Club of bologna proceedings

Table 
1
. The crop with the highest use of conservation 
tillage (includes no-till, ridge-till and mulch-till) is 
for double-cropped soybeans, 74.2%. Double-
cropped soybeans are usually grown following 
spring-seeded small grain, where the grain 
residue is left on the soil surface and the 
soybeans are directly planted into the soil. The 
crop with the least use of conservation tillage is 
cotton, although there continues to be a steady 
increase in the amount of acreage using various 
conservation tillage techniques. The total acreage 
using intensive tillage is less than 40% for corn, 
small grain and soybeans. Due to wet weather 
conditions the past few years in the mid-west 
there has been a trend back to intensive tillage 
practices. In Iowa, 1998, there was 1.4 million 
acres (0.5 million hectares, 6.5%) less area in 
conservation tillage than in 1997. Minnesota and 
Illinois had similar reductions in conservation 
tillage acreage. 
There has been a significant increase in 
conservation tillage in Argentina, Brazil and 
Canada. With large farms, the advantage of 
fewer trips across the fields makes conservation 
tillage attractive. It also has the benefit of 
retaining soil moisture, which is particularly 
important for the regions where rainfall is 
deficient. This makes it possible to grow 
soybeans in regions which did not have them 
before. It is expected that conservation tillage will 
continue to increase in South America. In the 
U.S. there will probably be an increase in 
conservation tillage for soybeans, but less so for 

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unless farm legislation continues to require 
farmers to adopt these practices. 
The distribution of no-till, ridge-till and 
mulch-till is shown in 
Table 2
. No-till 
practices are used mostly with corn and 
soybeans. The total area of no-till is 16.4% 
for full-season corn and 26.9% for double-
cropped corn. Although double-cropped 
corn is a very small compared to full-sea-
son corn acreage, 0.5 million hectares vs. 
32.5 million hectares. Ridge-till is used 
very little for row crops and not at all for 
small grains. With the increased use of nar-
row rows for corn and soybeans, down to 
7.5 inch row spacing (190 mm) ridge till 
cannot be used. The use of mulch-till 
ranges from 16.6% to 24.2% for corn, small 
grains and full-season soybeans. 
Tillage tools that have gained in acceptance 
are those that can reduce the compacted 
clay layer with little disturbance to the soil 
surface. The two shown in