LIVE-STOCK FARMING 233 



cient manure of good quality to maintain or even to increase the 

 fertility of his own farm. 



In specially favored localities, a few farmers haul manure from 

 town, or even ship it from the larger cities, especially for use in 

 market gardening, and they, too, are thus enabled to enrich their 

 lands at the expense of many other farms; but no extensive state 

 or nation ever has or ever can maintain sufficient live stock, even 

 in country and city combined, to furnish manure with which to 

 maintain the productive power of .all the farm lands. 



Even under the best system of independent live-stock fanning; 

 that is, without dependence upon the purchase of supplementary 

 food stuffs or the use of manure from town, it is necessary to pur- 

 chase and apply some phosphorus in order to replace that sold in 

 the animals and animal products, butter and cream being the only 

 important farm products that do not contain appreciable amounts 

 of phosphorus. 



In order to increase the phosphorus content of normal soils, 

 phosphorus should be applied in live-stock farming the same as 

 in grain farming, but to merely replace that sold in animal products 

 will require applications of only one half as much phosphorus as 

 is required for grain farming, assuming that all of the grain and 

 clover and part of the corn stover and oat straw are eaten by the 

 live stock. Thus, for the larger yields, the loss of phosphorus 

 would be about 20 pounds per acre in four years with live-stock 

 farming, and 30 pounds in three years with grain farming, as can 

 readily be determined by computation from the data given in 

 Table 23 and the results of the digestion and feeding experiments 

 with dairy cows by the Illinois Station, with dairy cows and steers 

 at the Pennsylvania Station, and with sheep at the Ohio Station, 

 from which we must conclude that as an average at least one fourth 

 of the phosphorus contained in the feed is not recovered in the 

 manure. 



In comparison with these permanent systems of agriculture, it is 

 worth while to compute the results of a four-year rotation of three 

 crops of corn and one of oats, seeded with clover to be plowed under 

 the next spring, assuming that the corn is husked and the stalks 

 burned (except the third year, when the stalks are disked down for 

 oats), that the oat crop is all removed, and that the total growth 



