals might do injury, as in 

 an orchard. But, in general, it is best to either harvest, 

 o 



