234 



carries the iron upward and in many cases cements the sand grains in the 

 soil at the usual height of the ground water level in such a way that often in 

 laying a drain, a hard, stone-like, red soil is found. By laying drains cor- 

 rectly and systematically, with the horizontal drains intersected at right 

 angles by the absorbing drains, the latter having at least a depth of 1.2 m. 

 and the distance between every two drains being kept 10 times the depth, 

 the level of the ground water will be lowered to the depth of the drain and 

 no more iron will be carried to the soil above the pipes. The iron already 

 present in the soil will be dissolved by t^e atmospheric precipitation and led 

 to the dainage pipes or it will remain in the soil as the non-injurious oxid." 



Working of the soil. Where there is no need of carrying away 

 excessive water, furrowing and deep plowing, instead of drainage, will often 

 serve the same end. In this care must be exercised if, with fertile, friable 

 soil, there is a prospect of bringing a dead subsoil to the upper surface by 

 the furrowing or plowing. In addition to fertilizing each time, the gradual 

 deepening of the friable soil should take place at least over a period of 

 several years. Since, with the deepening of the friable soil, the root surface 

 becomes extended and, accordingly, an increased harvest takes place with a 

 greater utilization of the soil, an increased supply of manure is demanded 

 with the increasing- loosening of the soil. 



In soils inclined to crust, but otherwise not unfavorably constituted 

 physically, hoeing and hilling suffice for increasing the soil aeration. Thib 

 cultivation, which can scarcely be sufficiently recommended to the agricul- 

 turist and the gardener, and which can be used in any soil, regulates the soil 

 moisture. 



Some good, practical experiences as to the advantages of loosening the 

 soil, may be found in the reports of the German Agricultural Society's 

 special committee for the protection of plants (Landwirtschaft-Gesell- 

 schaft). We will cite a single example which is supported by comparative 

 experimental cultures. In SkoUmen^ (East Prussia) Mentzel divided into 

 two parts a field planted with mixed Swedish wheat, Epp wheat and Kas- 

 tromer wheat, and kept one half of it loose by harrowing after every rain, — 

 1. e. by working with the narrow bladed cultivator, — but did not work the 

 other half. Although its soil was better, the latter half yielded only 2160 

 kg. per acre, the former, however, 2650 kg. 



A green manure fertilizer turned over deep in light soils and super- 

 ficially in heavy soils, acts in the same way as this loosening of the soil sur- 

 face. By means of this green manure the capillary raising of the water 

 from the underlyng soil layers especially is interrupted". On the one hand, 

 the moisture is thus retained in the deeper layers of the lighter soil ; on the 

 other hand, in heavy, wet soils, a well aerated, friable surface is formed so 



1 Jahresb. d. Sond.-Aussch. f. Pflanzenschutz. Arb. d. Deutsch. Landwirtsch. 

 Ges., Part 107, 1905, p. 64. 



- King-, F. H., Tenth Annual Report of the Agric. Exper. Stat, of -Wisconsin, 1884 

 p. 194. 



