lifetime of 2.7 years. When she reached the age of 9 she had a life expectancy 

 of 2.1 years. Thus a cow bought at the age of 6 would have a life expectancy 

 of 2.7 years while a heifer freshening at the age of 2 would have 4.1 years. 

 The 2-year-old cow could be expected to be in the herd only 1.5 years 

 longer than a 6-year-old. This helps to explain the longer total productive 

 life of purchased cows. 



Yields for Hay, Silage Crops, and Pasture 



The soils of New England are not particularly noted for their native 

 fertility. A recent study of soil resources states: "Since only small amounts 

 of nutrients are present in the soils in New England, these soils are in- 

 fertile in their natural state. Although the soils in New England are natural- 

 ly infertile, they are highly responsive to fertilization."-- The fact that 

 the infertile soils in New England and in New Hampshire respond to fer- 

 tilization and good management partly explains much of the variation 

 among farms in yields per acre of forage crops. The most productive soils 

 that are used for cultivated crops hold moisture well during the critical 

 growing seasons.'--^ Differences in moisture also account for variations in 

 yields between farms and between and within fields on individual farms. 



The average yields for all classes of hay in New Hampshire in 1954, 

 as reported by the Crop Reporting Service, was 1.28 tons per acre.-^ The 



Table 12. Effect of Level of Fertilization on Yields of Forage Crops, 

 Experimental Plots, New Hampshire 



Plant Nutrients 

 per Acre 



Crop and Fertilizer Yield 



Applied per Acre Nitrogen Phosphorus Potash per Acre 



Pounds Pounds Pounds Tons 



Clover-grass^ 



Check 0.95 



134 pounds of muriate of potash 80 1.52 

 400 pounds of 20-percent superphosphate 



and 134 pounds muriate of potash 80 80 2.46 

 125 pounds of ammonium nitrate, 



400 pounds of 20-percent superphos- 

 phate and 134 pounds muriate of potash 40 80 80 2.89 

 Alfalfa2 



375 pounds of 8-16-16 30 60 60 2.20 



750 pounds of 0-16-16 120 120 2.45 



750 pounds of 4-16-16 30 120 120 2.90 



750 pounds of 8-16-16 60 120 120 3.08 



1,500 pounds of 4-16-16 60 240 240 3.31 



Derived from Table 1, New Hampshire Agr. Expt. Sta. Cir. 74, F. S. Prince, P. T. Blood, and 

 in "^'^^ «eipon5c of Clover and Total Forage to Top-Dressing Fertilizers, 1917. 



Uerived from Table 5, New Hampshire Agr. Expt. Sta. Cir. 58. F. S. Prince, P. T. Blood, G. P. 

 rercival, and P. N. Scripture, Fertilizer Needs of Alfalfa on New Hampshire Soils, 1942. 



22 C_ L W. Swanson, et al., The Changing FertiUtv of New England Soils, Agr. 

 Info. Bui. No. 133, U. S. Department of Agricuhure, 1954. 



23 W. H. Lyford and J. C. Craddock, Jr., Land Use and Soil Relationships of 



Strafford County, New Hampshire, in 1938-40, New Hampshire Agr. Expt. Sta. Bui. 

 (Jn process) . 



24 Crop Production, Crop Reporting Board, Agricultural Marketing Service, U, S. 

 Uept. of Agriculture, Annual Summary, December, 1954. 



28 



