2 BULLETIN 320, U. S. DEPARTMENT OF AGRICULTURE. 
growing a crop of corn is the elimination of weeds, but these studies 
gave no information as to the reason for the great variation in tillage 
practices prevailing in the different sections of the country. It was 
quite natural, therefore, that the work originally undertaken should 
lead to a study of these variations in local practices, with a view to 
ascertaining the fundamental causes of existing differences, and of 
determining whether these differences were due merely to difference 
in the weeds which must be combated or to difference in economic 
conditions in the various agricultural sections of the country. 
The fact that the local practice in the preparation of the seed bed 
for corn varies as widely as do the local practices with reference to 
intertillage itself suggested that the differences in methods of inter- 
tillage were due not merely to differences in the weed population. 
It was therefore decided to extend the study so as to include local 
practices in the various agricultural regions having to do with the 
preparation of the seed bed. as well as the intertillage of. the corn 
crop. It was recognized that on the average the farmers in the dif- 
ferent agricultural areas had worked out methods of tillage which 
were at least fairly satisfactory under their conditions, and it was 
therefore believed that a study of these various methods which have 
proved profitable through long experience in various localities, and 
studies of the conditions under which they prevailed, might lead to 
the discovery of the factors which control differences in local prac- 
tice. As will be seen in the following pages, this expectation was 
fully realized. 
These studies were made in selected regions (fig. 1) which include 
in a general way all important corn-growing sections of the country. 
In selecting these regions it was the aim to choose those having con- 
ditions and methods which are representative of large areas. The 
studies herein set forth, therefore, give the reader a broad, general 
idea of the tillage methods actually employed in corn growing. Inci- 
dentally, the yields related thereto are also given. 
In all, 21 regions were covered. About 25 representative farms 
were studied in each region. A record was taken from each farmer 
visited, showing in detail his tillage practices with corn and also the 
general practices and conditions on his farm. The detailed results 
of these studies are presented in tabular form. The general infor- 
mation is first presented and then the tillage data. 
The records for each region were tabulated and the averages as 
presented in Tables I and II will give the reader a good general idea 
of farming conditions in the regions under discussion. Other tables 
are presented which relate to plowing, planting, subsoiling, and mis- 
cellaneous tillage operations. 
A table relating entirely to tillage is given for each section. This 
table shows in detail the tillage operations for corn after plowing 
