6 MASS. EXPERIMENT STATION BULLETIN 322 



its composition, a result in line with the general conclusion stated by Russell. 6 

 There was no pronounced or consistent effect of the different quantities of phos- 

 phoric acid on the percentage of this nutrient in the plant, but, as already pointed 

 out, it runs higher in all treatments in these experiments than the average re- 

 ported by Henry and Morrison. 



Table 4. — Percentage of nutrients in the dry matter of hay from 

 Experiment IB in 1933*. 



First Cutting Second Cutting 



N P,0 S K.,0 N PaO s K,0 



Nitrogen Series: 



High 1.60 0.37 1.12 2.24 0.63 1.04 



Medium 1.41 0.54 1.32 2.26 0.82 1.42 



None 1.39 0.49 1.28 2.26 0.60 1.45 



Phosphoric Acid Series: 



High 1.44 0.4.3 1.55 2.11 0.77 1.35 



Medium 1.39 0.43 1.40 2.30 0.68 1.38 



None 1.33 0.35 1.48 2.14 0.53 1.51 



Potash Series: 



Hieh 1.49 0.56 2.36 2.18 0.70 1.66 



Medium 1.39 0.51 1.62 2.20 0.80 1.53 



None 1.54 0.56 0.80 2.33 0.84 1.10 



*Dry matter and nitrogen determinations reported in this bulletin were made 

 in the Feed Control Laboratory under the direction of Philip H. Smith. Phosphoric 

 acid and potash were determined in the Fertilizer Control Laboratory under the direc- 

 tion of H. D. Haskins. 



The percentage of potash was considerably increased by fertilizer treatment. 

 According to figures given by Henry and Morrison 7 for the average potash content 

 of mixed grasses, it might be concluded that there was a luxury consumption of 

 potash in all but the check plot. However, the soil conditions under which the 

 samples reported by Henry and Morrison were grown are not known to the present 

 writer and probably not to anyone. It is possible that they were grown on potash- 

 deficient soils. In view of the increases obtained by increments of potash in this 

 experiment, it seems that this nutrient was a limiting factor. It is quite possible, 

 however, that the highest quantity of potash applied (133.4 pounds) was more 

 than was necessary for the quantity of nitrogen (50 pounds), or even of phos- 

 phoric acid, with which it was used. 



Experiment 1A was redirected in 1933. The field was plowed and reseeded. 

 Superphosphate was applied to the plowed ground and harrowed in, in amounts 

 equal to a 5-year application at the rates previously used. The experiment will 

 be continued under the previous plan of fertilization. Results to date have been 

 very similar to those of the previous period; namely, showing a response to 

 nitrogen and potash. 



Conclusions. — On soils of this type in Massachusetts, the quality and yield 

 of the forage can be improved and the life of the mowing prolonged by the use 

 of fertilizers. However, the quality of hay will deteriorate to such a point in 

 6 to 8 years that reseeding is advisable, even if fertilizers are used at fairly high 

 rates. On this and closely related soil types, which have been fertilized for a 

 number of years with phosphatic fertilizers, the best returns may be expected 

 from fertilizers high in nitrogen and potash, provided the reaction of the soil 

 is not strongly acid. A fertilizer having a ratio of N, P 2 0si and K 2 of about 

 3:1:2 is recommended. 



•Russell, E. J. Soil conditions and plant growth. Longmans, Green & Co., London. 1932. 

 'Henry, \V. A., and Morrison, F. B. Op. cil. 



