10 N. H. Agr. Experiment Station [Bulletin 289 



to large areas of marginal lands now in agricultural use and sustains the 

 significance of sound land-use policies. (//. C. Grinnell, H. C. Woodzvorth, 

 E. H. Rincar, L. A. Dougherty and A. J. Hangas — Purnell and U.S.D.A. 

 Funds. ) 



Soil Fertility Studies 



Soil fertility experiments carried on over a period of years include : 

 An experiment with hay on neglected haylands, an experiment with legumes 

 on neglected hay lands, an experiment with potatoes in a three-year rota- 

 tion, a fertilizer experiment with legumes in the Connecticut Valley, experi- 

 ments with top-dressing old pastures, and a soil survey of New Hampshire. 



An Experimont zmth Hay on Neglected Hay Lands. A field on the 

 Whenal farm in Greenland was used for this work, and a catch of timothy 

 was secured in 1934 after two unsuccessful attempts. The plots were top- 

 dressed in 1935 and harvested in July. The treatments applied were nitro- 

 gen alone ; phosphorus and potash ; and nitrogen, phosphorus and potash. 

 The difi"erences for all three treatments were positive and significant, show- 

 ing increases respectively over the check of 1,291, 704 and 2,213 lbs. respect- 

 ively per acre. The efifect of the phosphorus-potash treatment in stimulating 

 grass on these plots is rather striking. In the original trials superphosphate 

 alone failed to give a significant response after the first season. In 1934 

 when the grass was seeded, a uniform fertilizer treatment was applied to 

 all plots to iron out any possible difiference in stand due to this factor. The 

 combination of superphosphate and potash appears to cause more stimula- 

 tion to timothy growth than superphosphate alone, either because of the 

 efifect of the potash itself or on account of the combination of the two ele- 

 ments. 



Experiments with Legumes on Neglected Hay Lands. Forty-eight 

 alfalfa plots on the Whenal farm were again harvested twice in 1935 under 

 dififerent fertilizer and lime treatments. The plots in the experiment in- 

 cluded those which had received one ton of lime in 1933, those receiving 

 no lime that year, those receiving 100 pounds nitrate of soda annually, 500 

 pounds of superphosphate annually, 150 pounds of muriate potash annu- 

 ally, and 20 tons of manure in 1926. 



While good alfalfa w^as produced during the first course of the experi- 

 ment with two tons of lime, it is apparent that the extra lime applied in 1933 

 is of benefit to the alfalfa when the check plot with lime is compared to the 

 check minus lime. Nitrogen, phosphorus, and potash all increased the yield 

 of alfalfa in ascending order. 



Among the plots that had no additional lime in 1933, those that had four 

 tons of lime in 1926 outyielded plots that had but two tons of lime in the 

 same year by almost 1,100 pounds per acre. The plots receiving complete 

 fertilizer yielded more than 4^ tons of hay per acre in 1935, even though 

 no manure nor lime have been added since 1926. 



A sub-project of the legume experiment located on the Ireland farm, 

 which is adjacent to the Whenal farm, is an efifort to grow alfalfa largely 

 without manure but with moderate to heavy applications of fertilizer varia- 

 bles. The stand secured in 1934 was harvested twice in 1935. Prior to 

 seeding, one ton of lime was applied to all save three plots and also those 

 which are embraced in the lime test. The alfalfa was seeded in 1934 with a 



