No. 7. DEPARTMENT OF AGRICULTURE. 499 



method most generally followed as to drain by ditching with or 

 without the use of a subordinate system of tile drains. The water 

 relations of these soils suggest and the extensive experience of 

 German farmers in the management of the moor lands which form 

 so important a portion of the area of northern Germany, have proven 

 that the drainage of cumulose soils require plans different from those 

 required in the case of mineral soils. In general, the water-table 

 should not be more than twenty to twenty-eight inches below the 

 surface and, where tile drains are used, the lateral ditches may 

 be spaced so as to have an interval of sixty or ninety feet ; and it is 

 particularly important that the ditches be provided with dams, so 

 that the drainage water may be dammed back to make it possible to 

 hold the water in the soil during dry seasons. Irrigation systems 

 also have been found especially advantageous for these lands in such 

 seasons. Many of the peat beds of Pennsylvania are so situated that 

 their drainage can be accomplished quite simply. There are others 

 however, whose water level is determined by that of a large open body 

 of water near whose outlet the peat bed is located. In the latter case 

 they do not promise convenient control of the water relations, except 

 where the peat beds lie at a level considerably above that of the lake. 



As the water is drained away, the air enters these lands and begins 

 very promptly their improvement by its oxidation process. A year 

 or more is, however, often required to promote sufficiently the con- 

 version of these soils by oxidation to fit them for cropping. 



The process of oxidation is not in all cases productive of entirely 

 beneficial changes in the land. This is particularly the case where 

 the latter contains, in considerable quantities, iron pyrites, bisulphate 

 of iron, for when pyrites are brought into contact with air, they 

 oxidize and form sulphuric acid and oxyhydrates of iron. In lands 

 still holding sulphuric acid, it works marked injury to crops started 

 upon the soil and the removal of this acid by drainage is very slow. 

 It will be recalled that these lands hold relatively small amounts of 

 mineral matter such as might combine with the sulphuric acid to 

 form harmless compounds. 



The general method of remedying this defect is the addition of 

 lime or of carbonate of lime. The range of recorded experience in the 

 application of lime to these soils is too small to warrant the formula- 

 tion of any rules as to the quantities in which they should be applied ; 

 in general, however, the dressings are relatively abundant. The 

 line not only neutralizes the sulphuric acid and decomposes any 

 sulphate present in harmful compounds, but, also like the air, 

 changes the character and proportions of the lower organisms living 

 in these soils and working over their materials. Some cultivators 

 have found that the ashes left by the burning of the weeds and other 

 waste growths upon the surface of the land, yielded sufficient 

 alkaline material to make possible the growing of satisfactory crops 

 on peat beds without the use of lime or of similar alkaline amend- 

 ment during the first year. In such cases, the burning was conducted 

 in the early spring while the soil was sufficiently wet to prevent the 

 fire from extending downward into the peat bed and thus destroying 

 it and liberating a large amount of available nitrogen. 



It has already been pointed out that the plants from whose decay 

 these peat beds are formed, are usually poor in phosphoric acid and 

 potash, particularly the latter. It is readily understood, there-^ 



