Fertilizing fescue

[denoginnizer]

My soil samples called for about 40 pounds of nitrogen to the acre. Doesnt it take more nitrogen than that to do a signifacant amount of good for fescue? Do I disregard the soil samples?

Does fertilizing fescue increase the amount/strenth of the toxic endophyte in the endophte infected type fescue?
I asked one time before but didnt get an answer.

 

[Chris H]

Here in southwest Ohio, 50 lbs of nitrogen does a significant amount. Most recommendations are for about 50 lbs, you'll get more grass with more N but it is not cost effective, generally.

I don't know when the best time for you to put it on but here we aim to get it on the 1st two weeks of August.

I've never heard anything about increased N affecting the endophyte in any way. However, since the endophyte concentrates in the seed head and near the ground it sounds reasonable to think you'd have more non-toxic growth with additional N.

 

[J. T.]

I've never read or heard anything about fertilizing fescue affecting the strength or amount of endophyte in the grass. As far as how much to fertilize with, I aim for 60 lbs. of N/acre. That is without doing a soil test. If the results came back stating 40 lbs/acre, I'd try that. Do you have a legume growing with the grass? Maybe that could account for the low N recommendation. If you don't follow the soil test results, I wouldn't go to the trouble of taking samples. BTW, by stockpiling fescue last year, I fed 0 hay this past winter. Cows came through the winter in good shape.

 

[denoginnizer]

I've never read or heard anything about fertilizing fescue affecting the strength or amount of endophyte in the grass. As far as how much to fertilize with, I aim for 60 lbs. of N/acre. That is without doing a soil test. If the results came back stating 40 lbs/acre, I'd try that. Do you have a legume growing with the grass? Maybe that could account for the low N recommendation. If you don't follow the soil test results, I wouldn't go to the trouble of taking samples. BTW, by stockpiling fescue last year, I fed 0 hay this past winter. Cows came through the winter in good shape.

My mineral supplier says fertilizer tripples the toxicity. I noticed he has a new truck . You dont suppose he would like to sell a few more sacks of fescue mineral do you ;-) ?

 

[john250]

The N reccomendation is likely based on a yield goal and not on the soil test. Because N is mobile and subject to leaching, the labs I use don't make it part of the standard test. There are agronomic "best guesses" for the contribution of whatever legume you have, if any. Beyond that, I got a good bang from 30 lbs of N on fescue this spring. 40 would be better. I think 60/application and 100-120/yr are the high production recommendations around here.

High N application increases the risk of "grass tetany", which is counter acted with "hi Mag" minerals. I'm not aware that it increases the endophyte. I think that is incorrect.

 

[dj]

I didn't say it he did.

Fertilizing Pastures in the Spring- Jeff McCutcheon, Extension Educator, Knox County

Every spring I get questions from producers about fertilizing their pastures with nitrogen, phosphorous and potassium. Many producers coming out of winter want to give their pastures a boost or they are fertilizing crop fields and figure they might as well do their pasture while they are thinking about it. Eventually I lead the conversation to the question of is this really the best time to fertilize pasture?

Now, I am not totally opposed to fertilizing pastures in the spring. Applications of phosphorus (P) and potassium (K) should be made prior to establishing a new seeding based on soil test results. A light application of nitrogen (N), 20-40 lbs. N/ac. in March could be used to jump start spring growth and allow for earlier grazing. This could potentially give about two weeks of earlier grazing if environmental conditions are favorable. But the acreage for this N application should be limited. The spring flush is coming and most producers can't normally harvest it all with grazing animals. Why add to the amount of forage produced when you don't need it? An early nitrogen application also can increase the potential for grass tetany and excess nitrogen in the spring may possibly increase toxins in endophyte-infected tall fescue. Generally, one acre of pasture for every two cows should be fertilized with N in early spring and never more than a third of the total pasture acreage.

All applications of K should wait until the plants can utilize it better. If we were to look at soil levels of potassium during the year we would find that it is in greater concentration during the spring (due to mineralization of K during the winter. Plants have the ability to take up more potassium than they need. This is called luxury consumption. Luxury consumption can occur when there are high soil levels of potassium, like what we see in spring. High concentrations of potassium can affect magnesium uptake by plants. This not only affects the plant physiology but can also cause metabolic imbalances in animals that consume mainly forages. The metabolic imbalance in animals is usually referred to as grass tetany. Why apply potassium at a time when more is already available and plants can take up more than they need?

So when is the best time to apply fertilizer to pastures? Research shows that if one application of P and K is being done, then fall is the best time for the application. By applying P and K in September or October plants develop a healthier root system and improve winter survival. This results in plants better able to withstand drought the following year. If high rates of phosphorus and potassium are recommended by soil test, then there is an advantage to splitting the application. Some of the recommended fertilizer should be applied after the first hay harvest, early summer, with the balance being applied in the fall. This will help reduce the luxury consumption of potassium by the plants and improve the efficiency of K use.

Fertilizing pasture in the spring is not the best use of your time or fertilizer dollar.

 

[john250]

An early nitrogen application also can increase the potential for grass tetany and excess nitrogen in the spring may possibly increase toxins in endophyte-infected tall fescue.

OK, thinking people believe it is possible that N increases endophyte. But "may possibly" is awfully wiggley. Maybe we just don't know.

 

[dj]

Or you can read more here if you want or not.

http://www.plantmanagementnetwork.org/p ... toxicosis/

Nitrogen fertilization. If producers are trying to reduce toxin loads in the field, they should not fertilize E+ tall fescue pastures with high rates of nitrogen fertilizer. Alkaloids contain nitrogen, and ergot alkaloid concentrations are rapidly increased following N fertilizer application (30) (Fig. 27). Severity of both fat necrosis and fescue foot appears to be positively related to high application rates of either nitrogen or poultry litter (36).

 

[dj]

course that says "appears to" also so i'd discard the whole thing

 

[john250]

course that says "appears to" also so i'd discard the whole thing

I'm not discarding it out of hand. Still, when a researcher says "appears to" and "maybe" it means that their study didn't prove anything. "Conclusively" is the word when you got it nailed. Doesn't happen very often.
But I ramble. Fescue is important to me, and Fescue isn't very good to me without some N. For the short run, if fertilizing fescue makes it troublesome, I'll have to deal with that through amendments. In the long run, I won't go to low-producing fescue. That's a loser. I'll go to other grasses and alfalfa.
Fertilize Fescue. Graze it hard. Watch your minerals. Mow it. That's the plan till it changes.
We have to watch our ground around here. 45" annual rainfall wants to wash it away. Nothing makes a sod like fescue.

 

[NorCalFarms]

Fescue will respond to N applications as low as 5 units. I have some sprinkler irrigated places that are very sandy, I apply around 70 units/year as the soil is already fertile from being in row crops/alfalfa but I do it in many different applications. 10 units is about all that I will put on at once, otherwise it will all leach away. I do put it in through the water so it it very easy to do, but I like to give it just a little N each irrigation and it works surprisingly well. Solit and small application reduce the danger of leaching and help keep the grass growing in the summer, when it gets hot and it quits growing an application of N does wonders.
We grow only endofyte free varieties here so I can't help with that.

 

[Cabo]

My soil samples called for about 40 pounds of nitrogen to the acre. Doesnt it take more nitrogen than that to do a signifacant amount of good for fescue? Do I disregard the soil samples?

Does fertilizing fescue increase the amount/strenth of the toxic endophyte in the endophte infected type fescue?
I asked one time before but didnt get an answer.

Need to keep in mind that the soil test is refering to units of nitrogen not pounds of ammonium nitrate, etc.