Consider Seeding Red Clover In Spring Wheat

Mar 09, 2015

In recent research, red clover underseeded into spring wheat provided up to an extra $100/acre in grain corn yield the following year without reducing spring wheat yields!

A four year study (2009 - 2013) was initiated at the Winchester Research Station to look at the effect of underseeding red clover into spring wheat and its impact on the spring wheat yield as well as the corn yield the following year. The red clover was broadcast seeded at four different times:

at planting,
at herbicide application (Zadok's 26-30),
flag-leaf emerged stage, (Zadok's 37 - 39) and
after wheat harvest.

Single-cut and double-cut red clover was broadcast into the spring wheat at 7 lbs/acre. Nitrogen was applied to all treatments at 90 lbs/ac in the spring wheat crop and at 100 lbs/ac in the corn crop the following year.

Results

Table 1 summarizes 3 year average corn yield for each of the previous year's red clover treatment. Based on a corn value of $4.50/ bushel, red cover added $33 - $100 per acre as compared to where no clover was underseeded in the spring wheat. As expected, red clover underseeded at earlier spring wheat stages (at planting or at herbicide application) rather than at flag-leaf or after harvest, provided more yield benefit to the following corn crop.

Table 1: Average Corn Yield (2010, 2011 & 2012) following red clover underseeded in previous year at various spring wheat stages.

Treatments (Timing of Red Clover Seeding)	3 Year Average Yield (bu/ac)	Yield Difference from No Clover (bu/ac)	Additional Value of Red Clover Per acre with Corn @ $4.50 per bushel
No clover	144
Single Cut - @ planting	167	23	$102.47
Double Cut - @ planting	163	18	$80.64
Single Cut - with herbicide	160	15	$68.96
Double Cut - with herbicide	157	12	$53.60
Single Cut - flag leaf emerged stage	161	17	$74.90
Double Cut - flag leaf emerged stage	152	7	$33.71
Single Cut - post-harvest	154	9	$39.81
Double Cut - post-harvest	157	12	$54.14

Due to the high yield variability the 2013 corn yield, it is not included in the above table.) Single cut red clover appears to have greater yield advantage in corn than double cut red clover, however the difference was only statistically significant in 1 of the 3 years.

Spring wheat growers are often reluctant to underseed red clover in spring wheat due to concerns that the red clover will compete and suppress the spring wheat grain yield. Table 2 summarizes the average spring wheat yield of each treatment.

Table 2: Spring Wheat Average Yield (2009, 2010, 2011 & 2012) with red clover underseeded at various spring wheat stages.

Treatments (Timing of Red Clover Seeding)	Average Yield (bu/ac)	Yield Difference to No Clover (bu/ac)
No clover	53.9
Single Cut - @ planting	58.4	4.5
Double Cut - @ planting	55.5	1.6
Single Cut - with herbicide	58.4	4.6
Double Cut - with herbicide	57.7	3.8
Single Cut - flag leaf emerged stage	57.5	3.6
Double Cut - flag leaf emerged stage	57.5	3.6
Single Cut - post-harvest	59.4	5.5
Double Cut - post-harvest	58.1	4.2

Although the yield numbers showed that the inclusion of red clover slightly increased wheat yield, statistically there was no difference in yield of the spring wheat with or without red clover.

Summary