730 EXPERIMENT STATION RECORD. 



ditches commonly practiced. Terracing is recommended as "the most, 

 and in fact the only, reliable means of preventing injurious surface 

 washing upon cultivated hillsides," and directions are given for the 

 construction of terraces. 



The value of Bermuda grass in preventing washing of the soil and 

 of green manuring in restoring the fertility of washed soil is briefly 

 discussed. 



"By a judicious rotation of crops, alternating nitrogen collectors and nitrogen 

 consumers and clean crops with those which supply humus, rapid improvement in 

 both the mechanical condition and t lie chemical contents of soils may he wrought. 

 Growing renovating crops affords the only practicable means of broadcast manuring 

 on a large scale in a country in which so few stock are kept as in the cotton belt. 

 In our climate we can grow two renovating crops — peas and crimson clover — in one 

 year, li' peas are planted in the whole corn crop and follow small grain, renovation 

 will be both certain and rapid." 



The value of plant roots as tillers of the soil, R. H. Elliot (Jour. 

 Roy. Agr. Soe. England, 3. ser., 8 (1897), pt. Ill, pp. 407-477). — In this 

 paper the author discusses the action of roots in disintegrating the 

 soil, their effect on the subsoil, and their direct manurial action as they 

 decay. 



The value of roots in maintaining the physical condition of the soil 

 is pointed out. Attention is called to the fact that when land is first 

 plowed up, either from the original turf or an old grass land, the soil 

 is in the same condition as new forest soil, owing to the numerous roots 

 which penetrate it, and that the decline of its fertility is not apparent 

 until this matter has become exhausted, causing the soil to solidify and 

 to become tough and shallow, the physical conditions having been so 

 changed that the land has become a poor medium for plant growth. 



In connection with the discussion on the action of roots as subsoiling 

 agents, several examples are given as illustrations. On his own place 

 the author found that chicory penetrated apparently with little diffi- 

 culty a hardpan about 1 ft. thick and II in. below the surface. The 

 roots of buruet and kidney vetch had gone about HO in., but the alfalfa 

 roots only from 8 to 10 in. It was observed that the strong roots of 

 chicory and burnet had disintegrated the hardpan s with their laterals 

 or off shoots. The author considers cropping and drainage the means 

 by which humus is partly consumed and partly washed out of the soil 

 and the protection of a turf composed of deep and strong rooting plants 

 which at once disintegrate the soil and till it to its lowest possible 

 depth the means by which humus can be most profitably restored. By 

 comparing the results obtained from 2 fields after each field had been 

 sown with a mixture of grass, clovers, and deep rooting plants like 

 chicory and burnet, it is shown that an inferior soil, with no manure 

 other than that of a good turf, and which had never been dressed with 

 barnyard manure, is capable of approximating in yield the best land 

 which has been aided by barnyard manure from time immemorial. 



