# Alfalfa yield



## hog987 (Apr 5, 2011)

Here is a question I have me thinking about for awhile. I will use alfalfa in my example but other forage crops will work too.

If everything was perfect for the plant what would the yield be? If it had the right heat for growth, the right moisture at the right time, growing in the right balance of soil for ph and fertility. There is always a limited factor in growth. But if all these factors were gone what could the yield be?


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## IAhaymakr (Jun 4, 2008)

Your first big determining factor of alfalfa yield is where you raise it. The further north you go the shorter your growing season, and the lower your yield even assuming perfect growing conditions. The second factor is harvest method. Are we also assuming perfect harvesting to go with your perfect growing conditions? Probably better chop it for haylage if you wish to consistently maximize dry matter yield. 
In my part of northern Iowa, we plan for 6.5 ton per acre per year. However I have harvested up to 8.25 ton DM per acre in a year that spring came early, rain was fairly regular, and the history of applied dairy manure to the farm was documented. This was a five cut per year system, where four is likely more common. If you travel south down I29 into southern Nebraska, I have no doubt that pivot irrigated alfalfa can make ten ton per acre. California growers who can still get water get even more.


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## vhaby (Dec 30, 2009)

When all other growing conditions are perfect, carbon dioxide might become the limiting factor.


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## hog987 (Apr 5, 2011)

vhaby said:


> When all other growing conditions are perfect, carbon dioxide might become the limiting factor.


Its a good thing we are doing are part to help with the CO2 than.

Do breeders even know what the genetic potential of there forage is???


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## aawhite (Jan 16, 2012)

The most I have ever heard of was alfalfa in New Mexico under heavy pivot on an 8 cutting per year rotation, all fertilizer applied thru the pivot.. 12 ton/acre dry matter. They put up damn good hay, about 3,000 acres worth.

What we got with our 70% alfalfa/30% orchard grass mix in southern IA on 4 cuttings: consistently cut 9 ton/acre when chopped as hayleage. Lose a ton or more per acre when baled. Lose another ton or so if pure alfalfa. This is heavy clay loam soils on hill ground with lots of manure applied from the dairy.

Cutting system made more of a difference than anything. The more we had to bale vs. chopping, the less tonnage we harvested. We could lose a cutting if we ended up bogged down with baling too much.


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## Gearclash (Nov 25, 2010)

Best thing we ever did for our alfalfa yeilds was quit applying liquid dairy manure right after a cutting was removed. At the time we had no choice because our manure storage was very limited.


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## IAhaymakr (Jun 4, 2008)

Gearclash said:


> Best thing we ever did for our alfalfa yeilds was quit applying liquid dairy manure right after a cutting was removed. At the time we had no choice because our manure storage was very limited.


Really? Why is that? Yield drag from tanker tracks? That can sure be a problem. We like to get the dragline outfit to apply it to get away from those heavy tanks. Is there something else I am not aware of? I have always been in favor of applying 8-10 thousand gallons after removing a cutting and noticed positive yield response every time.


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## Teslan (Aug 20, 2011)

So I'm sort of confused by this talk of applying fertilizer on alfalfa? Especially the applying liquid dairy manure right after cutting? Is that each cutting every year? Are you talking fertilizing every year with something? Or just keeping an eye on PH. The only thing that farmers do for alfalfa in this area is maybe add a little sulfur every few years. We get 4 cuttings a year if going for highest RFV for dairy or 3 cuttings for more tons per cut and a longer stand life. Average 6-7 tons an acre.

Oh and I saw an ad on craiglist from a guy selling his Premium high quality alfalfa with 140 RFV and 17% protein. That just made me laugh. I get 17% protein with my grass hay.


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## Gearclash (Nov 25, 2010)

> Really? Why is that? Yield drag from tanker tracks? That can sure be a problem. We like to get the dragline outfit to apply it to get away from those heavy tanks. Is there something else I am not aware of? I have always been in favor of applying 8-10 thousand gallons after removing a cutting and noticed positive yield response every time.


I cannot give a solid answer why. We didn't put a lot on, in the order of 4,000 gallons an acre. We used a relatively small tank at 4200 gal, so the wheel tracks weren't bad. Even though we almost always only ever put it on after taking off silage (little or no regrowth yet), it still seemed to slow the regrowth after that. It just didn't seem to do us any good.



> So I'm sort of confused by this talk of applying fertilizer on alfalfa? Especially the applying liquid dairy manure right after cutting? Is that each cutting every year? Are you talking fertilizing every year with something? Or just keeping an eye on PH. The only thing that farmers do for alfalfa in this area is maybe add a little sulfur every few years


We didn't put manure on after every cutting. It depended on whether storage was near full ot not. PH here tends to decrease over time, but not to the point that it would need amending in the lifetime of an alfalfa stand. My dad always used to run a fertilizer cart over his alfalfa fields after first cutting was off. I assume it was only P and K.


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## IAhaymakr (Jun 4, 2008)

Teslan said:


> So I'm sort of confused by this talk of applying fertilizer on alfalfa? Especially the applying liquid dairy manure right after cutting? Is that each cutting every year? Are you talking fertilizing every year with something? Or just keeping an eye on PH. The only thing that farmers do for alfalfa in this area is maybe add a little sulfur every few years. We get 4 cuttings a year if going for highest RFV for dairy or 3 cuttings for more tons per cut and a longer stand life. Average 6-7 tons an acre.
> 
> Oh and I saw an ad on craiglist from a guy selling his Premium high quality alfalfa with 140 RFV and 17% protein. That just made me laugh. I get 17% protein with my grass hay.


In order to maintain soil fertility here we need to either apply manure or commercial fertilizer. Generally manure application done correctly and with nutrient analysis to compliment a specific rate will provide all the alfalfa needs. Without manure it can get pretty expensive applying large amounts of P and K, as well as sulfur and boron to maximize yield. Ideally the manure is applied before seeding, either as liquid or solid, then not applied again till after the stand comes out. However I have seen and done a lot of both solid and liquid manure application between cuts, usually only once per season. Often the applicator guys will have a better rate mid summer to move liquid when they can't go in row crop fields, and often dairies need to get rid of some then too. Ten to fifteen thousand gallons per acre is common. I much prefer the dragline method to using those giant tanks. The other advantage to manure is it can generally be had for a portion of the application cost, which is a whole lot less than fertilizer. I am truly amazed that you get by without adding anything. Is the fertility managed for alfalfa prior to seeding?


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## Teslan (Aug 20, 2011)

IAhaymakr said:


> In order to maintain soil fertility here we need to either apply manure or commercial fertilizer. Generally manure application done correctly and with nutrient analysis to compliment a specific rate will provide all the alfalfa needs. Without manure it can get pretty expensive applying large amounts of P and K, as well as sulfur and boron to maximize yield. Ideally the manure is applied before seeding, either as liquid or solid, then not applied again till after the stand comes out. However I have seen and done a lot of both solid and liquid manure application between cuts, usually only once per season. Often the applicator guys will have a better rate mid summer to move liquid when they can't go in row crop fields, and often dairies need to get rid of some then too. Ten to fifteen thousand gallons per acre is common. I much prefer the dragline method to using those giant tanks. The other advantage to manure is it can generally be had for a portion of the application cost, which is a whole lot less than fertilizer. I am truly amazed that you get by without adding anything. Is the fertility managed for alfalfa prior to seeding?


Nope. The only time I ever see manure spread on an alfalfa field is before it is torn up to be planted in corn. I don't know of anyone that puts fertilizer on alfalfa here besides maybe like I said some sulfur at about year 4. Generally alfalfa is planted after corn or a row crop, but a direct answer is no fertilizer before planting. I'm planting alfalfa this year in a field and I'm not doing anything besides get the seed bed ready.


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## aawhite (Jan 16, 2012)

We did it out of need. last opportunity to lower/empty the pits until corn silage comes off, and we usually need every bit of time we had. We also notice an improvement in yield, of course we didn't grow pure alfalfa either.


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## hog987 (Apr 5, 2011)

I can see over time that too much manure would hurt yields. Manure has salt. Too much salt is not good. At dads there is an old hog pen on about a 1/2 acre of land. Have not had hogs in 10 years. Some spots are growing good. Some are too salty and only green foxtail will grow.


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## aawhite (Jan 16, 2012)

I can see hog manure as an issue, but cattle manure is not the same. We had 600 head on concrete when we shut down the dairy. We didn't add P or K to any of our fields in over 20 years. I've seen the corn bottoms in manure over 6 inches thick across the fields, and we have still cut 300 bu. corn. Our neighbor, on the other hand, had a small field he kept pumping hog manure over with a pivot. It looks like a desert, nothing grows. He tried planting corn once, got up about a foot before it all died.

It probably helps us that our cattle are all on sand in the free stall barns, all that sand eventually makes it to the field in the manure. Helps loosen our heavy clay soils. The guy who bought the farm grows organic crops. Either last year, or the year before, when the county was burning up and growing very little, he cut 60 bu. beans on the upland hills, and 70 bu. beans on the bottom ground.


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## endrow (Dec 15, 2011)

10 pounds of phosphorus and 55 pounds of potash removed for each ton of alfalfa. I cant believe you can grow this crop without adding potash. Back in a day I remember an old agronomist used to say there is a hell of a lot more alfalfa that starved off sooner than froze off like the farmer said.


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## endrow (Dec 15, 2011)

If you are going to spread liquid dairy manure on a field do not overseed or notill plant alfalfa or grass seed for 2 months the salts in the manure will not allow the seeds to germinate . Please don't ask me how I know this


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## hog987 (Apr 5, 2011)

endrow said:


> 10 pounds of phosphorus and 55 pounds of potash removed for each ton of alfalfa. I cant believe you can grow this crop without adding potash. Back in a day I remember an old agronomist used to say there is a hell of a lot more alfalfa that starved off sooner than froze off like the farmer said.


What you say is true. I remember reading an article awhile ago about how low fertility will make the alfalfa more likely to winter.

Of course when you think about it any stressed plant is easier to kill.


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