4 MASS. EXPERIMENT STATION BULLETIN 444 



Two papers giving the results of this work have been published. ^ 

 The annual fertilizer applications over a period of 45 years have made small 

 changes in the available nutrients in the soil and subsoil (Table 1). Phosphorus 

 may be slightly higher where applied on the limed plots. Potash is extremely 

 low where none has been added and very low even on the plots that have had 

 annual applications. 



Calcium is extremely low on the unlimed ends of the plots. The limed ends 

 show much more calcium and a pH value near neutrality, while the pH of the 

 unlimed area is generally less than 5 for the surface soil and over 5 for the subsoil. 

 Probably the lime used was usually, if not always, a dolomitic limestone. This 

 would account for the fact that the magnesium was uniformly low on the unlimed 

 plots and uniformly low to medium on the limed plots. 



Table 2. — Available Nutrients Beneath Good And Poor Trees, 1936. 



* These figures are based on Morgan's test and give only estimated relative amounts of available 

 nutrients per acre. 



The presence of extremely poor trees on some of the plots was frequently 

 observed and there seemed to be no obvious cause of their poor growth. In 1936 

 six poor trees on as manj' plots were selected and each paired with a good tree 

 on the same plot. Table 2 shows the trunk diameter of the good and poor trees, 

 the pH,and the exchangeable phosphorus, potassium, magnesium and calcium in 

 the soils which the roots of the trees exploited. It is evident that the soil factors 

 measured show no relationship to the growth of the trees. 



The response of the fruit plants to the abnormal fertilizer program on these 

 plots was measured by the trunk diameter and by shoot growth. Because the 

 plots were narrow, trees could not be grown for many years. Two lots were 

 grown for eight years each. The average trunk diameter of the two plantings 

 of apple trees and weights of the peach trees when they were removed are shown 

 in Table 3. The growth of the Mcintosh should be the most dependable because 

 there were eight trees of exactly the same diameter planted on each plot. There 

 were only two trees per plot of Wealthy. 



There were four scattered check plots that had received no fertilizer whatever 

 since 1889. The differences in growth on these plots are difficult to explain and 

 give warning of the care necessary in ascribing differences of growth on the 

 fertilized plots to the various fertilizers applied. The use of lime on these un- 

 fertilized plots seems to have been harmful rather than beneficial. 



'Shaw, J. K. Some Unusual Results in Fertilizing Fruit Plants. Proc. Amer. Soc. for Hort . 



Sci. 21:281. 1924. 

 Shaw, J. K. Further Evidence of a Potash-Lime Deficiency in a Sandy Loam Soil. Proc. Amer 



Soc. for Hort. Sci. 27:12. 1930. 



