EIGHTH ANNUAL YEAR BOOK- PART X. 705 



to follow one crop with another which takes different properties of fertility 

 than the preceding one, with benefit to the crop as well as to the pro- 

 ducer. But if it were so that there were only a certain amount of fertility 

 or elements of crop growth stored in a given soil and there was no way 

 of getting an additional supply, even by rotating intelligently, we would 

 soon be, as the boys say, "up against it." But we find the soil is not 

 the only storehouse of fertility — the very air is a vast storehouse of cer- 

 tain elements of growth, which we may, and do, draw upon to our benefit, 

 more or less, as we undersfand the structure or elements of the different 

 crops. 



To illustrate: As you perhaps know, wheat, Indian corn, oats, etc., 

 draw their elements of growth almost entirely from the soil, while the 

 scientists tell us, and we find it works out in practice, that that list of 

 crops called the legumes — clover, cow peas, etc., draw the most of their 

 substance from the air and not only make the present crop but store up 

 certain elements in the soil for the use of the future crops of corn, wheat 

 and such crops as do not draw fertility from the air. 



Now we are told by our experiment stations (and we know it ourselves 

 if we only stop to think of it) that even an intelligent system of crop 

 rotation is only a clever trick on the part of the farmer to draw the 

 supply of available fertility stored in the soil out the quicker. In that 

 case, what is the remedy? Do not sell anything off of the farm that can 

 be fed at home. Do not sell your raw material, but sell the finished 

 product. You would think the manufacturer needed a conservator 

 appointed who would sell his raw material as soon as he received it, 

 instead of making it into a finished product. 



We find by reading the station bulletins that when we sell one ton of 

 corn we sell in it fertilizing ingredients which if purchased in the form 

 of commercial fertilizer would cost us $3.78; one ton of timothy hay, 

 $5.10; one ton of wheat, $7.91; one ton of clover hay, $9.07, etc. Now, if 

 these crops are fed to animals upon the farm it is found in the mature 

 animals, which are neither gaining or losing in weight, that they return to 

 the soil practically all the fertilizing ingredients contained in the food con- 

 sumed; growing animals and milk cows, from 50 to 85 per cent; fattening 

 or working animals, 90 to 95 per cent. Now, to go a step farther; if it 

 pays to feed what we grow upon our farms it pays to huy additional 

 feeds and fed them for the manurial benefits to be derived, for it is 

 assumed that we will get a profit from the feed bought, through marketing 

 the animal, besides being ahead on the fertilizing question. 



To guide us a little on what feed to purchase, from a fertilizing stand- 

 point — that is, to see what kinds of feed give us the most manurial value 

 for our money — let us again consult the bulletins and quote: "As regards 

 the value of manure produced, the concentrated feeding stuffs, such as 

 meat scrap, cotton-seed meal, linseed meal and wheat bran stand first; 

 the leguminous plants (clover, peas, etc.) second; the grasses, third; 

 cereals (oats, corn, etc.), fourth; and root crops, such as turnips, beets 

 and mangle-wurzels, last." And, by the way, the feeds which we find 

 have the largest manurial value have also the largest protein content, 

 which food element is the most expensive for the farmer in Iowa to obtain. 

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