EXPERIMENT STATION BULLETINS. 



493 



Description: 



The surface soil to an average depth of 10 inches is a black clay loam, 

 quite friable due to the high content of organic matter. Occasionally in 

 the lower laj'ers of the surface soil there are yellow to brown mottlings. 

 The subsoil is a yello-wish browTi clay well mixed from 10 to 20 inches 

 with the larger silt particles. This stratum also contains grajdih brown 

 mottlings. Below 20 inches is a ^^ellowish clay quite impervious to water. 

 Occasionally a sandy clay subsoil is encountered just beneath the surface 

 soil but at 20 inches it changes into the impervious clay so tj^iical of this 

 area. Granular subsoils are also to be found just beneath the surface soil 

 but such variations are only small in extent. 



Fig. 6. — Small grains are the principal crops grown on the heavy land. 



satisfactory when the soil is properly fitted. 



Usually the yields are 



Drainage: 



This tjTDC of soil has the poorest natural drainage of any in the area and has 

 caused a demand for artificial drainage. Dredged ditches, surface field and 

 tile drains have been constructed until now this network of channels carries 

 away the water sufficiently for field crops to grow. Surface field drains are 

 probably in use more than are tile because of their inexpensive installment, 

 yet they necessitate an excessive amount of waste land in the cultivated 

 field. Tile drains for the fields are quite expensive, the heavy subsoil neces- 

 sitating the placing of laterals close together, however, they furnish the most 

 efficient means of drainage. Field results show that for greatest efficiency 

 tile lines should be placed not more than 4 rods apart. Where the sandy 

 clay or granular subsoil occur tile lines can be placed from 6 to 8 rods apart 

 and yet give efficient results. Although large amounts of money have 

 been invested in drainage systems it can be truthfully said that the lack of 

 drainage is still the first limiting factor to the most successful agriculture. 



