March, 1936] Agricultural Research in N. H. 11 



uniform application of fertilizer. In the spring of 1935 the fertilizer vari- 

 ables were applied. 



Seeded without manure, it is quite evident that the nitrogen in the ferti- 

 lizer is utilized by the alfalfa crop. Yields for the first cutting on those plots 

 where nitrogen was omitted in the formulas are below the check plot yields 

 in four cases out of five, regardless of the other fertilizer treatment. In 

 these experiments where no manure was applied as a general treatment, it 

 appears that phosphoric acid and potash both stimulate the yield of alfalfa, 

 and to about the same degree where equal quantities of the elements are 

 applied. 



Potatoes ill the Legume Experiment. Potatoes were grown on one sec- 

 tion of the Whenal farm field in 1935 on land that had been previously 

 limed, but on certain plots aluminum sulphate and sulphur were applied 

 prior to planting the potatoes to note the effect of these substances on scab 

 control. While the degree of acidity does not absolutely follow the amount 

 of acidulating material applied, the trend is for these materials to depress 

 the pH and to control scab. 



A Dairy Farm Rotation on Worn Out Hay Lands. A three-year rotation 

 in potatoes, oats and clover is in progress on the Lane farm in Pittsfield, 

 1935 being the third year of the experiment. Potatoes were grown on one 

 section of the field with varying fertilizer treatments. 



Decreases for the omission of phosphorus, potash and for the no-ferti- 

 lizer plots proved significant. 



The first three years of this experiment indicate that varying the potash 

 in the formula has more influence on yields than any other element, that 

 magnesium is not a factor in potato production on this field, that broadcast- 

 ing is equal to drilling as a means of distributing the fertilizer and that 

 double strength fertilizers are slightly better than single strength materials 

 for stimulating yields. 



Oats were seeded on the plots that were in potatoes in 1934 without addi- 

 tional fertilizer. It is interesting to note that leaving out an element de- 

 pressed the yield, and that doubling an element increased the yield to a 

 slight degree. The no-fertilizer series yielded about three-quarters of a ton 

 less oat hay than the average of the check plots, — a significant difi^erence. 



Clover was harvested from these plots which were in oats in 1934 and 

 potatoes in 1933. As no fertihzer was added to either the oats or the clover, 

 yield difi^erences were slight from the various series. The 4-8-14 series 

 which yielded over one-quarter ton more dry hay than did the 4-8-7- 

 check plot was the only significant difi^erence. 



Potatoes in a Three Year Rotation. Growing conditions for the three- 

 year rotation of potatoes on the Jackson farm, Colebrook, were not as satis- 

 factory in 1935 as in previous years. Yields were low for the area, and there 

 seemed to be more variation than usual within the plot series, a fact which 

 results in fewer significant differences for the various treatments. 



Ammo-phos-A and nitrate of potash did not do as well as formerly. It 

 is possible that these acid-forming fertilizers increase the acidity of the soil 

 enough to be detrimental to the potato crop. Leaving potash out of the ferti- 

 lizer mixture has seriously depressed the yield of potatoes. 



