Fertility

Fertilizer Prices Climb; and Injunction for Largest Proposed Fertilizer Mine in Brazil Overturned

Source: Farmdoc, University of Illinois

DTN Farm Business Editor Katie Micik Dehlinger reported yesterday that, “The retail prices of all eight major fertilizers climbed higher in the second week of October, with anhydrous, MAP and UAN32 posting the largest gains.

“DTN polls retail  fertilizer sellers each week to compile price estimates and considers a price change of 5% or more to be significant.

“Anhydrous prices climbed 16% on average to $804 per ton. MAP and UAN32 each climbed by 7% to $794/ton and $418/ton, respectively.”

Dehlinger explained that, “The prices of the remaining five fertilizers were all higher than last month, but less significantly. DAP cost an average of $711/ton; potash, $506/ton; urea, $575; 10-34-0, $613/ton; and UAN28, $356/ton.”

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Wheat Planting Management Considerations for Fall 2023

This year, wheat yields were extremely high across Ohio. In the Ohio Wheat Performance Test (https://ohiocroptest.cfaes.osu.edu/wheattrials/default.asp?year=2023), grain yield averaged between 86 and 126 bu/acre across five Ohio counties. Cool temperatures and adequate subsoil moisture led to a long grain fill period. The long grain fill period coupled with low disease resulted in high-yielding conditions. Mother nature certainly helped us out in 2023; however, fall wheat management is important to set your crop up for success.

Now that we’ve entered mid-September, wheat planting is just around the corner. Here are our key management strategies for this fall:

  1. Plant within the 10-day period starting after the county fly-safe date. It can be tempting to plant wheat before your county’s Hessian fly-safe date (Figure ; however, the best time to plant wheat is the 10-day period starting the day after the fly-safe date. Planting before the fly-safe date increases the risk of insect and disease problems including Hessian fly and aphids carrying Barley Yellow Dwarf Virus. Our wheat planting date field trials have shown no yield benefit of planting prior to the county fly-safe date.
  2. Select high-yielding varieties with high test weight, good straw strength, and adequate disease resistance. Do not jeopardize your investment by planting anything but the best-yielding varieties that also have resistance to the important diseases in your area. Depending on your area of the state, you may need good resistance to powdery mildew, Stagonospora leaf blotch, and/or leaf rust. Avoid varieties with susceptibility to Fusarium head scab. Plant seed that has been properly cleaned to remove shriveled kernels and treated with a fungicide seed treatment to control seed-borne diseases.
  3. Optimum seeding rates are between 1.2 and 1.6 million seeds/acre. For drills with 7.5-inch row spacing, this is about 18 to 24 seeds per foot of row. When wheat is planted on time, the actual seeding rate has little effect on yield, but high seeding rates (above 30 seeds per foot of row) increase lodging and risk of severe powdery mildew development next spring.
  4. Planting depth is critical for tiller development and winter survival. Plant seed 1.5 inches deep and make sure planting depth is uniform across the field. No-till wheat seeded into soybean stubble is ideal, but make sure the soybean residue is uniformly spread over the surface of the ground. Shallow planting is the main cause of low tiller numbers and poor winter survival due to heaving and freezing injuries. Remember, you cannot compensate for a poor planting job by planting more seeds; it just costs more money.
  5. Follow the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa (https://agcrops.osu.edu/FertilityResources/tri-state_info).
  6. Apply 20 to 30 lb of actual nitrogen per acre at planting to promote fall tiller development. A soil test should be completed to determine phosphorus and potassium needs. Wheat requires more phosphorus than corn or soybean, and soil test levels should be maintained between 30-50 ppm (Mehlich-3 P) for optimum production (Table 1). Do not add phosphorus if soil test levels exceed 50 ppm.

Table 1. Wheat phosphorus recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.

Table 1. Wheat phosphorus recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.

Soil potassium should be maintained at levels of 100-130 and 120-170 ppm (Mehlich-3 K) on sandy soils (CEC < 5 meq/100 g) and loam/clay soils (CEC > 6 meq/100 g), respectively. If potassium levels are low, apply K2O fertilizer at planting, depending on soil CEC and yield potential (Table 2).

Table 2. Wheat potassium recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.

Table 2. Wheat potassium recommendations from the Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat, and Alfalfa.

Soil pH should be between 6.3 and 7.0. In Ohio, limed soils usually have adequate calcium and magnesium.

Poultry Litter Application

By: Glen Arnold, OSU Extension

Stockpiles of poultry litter can be seen in farm fields across Ohio. While common each year in wheat stubble fields, there are also stockpiles commonly found in soybean fields. Getting the poultry litter to the fields ahead of spreading makes time makes the whole process more efficient. Poultry litter is an excellent source of plant nutrients and readily available in most parts of the state. With fall harvest just around the corner these poultry litter piles will soon be spread across farm fields.

Poultry litter can be from laying hens, pullets, broilers, finished turkeys, turkey hens, or poults. Most of the poultry litter in the state comes from laying hens and turkey finishers. Typical nutrient ranges in poultry litter can be from 45 to 57 pounds of nitrogen, 45 to 70 pounds of P2O5, and 45 to 55 pounds of K2O per ton. The typical application rate is two tons per acre which fits nicely with the P2O5 needs of a two-year corn/soybean rotation.

Like all manures, the moisture content of the poultry litter greatly influences the amount of nutrients per ton. Handlers of poultry litter have manure analysis sheets indicating the nutrient content.

Poultry manure from permitted operations needs to follow the Ohio Department of Agriculture standards when being stockpiled prior to spreading.

These include:

– 500 feet from neighbors

– 100 feet from a public road

– 300 feet from streams, grassed waterways, wells, ponds, or tile inlets

– not on occasionally or frequently flooded soils

– stored for not more than six months

– not located on slopes greater than six percent

– located on soils that are deep to bedrock (greater than 40 inches to bedrock)

Farmers who want to apply the poultry litter delivered to their fields are required by Ohio law to have a fertilizer license, Certified Livestock Manager certificate, or be a Certified Crop Advisor.

Field Observations Thru July 21

Corn

Corn growth varies greatly throughout the county, but, more fields are beginning to tassel.  As corn begins to tassel, nutrient (K > N > P) and water (0.30 inch per day) demands for the crop are close to maximum. Heat and drought will affect potential number of kernels.  Scout for insects (e.g., corn leaf aphid, western bean cutworm, corn earworm, fall armyworm) and diseases (e.g., gray leaf spot, southern rust, northern leaf
blight). Total leaf defoliation severely affects final yields.

VT (Tasseling) – Stage VT occurs two to three days before silking, when the last branch of the tassel is completely visible but silks have not emerged yet from the ear shoot. The plant has reached full height and the pollen shed begins. The time between VT and R1 can vary with different hybrids and due to environmental conditions.
Pollen shed (pollen drop) normally occurs during the late morning or early evening. Hail damage is more serious at this time than for any other growth period. All leaves have emerged and the complete loss of a pollen source would result in no grain formation.

We are nearing a point in the growing season where it is time to scout your corn fields and make a decision regarding fungicide applications. Click here to view the 2023 corn fungicide ratings.

Soybeans

Postemergence herbicide applications – Don’t forget the preharvest intervals (PHI) for grazing or harvest. Read more here.

 

Soybean Postemergence Weed Control – Grasses

Soybean Postemergence Weed Control – Broadleaves

Soybean Growth & Development – R2: Full Bloom

  • Open flower at one of two uppermost main-stem nodes
  • About 50% of the total mature node number has been established.
  • Very rapid nitrogen (N), phosphorus (P), potassium (K) and dry-matter accumulation is occurring and will continue through R6.
  • Defoliation of the plant of 50% at this stage will reduce yield by 6%.
  • Approximately 60 days away from beginning of physiological maturity (R7).

County Rainfall Update

Mount Vernon, OH

Corn Water Requirements

Soybean Water Requirements

Why are my soybeans yellow? Part 4

Soybeans throughout the county are beginning to look better.  Development has been slowed and many fields have areas (sometimes large areas) with a light green or yellowish tint to the beans.  What is causing this yellowing? One possibility is:

Nutrient Deficiencies

NITROGEN DEFICIENCY

Caused many fields to turn yellow in late June and July.  A dry spring delayed nodulation, then heavy rainfall saturated soils just as plants required large amount of N during the rapid growth phase. There is often a lag phase when nodulation and N fixation is insufficient to supply enough N for the plants demands early in the season.
The good news is that most fields will recover as soils dry out and biological nitrogen fixation catches up to demand.
Some farmers have asked if N fertilizer could be added to these fields to help them through this yellow phase.  Although applying N fertilizer does help green up the plants there is no economic benefit.  Numerous trials conducted in Ontario, Canada  show the average yield response to N fertilization is less than two bushels per acre.

Reposted from Tim Barnes, OSU Extension Marion County July 16,2023

POTASSIUM DEFICIENCY

Potassium (K) deficiency symptoms are frequently seen on soybean at early development stages (starting as early as V3) but can also develop on plants throughout the growing season. Potassium deficiency symptoms include yellowing of leaf tissue starting at the leaf tip and moving down the leaf margin (outer edge of leaf) (Figure 1). Severe K deficiency can lead to pre-mature leaf fall of the older leaves.

Potassium deficiency symptoms are often more severe in years where root growth is slowed or delayed (wet or dry years) and can be observed in fields with adequate soil test K levels.  A poorly developed root system can limit nutrient uptake causing what is likely a temporary nutrient deficiency.   These deficiency symptoms often decrease or disappear once adequate root development and soil conditions improve.

IRON DEFICIENCY CHLOROSIS

Iron deficiency chlorosis (IDC) is most common in poorly drained areas of the field. Plants with IDC tend to be stunted and yellowing occurs between the leaf veins while veins remain green (interveinal chlorosis). Leaves may also develop brown and necrotic spots in leaf margins. Iron is an immobile nutrient, so these symptoms most often occur first on newer, upper leaves.

IDC  symptoms are more common in years where root growth is slowed or delayed (wet or dry years).  A poorly developed root system can limit nutrient uptake causing what is likely a temporary deficiency symptomology.   These deficiency symptoms often decrease or disappear once adequate root development and soil conditions improve.

 

Why are my soybeans yellow? Part 3

Soybeans throughout the county are beginning to look better.  Development has been slowed and many fields have areas (sometimes large areas) with a light green or yellowish tint to the beans.  What is causing this yellowing? One possibility is:

Too much water/waterlogged roots

In some fields, the pale green to yellow leaves are the result of very wet soil conditions. Soybeans are a legume (like alfalfa) and do not like wet feet (roots)! This problem is commonly seen in low areas of the field or on poorly drained soils where water tends to stay for a prolonged period of time. When digging up plants in wet areas of the field you will find poorly developed or weaker root systems when compared to a healthy plant.

Soil water content is critical not only to supply the water needs of the plant, but to also dissolve nutrients and make them available to the plant. A poorly developed root system can limit nutrient uptake causing what is likely a temporary nutrient deficiency.

Temporary nutrient deficiencies can be observed when excess water in the soil depletes oxygen and builds up carbon dioxide levels. Although oxygen is needed by roots to grow and take up nutrients, high carbon dioxide levels are toxic and limit root growth and activity.

With better weather conditions plants will usually (sometimes slowly) grow through this phase.

Soybean nutrient deficiencies will be discussed in a different post.

Consideration for Corn N Management under Dry Soil Conditions

Source: C.O.R.N. Newsletter

Sidedress applications of nitrogen have begun and many more fields will receive applications in the upcoming week.  The information below from the C.O.R.N. Newsletter maybe of some interest.

When considering adjusting your corn nitrogen program for dry weather conditions, consider how N gets to the root system for uptake. Mass flow is the primary mechanism for nitrogen (also sulfur, magnesium, and calcium). Mass flow is where nutrients in soil solution move toward the root as the plant takes up and transpires water through the crop canopy. Also, consider how dry weather affects the plant root system. Root growth will slow in dry soils, the situation we are now experiencing in the upper soil depths. Fortunately, root growth will re-establish, and the mass flow of nitrogen will quickly improve with rainfall. Here are a few considerations for managing N applications.

Nitrogen placement is one area to consider changes within the limitation of equipment available. The nodal root system originating from the lowermost nodes will take up nearly all N. Normally we discourage surface applications of nitrogen due to potential volatilization losses of N in urea form found in UAN or urea. Under dry weather conditions, we have limited opportunities for rainfall to move N into position for uptake. The goal should be to have nitrogen close to the root system and close to roots actively taking up water. So, moving UAN placement closer to the row and a little deeper will improve plant access. Anhydrous application is already deep enough and moving closer to the row increases root injury potential, so no adjustment is needed.

Nitrogen rate is another consideration. Looking at our N yield response data from 1998-2022 does not show that lower yields usually require less fertilizer N than higher yields. We think that’s because the causes of lower yields, which are typically stress from having less available water at critical times, often affect root growth, and so may make it harder for plants to take up the N that is in the soil. If your plan was to apply a rate based on the Corn Nitrogen Rate Calculator (https://www.cornnratecalc.org) which is for corn after soybean and a N:Corn Price between 0.1 and 0.15, the rate is 160 to 181 pounds of N per acre then stay with that amount. If the plan was to apply more than that, then cutting back would be reasonable.

A final consideration is timing. Application systems that make late-season applications possible have become more common. Putting down a reasonable side-dress rate and then basing a later application on rainfall could be a reasonable strategy.

Cover crops would also be something to start looking at now. We know if the yield falls short of normal, we will have excess soil nitrogen left after the growing season. The edge of field studies conducted by USDA-ARS has shown we can recover a substantial amount of this residual N through a cover crop. Exploring available cost-share programs with NRCS and SWCD would be a reasonable way to retain that valuable N on your field for a future crop.

When and How Much Nitrogen to Apply to Wheat

Wheat has already reached green-up across the state so spring N may be applied anytime fields are fit. Keep in mind that research has shown no yield benefit to early N applications as long as the application was made by Feekes – 6 (one visible node).  If you need a reminder on how to assess if wheat is at Feekes GS 6, see this video: https://www.youtube.com/watch?v=D_f3VrqzV5c.  Nitrogen applied early has the potential to be lost since wheat will use little N until after jointing. Urea-ammonium nitrate (UAN) or 28% has the greatest potential for loss and ammonium sulfate the least. Urea will have little potential for loss as long as it does not volatize. No stabilizer will protect the nitrate component of UAN, which is roughly 25% of the total N in UAN at application time.

Ohio State University recommends the Tri-State Fertilizer Recommendation Bulletin for N rates in wheat. This system relies on yield potential. As a producer, you can increase or reduce your N rate by changing the value for yield potential. Thus, a realistic yield potential is needed to determine the optimum N rate.  To select a realistic yield potential, look at wheat yield from the past five years.  Throw out the highest and lowest wheat yield, and average the remaining three wheat yields.  This three-year average should reflect the realistic yield potential.

Table 10 in the Tri-State Fertilizer Bulletin recommends 120 lb N for yield goals of 100 bu/A, 110 for 90 bu/A crop, 90 lb for 80 bu/A crop, and  80 lb for a 70 bu/A crops. These recommendations are for total N. If you prefer to be more specific, the following equation may be used for mineral soils, which have both 1 to 5% organic matter and adequate drainage:

N Rate = (1.33 x Yield potential) – 13.

No credit is given for previous soybean or cover crops, since it is not known if that organic N source will be released soon enough for the wheat crop. The Tri-State Fertilizers Bulletin recommends that you subtract from the total (spring N) any fall applied N. I would take no more than a 20 lb/A credit even if you applied a larger amount. Whether you deduct fall N depends how much risk you are willing to take and your anticipated return of investment from additional N. Based on the equation above and deducting 20 lb from a fall application, a spring application of 100 lb N per acre would be recommended for a yield potential of 100 bu, 90 for 90 bu potential; and 70 for a 80 bu potential.  Nitrogen rate studies at the Northwest Agricultural Research Station over the past 20 years have shown the optimum rate varies depending on the year. However, averaged over years, yield data from these studies correspond well with the recommendation equation given above. These studies have also shown apart from one year, yields did not increase above a spring rate of 120 lb N per acre.

Wheat generally does not benefit from a nitrification inhibitor since temperatures are relatively cool at application time and the application is made to a growing crop, this is especially true as the crop approaches Feekes – 6. However urea may benefit from a urease inhibitor (products containing NBPT) if conditions for volatilization exist for several days after application. These conditions would include an extended dry period with warm drying temperatures (risk increases with temperatures above 70°F) and evaporating winds. Urea applications need at least a half inch rain within 48 hours to minimize volatilization losses unless temperatures remain relatively cool. The urease inhibitor will prevent volatilization for 10 to 14 days with the anticipation of a significant rainfall event during this time.

ESN or polymer coated urea will reduce the potential for N loss from leaching, denitrification, and volatilization. Since these conditions are unlikely to occur in most years, it may not be economical to use this product. Cool weather may prevent the timely release of N from ESN, so if ESN is applied, it should be mixed with urea or ammonium sulfate and be no more than 60% ESN.

A split application of N may be used to spread the risk of N loss and to improve N use efficiency. However, Ohio State University research has not shown a yield increase from this practice compared to a single application after green-up. In a split system, the first application should be applied no sooner than green-up. A smaller rate should be applied with the first application since little is needed by the crop at that time and the larger rate applied closer to Feekes – 6.

Wheat Growth Stages

OK, Mother Nature is not cooperating which means we can’t talk about corn and bean planting so let’s talk about the crop we do have growing – Wheat

Source: K-State University

Knowing what growth stage your wheat crop is at is essential for nitrogen, herbicide and possibly fungicide applications.  Most of the wheat I have seen in the county so far is between Feekes 5 and Feekes 6.

Feekes 5 is the time to be making your last nitrogen applications and applying herbicides as needed for weed control.  However at Feekes 6 you should cutoff for nitrogen applications to avoid leaf injury.  Additionally some growth regulator herbicides, like 2, 4-D and dicamba should not be applied.