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View Full Version : Whats the deal with clover and N


nc-jrock
06-18-2009, 09:37 PM
I just have A couple of questions about clover and N.
Does a lawn with alot of clover mean that the yard is lacking or is low in N?
does a large does of N kill clover?
Have plenty of stuff to kill clover so no advice on that please.

Think Green
06-18-2009, 09:59 PM
Jrock,
Clover has been used for several generations as a cover crop to add nitrogen back to the ground. Yes, Areas with heavy infestations of clover exhibit below adequate levels of nitrate in the soil. Clover fixates nitrogen from the air and when the weed (Crop) is tilled into the soil, it redelivers the nutrient. Some farmer's grow clover for feed as it is high in Nitrogen and Calcium for cattle. Clover is used by the highway departments for control of erosion. Often you will see clover growing on barron-waste sites where the soil is poor in construction and always lacking in nutrition. Other weeds are indicator's of soi problems too but that is another topic.....!
On my new lawns that is riddled with clover, we treat the existing weed first (3-way) either Ester or Amine formulations depending on the temperatures. The next thing we do is keep the seed vaccumed up until the herbicides kill what it will. Multiple doses will need to be done to be effective. Fertilizer high in Nitrogen are part of our control as we feed the desireable turfgrass to flourish and maintain the level of nitrogen that is consistent for the health of the turf. The nitrogen of slow release form will maintain what we want to feed the lawn.
Sometimes, the turfgrasses are mowed too low and are lacking in nitrogen, and the clover can get a foothold in the soil. Thick turf and nitrogen balanced soil will not allow clover to grow very well. During the spring, my one acre lawn took 4 applications of 3-way and sufactant applied at 2 oz. per gallon spot spraying to eliminate the weed. This is all good until next season. I have been too busy with everyone else's lawns that mine was neglected. I didn't use any preemerge this spring as I should have. Now I had to pay the piper in extra work!!!!!!!!!!

Young Bros
06-18-2009, 10:09 PM
That is right, clover produces N so it thrives in N poor soils.

DiyDave
06-18-2009, 10:17 PM
Clover fixes nitrogen from the atmosphere, using mycho rhyzae (spelling not right, I am sure), which are nitrogen fixing bacteria that live in little nodules on the clover roots. In this symbiotic relationship, the bacteria fix the N from the air, release it to the soil around the nodule, and to the plant. Not sure what the bacteria get out of the relationship but to each his own, I guess! The important thing to remember is that legumes such as clover provide nitrogen to the grass they are living in and amongst. In some areas where grass is seeded, the clover is interseeded to provide N to the mix, saves money for fert. In my lawn, I let it grow, and the grass is always green, as long as there is ample moisture.:cool2:

Young Bros
06-18-2009, 10:21 PM
Good to know Dave. :)

treemonkey
06-18-2009, 11:29 PM
This thread makes me step back and ask myself, is there something wrong with our ideas about lawn maintenance?

Think Green's answer says this: We have a situation where the soil is not suitable for this "crop" we are trying to grow. Nature handles the situation by allowing plants to grow there that are suited to those conditions.

We come along and dump pesticides and fertilizer on to kill what grows well there and sustain the "crop" that isn't suited for this soil.

I'm not organic. I use fertilizer and pesticides, but somehow Think Green's answer seems counter intuitive to sustaining healthy systems. Makes me wonder sometimes.

Are there references to this idea that clover is an indicator to low N. Or, is clover just a "symptom" of unhealthy turf maybe suffering from multiple problems.

Not stirring the pot here. I would like to see some references to explain that clover indicates low N. I have seen this idea stated several times.

rcreech
06-18-2009, 11:39 PM
This thread makes me step back and ask myself, is there something wrong with our ideas about lawn maintenance?

Think Green's answer says this: We have a situation where the soil is not suitable for this "crop" we are trying to grow. Nature handles the situation by allowing plants to grow there that are suited to those conditions.

We come along and dump pesticides and fertilizer on to kill what grows well there and sustain the "crop" that isn't suited for this soil.

I'm not organic. I use fertilizer and pesticides, but somehow Think Green's answer seems counter intuitive to sustaining healthy systems. Makes me wonder sometimes.

Are there references to this idea that clover is an indicator to low N. Or, is clover just a "symptom" of unhealthy turf maybe suffering from multiple problems.

Not stirring the pot here. I would like to see some references to explain that clover indicates low N. I have seen this idea stated several times.

WHERE HAVE YOU BEEN?????

Good to see you on here!

treemonkey
06-18-2009, 11:51 PM
I lurk here almost weekly, but only post on rare occasions. I spend a bit more time with a bunch of loonies that obsess about motor oil, of all things! In fact, that's why I wandered over here in the first place, to see what the lawn "experts" were using, in order to answer a question.

Lawn maintenance is just a tiny fraction of my workplace duties. I know just enough to get into trouble on occasion.

Jack of many trades, master of none.

Blood Bought
06-19-2009, 08:53 PM
Clover is a good indicator of nitrogen levels in the soil. Look at a lawn that has not been fertized. Any where there are clover patches the grass in and around the clover will be nice and green. The grass outside the clover areas will be yellow or pale. The grass around the clover benefits from it's ability to pull nitrogen from the air. Clover will grow in well maintained areas, otherwise all you would need to do to get rid of it is fertilize. Just because clover is present does not mean nitrogen levels are low. Once the clover is removed and a healthy thick stand of grass is established clover will have a difficult time establishing itself again. If all the grass in the lawn is as green as the grass in the clover areas nitrogen levels are good all over the yard.

Think Green
06-20-2009, 11:10 AM
Treemonkey,
Clover is just one of the problemiatic weeds,yet indicative weeds that we have all over our country sides. It is grown in shrubbery beds as clumping groundcovers (Why I don't know because of the invasive properties and seed formations.) I remember my grandfather telling me that clover was used on the farm as cover crops that would be tilled back into the soil at planting. It fixates nitrogen from the Atmosphere and air, which stores it in it's foliage. Of course it is greener than most unhealthy turf around it, because that area has more nitrogen with in the plant!!!!!!!!!! IF you want that extra nitrogen content introduced back into those spots of land----then till the clover in!!
In all of my yearly state recirtification classes, clover has been at least one topic for discussion as it is the most misunderstood weeds in this erea. May it be from the lack of field study for its control, or the lack of education to the applicator's, but from what I have been tought by the U of A clover is an indicator of low nitrogen in that spot. I can't really say no more. You can go and google white clover and discover a slew of uses and reasons for seeding with this plant. If a person maintains high levels of N on a lawn then it makes it impossible for the weed to thrive. IF this weed is a desireable turf, as it has been in some states, then let it be and don't feed the soil. But if you have other desireable turfgrass like St.Augustine--Centipede--Bermuda--Buffalograss--Zoysia--Fescues, the clover will compete and shade out the turf and make shallow hollow spots that have to be overcome by the desireable turf.
I don't have any literature on clover saved, all you can do it search for the biology of clover and do the research.

Blood Bought,
You have touched the other end of the spectrum with clover. However, in our erea with highly fertilized thick lawns, we do not see clover encroachment unless the areas of turf are too thin. Curbsides, around sidewalks,etc we will sell clover or as funny as it seems, it will grow in the middle of the lawn like a nice shiney north star on a teenager's nose.
Down South, the clover is mixed with other wild seed to cover the newly constructed ramp ways because it is a fast grower and once established, it holds down erosion. What I am saying is, the weed has a purpose, but it is vigorous on establishing in these areas of low fertility. I know that everyone reading these reponses will understand that there is no perfect growing situation. Clover is here to stay and is a yearly battle to keep it out of desireable turfgrass. Nitrogen applications to encourage the other turf to outgrow the spots where clover invades and thins out is the key to controlling it. Bagging of the seeds at mowing will control the weed seeds from floating around. These are a couple of IPM practices that we use down south.
I know that each state may use different approaches to controlling different weeds as their encroachments cause different economical and physical harm to each state or county. That is why each state offers an extension service for advice like this and they can give any person literature on effective control..................at least they do around here!

Thanks!

nc-jrock
06-20-2009, 05:30 PM
Thanks for your responses guys.

Think Green
06-20-2009, 05:53 PM
Any other queries go to::

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7490.html

This is somewhat a good site for the species in the pea family of legumes..

treemonkey
06-21-2009, 07:25 PM
Thanks, Think Green.

I think some of my confusion comes from your "regional thinking" about clover vs. ours in the lake states. As mentioned by Blood Bought, some (a few) people up here actually encourage clover in their lawns. Also, clover WILL start up and spread even in a thick, lush lawn that has adequate N. However, a healthy turf does inhibit it in most cases.

I already knew about clover's life cycle and nitrogen fixing ability and your explanation is excellent. In fact, I am involved in some sandy soil Christmas tree research with the idea of inter-planting clover for it's N fixing attributes, but trying to not let it compete for moisture and other nutrients with the trees. Unfortunately, it's a deer magnet and they browse the trees too.

I might add that clover seeds are like cockroaches regarding their toughness to survive. Where we fumigate with methyl bromide, we sometimes get a bloom of clover....some say it "scarifies"/encourages the seed in effect.

Thanks again. We are more or less on the same page, with some slight differences due, I think, to regional climate, soil, and turf types.