CORN IN THE GREAT PLAINS AREA. 9 



plants is increased until in some cases it is as much as 24 inches. It 

 seems possible that this distance should be made still greater at 

 some of the stations. 



SEED-BED PREPARATION. 1 



The results from different methods have been tabulated and are 

 here presented in such a manner as to show the effect of the crop- 

 ping or cultivation and preparation of the land in the one year 

 prior to the corn planting. The tables show the effect of plowing 

 for corn both in the spring and in the fall and after both corn and 

 small grain, the effects of listing and of subsoiling where these have 

 been tried, and the effect of summer tillage. 



In the tables as presented, the yields reported in the columns 

 headed "Spring plowed, after corn" are from plat A, continuously 

 cropped to corn. This plat is shallow spring plowed and is given a 

 minimum of cultivation. 



The yields reported in the columns headed "Fall plowed, after 

 corn" are from plats continuously cropped to corn under a system 

 of fall plowing and cultivation for the conservation of water both in 

 the fall and in the spring. Fall plowing is done as early as prac- 

 ticable. It is done to a good depth, the standard being set at 8 

 inches. The ground after plowing may be worked down or left 

 rough through the winter, as seems advisable. This plat at each 

 station is generally known in this work as continuous-corn plat B. 



The yields reported after summer tillage are from two plats alter- 

 nately summer tilled and cropped to corn. One of the pair is in 

 corn and the other is summer tilled each year. These are the plats 

 generally known as C and D in the continuous-corn series. Summer 

 tillage is of the intensive type. The land lies fallow one year and 

 until planting time the following year. In so far as it is practicable 

 to do so the plat is kept free from weeds and a mulch is maintained 

 on it during the period between the time of harvesting the preceding 

 crop and the time of planting the corn. This period in some cases is 

 as long as 18 months. In some cases it is necessary to plow the land 

 more than once during this period, either to maintain a surface 

 receptive to water and that will resist blowing or to prevent the 

 growth of weeds. The long period of summer tillage, involving the 

 nonproduction of a crop for one year, together with the intensive 

 methods practiced, have made this an expensive system of treatment. 



The subsoiled plat is continuously cropped to corn. It is handled 

 the same as plat B except that at the time of plowing it is subsoiled. 

 A depth of about 14 inches is usually reached. Where the history of 

 the station is sufficiently long for it to have been accomplished, it 

 has been subsoiled two years in succession. Subsoiling was then 

 suspended for two years and then resumed. The plat is known as 

 E in the continuous-corn series. 

 87563°— Bull. 219—15 2 



