Pasture Top-Dressing in New Hampshire 



CINCE 1929 the New Hampshire Experiment Station has been con- 

 ^ ducting experiments in old pastures to see what improvement can 

 he expected there from the application of lime and various fertilizer 

 materials. This work has been predicated on the conviction that the 

 low acre carrying capacity of New Hampshire pastures is due pri- 

 marily to the exhaustion of available plant food through years of 

 pasturing. Milk and livestock carrying plant food taken from these 

 pastures have been sold off the farm with no replacement of the vari- 

 ous elements that have been removed from the soil. 



That this conviction is true has been borne out by the results se- 

 cured. Experiment Station Circular 35, (February 1931) discussed 

 in detail the response secured in ten old pastures scattered over five 

 New Hampshire counties. While the results varied somewhat from 

 pasture to pasture with soil type, the original vegetation in the sod. 

 and particularly with the ability of the soil to retain moisture, the 

 response secured indicated that all the pastures gave increased yields 

 due to one or more of the top-dressing substances applied and that 

 the response secured from superphosphate, potash or nitrogen could 

 be rather accurately predicted. 



This prediction could be based upon the presence or absence of 

 wild white clover in the stand. If wild white clover was present or 

 could be induced by fertilization to grow and spread in a short time, 

 the sward responded more to superphosphate, potash and lime. If 

 clover did not appear in the stand the chief response came from ni- 

 trogen. 



Because of the interest in pasture improvement in New Hampshire 

 at the present time, and since lime, superphosphate and potash are 

 available to farmers under the Agricultural Conservation Program 

 for pasture and crop land improvement practices, it seems pertinent 

 to present again the data from these tests to indicate the relative 

 1 espouse that may be expected from these different substances when 

 used for pasture improvement. 



Taule 1. — Average yields on 10 pastures in 1930 



Pounds per acre Pounds per acre 



Treatment Dry matter Protein Gain for Dry matter Protein 



In the tests covered by tables 1 — 3 inclusive, the check plot was 

 untreated, superphosphate (P) was applied at the rate of 600 pounds 

 of 16 per cent to all treated plots, once in three years, potash (K) 

 was used at the rate of 200 pounds of 50 per cent muriate once in 



