198 



SCIENCE 



[N. S. Vol. XLVII. No. 120 



corn and sorglimn without producing a satis- 

 factory crop, and, in 1912, the first year it was 

 visited by the authors, the crop of corn was not 

 worth gathering. The next spring the west 

 half of the field was seeded to alfalfa alone, 

 but the east half to oats with alfalfa. As at 

 both ends the field extended beyond the cut so 

 as to include undisturbed ordinary black sur- 

 face soil there was a chance to compare the 

 growth of the two crops on the exposed yel- 

 low subsoil with that on ordinary surface soil. 

 The whole of each half had been seeded by the 

 same man, at the same time and with the 

 same seed. Whan visited in July the alfalfa 

 on both was found fully inoculated; on the 

 portion seeded without nurse crop it was prac- 

 tically as good as on the black surface soil, but 

 on the other half of the field marked differ- 

 ences were shown by subsoil and surface soil. 

 The oats on the former were yellowish-green 

 in color, with short straw and poorly filled 

 heads, while on the latter they were dark 

 green and tall with well filled heads; the al- 

 falfa on the exposed subsoil showed a good 

 stand and the plants were almost as large as 

 where seeded without a nurse crop, but on the 

 surface soil they were few in number and 

 small, evidently having succumbed to the oats 

 in competition for moisture. 



In his communication Dr. Lipman appears 

 to have made the mistake of considering the 

 l^ebraska subsoils involved in our field ob- 

 servations as semi-arid. We regard them as 

 strictly humid as pointed out in earlier papers 

 of the series. Further, he considers them rep- 

 resentative of all Nebraska subsoils; a view 

 for which there appears no justification. 

 They represent only the loess subsoils of east- 

 ern Nebraska. He is in error in stating that 

 we claim legumes will not grow on subsoils of 

 humid regions. On the contrary, while we 

 pointed out that the " rawness " of humid sub- 

 soils toward legumes as well as non-legumes is 

 generally assumed by soil investigators, the 

 burden of our paper was to prove that in the 

 case of the loess subsoils of the humid portion 

 of eastern Nebraska there was no rawness 

 toward inoculated legumes. We offered no 

 evidence and made no claims as to the raw- 



ness of any subsoils other than those of the 

 loess region of Nebraska. A forthcoming 

 paper by Mr. P. M. Harmer, of this labora- 

 tory, will deal with the growth of alfalfa on 

 subsoils from widely separated points in 

 Minnesota, a humid state. 



In one of his last articles (1912) Hilgard 

 mentioned a heap of subsoil at Berkeley, ex- 

 cavated from a depth of over twelve feet, 

 which had become covered with a thick stand 

 of grasses and weeds of all kinds. Lipman 

 suggests that this may have consisted of sur- 

 face material which had been buried in previ- 

 ous cutting operations. A very similar, but 

 evidently distinct example is furnished in a 

 letter which the writer received from Hilgard 

 in May, 1907. 



Last winter a foot-baU field was excavated here 

 (Berkeley) to a depth of 16 feet at one end, and 

 a hank of yellow-brown clay was thrown up on the 

 surface 6 feet high. Now I find this clay almost 

 covered with a growth of the usual weeds whose 

 seeds were blown there by the high winds. Sherry 

 and dock are most luxuriant, but oats, barley and 

 ray grass are also as common as on the surface 

 soil adjacent. I remember a similar clay pile at 

 my old home in Illinois where nothing ever grew in 

 ten years after it was dug out of the cellar. 



Doubtless there are many in California and 

 in other arid lands who have valuable obser- 

 vations upon the subject which should be pub- 

 lished. No one appreciated the value of such 

 more than did Hilgard, who, in the letter 

 quoted above, inquiring as to the growth of 

 plants on exposed subsoils in western Ne- 

 braska, wrote: 



Such observations as that are just as valuable as 

 if a special expedition had been sent out by the 

 Carnegie Institute. Please do not forget to have 

 them gathered up while your state is young, for 

 they will be much more difiicult latter. Field ob- 

 servations under normal conditions by experienced 

 investigators are far more cogent than any num- 

 ber of vegetation or pot experiments. 



It is to be hoped that any extant records of 

 such observations on California and other arid 

 subsoils will soon be published. 



F. J. Alway 



UNrVEESITT OF MINNESOTA 



