May 23: Corn is looking good for the most part with few major concerns yet. Some have commented on the yellow-looking corn. This is most likely due to cool, wet soils rather than any nutrient issues. There may be field-specific issues such as saturated soils, compaction, and some herbicides that can cause this yellowing too. Also had a call on cutworms in seed corn but not widespread calls on this yet. Extension Educators have set up light traps for tracking cutworm moths and you can find that information here: http://go.unl.edu/rhhe. Cutworms will cause the most damage the first 7 days after corn emergence so scouting is important. The York County Corn Grower Plot was planted on April 24th with the corn currently at 2 leaf stage. Special thanks to Ron, Ray, and Brad Makovicka for hosting and the work put into this plot each year!
May 1: It never ceases to amaze me how quickly planting occurs each year! Corn planted the week of April 10th has emerged and for those fields that received hail from last week’s storms, I’m hoping we don’t see disease issues later on. Also of note, some have asked me about the CropWatch soil temperatures as they are higher than what some of you have been measuring in your fields before planting. The CropWatch soil temps at http://cropwatch.unl.edu/cropwatchsoiltemperature are averages of 24 hours under bare soil which may be different than the residue conditions in your fields and is an average of the entire day vs. one point in time. This may help explain some of the differences.
Many stands of alfalfa are lush green with over a foot of growth at this point. I looked at some alfalfa in Clay County that got dinged by cold temperatures in areas of the field and stopped growing. At this time I’m also finding quite a few aphids and a few alfalfa weevils. A disease common this time of year called spring black stem can be observed in nearly all alfalfa fields right now in the lower canopies. This disease consists of small black lesions on the leaves which eventually cause the leaves to turn yellow and drop. Normally this disappears with later cuttings as humidity and rainfall are typically high during the first cutting and can be managed with cutting the alfalfa. One option to consider according to Dr. Bruce Anderson, our Extension Forage Specialist, is to consider cutting alfalfa before bloom. He shares that weather can cause long delays and alfalfa doesn’t bloom very aggressively during spring. Bruce felt there were advantages to cutting alfalfa when it is 15-20” tall before bloom during first cutting including: weather compared to later spring, spread out alfalfa harvest if you consider cutting one field earlier, reduction in insect and disease problems by early harvest, and high feed value. It also potentially allows the second cutting to be ready before the summer heat which can lower forage quality. Disadvantages include lower yield from cutting early which could be made up in later harvest, regrowth may be slower if cut early, and the need to allow for longer recovery after first or second cutting to maintain long-term stands. So, harvesting before bloom may be something you wish to test in one of your fields this year and consider how this works for you, especially if you did have some frost damage or are having insect/disease issues in your alfalfa right now.
The field assessment workshops in Nebraska are hands-on and will show growers how to document eight sustainability and efficiency indicators via use of a laptop computer. The indicators are:
- land use,
- soil carbon,
- irrigation water use,
- water quality,
- energy use,
- greenhouse gas emissions, and
- water quality.
Computer laptops are provided or participants can bring your own. No prior computer knowledge is necessary and experienced users will be available to provide assistance.
Please contact the Extension Educator listed for each site to preregister by Dec. 3.
Monday, December 7, 9 a.m. – 1 p.m.
UNL Extension Office in Lancaster County, 444 Cherrycreek Road
Contact: Tyler Williams, (402) 441-7180 or firstname.lastname@example.org
Monday, December 7, 5:30 – 9 p.m.
UNL Extension Office in Gage County, 1115 West Scott St.
Contact: Paul Hay, (402) 223-1384 or email@example.com
Tuesday, December 8, 9 a.m. – 1 p.m. Nemaha County Hospital Meeting Room, 2022 13th St.
Contact: Gary Lesoing, (402) 274-4755 or firstname.lastname@example.org
Tuesday, Dec. 8, 5:30 – 9 p.m. UNL Extension Office in Fillmore County, 1340 G St.
Contact: Brandy VanDeWalle, (402) 759-3712 or email@example.com
Wednesday, Dec. 9, 9 a.m. – 1 p.m.
UNL Extension Office in Clay County, 111 West Fairfield Contact: Jennifer Rees, (402) 762-3644 or firstname.lastname@example.org
Wednesday, Dec. 9, 5:30 – 9 p.m.
UNL Extension Office in Merrick County, 1510 18th St.
Contact: Troy Ingram, (308) 946-3843 or email@example.com
Thursday, Dec. 10, 9 a.m. – 1 p.m. UNL Extension Office in Dodge County, 1206 West 23rd St.
Contact: Nathan Mueller, (402) 727-2775 or firstname.lastname@example.org
Friday, Dec. 11, 9 a.m. – 1 p.m.
UNL Extension Office in Saunders County, 1071 County Road G
Contact: Keith Glewen, (402) 624-8030 or email@example.com
Many stalks in Nebraska are left ungrazed for various reasons. One reason I’ve heard is the potential impact of increased compaction and reduced yield of the next crop. Nebraska Extension has long-term research addressing this concern…in fact, 16 years of research conducted at the Ag Research and Development Center near Mead. There’s various components to this study and you can view the full report at: http://go.unl.edu/8mp6.
In this study, cattle were allowed to graze corn residue in the spring (February to mid-April) or the fall (November through January) and these treatments were compared to an area not grazed. Corn and soybeans were planted the spring after grazing the residue for 16 years to determine the effect of grazing on the subsequent crop yield.
In the fall grazing treatments, the corn and soybeans were planted no-till. For corn or soybeans planted into the spring grazing treatments, three tillage treatments were also implemented for nine years: no-till, ridge-till, and spring conventional till, after which all treatments were converted to no-till. This result of the tillage by spring grazing treatments for either corn or soybean yield over nine years showed no interaction and suggested the same effect on yield regardless of tillage treatment used after spring grazing.
Spring grazing across all tillage treatments did increase soybean yields statistically (58.5 bu/ac for spring grazed vs. 57.0 bu/ac for ungrazed) and had no effect on corn yields. The results were similar looking at 16 years of grazing vs. not grazing under no-till for both corn and soybeans in the spring; there was no yield effect found for corn and the soybeans showed a slight yield increase with grazing.
Looking at a 10 year period of no-till management for both spring and fall grazed corn residue and subsequent corn and soybean crops, fall grazing statistically improved soybean yields over both spring grazing and no grazing (65.5 bu/ac vs. 63.5 bu/ac and 62.1 bu/ac respectively). No grazing effects were observed on corn yields in either season. All statistics were at the 95% confidence level meaning the researchers were 95% confident any yield differences were due to the treatments themselves vs. random chance.
Regarding compaction, in the fall, the field was typically frozen and the researchers felt any mud and compaction associated with grazing cattle was minimized; highest subsequent soybean yields were achieved with fall grazing. The spring treatment was designed to look more at potential compaction and muddy conditions after spring thaw till right before planting-thus the implementation of different tillage treatments as well. They used a stocking rate consistent with UNL grazing recommendations resulting in removal of half the husks and leaves produced (8 lbs of leaf and husk per bushel of corn grain produced). Results of this study indicate that even with muddy conditions in the spring, grazing increased subsequent soybean yields compared to not grazing regardless of tillage system used and that corn yields were not different between grazing vs. not grazing and regardless of tillage system used in the spring. This study was conducted in Eastern Nebraska in a rainfed environment with yields ranging from 186-253 bu/ac with a 16 year median yield of 203 bu/ac.
Additional Grazing Study
A five year fall grazing study (December through January) was conducted in an irrigated continuous no-till corn field at Brule, NE to determine the effect of corn residue removal via baling corn residue or fall grazing on subsequent corn yields. That environment receives limited rainfall and residue is deemed important for reducing evaporation of soil moisture in addition for catching/keeping snow on fields. Farmers were questioning the effects of any residue removal on subsequent corn yields and the study was implemented.
Treatments were 1) fall grazing at 1 animal unit month/acre (AUM), 2) fall grazing 2 AUM/ac, 3) baled, or 4) ungrazed. The researchers found that residue removal did not affect corn grain yields from 2009-2013 in the continuous corn rotation. There were no statistical yield differences with 5 year average yields of: 152 bu/ac, 155 bu/ac, 147 bu/ac and 148 bu/ac respectively for the above-mentioned treatments.