10 X. H. Agr. Experiment Station [Bulletin 313 



composition of the alfalfa produced is now being studied. The 24 

 plots included in the lime test were planted to soybeans, fertilized 

 alike and harvested to note differences in response to the lime vari- 

 ables (zero to eight tons per acre) perviously applied. Where no 

 lime was applied, the yield was only 5,81P> pounds per acre; lime at 

 the rate of one ton per acre increased the yield to 9,991 pounds per 

 acre. 



On the remaining 72 Ireland plots two cuttings of alfalfa were 

 made after top-dressing in the spring according to the plan of the 

 experiment. The gain, subsequent to the use of nitrogen, seemed to 

 be more than sufficient to warrant its cost. It also appears that a 

 gain of 1,621 pounds of hay each year for three years as a result of 

 300 extra pounds of 10-20-20 is worth the expense when one takes 

 into consideration the current fertilizer costs and hay prices. 



The use of magnesium in magnesium sulphate has given consist- 

 ent increases on this soil, the response for the 100-pound application 

 being 716 pounds of cured hay per acre each year. 



A Dairy Farm Rotation on Neglected Hay lands 



This experiment on the Lane farm in Pittsfield has now proceeded 

 through two courses of the three-year rotation of potatoes, oats and 

 clover. Next year sweet corn will be included in the rotation instead 

 of potatoes since sweet corn is an important canning crop in this 

 section of New Hampshire. The field will also be laid out in a system 

 of strip cropping for erosion control. 



The field is divided into three sections so that each of the crops 

 has been in production every year. The fertilizer is applied only to 

 the potato crop, the oats and clover that follow being produced on 

 any residue the potato crop leaves. Yields have been secured on the 

 potatoes each year and the following table gives an average of the 

 six years for this crop under different fertilizer treatments: 



-1 

 1 



-8 

 12 



-42 

 14 



-59 



15 



25 



12 



9 



-80 



Omitting phosphorus from the formula has caused a significant 

 decrease in yield, 42 bushels per acre, while doubling the phosi)horus 

 has brought a gain of 14 bushels per acre. Potash variations give 

 similar results. Included in (his experiment is one series of i)lots 

 which received no fertilizer whatsoever. While the yield has aver- 

 aged 80 bushels less than the plots receiving one ton of 4-8-7 ferti 

 lizer, the relatively high yield of 164 bushels per acre causes us t( 



o 



