22 BULLETIN" 721, V. S. DEPARTMENT OF AGEICULTURE. 



Natural drainage. — Fortunately a large part of the tillable area 

 now devoted to sugar-beet culture has a natural drainage. This may 

 be due to one of several conditions. 



(1) The surface of the ground may be sufficiently rolling to drain 

 naturally. In some instances the slope is so great that the water 

 passes off too quickly, and consequently the land is unproductive 

 because of excessive surface drainage. 



(2) Certain areas have a natural drainage due to a sloping sub- 

 soil. As previously noted, some areas have a subsoil that is more 

 or less impervious to water. If the impervious subsoil is sloping, 

 the water falling upon the surface soil will pass through to the sub- 

 soil and gradually disappear along the sloping subsoil. In this case 

 natural drainage is satisfactory and needs no particular attention 

 provided the impervious subsoil is not too near or too far from the 

 surface, and provided further that there is a natural outlet, so that 

 the water will not eventually back up along the slope or incline of 

 the subsoil, 



(3) The natural drainage accomplished by means of a porous 

 subsoil has been already noted. There are localities in which the 

 subsoil is so porous that it is almost impossible to hold sufficient 

 water in the seed and root beds to produce a crop of beets. There 

 are therefore localities in which the natural drainage is of such a 

 nature, either through a lack of of moisture or through an excess of 

 water, that natural drainage constitutes a limiting factor in sugar- 

 beet production. 



On the other hand, there are areas and fields in which artificial 

 drainage must be practiced in order to put the soil in condition for 

 sugar-beet production. Several systems of artificial drainage are 

 in general use. 



The open ditch. — An open ditch constitutes one of the methods by 

 which this limiting factor of excessive moisture is removed. It is 

 the least expensive method of providing artificial drainage, especially 

 from the standpoint of labor and material involved. However, 

 considerable tillable ground is lost through the construction of open 

 ditches. This loss is due to the space occupied by the ditch and by 

 the ditch bank. In constructing an open ditch these points should 

 be kept in mind, so that the least possible loss of tillable area will 

 result. The open ditch constitutes a barrier which can not readily 

 be crossed in the usual farming operations. It is advisable, wherever 

 practicable, to construct these ditches along the edges of the field, 

 along roadsides, and in places where they will interfere least 

 with the farming operations. Sometimes it is necessary to cross 

 the fields with ditches in order to drain the soil properly; in such 

 cases the fields and ditches should be so laid out that the ditches 



