Crop Rotations and Cover Crop
Effects on Erosion Control, Tomato Yields and Soil Properties in Southwestern
Researcher: R.W. Johnston, Ag. Chemistry Section,
RCAT, Principal Researcher
- To enhance and maintain the physical and chemical properties
of coarse textured soils suitable for vegetable production,
and to find cost effective water and wind erosion control measures
to reduce soil degradation.
- The impact of adopting stewardship cropping practices in
vegetable production on coarse textured soils will be the preservation
and enhancement of the soil resource.
- Improved structure and organic matter reduce problems due
to root rots (vegetable crops are very susceptible to this).
Better soil structure will result in more even crops and growth.
This should result in higher yields and lower production costs
resulting in higher profitability for the farmer.
- The use of appropriate soil conservation measures within
the vegetable production systems will help to reduce wind and
water erosion on the farm as well as off site.
Weed control was more of a problem in 1992 due to frequent rains.
The tomatoes following the rye cover crop had the least weed escapes
from the first herbicide application. This was also true where soybeans
followed a rye cover crop (rotation Soybeans-Tomatoes).
In 1992, no replanting was done with the transplanter due to
Colorado potato beetle, however, some plants were replaced by hand
at both locations to fill in for dead plants or those eaten off
at both locations to keep an even plant population.
As a result of crop rotation, soil structure and drainage appears
to be improving at both locations. Measurements need to be taken
to substantial these observations.
Yields at Leamington in 1992 were the highest since the project
began. The soil improving benefits of rotation appear to be gaining.
Continuous tomatoes continues to be the lowest yielding culture.
Those rotations in which tomatoes followed a legume - red clover
or alfalfa and those tomatoes following incorporation of large amounts
of straw showed improved growth and yield. The rye-tomato rotation
was one of the lower yielding rotations in 1992.
The continuous tomato culture has declining yields at Dresden
and is the lowest yielding culture each year. Similar to Leamington
the Soybean-Tomatoes rotation is next lowest yield rotation to continuous
culture. The highest yielding rotations at Dresden have been Alfalfa-Alfalfa-Tomatoes,
W. Wheat-Soybeans-Tomatoes and W.Wheat-Red Clover-Tomatoes which
indicate the desirability of a legume to be included in the rotation
and/or crop with large amount of residue.
Tomatoes have been quite response to nitrogen particularly in
Leamington and under continuous tomato culture at both locations.
Although the effect is not significant, nitrogen tended to increase
the green tomatoes slightly and Leamington and did give a significant
effect in Dresden in 1992.
In 1992 no yield results were taken as cover crops were set up very
late in the season. The tomatoes planted on fall beds with no tillage
in Dresden were struck by frost on May 24 and 25 and again on June
22. On the no tilled fall beds, growth was slowed severely. Plots
for 1993 had very good cover crop growth.
Tuesday, May 10, 2011 11:37:55 AM