- Roger Samson, Allison Arkinstall and Jeff Quinn, Resource Efficient
Agricultural Production (REAP) Canada, Ste. Anne de Bellevue, Quebec.
(Tech. Transfer Report Summaries)
View / Download Final Report [111 KB pdf]
Associated SWEEP/LSP Research
Completed: June, 1992
catch crop, cover crop, rye, oilseed radish, corn, soybeans, red clover,
hairy vetch, no-till
Experiment 1. Field Testing of Cover Crop Systems
Promising cover crop species including hairy vetch, oilseed radish and winter
rye were evaluated on 6 farms in southwestern Ontario. Cover crops proved
to be economical by either reducing production costs or increasing yields.
Oilseed radish appeared to be the most promising new cover crop as it showed
potential to reduce production costs, improve weed control and increase
corn yields. Hairy vetch provided similar yields and input costs as red
clover when used as a legume cover crop prior to corn. Promising rye management
systems included using winter rye as a double crop forage before conventionally
planted soybeans and using winter rye as a weed suppressing mulch for no-till
Experiment 2. Evaluation of the N Contribution of Cover Crops using
a Nitrogen Soil Test
Corn grown on plots fertilized with manure and/or cover crops (oilseed radish,
red clover and hairy vetch) were sampled biweekly after planting to determine
spring soil N transformations and to determine if the N soil test (taken
in the top 30 cm of soil at time of sidedress) was a useful indicator of
N availability from these sources. Other researchers working in the U.S.
corn belt have shown that 21 ppm NO3-N is the critical N level,
above which no N fertilizer response is observed, when legumes and manure
are the N sources used for corn production. In this study, N fertilization
of sites having NO3-N levels of 23 ppm produced a corn yield
response at two sites. A value of approximately 25 ppm NO3-N
appeared to be a better indicator of fertilizer N response in this one year
study. Use of an N soil test appears to be a valuable tool in identifying
sites which have an excess supply of N, rather than predicting fertilizer
N requirements. It could be a useful tool in helping farmers better understand
and manage the N cycle on farms with cover crops and manure as N sources.
(From Technology Transfer Report Summaries - A. Hayes, L. Cruickshank, Co-Chairs)
The study was divided into a number of sections dealing with various aspects
of catch crop and cover crop management.
Experiment 1.1 was divided into 3 parts, each comparing some
aspect of the use of rye in a soybean production system. No significant
difference in soybean yield was observed. The rye harvested for a forage
system gave the only positive economic return.
Experiment 1.1a studied the use of winter rye as a double crop
forage before soybeans. The treatments were winter rye spring plowed (control)
and rye harvested as a forage (test). The harvested rye produced hay with
low crude protein and low digestibility. Soybean yield was low due to weed
Experiment 1.1b compared rye killed with herbicide to mow killed
for use as a mulch for soybean production. The rye in the mowed plot regrew
and crabgrass was affected very little by the mowing. The entire plot area
was sprayed with herbicide and inter-row cultivated. The mowed treatment
appeared weedy even with the grass treatment.
Experiment 1.1c compared no-till soybeans and no cover crop
with no-till soybeans into winter rye which was killed with a herbicide.
Both treatments received a comprehensive herbicide program. It was observed
that the soybeans with the rye had better weed control.
Experiment 1.2 compared red clover frost seeded into winter
wheat to hairy vetch drill seeded into winter wheat in early May and the
effect of both treatments on corn the following year. No significant difference
in biomass production of the interseeded legumes was observed. However,
because of weather conditions, the red clover produced more biomass than
anticipated. No significant difference in corn yield was observed between
treatments in the year following the legume interseeding.
Experiment 1.3 compared solid and liquid manure as a nutrient
source with oilseed radish catch crop for corn. The treatments were manure
incorporated with and without the oilseed radish catch crop. No significant
difference between corn yield occurred between liquid swine manure with
and without the oilseed radish. However the control treatment received 60
kg N/ha side dressed. A significant difference in yield occurred between
the solid manure treatments. The treatment with the oilseed radish yielded
more than the control. However since the soil N and the ear leaf N were
similar the difference in yield was attributed to decreased weed pressure
in the test plot.
Experiment 2.1 evaluated the nitrogen contribution of cover
crops. The cropping system studied was corn following red clover and hairy
vetch cover crops. The treatments were frost seeded red clover (control)
and May drill seeded hairy vetch (test), with 0, 40, and 80 kg N/ha. Two
depths were sampled at the prescribed corn height to determine if movement
of nitrogen had occurred in the hairy vetch plot. No significant difference
between nitrogen levels at the lower depth (30-60 cm) was found. At the
shallow depth (0-30 cm) the level of NO3 was higher under the
red clover plot.
Experiment 2.2 evaluated the nitrogen contribution of oilseed
radish as a catch crop with manure fertilized corn. The treatments were
a control and oilseed radish, with 0, 40, 80 kg N/ha on two separate farms.
All of the sampling dates on the first farm resulted in the oilseed radish
plots having higher levels of NO3 than the control. The level
of NO3 increased from 8 ppm to 23.1 ppm in the 36 days between
the first and last soil sampling. The control plots showed a significant
response to fertilizer while the oilseed plots did not. The oilseed radish
plots on the second farm were similar to the control plots in the amount
of NH4 and NO3 in the soil tests. The level of NO3
increased in both treatments between the first and last soil samples. Both
treatments responded significantly to the addition of fertilizer. It was
indicated that the oilseed radish yield was less than the first farm and
this was given as the reason for the response to fertilizer in the oilseed
The studies were conducted for only one year and the sample size was extremely
small. For that reason the studies can not be considered to indicate trends
but are only observations of what happened in that year.
In Experiment 1.1a it was observed that the weed pressure was
less in the harvested plots. The explanation given for the lower weed growth
was the removal of nitrogen from the system with the harvested rye. However
the rye forage was reported to be low in crude protein and would not be
a very large source of nitrogen. The reduced weed pressure could be likely
due to the removal of weeds through the harvesting of the rye.
The report indicates that oilseed radish increases soil nitrogen levels.
Oilseed radish is not a legume and therefore can not increase soil nitrogen
levels. However, it may conserve N which otherwise could be lost.
- SWEEP Report #12 - Choice and Management of
Cover Crop Species and Varieties for Use in Row Crop Dominant Rotations
- SWEEP Report #19 - Studies on the Control of
Problem Weed Species in Conservation Tillage Systems
- SWEEP Report #19A - Weeds of Corn, Soybeans,
and Winter Wheat Fields Under Conventional, Conservation and No-Till Management
Systems In 1988 and 1989
- SWEEP Report #32 - Optimal Herbicide Use in
Conservation Tillage Systems
- SWEEP Report #36 - Red Clover Cover Crop Studies
- SWEEP Report #43 - The Use of Cover Crops for
- LSP 7005 - Crop Rotations and Cover
Crop Effects of Erosion Control, Tomato Yields and Soil Properties in Southwestern
- LSP 7009 - A Cover Cropping Strategy
for First Early Potato Production
Future Research: ( ) indicates reviewers suggestion for
priority, A - high, C - low.
None required. Future research of this type is not justified unless a much
stricter scientific method is followed.
Thursday, May 19, 2011 04:11:47 PM