12 MASS. EXPERIMENT STATION BULLETIN 306 



3. In the Amherst experiments nitrogen was more effective than an\- other 

 single element, but was not so effective as the best combination of mineral elements. 

 Nitrogen and minerals were mutually helpful in increasing yields. 



4. Certain combinations of minerals, especially those containing limestone 

 and (or) potassium, were effective in increasing the proportion of white clover 

 in the vegetation. In some cases, particularly with heavy applications, the 

 addition of phosphorus further increased the proportion of clover. 



5. The previously noted toxic effect of nitrate of soda for haircap moss 

 (Polytrichum commune L.) was corroborated by the Worcester experiments, and 

 it was observed that a small, yellowish green moss {Funaria hygrometrica (L.) 

 Sibth.) grew especialh' well on bare spots of limed soils or heavih' phosphated 

 soils. 



6. An attempt was made to correlate phosphorus response with certain 

 physical and chemical characteristics of soils. Readily available phosphorus and 

 the fixing capacity of the soil for phosphorus were factors. Little direct relation 

 was noted between phosphorus response and colloidal content, organic matter, 

 and loss on ignition. 



7. It was shown by chemical analysis that large amounts of applied phosphates 

 were both "positionally" and "chemically" fixed in the pasture soils studied. 



8. It was shown that many Massachusetts soils contain comparatively large 

 potential supplies of native phosphorus, but in a form only slightly available. 



9. Further, it was shown that even if from heavy fertilization large amounts 

 of readih' available phosphorus were present in the soil, other nutrient deficiencies 

 may limit the growth of pasture plants. 



10. Lime increased the amount of readily available phosphorus in soils treated 

 with phosphates. There was some evidence that nitrate of soda, also, increased 

 the availability of applied phosphates. 



References 



1. Beaumont, A. B. Experiments with permanent pastures. Mass. Agr. Expt. 



Sta. Bui. 281 (1932.) 



2. Brown, B. A. Pasture investigations (Fourth Report). Conn. (Storrs) 



Agr. Expt. Sta. Bui. 189 (1933). 



3. Lindsey, J. B. Compilation of analyses. Mass. Agr. Expt. Sta. Spec. 



Bui. (Nov. 1919). 



4. Midgeley, A. R. The movement and fi.xation of phosphates in relation 

 » to permanent pasture fertilization. Jour. Amer. Soc. Agron. 23: 788-799 



(1931). 



5. — — and Weiser, \'. L. Skill in using superphosphate. Eastern States 



Cooperator 9 (11): 4-5 (Nov. 1933). 



6. Truog, Emil. The determination of readily available phosphorus in soils. 



Jour. Amer. Soc. Agron. 22:874-882 (1930). 



7. Weiser, V. L. Fixation and penetration of phosphates in Vermont soils. 



Vt. Agr. Expt. Sta. Bui. 356 (1933). 



Publication of this Document Approved by Commission on Ax).ministration and Finance 

 4M-2-':54. No. 484. 



