Ways to get higher yields for your forage

Wednesday, June 1, 2011

Too many producers are trying to save money at the expense of better yields. You can get higher forage yields, but you have to work at it

by PAT LYNCH

A quick check of the Ontario agriculture ministry's record of historical yields by crop is interesting. In the last 20 years, soy yields have increased some, wheat yields have had a higher percentage increase than soys, and corn has almost doubled the provincial average yield in the last 20 years.

Forage yields on the farm have pretty much stayed the same over the past 20 years. Part of this is due to better quality and less volume, and part is due to the way data is collected. But the reality is that forages are treated less like a cash crop than they should be.

The facts are simple. Too many producers are trying to "save money" when it comes to growing forages. It starts with the seed. Too often, seed is purchased from whomever can sell at the lowest price. When you buy this way, there is no time to discuss how to get higher yields.

The number one reason for lower yields is stand life. Too many fields are too old. You should kill a good alfalfa stand and not leave it to die. One of the reason producers want to leave a stand is seed cost. The reality is that, at 20 pounds per acre of seed at $7.25 per pound spread over three years, seed costs less than $50 per acre. This is significantly less than corn or soy seed costs.

When you factor in nitrogen credits, more acres and more acres receiving higher yields because the previous crop was forages, freeing up acres, using shorter rotations pay off.

I have summarized yield data from various places to come up with numbers for the value of a shorter rotation. You can do your own quick and dirty calculation. My base assumption is that you need 500 tonnes and the average yield is around six tonnes per acre. I used U.S. data to come up with yield loss as a crop stand ages. These yield loss - stand aging numbers are probably conservative since they do not take into account stand damage due to compaction of harvesting. When you look at all the factors for reducing the life of a stand, shorter stands pay. The table below depicts this. I have put a value to nitrogen credits, rotational benefits, fewer acres required. I have not put a cost to seed, or a value to higher quality feed, or a savings value for harvesting fewer acres.

In this case, if you need 500 tonnes of forages you gain over $18,000 by switching to a seeding year plus two years as opposed to a seeding year plus four years. A seeding year plus three years is in between.

Among other reasons for low forage yields, forages are not fertilized as they should be. Typically, forages are removing 60 to 70 pounds per acre of phosphorus and 240 to 300 pounds per acre of potassium. Seldom are as many nutrients put back during the life of the stand. These amounts of nutrients are in 9,000 gallons of liquid dairy manure. If you apply this much manure to a stand, you are wasting a lot of nitrogen.

Seldom do producers spray for insect control. Typically, leaf hopper levels in new seedings will reach threshold levels long before growers realize it. Once it is recognized, it is too late to spray.

You can get higher forage yields, but you have to work at it. BF

Consulting agronomist Pat Lynch, CCA (ON), formerly worked with the Ontario agriculture ministry and with Cargill.