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Post by Oatking on Sept 20, 2022 5:56:27 GMT -6
I thought this would be a good time of year to discuss soil testing and the results we get from the lab. How close do you follow the results you receive from the lab. This year in my area we are getting very low levels of nitrogen due to the bumper crops. I have been told the HANEY SOIL TEST is the most accurate , but normally just go with the cheapest option my retailer offers.
Also when is the best time to soil test? early fall after the combine, late fall just before freeze up or do some guys test before seeding in the spring.
What factors on the soil test do you find the most important?
With the high cost of fertilizer, and the looming Federal liberals, fertilizer reductions, will soil testing be mandatory. ?
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Post by Oatking on Sept 20, 2022 5:58:44 GMT -6
Interesting to note, my neighbour soil tested with the big pea crop , showed next to no n in the top 6 inchs and beyond that. I think another member here commented on the same findings. Originally the farmer thought the big pea crop would return plenty of n to the land.
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Post by meskie on Sept 20, 2022 7:09:16 GMT -6
We soil test all our acres. We have an agronomist make recommendations of the lab results. It costs a couple bucks an acre but we feel it’s worth it as there are some surprising results at times. It gets done about this time (just got an email that they are ready to start sampling) and we have done some in the spring also and results are close to the same.
It was me who had said that our pea crops aren’t putting any N into the soil. Without soil testing it would not have been known and going off historical data or experts recommendations the crop after could have suffered. I was talking to a different agronomist and she had seen Similar results to ours in peas with not much extra N in the soil.
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Post by cptusa on Sept 20, 2022 7:10:37 GMT -6
I used to test right after harvest but sunce switching retailers a couple years ago they prefer spring testing, or even in crop. I do a 2 acre grid every 3 years and spread VRT commercial P and K fertilizer on ground nit receiving manure. Blanket N across all acres going to corn in the form of manure or NH3. Sidedress 32% in crop.
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Post by victory on Sept 20, 2022 8:11:35 GMT -6
I believe there is always a benefit following a pulse crop, regardless of what the soil test shows. That said, I do always soil test in the spring.
Studies have been done more than once and no one seems to be sure exactly what it is that the pulse crop changes that makes the following crop do better. With peas it occurs the following year and then tapers off. With faba beans the biggest bump seems to be two years after the faba crop.
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Post by SWMan on Sept 24, 2022 22:06:26 GMT -6
I think it is important to have geo-referenced locations where the probes are taken, and if possible same guy doing them every year. My agronomist tested half the farm today, he sends to A&L Labs in Ontario, seem to get very good results from there. I usually follow them pretty close.
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Post by snapper22 on Sept 25, 2022 4:52:07 GMT -6
I did farmers edge a couple years. Think the soil tests aren’t bad but I found it bizarre them out in the snow taking samples. Does that skew anything? Done with them now cause I saw no value in their service other than soil tests. Id like to try a Haney test and imagine for what I give farmers edge at the last could test a cross section of the farm for less money.
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Post by kenmb on Sept 26, 2022 8:08:46 GMT -6
I would think with peas and the nitrogen fixing component tied to nodules that you need time for those nodules to break down and enter the soil to really know the nitrogen contribution. Much like other organic matter being available for the new crop as it is converted by micro organism activity. Agronomist here does a calculation on organic matter to figure out how much will be available for the new crop rather than just looking at soil test result for nitrogen, and it seems to be working as have cut back on nitrogen and gotten better yields. Although that could be the soil improving generally speaking as I do things a little different then dad did. I would assume this is standard practice but the reason I mention this that the same guy has been putting in soil probes and doing his own research to try an anticipate the soil activity and therefore as it pertains to soil tests and time of year and such. If I remember right, as this was in winter we were talking, that soil activity will go right until the soil freezes but more importantly, soil moisture plays the biggest role. So soil tests in one late fall may give different results vs another late fall based on if it is a wet fall or not. I will have to ask him again about it since these tidbits don't always stick in memory so well because I wonder if much is converted before freeze up anyway, regardless of moisture. Most is probably converted the following season.
It's a simple enough concept though. There is a fair portion of nitrogen tied up in organic matter that can feed the next crop so there is a time component to it becoming available and therefore when it shows up in soil tests.
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Post by torriem on Sept 26, 2022 12:27:35 GMT -6
I've never seen anything on a soil test after peas that was significant, and I have never seen a measurable yield bump in the crop the following year in those fields either. Not sure why!
With fertilizer prices remaining inflated, we're seriously considering having someone come in and do some soil type mapping, and some geo-referenced soil sampling, and then try some VR to reduce our dry fertilizer application by 10-15% or so. Might do my own VR prescriptions, just reducing it on the hill tops that never produce and putting more on the slopes that perform the best. Probably reduce it in the wet valleys too. I'll probably post a new topic about this some time.
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Post by northernfarmer on Sept 26, 2022 14:37:57 GMT -6
We used to grow peas years ago and I can't recall any exact number from the soil samples we had done back then but I don't believe anything much showed up nitrogen wise on soil samples after the pea crop and while some claimed there should be nitrogen, there were others that said no no, its the plant that with the proper growing condition and using the applied inoculation to trigger the plant to produce the nodules on the roots and in turn its turning the plant into a nitrogen gathering factory from the nitrogen in the air for "its own use" rather then adding much of any extra nitrogen after the fact to the soil. That to me makes far more sense and in fact if things go sideways and get excess rain and the nodules rot, the plant is now trying to suck nitrogen from the soil like any other plant would do. Today reading something on field peas and it mentioned two things, either working the pea crop under before the pea seeds begin to form at all can add nitrogen as the plant gathers the nitrogen and then gears up to put that nitrogen its gathered to sent into the seeds its going to produce. Also the time factor after lets say a harvested pea crop as the plant material takes time to break down and put back any nitrogen its got left in the pea stalk and that won't show up in a fall soil test.
Be this all correct or not, that is how I have viewed the picture and so looking at it in terms of a crop not requiring nitrogen put down for the pea crop rather then one of assuming by magic that it produced a massive excess of nitrogen beyond its own requirements which would seem far too good to be true.
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Post by torriem on Sept 26, 2022 17:14:36 GMT -6
That makes a lot of sense. It wouldn't be terribly efficient if the plants were to put nitrogen into the soil rather than just making what they need to grow themselves.
There is some evidence, however, that when intercropping legumes seem to be doing some kind of symbiotic thing with regards to nitrogen and carbon with the companion crop. I've had some amazing wheat yields with much reduced fertilizer rates when undercropped to alfalfa.
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Post by garyfunk on Sept 26, 2022 17:55:33 GMT -6
One wet fall Western Ag Labs said I didn't need any nitrogen to get 140bu oats after my pea crop. Good thing I didn't trust the test. Put on 35lbs. Went 100 - what a disappointment.
Watch soil tests after warm moist falls. Lots of microbial activity that will release nitrogen that usually doesn't happen until June.
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Post by victory on Sept 26, 2022 19:00:43 GMT -6
I've never heard of someone recommending no nitrogen after a pea crop. We have no problem cutting back 10-15% on nitrogen after a pea crop.
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Post by Oatking on Sept 26, 2022 19:48:36 GMT -6
I was shocked how low my nitrogen levels are this fall on my oat ground. Got my tests back today and had a whopping 7lbs in the 0-15 inch range. less in the 0-6 inch range ( 3lbs). I will be putting soybeans on this land because the thought of putting canola on this land and putting 160lbs n down is not making a whole lot of sense now. Some of these same fields last year showed upwards of 70lbs available in the top 6 inches. At least if you do the math 70lbs of n in the soil and another 70lbs added got a 200 bpa oat crop this year.
Slow release fertilizer might have to be a real option next year to get the best bang for your buck.
Interestingly my phosphate and other key nutrient levels all showed very high ppm.
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Post by torriem on Sept 26, 2022 20:11:12 GMT -6
I typically use ESN for about 30% of my N needs, except on corn where I make it closer to 45%. Jury is still out on ESN on wheat, frankly. But it seems to work fairly well for corn, canola, and winter wheat. Of course I control my rain here.
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