PHOSPHATES IN MASSACHUSETTS AGRICULTURE. 155 



30 and 44 per cent., respectively; they were highest on the South Carolina 

 rock, 87 per cent.; the average for all the natural rock phosphates was 

 63 per cent.; for the no-phosphate plots it was 71 per cent. The propor- 

 tions of soft corn on the different plots were in my judgment affected by 

 the physical differences in the soil of the plots, but there can be no doubt 

 as to the general effect. 



In 1914 the summer temperature was below the normal, but the crop 

 was cut and shocked before frost. There was, however, some soft corn. 

 The percentages were: no-phosphate plots, 12; natural rock phosphate 

 plots, 9; slag, bone meal and soluble phosphate plots, 5. 



5. The effect of the more soluble and available phosphates in pro- 

 moting maturity is strikingly apparent, also, in the case of the onion 

 crop grown in this series of experiments. The presence of scallions in- 

 dicates imperfect maturity. Two onion crops have been grown in this 

 experiment, — 1901 and 1902. Neither gave a satisfactory yield, and 

 the proportion of scalhons on all plots was much larger than normal, 

 in my judgment, due in part to the fact that the field is not sufficiently 

 heavily fertilized for the crop, and in part to the unfavorable physical 

 characteristics which, as already pointed out, vary considerably on the 

 different plots. The greater proportion of scallions on the rock phosphates 

 shown in the following table is the more significant for the reason that 

 in the plots where these were used the physical conditions were more 

 favorable than on the other plots. The steamed bone meal, dissolved 

 bone meal and acid phosphate plots have not been used in computing the 

 averages shown because of the very unfavorable soil texture of these plots 

 for the onion. The fact that the acid phosphate had been applied in 

 only about one-half the amount needed to furnish equal phosphoric acid 

 constituted a second reason for the omission of tliis plot. 



Proportion of Scallions in Onion Crop (Per Cent, of Total). 



No-Phosphate 

 Plots. 



Dissolved Bone 



Black, Slag and 



Bone Meal. 



Natural Rock 

 Phosphates. 



1901, 

 1902, 



6. The relation between hard and soft heads in the cabbage crops 

 grown in these experiments points also to the conclusion that the more 

 soluble and available phosphates promote rapid early growth and ma- 

 turity. In all cases there have been more soft heads on the no-phosphate 

 and the rock phosphate plots than on the others. The slag plot has 

 been among the best in the quaUty, sohdity and weight of the crop. Full 

 details have been pubUshed and figures will not now be given. ^ 



1 For relative weights, soft and hard heads, see sixteenth annual report. Hatch Experiment 

 Station, p. 136. For crop in other years see eleventh and twentieth annual reports. 



