22 BULLETIN 218, U. S. DEPARTMENT OF AGRICULTURE. 



Spring plowing has given markedly better results than fall plowing 

 in two of the three years. Disked corn ground and disked potato 

 ground have been about equal to spring-plowed land in crop-producing 

 power. Summer tillage has failed at this station to be productive of 

 the increases in yields that have attended its use at the other stations 

 in the State. In 1914 this may have been due to the fact that the 

 fallows were allowed to become weedy in 1913. 



The lowest yields have followed the breaking of sod and the use of 

 green manure. 



When methods are considered in broad groups and production is 

 combined with cost, as in the second part of Table X, the data become 

 more instructive. This shows that green manuring, the most expen- 

 sive method, has been at the same time the least productive. Instead 

 of providing a profit it has been a source of the greatest loss, $7.70 

 per acre. The disking of potato or corn ground is the least expensive 

 preparation and has been the most productive of the general groups 

 in bushels per acre, as well as in dollars per acre. It shows an average 

 profit of $6*.03. 



Spring plowing and fall plowing both show profit, the greater profit 

 being from the spring plowing. 



Summer tillage, with its high production cost, gave only slightly 

 greater yields and has not been able to pay for the labor and the use 

 of the land. It is debited with an average loss of $1.62 per acre. 



While the general trend of these results is reliable, it is very likely 

 that their detail will be subject to change by the extension of the 

 record. 



BELLE FOURCHE FIELD STATION. 



The field-station farm near Newell, S. Dak., on the Belle Fourche 

 Reclamation Project, is located on a heavy gumbo clay soil. The 

 soil is derived from decomposition of Pierre shale. From the soil at 

 the surface there is a rapid change to broken but undecomposed shale. 

 Near the bottom of the second foot is a comparatively impervious 

 layer of soil. The first foot and at least a part of the second foot 

 carry a large supply of available water. It is probable that but little 

 use is made of either water or soil below the first 2 feet. In spite of 

 the heavy soil and the large supply of water that can be obtained by 

 the plant from that portion of it near the surface, the shallowness of 

 feeding reduces the quantity of water that can be carried in the soil 

 to about one-half of that available in deeper soils. The result of 

 this is shown in the yields. 



The results of six years are shown in Table XI. In one year pro- 

 duction was heavy, in two years it was fair, in one it was very poor, 

 and in 1911 the drought was so extreme that no method was able to 

 overcome it. The preceding year had been so dry that practically 

 no water was stored in the soil by any method. 



