Crops - The Lynch File: Now may be the time to reconsider red clover

Friday, February 29, 2008

It may not be very exciting and there are no proprietary varieties. But the advantages of mastering the art of red clover establishment make it well worth the effort

by PAT LYNCH

In the early 1970s, we had just come through a period of low crop prices. This was followed by a series of events, including a weather change, which prevented the Peruvian fishing fleet from being able to find anchovies.

In turn, this resulted in a dramatic increase in fishmeal and fish oil prices, and triggered other events leading to high crop and high commodity prices, including nitrogen. We started to reuse red clover as a nitrogen source.

In the last few years, lower commodity prices, the switch to no-till and relatively lower nitrogen prices have led to a drop in red clover use as a plowdown in winter wheat. The time is right to take another look at red clover.

Research indicates there is at least a 50-pound per acre nitrogen benefit to using red clover. There is also an increase in corn yield of five to 10 bushels per acre, depending on the year and the field. This is extra yield that is not there even with additional commercial fertilizer. There are suggestions that there is also an increase in the soybean yield the following year.

Research indicates that red clover is much harder to establish in no-till wheat than in wheat that has been conventionally tilled. I believe this is due to the excess amount of trash on the soil surface. This trash prevents red clover from establishing and also makes red clover more prone to being frozen off. When there is trash on the ground, there is more chance of cold night air freezing these plants. There is also less heat given off from this trash than from bare soil, as is the case when wheat is planted into tilled ground.

If you are interested in seeding red clover this year, pick the fields with the least trash. A field that is coming out of two years of soys planted to wheat will have a higher probability of establishing a stand than fields which had lots of corn trash from the great yields in 2006. The absolutely must fields are those in edible beans where the ground was worked.

Early seeding is essential. If you wait to apply the red clover with nitrogen, you reduce the probability of success.

I know one grower who gets good stands by seeding in January. Most good stands are seeded in March.

Another reason for the lack of red clover plow downs is tied to weed control. Herbicides that are safe on red clover have no control on perennial weeds like dandelion. We have a lot of fields with dandelion. Typically, fields which were worked before planting have few perennial weeds. Also fields with a preharvest glyphosate treatment have fewer weeds.
For next fall, you should consider a glyphosate application before wheat is planted. And you may even want to consider some tillage.

And if you underseed red clover, be sure to put crop insurance on it. It is one of the few almost guaranteed winners. (Some conditions apply.) If you get a stand of red clover you can count on about $25 of nitrogen and a crop yield increase of another $20-50.

Red clover is not very exciting. There are no proprietary varieties. There is little promotion of this crop. But, with the times we are in now, it is time to reconsider it. It will be harder to do than it was in the 1970s, but the advantages of mastering the art of red clover establishment make it well worth the effort. BF

Pat Lynch CCA (ON) is head agronomist for Cargill in Ontario.