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Robert Nielsen
เข้าร่วมเมื่อ 9 ส.ค. 2009
I was raised on a farm in eastern Nebraska, obtained a B.S. degree at the Univ. of Nebraska and graduate degrees at the Univ. of Minnesota. I joined the Agronomy faculty at Purdue in 1982 with statewide responsibilities for applied field research, graduate student training, and Extension programming with an emphasis on optimizing yield, profitability, and stewardship of corn production for growers in Indiana and throughout the eastern Corn Belt. After 40 years of having the privilege to serve Indiana agriculture as Purdue's "Corn Guy", I retired from Purdue on 31 December 2022.
Over those 40 years, I shared my experience and knowledge of corn with more than 720,000 farmers and their advisors at over 2,000 Extension programs in Indiana and elsewhere in the U.S. I also had the opportunity to travel internationally, with invited participation in farmer conferences in Canada, Hungary, Argentina, New Zealand, Russia, Italy, South Africa and Mexico.
Over those 40 years, I shared my experience and knowledge of corn with more than 720,000 farmers and their advisors at over 2,000 Extension programs in Indiana and elsewhere in the U.S. I also had the opportunity to travel internationally, with invited participation in farmer conferences in Canada, Hungary, Argentina, New Zealand, Russia, Italy, South Africa and Mexico.
Yield Response to Plant Populations in Corn
Posted 9/26/2023. @purduecornguy
The cost of seed corn represents 17% of farmers' variable cost of production, second only to the cost of nitrogen (N) fertilizer. Every thousand seeds planted per acre that does not increase grain yield represents $3 to $4 per acre of lost profit for the farmer. Grain yield response of commercial dent corn to plant density (number of plants per acre or "population") is typically not linear. More commonly the response takes the form of a quadratic or quadratic plateau function. As population increases, the magnitude of the yield response decreases until ultimately yield response ceases or even decreases due to the stress imposed on the plants. The "balancing act" of determining the "optimum" plant population is not just about maximizing grain yield, but also about avoiding unnecessary seed expenses as yield response to population decreases.
Dr Jim Camberato and I began conducting field scale research trials in 2008 to evaluate corn responses to plant population. Over 16 years, we accumulated nearly 100 datasets from different geographic regions and growing conditions throughout the state. Questions addressed in this presentation include 1) whether hybrids respond differently to plant population, 2) whether high plant populations require higher N fertilizer rates, and 3) whether site-specific yield responses to plant population warrant variable rate seeding.
Related resources:
* Nielsen, Camberato, and Lee. 2019. Yield Response of Corn to Plant Population in Indiana. www.kingcorn.org/news/timeless/CornPopulations.pdf
* Nielsen, Quinn, and Camberato. 2022. Optimum Plant Populations for Corn. www.kingcorn.org/news/timeless/PlantPopulations.html
The cost of seed corn represents 17% of farmers' variable cost of production, second only to the cost of nitrogen (N) fertilizer. Every thousand seeds planted per acre that does not increase grain yield represents $3 to $4 per acre of lost profit for the farmer. Grain yield response of commercial dent corn to plant density (number of plants per acre or "population") is typically not linear. More commonly the response takes the form of a quadratic or quadratic plateau function. As population increases, the magnitude of the yield response decreases until ultimately yield response ceases or even decreases due to the stress imposed on the plants. The "balancing act" of determining the "optimum" plant population is not just about maximizing grain yield, but also about avoiding unnecessary seed expenses as yield response to population decreases.
Dr Jim Camberato and I began conducting field scale research trials in 2008 to evaluate corn responses to plant population. Over 16 years, we accumulated nearly 100 datasets from different geographic regions and growing conditions throughout the state. Questions addressed in this presentation include 1) whether hybrids respond differently to plant population, 2) whether high plant populations require higher N fertilizer rates, and 3) whether site-specific yield responses to plant population warrant variable rate seeding.
Related resources:
* Nielsen, Camberato, and Lee. 2019. Yield Response of Corn to Plant Population in Indiana. www.kingcorn.org/news/timeless/CornPopulations.pdf
* Nielsen, Quinn, and Camberato. 2022. Optimum Plant Populations for Corn. www.kingcorn.org/news/timeless/PlantPopulations.html
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In this recorded seminar from Nov 2021, I reflected on my career in agronomic Extension and research at Purdue University. The topics I covered in that seminar included: 1. Extension and its role at a land-grant university 2. My approach to crops Extension and research over a nearly 40-year career 3. Relevance and challenges for crops Extension & research in the future.
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Posted 12/14/2021 by Bob Nielsen, Purdue Corn Extension Specialist. This presentation shares what we know and don't know about corn response to applied sulfur fertilizer in Indiana, based on field scale research we conducted throughout the state from 2017 - 2021. While it is true that more fields of corn respond to sulfur today than decades ago, it is also true that many fields do not require s...
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Crop Resilience to "Normal" Weather
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Posted 1/26/2021 by Bob Nielsen, Purdue Corn Extension Specialist. Concepts and strategies on how to improve crop resilience to increasingly variable, and extreme, weather patterns.
High Yield Corn: Focus on the Fundamentals / Part 3
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Posted 1/5/2021 by Bob Nielsen, Purdue's Extension Corn Specialist. Achieving high yields in corn requires attention to detail and a focus on agronomic fundamentals. This video is Part 3 of a 3-part series, created from the overall longer version of the presentation that was initially posted 11/30/2020.
High Yield Corn: Focus on the Fundamentals / Part 2
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Posted 1/5/2021 by Bob Nielsen, Purdue's Extension Corn Specialist. Achieving high yields in corn requires attention to detail and a focus on agronomic fundamentals. This video is Part 2 of a 3-part series, created from the overall longer version of the presentation that was initially posted 11/30/2020.
High Yield Corn: Focus on the Fundamentals / Part I
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Posted 1/5/2021 by Bob Nielsen, Purdue's Extension Corn Specialist. Achieving high yields in corn requires attention to detail and a focus on agronomic fundamentals. This video is Part I of a 3-part series, created from the overall longer version of the presentation that was initially posted 11/30/2020.
On-farm Research: Why & How
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Posted 11/30/2020 by Bob Nielsen, Purdue Corn Extension Specialist. A review of the ins and outs of conducting on-farm or field scale row crop production research.
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Posted 11/30/2020 by Bob Nielsen, Purdue's Extension Corn Specialist. Strategies for increasing corn yield profitably.
Check Corn Fields for Stalk Rot
มุมมอง 3.8K13 ปีที่แล้ว
Severe stress in corn during the grain filling period can cause cannibalization of the lower stalks in response to the physiological demands by the developing ears. This remobilization of stored carbohydrates from the lower stalks literally decreases the structural integrity of the stalk tissue and increases its vulnerability to fungal root rot and stalk rot organisms. Scouting fields prior to ...
VERY informative. Thanks so much!!!
What a thorough presentation. You often find 5 minutes here or there on YT. Our farm is less than 30 miles from the Canadian Shield...we run 72 to 78 day corn hybrids. Although we do not have the disease pressure found in the lower states, we do corn on corn on some fields for 12+ years. We hit a high yield of 288bu on a very small stretch in 2023...overall farm yield after drying was 147bu per acre. So what did we do right on that one spot? That spot was: -planted 3k less per acre -spring broadcast for 180bu corn -chicken manure -dropped planter speed by 2 mph -well drained spot(no tile) -typical wet spot -2 passes of Roundup and no fungicide. My kernel counts were spot on shortly after pollination. With great germination and no drought stress on that spot, those plants grew a 16x35 cob and a 12x25 second at 30k plants per acre. My sugguestion is to try on your smallest worst field in 2025...drop the pop, slow the planter way down and fertilize like you normally would and see of there is a difference.
Great work. Thanks for the information. Really shows the spin off of Corn Warriors...I had the pleasure of combining corn planted at nearly 40k per acre. No cobs over 30% of the field. I want to increase my 10 year average...not my year after year...
Very useful information. Our local seed salesmen are always pushing higher populations, despite this being a stress prone area.
We've upped our total farm yield by dropping plant pop by 4k...
Thanks for the great videos. Have you ever done trials including plant sap analysis for determining yield loss?
No, I have not.
I had used most of your Fundamentals to make field average of 200 bu/ac in my farming operation in the 1960's. I had a Soil Science degree in those years while starting to farm. Back then there were not many Midwest farmers who made 200 bushel yields. We were planting up to 34,000 and they used 10,000 less. One exception was from Decatur Illinois area. It was good to talk to them at the awards banquets. In Texas we were much less traditional than the Midwest as this was a new corn area.
it is true that transgenic corn , soy and others sparking 5 time insuline in human being higher that sugar , and some say 50% of people in hospital today are because of this acccording to Dr Fung from Toronto.Does the health care system can survive to the transgenic revolution? as they put corn syrup in so many foods now??
I am in a very yield limited environment in East Central Minnesota. Did a lot of population studies with Pioneer. We had a 24, 30, 36 and a 42k population across four hybrids each year. And every year the higher population made the most yields. But the 36,000 consistently made better money. 32 or 34 is the common upper end and there's still a lot of areas that 27 and 29 are the best bang for the buck
Thank you Sir for your informative and educational techniques and knowledge about planting maize..it helps a lot as a young farmer..very interesting
Sir how many kilos you produce per hectare..may we know .bec here in our country we calculate pwr hectre in kilos..per sacks also .we produce 10k-16 tons per hectare ..may u know your calculations Sir..Thanks..im interested for your teaching in maize and technique..it can helps us a lot as a millenial farmers..
To convert corn grain yield in bushels per acre to kilograms per hectare, multiply by 62.9. For example, 200 bushels per acre = 200 x 62.9 = 12,580 kilograms per hectare = 12.580 tons per hectare.
Curious if the chart at 5:50 showing increasing population tolerance of hybrids, due to selecting for that feature alone, has reduced other important variables like nutrients and protein in the corn? .. Seems like I've seen "the great pursuit of yield" has lost most of the protein, as low as 3-5% protein remains from what started as 9% protein in source yellow heirloom corn (such as Reids Yellow Dent). I started growing red and blue heirlooms that run 12-15% protein. Impact is real, a pig farmer I know found a 20% increase in litter sizes after he switched to high protein heirloom corn. I found heirloom varieties do best at lower population rates like 22-24k, but the yield loss from fewer plants is more than balanced out by the increased bacon! Last winter's drop in egg production rates noted by many homesteaders revolved around too-low of protein in the common retail brand of chicken feed to lay eggs, such as a batch of low protein corn substituted in the recipe, because when homesteaders switched feed brands their egg production returned. Perhaps there is a future research project in high protein/nutrient corn? Quality vs Quantity?
Excellent point you raise, however I doubt that modern hybrids' tolerance to population is the CAUSE of lower protein in and of itself. It's long been recognized that there is a negative relationship between grain yield and protein in corn, but the physiological cause/effect for this relationship is not well understood. So, for now, all I can say is that the yield improvement that's occurred over the decades has simply unintentionally resulted in lower protein content.
I forgot where I heard it but by taking protein out of the Corn you get a lot more kernels with the same amount of nitrogen. But like you said the colonels are just empty
Thank you
they harvest 400 bu per acre ... and when i go to the feed store i have to pay $11 per bu of bagged feed corn.....it used to be $3 per bu ..... why is feed corn so expensive when we have millions of acres of corn growers yielding 300 to 400 bu per acre
Two comments I can offer... 1. Average corn yields are way less than the 400-600 bu/ac yield contest winners and 2. Feed prices are set by the processor and sellers of the feed corn, not by the farmers who grow the corn.
What was the sulphate rate used in the 2X2 that was responsive other than 5 lb/ac?
Not sure I understand your question. In the few trials where we evaluated S in the starter 2x2, the rate was 5 lbs S per acre in the form of ATS. Only 1 of 9 such trials did we see a benefit from 5 lbs S in the starter.
Thank you !! Very structured information!
Boiler up 😂 😂😂 Randy dowdy
I don't understand why we have very low yields per acre in Kenya
How low yields?
😭
Muchas gracias profesor, thanks great presentation.
Thanks fir the video! Any thoughts on application of S fertilizer on fields with recent manure application history?
Tell me something about cabbages
Thanks Dr. Nielsen. I am here in Malaysia trying to plant some maize. Your lecture is eye opening. We have so much rain and sunshine, I guess our challenges here are seeds and disease.
Thanks from india👌👌
Wow Bob! I talked to you back in 1983 about compaction in my corn. As you probably remember that was a crazy year. Lots of rain early, then the big drought. Tough year getting the crop in. I planted some corn fields when it was to wet. Hello from South Central IN.
Ag academia has an absolute unwillingness to learn anything about soil biology. You’re so close. Yes if we increase kernel weight our yields go up. Yes kernel weight is affected by photosynthesis. How do we increase photosynthesis!? Yes dropping our populations can increase it, but how else!? Increasing the relationships between plants and soil biology. The microbes in the soil, if given the chance to make connections with plants, actually incentivize them to photosynthesis more! If we stop tilling, stop adding synthetic fertilizers, and stop leaving our ground in bare fallow after harvest we can increase our yields and profits by pretty amazing amounts. I’m currently a student at Purdue and I’m tired of my professors unwillingness to even just entertain science that contradicts what they teach. I’ve had several refuse to give me their opinions on scientific papers from their colleagues at other schools. The agronomy here, on the whole, is seriously outdated.
Very interesting, thanks for uploading the video. 😄👍
At what stage you recommend sulphur application to corn?
See our related online research summary... ag.purdue.edu/agry/Documents/Sulfur%20deficiency%202017.pdf
Hello sir
Thanks for the great presentation! What’s the most important yield component number of kernels harvested or kernel weight?
That is a difficult question to answer. Both components are obviously important and growers should aim to optimize each one in order to maximize yield. It's useful to remember that kernel number per ear influences kernel weight inversely, meaning that ears with high kernel counts typically have lower weight per kernel, and vice versa.
It never fails to blow my mind that soil biology / health and how well the end product performs at it's intended use are barely, if ever mentioned by ag academia. I have specialty corn that would really make me worry if I saw yields over 125, because the lab results might show less protein, and it's entire purpose is to provide feed that requires no, or very little soy supplement. These modern hybrids are so much better than the ones from 30 years ago, but 30 years ago, livestock farms and dairy's didn't have to use near as many supplemental additives to their feed. A lot of great info here, don't take me wrong, and I appreciate the effort. I don't expect the whole world to go organic, heck, I don't want anyone else to go organic. I set my own prices and the last thing I want is to be dependent on the commodities market. For the record, the longer RM organic corn I plant has hit 140, 160, and 190 the past 3 years. I attribute the increases to stocking more livestock that graze on the cover crops. I also sold it all for $9-$10. I'll never go over $10, even if conventional GMO corn is bringing $9. Won't do that to my customers and I start making money at about $2.50, but I add 2 bucks to fund growth, equipment and infrastructure.
Somehow when I was in elementary school many years ago, I stumbled across a copy of a book called "How to Lie with Statistics" in the school library. Not anywhere near the normal educational program of K-6th grades so it was a bit odd that it was there. But there it was and it provided more insight than a lot of the regular classwork. It showed you need to look with a keen eye to see what the charts are selling you. I later went through an engineering program, MBA, and decades of work in manufacturing, including Quality functions ... However, at the end of the day all that training and experience revealed that if you needed statistics to prove A is better than B then while the change is statistically an improvement it's rarely 'real world' important. A change needs to be distinctive 'to the casual observer' to be a valuable commercial finding.
There is a similar good book titled "A Field Guide to Lies / Critical Thinking in the Information Age" authored by Daniel J. Levitin. It is a very good read on this important topic.
Dr. Nielsen, this is a really great presentation. Thanks for taking the time to share this with the public. I have taken away some good tips. I have been researching soil health and fertility with a goal to hit 300 bpa field average in the very near future.
South Carolina skewed the 2017 NCGA dryland average with 9 entries over 320 bpa. Google his 2017 supervisor, charged with embezzling money from Clemson the following year. His yields are completely made up and it's sad people what level some people will stoop to.
An excellent presentation. Covers many factors well beyond fertilizers that effect corn yield. The details provide a real insight as to how to recognize the problems.
Excellent info