C.O.R.N. Newsletter: 2016-08
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Weather outlook
After a very warm March with temperatures 5-10 degrees above normal, April got off to a cold start with temperatures running 5-10 degrees below normal.
After early week rain and some mid-week temperatures near or just below freezing, a warmer and drier period is in store through about April 19. The week break with lots of sunshine, warmer temperatures and drier conditions should allow for some needed drying.
The next rain chance will come either on April 19 or 20. Rainfall for the remainder of April looks to be mainly under 2 inches which is near normal.
April does not appear as warm as earlier thought. It looks like April will go down with slightly below normal temperatures and near normal precipitation.
The risk for last spring freezes appears on track to be about normal which means the last hard freeze occurs in mid April in southern Ohio and closer to late April in northern Ohio. It is not uncommon to see frost in low lying areas into early May.
Risk Outlook April May June
Temperatures Slighty Below Slightly Above Above
Rainfall Normal Slightly Below Slightly Below
Freeze Normal
4 inch soil Normal Slightly Above Above
Evapotranspiration Slightly Below Normal Above
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Soybean Planting Date, Seeding Rate, and Row Width
Planting date. Planting date (both too early and too late) can reduce soybean yield potential. In 2013 and 2014, we conducted a planting date trial at the Western Agricultural Research Station near South Charleston, Ohio. In both years, soybean yield decreased by 0.6 bu/ac per day when planting after mid-May. (Note: Soil temperatures were >50°F at each planting date.) The greatest benefit of planting May 1 to mid-May is canopy closure which increases light interception, improves weed control by shading out weeds, and helps retain soil moisture.
Planting too early (before field conditions are adequate) comes with a risk. Factors such as damping-off and pressure from bean leaf beetle are concerns to keep in mind, as well as the possibility of a late spring frost. (Our early May planting date in northeastern Ohio in 2013 was damaged by bean leaf beetle and two frosts that occurred mid-May.)
Before heading to the field, consider the conditions you will be planting into. Soybean germination begins when soil temperatures reach 50°F and moisture is present at the planting depth of 1-1.5 inches. With these conditions, emergence can typically be expected 2-3 weeks after planting. Do not plant early if the soil is excessively cold or wet. Slower germination and compaction can negate the benefits of the earlier planting date. Timely planting is critical for maximizing yield in soybeans, but using good judgement on field conditions plays a role that is equally important to determining yield potential.
Seeding rate. What is the optimum soybean seeding rate? On-farm research conducted by the AgCrops Team from 2004-2014 indicates that
116,000 plants/acre at harvest resulted in a relative yield of 90% (i.e., If 100% yield is 50 bu/ac, 90% yield is 45 bu/ac) when soybeans were planted in May. In the seeding rate figure, the relationship between yield and final stand is a relatively flat line indicating that soybean can yield well over a wide range of seeding rates. (Note: All of the seeding rate work was conducted in either 15- or 7.5-inch row width.) Row spacing. In Ohio, most soybeans are planted in row widths ≤ 15 inches. Soybeans grown in narrow rows (≤ 15 inches) tend to out-yield soybean produced in wide row width (30 inches) due to increased sunlight interception in narrow rows. Row width should be narrow enough for the soybean canopy to completely cover the interrow space by the time the soybeans begin to flower.
In our 2016 row width study, soybeans grown in 7.5 and 15-inch rows yielded similarly while soybeans grown in 30-inch rows yielded on average 15-20% lower. Our trial located at the Western Agricultural Research Station in Clark County was planted the end of May (pictured below). In June, the soybeans planted in 30-inch rows looked better than the soybeans planted in 15 and 7.5-inch row widths.
However, the soybeans planted in 30-inch rows did not achieve canopy closure until after July 15. The 30-inch plot pictured below yielded 59 bu/acre while the 15 and 7.5-inch plots pictured below yielded 81 and 85 bu/acre, respectively. With funding from Ohio Soybean Council, this study will be repeated in 2016. -
Mining Ohio Historic Data that went into Tri-State Recommendations
The Tri-State Fertilizer Recommendations, published in 1995, provided a unified soil fertility framework between Michigan, Ohio and Indiana. These recommendations are based on, “field calibration and correlation studies that have been conducted over the past 40 years.” Although it was a collective scientific work, the extensive data that went into these recommendations were not systematically compiled and shared with the public.
At Ohio State, Dr. Jay Johnson was the Soil Fertility Specialist who conducted field trials and helped develop fertilizer recommendations. From 1976 – 1999, Dr. Johnson reported the results of his field trials from that field season in an annual report. We went through these reports and pulled out every field trial that looked at phosphorus and potassium fertilization. We found 85 P trials conducted over 8 sites: 47 in corn, 33 in soybeans and 5 in wheat. We found 102 K trials conducted over 8 sites: 68 in corn, 32 in soybeans and 2 in wheat.
For each trial, we calculated the percentage of relative grain yield by dividing the yield of the unfertilized plots by the yield of the fertilized plots and multiplying the result by 100. Since yields can vary greatly over sites and years, we use the relative yield to shows us how much fertilization increased or decreased grain yields. For each trial, we then took the relative yield and graphed it against the soil test P or K level. Figure 1 shows this relationship with P and Figure 2 shows the relationship with K. Each dot represents a single field trial from one year. The solid black horizontal line at 100% represents no change between unfertilized and fertilized plots. The dotted black line at 90% shows a 10% reduction in yield. The red dashed vertical line shows the Tri-State critical levels of 15 ppm Bray P1 (Figure 1) and 100 ppm Ammonium Acetate K (Figure 2). These are the data from Ohio that helped establish the critical soil test P and K levels found in the Tri-State Fertilizer Recommendations. A field with soil test levels to the left of the red dashed line has a reasonable chance of a yield response to fertilization and so fertilizer is recommended, while fields with soil test levels higher than the red line have a very low chance of a yield response to fertilizer, and so little to no fertilizer is recommended.
We can consider this information a ‘historic’ foundation and efforts are now underway to produce ‘current’ information to see if the fertilizer recommendations need to be revised. You can help with this effort by representing your region as a farmer cooperator and conduct on-farm strip trials. There is some financial support available for your time. More information can be found here: go.osu.edu/fert-trials
This work is supported by the Ohio Soybean Council and the Corn and Small Grains Marketing Program.
Figure 1. Relative Grain Yield vs. Soil Test Phosphorus
Figure 2. Relative Grain Yield vs. Soil Test Potassium
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Soil Amendment and Foliar Application Product Evaluation Trials Summary
In 2015, the Soil Fertility Lab at Ohio State started offering a third party evaluation of proprietary soil amendments and foliar applications aimed at improving the mineral nutrition and productivity of crops. This new service intends to provide timely and unbiased information on these products for farmers. In 2015, we tested submitted products from the following companies:
- AgZyme® by Ag Concepts
- AO Crop by Agrarian Organics
- Enersol ® and Enersol LDG® by AMCOL® Bio-Ag
- Liquid Carbon by Monty’s Plant Food
Methods: Corn and soybean trials were planted at three sites on Ohio State University Research Farms: 1) Clark County at the Western Agricultural Research Station in S. Charleston, 2) Wayne County at the Ohio Agricultural Research and Development Center in Wooster, 3) Wood County at the Northwest Agricultural Research Station in Custar.
Data collected include: 1) Complete soil sample analysis prior to planting, 2) Emergence counts at V5 for corn and soybean, 3) Whole plant sampling at V5 for total biomass and complete nutrient analysis, 4) Leaf sampling at R1 for corn and soybean for complete nutrient analysis, 5) Final stand counts at maturity for corn, and 6) Harvest grain yield with complete grain nutrient analysis.
Results: Across all three sites, no consistent trends were found with any of the tested products. No products significantly affected a measured property at more than 1 site. For both corn and soybean, no product treatment yielded significantly greater grain than the control. This was the first year of field data, so interpretations should be made with caution, especially considering the weather encountered in the 2015 field season.
The summary report can be found here: go.osu.edu/SAFA
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The Big Data Confusion: Part 5 – Notice
This week’s installment of “The Big Data Confusion” highlights “Notice”. According to the Privacy and Security Principles for Farm Data, “farmers must be notified that their data is being collected and about how the farm data will be disclosed and used. This notice must be provided in an easily located and readily accessible format.” A key component to any ATP contract agreement is the specifications of how and when data is being collected, and how and for what that data will be used for.
In addition to all other parts of a contract agreement, the notice to farmers should be clearly expressed. This notice can come in the form of an explicit statement, page, or separate document. The notice should be very obvious, perhaps using language to attract the reader’s (in this case, the grower’s) attention. Today, many apps are using a special screen requiring the user to acknowledge how the app can use data (see photo). Some sort of similar notice needs to be provided to growers when singing data contracts with Ag Technology Providers. Next week’s installment will focus on transparency, which ties in nicely with the need to provide specific data collection and use information to growers. The notice should use contain obvious and transparent verbiage so that no question is left as to how data is being used and by whom
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Temperatures Went the Wrong Way!
This was more for my own curiosity to see what has happened to the soil temperatures in the state following 2 weeks of cold, snowy weather. Our temperatures went down in almost all of the locations. From the weather stations at the OARDC branches, these are the soil temperatures at 2.5 inches, from March 21 and April 11:
County Research Branch Temperature (F)
March 21 April 11
Jackson Jackson 48.3 46.7
Noble Eastern 48.6 47.8
Piketon Piketon 49.3 47.1
Clark Western 48.0 45.9
Huron Muck Crops 43.5 41.9
Ashtabula Ashtabula 36.1 33.6
Sandusky North Central 44.8 41.4
Wood Northwest 43.7 43.8
Wayne Wooster 41.2 42.3
Crop Observation and Recommendation Network
C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.
Contributors
Disclaimer
The information presented here, along with any trade names used, is supplied with the understanding that no discrimination is intended and no endorsement is made by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.
CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For more information, visit cfaesdiversity.osu.edu. For an accessible format of this publication, visit cfaes.osu.edu/accessibility.