Revegetation of Soil 261 



Riimex acetoscUa as it may not reach the root stocks which are at vary- 

 ing distances below the surface. The soil recovers from the effect of 

 the salt in a comparatively short time or if plowed up and cultivated in 

 the spring- after being treated with salt in the fall, vegetation of the 

 desired kind when planted will grow uninterruptedly. 



Subsequently to the treatment with salt on the ground here referred 

 to — this plot was spaded and some time later was covered with 

 clay. This clay was removed from under a large building which had 

 stood over it for 19 years. Tests made on this clay soil showed that 

 it contained no seeds of plants that would grov/. The clay was deposited 

 in April on the ground above mentioned, in a few places two feet deep, 

 but in most places much less. The greatest depth of two feet happened 

 to be over the southeast portion toward which drainage was most ac- 

 tive. The swale above mentioned was preserved so as to provide drain- 

 age to the southeast as the slope of the land in general required. 



All plants having been killed by the salt treatment, the forms to 

 be enumerated later, which after a time appeared on this area, were 

 carried in by various agencies, especially the wind. Some put in their 

 appearance early, others not until considerably later, and most of them 

 when once started grew fairly well from the first. One thing that favored 

 the new in-coming forms of plants in this area was the rather perfect 

 retention of the moisture in this clay soil. In dryer parts of the sea- 

 son this was particularly noticeable, especially when a comparison was 

 made with other plants of the same kind in the same vicinity growing 

 on soil which was more quickly deprived of its water by more thorough 

 drainage. 



Other forms appearing in this area plainly showed that the con- 

 ditions were unsuited to their welfare since their growth was abnormal. 

 Some of the larger plants gained entrance through the agency of water 

 or animals, as in the case of Zea Mays. 



The drainage was in the direction of this area for more than 100 

 feet above it, a circumstance which caused a considerable amount of 

 water to cross this area to the southeast during heavy rains, and to 

 spread out over it in the lower parts. As usual, many of the plants 

 whose seeds were light and carried by the v^ind did not grow close to 

 the area, but were to be found some distance away. 



Plants started about the center of the area in question^ showing 

 that they had not simply broken through the thinner new soil at the 

 edges, even if the former plants had not previously been killed with 

 the salt application above mentioned. The spading of the area had 

 turned the old soil with its salted surface deeply under. The only op- 

 portunity for plants to again grow on this area was for those forms 

 which are generally disseminated by the usual agencies to find their 

 way to the surface of the new soil. An area near this which was 

 treated heavily with salt the preceding season and later plowed under, 

 raised the following season a heavy crop of Zea Mai/.'^ and other plants. 



Woods' mentions the fact that common salt is of value when applied 



•'■ Woods, Alfred F. Tho Relation of Nutrition to the Health of Plants, Yearbooit 

 of the Department of Agriculture, 1901, p. 165. 



