20 N. H. EXPERIMENT STATION [Bulletin 319 



acid increases yields of potatoes over and above the amount found in 

 a 4-8-7 fertilizer. They also demonstrate that extra potash added to 

 phosphorus causes a still further increase, but increased potash alone 

 on this soil is not effective. 



Lime seems to have very little influence upon potato yields, but 

 very much upon the oats and even more upon the hay yields that 

 follow. On the contrary, acid-forming fertilizers not only depress 

 hay yields, but yields of potatoes as well. 



The use of magnesium in the fertilizer has not given an increase in 

 potato yield. Likewise, boron used on certain plots at the rate of 20 

 pounds per acre has not increased yield. 



Yields of hay on the Jackson farm were not influenced particularly 

 by residual fertilizer application. They have, however, been dis- 

 tinctly benefited by lime or lime-bearing fertilizer. The data indi- 

 cate the extreme sensitiveness of hay crops to lime applications. 



This study will be reported in detail in bulletin form early in 1940. 



(Purncll Fund) 



A Fertilizer Experiment with Dairy Farm Crops in the Connecticut 

 Valley 



Although a variety of cro])s has been grown on these plots on the 

 Livingston farm in Claremont, the treatments have not varied since 

 the experiment was set up in 1929. \\'ith this background of contin- 

 uous treatment, deficiencies have shown up where one or more ele- 

 ments were omitted. While in 1938 there was a fairly uniform stand 

 of clover on all plots, by the spring of 1939 the clover had persisted 

 only on plots which had received potash during past years, while on 

 all other plots, no matter what treatment they had received, no clo- 

 ver lived over. In addition to the fair proportion of clover on potash- 

 treated plots, the total yield of hay was increased. 



Considering the yields of cured hay i)er acre in the first cutting for 

 1939. residual lime effects appeared to have been very slight, although 

 lime applied to plots receiving other minerals slightly increased hay 

 yield. The most striking results are those for potash ap]^lication. 

 All treattnents where potash appeared yielded over two tons of hay 

 per acre. Phosphorus alone does not appear to have much, if any, 

 effect in improving hay yield, although used with potash it promotes 

 a much larger yield of hay than can be accounted for by potash alone. 

 .Apparently what is needed on this soil is a balanced fertilizer appli- 

 cation. Potash is the element most likely to be limiting to legumes 

 and other hay crops, but for highest yields phosphoric acid should be 

 added to potash. Likewise, farmers who are dejiending upon lime 

 and su]^erphosi)hate with manure that has been indifferently cared 

 for or with no manure at all are not realizing their full rc^ughage 

 l^roduction possibilities. The fact that clover has persisted in the 

 plots receiving potash is a factor that no farmer can afford to over- 

 look. (Purncll Fund) 



Top-Dressing Old Pasture Lands 



The test of fertilizers on old pastures on the Seavey farm in Strat- 

 hani was continued through 1938 without change, but was modified 



