The Question Box. 133 



some plant food in them. If they are burned, the nitrogen is 

 lost, but the mineral elements go back to the soil. 



Mr. Smith. — There is $1.00 worth of nitrogen, potash and 

 phosphoric acid in one ton of potato vines, which, if they are 

 plowed under and left to rot, will be mostly saved. 



Mr. Bice. — A ton of potatoes has $1.20 worth of fertility in 

 them, not as much as the vines contain. 



Mr. Smith. — Nearly all the potato, aside from the water in 

 it, is starch, which contains no fertility at all. You could not 

 grow a potato in a ton of starch. 



Question. — Can cow peas be successfully grown as a fertilizer 

 in a cold section? 



Mr. Smith. — I know of no reason why they can't. You are 

 not in a very frosty country? We grow them in Geneva 

 without any trouble, and, it seems to me, you ought to grow them. 

 They are a bean, not a pea, and take nitrogen from the 

 air; therefore, they are a good crop to turn under, both to furnish 

 nitrogen tnd humus. But in the north, one must wait till all 

 danger of late spring frosts has passed. We grew some of them 

 and put them into the silo with the corn. The live-stock ate 

 the ensilage all right, but did not seem to relish the peas when fed 

 alone. We also grew some of the soja beans, but they also went 

 into the silo with the beans and corn. Any of these crops, when 

 turned under, provide humus, which holds moisture, to liberate 

 plant food, and thus helps the plant to grow. Even straw manure, 

 which we do not consider of much value, when turned under by 

 the plow, has a value in stimulating changes that release plant 

 food in the soil. 



A Farmer.— Will straw, plowed under, take nitrogen from 

 the air? 



Mr. Smith. — No; but when it decays it holds moisture, which 

 makes plant food already in the soil available for the use of the 

 plant. 



Question. — What is cottonseed meal worth per hundred pounds ? 

 Where can it be obtained ? Would it pay to use it to grow pota- 

 toes ? If so, how would you apply it ? 



Mr. Bice. — ■ I don't know what the price of cottonseed meal is ; 

 probably about $24 per ton. It is rich in nitrogen. It may be 

 mixed with South Carolina rock, and drilled in. It works through 

 the drill very nicely. If phosphoric acid and nitrogen are needed, 

 the mixture would be a good one. If only nitrogen is wanted, 

 nitrate of soda and dried blood, at present prices, might be accept- 

 able, but cottonseed meal would rank next. 



