2(i MASS. EXPERIMENT STATION Bl'LLETIN 281 



of its proximity to the barn, to a water supply, to other pastures which are pro- 

 ductive, or for any other reason, may well receive more attention than one not so 

 well situated. 



The experiments on the Tillson and Hobart Farms together with some un- 

 published results from ^^'orcester County experiments lead to the conclusion 

 that over a period of years the best results in the top-dressing of Massachusetts 

 upland pastures may be expected from an initial application of lime supplemented 

 with a phosphate, a potash salt, and a nitrogenous fertilizer. It is believed that 

 under our typical soil conditions 1 ton of ground limestone (or three-fourths as 

 much hydrated lime) every 6 years, 480 pounds of 16 per cent superphosphate 

 and 160 pounds of muriate of potash every 3 years, and 160-320 pounds of nitrate 

 of soda (or its equivalent in other available form) annually will be sufficient for 

 most demands. At present (early 1932) prices the initial cost of the mineral ap- 

 plication is $14.33 per acre. If the cost be prorated over the number of years 

 between applications, the annual cost becomes .13.69 plus a small interest charge 

 per year. The cost of 160 pounds of nitrate of soda is .13.94. Therefore, the total 

 annual cost as figured is .17.63 per acre. While the best return from nitrogen 

 may be expected when it is used on fair to good sods, the fact that the response 

 to nitrogen generally comes sooner than that to minerals, makes it seem ad- 

 visable to apply nitrogen from the beginning of the improvement program. 



If it were possible to predict early enough in the season whether a given year 

 was to be a "clover year," most or all the nitrogen might be omitted for the sake 

 of economy; and in off years for clover, the nitrogen ration might well be increased 

 50 or 100 per cent. This procedure appears feasible for those farmers who have 

 enough early pasture and are more in need of mid- and late-summer pasture. 

 Under such circumstances a decision as to the nitrogen application could be de- 

 ferred until the early part of June. It should be noted, however, that some 

 fertilizers, especially nitrate of soda, are poisonous to cattle, and a rain or several 

 d tys should intervene between the application of fertilizers and the return of the 

 cattle. 



These experiments are not capal^le of a .strict monetary interpretation because 

 of the many variable and uncontrollable factors which have contributed to the 

 results. Indeed, such an interpretation is always open to misconstruction and 

 abuse. Further, there is such a wide variation in individual ability, that what 

 one farmer may turn into success may prove a flat failure for another. However, 

 it is believed that an average annual investment of $5 to $10 in lime and fertilizer 

 for Massachusetts upland pastures will j-ield a fair return on the investment. 

 After all, the agronomic aspects of the question are fairly clear, and the rest of 

 it is largely a matter of business judgment. Fluctuation in prices of fertilizers 

 and of milk will largely determine the wisdom of the investment. 



From our data we have no evidence that smaller amounts of f(>rtilizer than 

 those mentioned cannot be used to advantage, nor that a better distril)ution 

 may not be possi])le. It is quite likely that it may be more advantageous to apply 

 lime in smaller amounts but more frequently. Furthermore, from the experiments 

 reported we have no evidence that certain other carriers of nitrogen, phosphoric 

 acid, and potash, different from those used in our experiments, cannot under 

 some circumstances be advantageously substituted for them. 



In this connection it should be remembered that not only maj' more feed 

 and more protein per acre be expected from top-dressing pastures, but also a 

 feed richer in calcium and phosphorus may be expected. Thus, the health of 

 the animals may be safeguarded or improved by the use of mineral fertilizers. 



