A PASTURE HANDBOOK 5 



In producing 100 pounds of beef per acre annually, approximately 

 3 pounds of nitrogen, 0.94 pound of phosphorus, and 0.17 pound of 

 potassium are taken from the soil and are retained in the carcass. 

 Estimating that only half of the manure is returned to benefit the 

 pasture, there is an additional loss of 12 pounds of nitrogen, 0.87 

 pound of phosphorus, and 9.96 pounds of potassmm. If about 35 

 percent of pasturage is legumes, the nitrogen content of the soil, 

 under ordinary conditions, would be maintained. To maintain the 

 phosphorus and potash in the soil by applying superphosphate and 

 muriate of potash once in 10 years would cost $6.60 per acre, or 66 

 cents per year, at 1932 prices in the eastern part of the United States. 

 If it were necessary to replace all the nitrogen lost there would be an 

 additional cost of $1.90, or a total cost of $2.56 per acre per year. 



The amount of soil nutrients removed by pasturing is small in 

 comparison with the amount removed in growing some of the common 

 cultivated crops. According to Warington^ a 30-bushel-per-acre 

 crop of wheat removes 48 pounds of nitrogen, 9.22 pounds of phos- 

 phorus, and 23. 91. pounds of potassium; a 30-bushel corn crop, 43 

 pounds of nitrogen, 7.86 pounds of phosphorus, and 30.13 pounds of 

 potassium; and a mixed-hay crop of 1}^ tons per acre, 49 pounds of 

 nitrogen, 5.37 pounds of phosphorus, and 42.25 pounds of potassium. 



Forests are even more effective than grasslands in controlling soil 

 erosion and conserving the rainfall. Trees are also able to grow on 

 soils that wiU not support the grasses. This is particularly true of 

 the conifers. Most of the land that has been under cultivation is 

 sufficiently fertile, however, to grow pasture plants, and under such 

 conditions grass is preferable to trees. This is true because it is less 

 expensive to establish grass and easier to return the land to cultivation 

 if later that is found desirable. Trees should be planted only on land 

 which it seems reasonably sure ought never to be used again for cul- 

 tivated crops. There is, however, some land that experience has 

 shown cannot be cropped profitably even under more favorable 

 marketing conditions than those prevailing at this time, and other 

 lands once cropped profitably that have been ruined by erosion. The 

 latter can be redeemed, if at all, only by being planted with the 

 hardiest kind of trees. 



The proper use of land as between crops, pasture, and forest depends 

 on several factors, such as climate, topography, productiveness of the 

 soil, distance from market, the cost and abundance of farm labor, 

 and prevailing economic conditions. 



In the follo\\dng pages the various kinds of pastures are discussed, 

 together with the type of pasture plants best suited to each kind in 

 the various sections of the country. The discussion is confined 

 chiefly to tame pastures, and as such is concerned almost entirely 

 with cultivable lands. 



KINDS OF PASTURES 



TAME PASTURES 



Tame pastures are lands once cultivated that have been seeded 

 wdth and are now occupied largely by domesticated pasture plants 

 and used chiefly or entirely for grazing livestock. They include the 

 following main tj^pes. 



' Warington, R. the chemistry of the farm, pp. 64-65. London. 1894. 



