Monthly Archives: August 2022

Some Early Thoughts On This Fall’s Soil Fertility Management

UK College of Agriculture, Food & Environment Corn & Soybean News (August 2022)

Dr. John Grove, Professor of Agronomy/Soils Research & Extension

SOIL TESTING for the next crop is important this fall. The summer season’s drought, after spring wetness (with compaction issues), is causing lower, more variable, corn and soybean yields. Lower grain yield means lower nutrient removal, but this is not perfectly predictable from a yield monitor. Drought affected grain is usually nutrient rich compared to rainy season grain. More corn acres will be harvested for silage rather than grain and nutrient removal is greater with silage. Soil test ‘problem’ fields/areas identified earlier this season. If you don’t do your own soil sampling, you might want to book sampling services early – this year there are more questions that need samples to inform deci-sion-making.

SOIL ACIDITY hurts root activity – a bigger problem in droughty seasons. Once soil test results are in, take a close look at soil pH. If needed, and if weather permits, lime should always be applied in the fall. Good quality lime takes time to dissolve and cause the carbonates to neutralize soil acidity.

DECIDING WHETHER TO APPLY fall nutrients, especially for corn and soybean, is more difficult this year. The decision generally depends on the target crop (wheat/forages vs. corn/soy); economics/value of fertilizer, time, and equipment; and the soil test value (low values mean higher recommended rates – better nutrient use efficiency when needy soils are fertilized to better match crop demand = spring for summer crops like corn and soybean). Fertilizer prices are lower (except for potash) now, but still high relative to prior years.

WHEAT follows corn in many areas. This year, most wheat will not need fall nitrogen (N). Lower corn yield causes less N removal. Tissue N will be higher in corn residues, giving greater N availability as residues decompose. Many grain producers have fields in forage production. Likely under fertilized this year, these crops/fields may really need some fall fertility to improve stand health, winterhardi-ness, and both forage quality and stand competitiveness with weeds next spring.

A WINTER COVER CROP can contribute. In addition to protecting against soil erosion (especially with less full-season soy residues this year), cover crops cause greater nutrient retention against fall-winter losses. One ton of rye dry matter (good stand, 12 to 18 inches tall) contains about 35 lb N, 45 lb K2O, and 10 lb P2O5. These nutrients won’t all be immediately available with rye termination next spring, but $32(N) + $33(K2O) + $7(P2O5) = $72 worth of nutrients, considering the most recent aver-age retail fertilizer price levels (https://www.dtnpf.com/agriculture/web/ag/crops/article/2022/08/02/summer-slump-retail-fertilizer), are retained.

FALL NUTRIENT SOURCE DECISIONS might also be difficult. This fall, the need for fertilizer N will be significantly lower. Fall application of N, regardless the nutrient source, will be less economical and losses are more likely, given likely greater fall background soil N levels. Nutrient sources containing N and other important nutrients (DAP, 18-46-0; MAP, 11-52-0; poultry litter) are usually priced consid-ering their N content, making them less desirable for fall application to wheat, corn, and soy acres this fall. DAP, 18-46-0, is a popular fertilizer P source and the most recent DTN survey average retail price (the URL just above) was $1005/ton. Urea, 46-0-0, was $836/ton ($0.909/lb N). This means that the 360 lb N in one ton of DAP was worth about $327, and the phosphate value was $678/ton DAP ($0.737/lb P2O5). About a third of the price of DAP is in the value of N it contains – N that is less likely to be needed this fall. You might ask your fertilizer retailer to bring in triple super phosphate (0-46-0) so that you can meet your fall phosphate needs without losing money on unnecessary N.

FERTILIZER PLACEMENT (banding) improves fertilizer P and K use efficiency, relative to broadcast fertilizer. AGR 1 (http://www2.ca.uky.edu/agcomm/pubs/agr/agr1/agr1.pdf) indicates that in spring, if soil test P and/or K are very low or low, one-third to one-half the recommended rates of P2O5 and/or K2O for corn can be used if it is banded 2 to 4 inches from the row. Relevant research for Kentucky soils is not available, but I’d estimate that precision (GPS guided) banding fall applied P and K would similarly improve their use efficiency relative to fall broadcast P and K. Precision fall banding would likely be superior to spring broadcasting, though not as good as spring banding, as long as corn is planted 2 to 4 inches from the banded P and K. Precision fall placement anticipates precision spring planting.

SBA Deadline Approaching for Working Capital Loans in Kentucky for Secretary of Agriculture Disaster Declaration for Tornadoes

Source: U.S. Small Business Administration

ATLANTA – The U.S. Small Business Administration (SBA) is reminding small businesses, small agricultural cooperatives, small businesses engaged in aquaculture, and most private nonprofit organizations that Sept. 19 is the filing deadline for federal economic injury disaster loans in Kentucky resulting from Tornadoes on Dec. 10-11, 2021.

Low-interest disaster loans are available in the following counties: Allen, Barren, Butler, Edmonson, Grayson, Hart, Logan, Simpson and Warren in Kentucky.

Under this declaration, the SBA’s Economic Injury Disaster Loan (EIDL) program is available to eligible farm-related and nonfarm-related entities that suffered financial losses as a direct result of this disaster. Apart from aquaculture enterprises, SBA cannot provide disaster loans to agricultural producers, farmers, and ranchers.

The loan amount can be up to $2 million with interest rates of 2.83 percent for small businesses and 1.875 percent for private nonprofit organizations, with terms up to 30 years. The SBA determines eligibility based on the size of the applicant, type of activity and its financial resources. Loan amounts and terms are set by the SBA and are based on each applicant’s financial condition. These working capital loans may be used to pay fixed debts, payroll, accounts payable, and other bills that could have been paid had the disaster not occurred. The loans are not intended to replace lost sales or profits.

Applicants may apply online using the Electronic Loan Application (ELA) via the SBA’s secure website at DisasterLoanAssistance.sba.gov/ela/s/ and should apply under SBA declaration # 17321.

Disaster loan information and application forms may also be obtained by calling the SBA’s Customer Service Center at 800-659-2955 (if you are deaf, hard of hearing, or have a speech disability, please dial 7-1-1 to access telecommunications relay services), or by sending an email to DisasterCustomerService@sba.gov. Loan applications can be downloaded from the SBA’s website at sba.gov/disaster. Completed applications should be mailed to: U.S. Small Business Administration, Processing and Disbursement Center, 14925 Kingsport Road, Fort Worth, TX 76155.

Submit completed loan applications to SBA no later than Sept. 19, 2022.

Feeding of Japanese Beetles on Soybean also Cause Injuries to Blooms

UK College of Agriculture, Food & Environment Corn & Soybean News (August 2022)

Dr. Raul Villanueva, Extension Entomologist

Japanese beetles, Popillia japonica (Coleoptera: Scarabaeidae) are native to Asia. This species was first detected in the early 1900s in New Jersey, but now occurs throughout many areas of the United States. This is a well-established pest in Kentucky.

Japanese beetles have only one generation per year. Its larval stage lives underground feeding on roots, with adults emerging in early-July through mid-September. The larval form of this carabid is called white grub.

Adult beetles are considered destructive pests of many ornamentals, turf, and landscape plants. In soy-bean fields, it has been observed feeding on leaf tissue between leaf veins; in many cases this feeding leaves a lace-like, skeletonized appearance. Figures 1A and 1B show initial feeding and advanced skele-tonized leaf, respectively. Leaf damage in soybeans can appear severe as leaves can be completely skel-etonized, and many beetles may be found aggregating on plants in a patchy distribution of the field. However, this injury seldom requires control measures.

At this time, I am reporting a not as well-known feeding habit of Japanese beetles in soybeans. I had heard that this insect was causing some damage to soybean blooms in the North Central region of the U.S. While conducting tallies for insects in soybeans, I observed that a couple of beetles were aggregat-ed under the foliage, and they were feeding on the blooms (Figure 2). Injury to soybean blooms may reduce pod development; however, studies to evaluate the impact of this feeding behavior have not yet been conducted. Feeding on flowers or fruit by Japanese beetles is typical for fruits or ornamental plants.

Late Season Weed Escapes

UK College of Agriculture, Food & Environment Corn & Soybean News (August 2022)

Dr. Travis Legleiter, Assistant Extension Professor & Jonathan Green, Extension Professor

Herbicide applications on full season soybean have been wrapped up on most acres for several
weeks now, and double crop applications will be wrapping up soon. Despite most herbicide application
being concluded, there are scattered fields with weeds such as waterhemp and Palmer amaranth poking
through the soybean canopy. Unfortunately, even with the most robust herbicide program a few escapes can occur, especially around field edges, planting skips, wheel tracks, and spots with underdeveloped soybean canopy. The questions that often occur is how to control these late escapes and what efforts are worth the cost to control these escapes.

What can I spray on escapes?
There is often the temptation to spray late season escapes in soybean, especially if escapes occur at
high densities. Although, the majority of postemergence soybean herbicides are not labeled for application either during or past the reproductive stages. Those without a reproductive stage restriction often have a restriction based on timing to harvest, most of which are labeled to be applied
no later than 45 to 70 days prior to harvest. We have already surpassed that date or are quickly approaching that time in most soybean fields. So, to answer the question, in most cases we unfortunately do not have products labeled for applications of herbicides this late in the season in soybean.
A few selected herbicide products that we often receive questions about for late season escapes are
listed in Table 1 along with the growth stage or pre-harvest applications restriction. A complete list
of soybean herbicide application timings can be found on page 100 of the 2022 Weed Control Guide
for Kentucky Grain Crops (AGR-6).

Outside of fact that most herbicide are not labeled to be applied this late in the season, the size of the
weed escapes is the other limiting factor. If you are seeing escapes in soybean at this time of year,
these plants are much too large to effectively control with postemergence herbicides. At best you
may stunt or suppress the escapes, but these plants are very likely to survive applications and potentially produce seed, if they have not already begun seed production. Additionally, within the list of
herbicides in Table 1 that you may still be able to be apply, many are PPO-inhibiting herbicides (i.e.
Cobra, Flexstar, Ultra Blazer, Phoenix). While it may be tempting to try to apply one of these herbicides to control late escapes of Palmer amaranth and waterhemp, it must be noted that many of our
pigweed populations are also resistant to the PPO-herbicides. Even if you do have a PPO-susceptible
population of Palmer amaranth or waterhemp, the plants are too large or mature at this time in the
season to be controlled by these herbicides. These PPO-inhibiting herbicides are only effective on
small pigweeds. Furthermore, some late season applications of PPO type herbicides such as Cobra
and Phoenix can cause severe leaf burn which could slow soybean growth and development as it recovers.


So what can be done on late season escapes of waterhemp and Palmer amaranth?
A primary goal for management of these two troublesome weeds is to reduce or eliminate new seed
production within infested fields. While this does not eliminate the current seed bank or keep seed
from moving into the field in the future, it is a large step in reducing the build of an unmanageable
seed bank.

If only a few escapes are occurring within scattered spots of the field or along the field edges, a few
hours of mechanically pulling plants and removing them from the field can go a long way. If you
choose to pull plants, you must remove the plants from the field as both waterhemp and Palmer
plants can re-root when simply laid back on the ground. Removal of even a couple of plants from a
field can go a long way considering a single plant can produce up to half a million seeds. This applies to plants that are growing just adjacent to your field as well, as these plants are also likely to
contribute to the seed bank within the field. The cooler temperatures that are forecast and ample
soil moisture in most of the state over the coming weeks will make for easier pulling of these plants.

In some cases, though, the number of escapes is too great to justify the labor to pull all the plants. In
these cases, your options really are limited. If the escapes happen to be a few dense pockets across
the field (too many weeds overall to hand pull, but only exist in a couple of areas or clumps within
the field), you may be wise to simple harvest around those pockets in the fall and sacrifice the soybean crop within those areas. Combines are a great source for spreading waterhemp and Palmer
seed. Any time you harvest through a patch of waterhemp or Palmer plants all of the biomass including seed is widely dispersed out the back end of the combine with the chaff, and is likely to be
transported to other fields. Harvesting around those pockets does not prevent the waterhemp and
Palmer seed from entering the seed bank, but it does help keep the weed seed localized to that spot;
whereas, a combine would spread that seed over the remainder of the field and onto others. If you
choose the option of harvesting around these pockets, make sure to note the locations for the coming years to possibly implement a more aggressive weed management program in those areas specifically.