212 EXPERIMENT STATION RECORD. [Vol.40 



went deeper as the water table was lowered. It is pointed out that the plants 

 were thus enabled to obtain the necessary moisture supply even in time of 

 drought. On the moss soil the plants developed a shallow root system regard- 

 less of the water table, which placed them at a disadvantage during dry periods. 

 The clovers were not successful on the bog soil, and hence the use of grasses 

 on this soil type is recommended. The results indicated that the best growth 

 of grass on the bog soil may be expected with the water table about 60 cm. (2 ft.) 

 below the soil surface. On the moss soil the grasses as compared with the 

 clovers made the poorer growth, and it is stated that on this soil type, as 

 shown by the experiment, the water table should not be deeper than 40 cm. 

 under the surface of the soil. 



Of the grasses, orchard grass (Dacti/lis plomcrata) on the bog soil was the 

 only species thriving best when the water table was lowest. Meadow foxtail 

 (Alopccunus pratensia) and meadow fescue (Festuca pratenHs) gave the best 

 yields when the water table stood about 60 cm. below the surface of the soil. 

 Timothy {Phleum proteose) and canary grass {Phalarit arundinocea) proved 

 more indifferent in this regard. Orchard grass even on the moss soil made 

 the best growth with the water table at the greater depth, but all other grasses 

 gave the best returns with the water table standing nearest the surface of this 

 soil type. On both kinds of soil the clovers grew best when the water table 

 stood high. Among the grasses, meadow foxtail and orchard grass were most 

 successful on the moss soil, while on the bog soil all grasses developed equally 

 well when the soil moisture conditions were favorable. Timothy, orchard grass. 

 and meadow fescue reached their highest yields the first or Becond year. While 

 meadow fescue and timothy lost in productive power from year to year the 

 reduction in yield of orchard grass was unimportant. Meadow foxtail and 

 canary grass contributed little to the yield during the first years but continued 

 each year to Increase in importance, and were as a rule the dominating species 

 toward the last. 



H. Osvald, in addition to describing his own experiments on the development 

 of root systems and reporting his results, briefly reviews the methods em- 

 ployed and the results Obtained in earlier work of this nature by other in- 

 vestigators. A list of 52 references on the subject is given. 



The results indicated that the nature of the soil is of decided Importance in 

 relation to soil moisture and root development in different soil strata. This 

 importance, it is pointed out. depends upon the degree of capillarity which de- 

 termines the upward movement of soil moisture and the retention of precipi- 

 tation. The moss soils are considered equally efficient with the bog soils in 

 retaining the moisture derived from SQOW or rain, but as standing far behind 

 this type of soils in capillary power. It is believed that, as the roots are not 

 likely to reach the ground water when this stands low, draining moss soils to 

 too great a depth exposes them to drought injury, especially in view of the Cad 

 that these soils in comparison with bog soils must hold relatively more moisture 

 to supply the growing plants. 



The relationship between absorption and coagulation with respect to the 

 mineral colloids of the soil, A. de Domi.mcis I 16*. in Intermit. Inst. Agr, 

 [Rome], Intcnuit. Rev. Sci. and Praot. Apr., 9 (1918), No. 9, /*/>. 10S6, 10S7).— 

 This article reports the results of a continuation of investigations previously 

 noted (E. S. It.. .'?">. p. S13), the general plan of the previous work being "to 

 determine the relationship between that which is absorbed and that which Is 

 coagulated, considering that each time a saline solution acts on a colloidal 

 solution -the resulting coagulation always determines a lowering of the conceu 

 tration of one of the electrolytic constituents of the dissolved salt." 



