Extension Update from Jenny Rees

Jenny’s REESources-November 6, 2016

UPCOMING EVENTS:  

Nov. 14:  Ag Land Lease Workshop 9:30 a.m. and Flexible Cash Lease Workshop, 1:30 p.m., 4-H Building, York, Please RSVP to 402-362-5508 or jrees2@unl.edu.  No charge and you¹re welcome to attend one or both workshops.  Other locations:  http://go.unl.edu/6mya
Nov. 15:  Principles of Soil Health, Adaptive Grazing and Cover Crop Integration, 10 a.m.-2 p.m., Adams Co. Fairgrounds, RSVP 402-461-7209
Nov. 15:  Principles of Soil Health, Adaptive Grazing and Cover Crop Integration, 5 p.m.-9 p.m., Gage Co. Extension Office, RSVP 402-223-1384
Nov. 17:  Grain Marketing Workshop, 9:30 a.m.-3 p.m., Dawson County Extension Office, 1002 Plum Creek Parkway, RSVP go.unl.edu/marketingworkshops <http://cropwatch.unl.edu/go.unl.edu/marketingworkshops>  or by calling Robert Tigner at 308-345-3390.
Nov. 28:  Market Journal Road Show, 1-4 p.m., Holiday Inn 110 Second Avenue Kearney,http://marketjournal.unl.edu/roadshow
Nov. 29:  Solar Energy in Ag Workshop, 7-9 p.m., West Central Research and Extension Center, North Platte.  Preregister at 308-532-2683.
Dec. 1:  Solar Energy in Ag Workshop, 1-3 p.m., 4-H Building, York, RSVP to 402-362-5508 or jrees2@unl.edu
Dec. 1:  Market Journal Road Show, 1-4 p.m., Lifelong Learning Center 701 E. Benjamin Avenue Norfolk,http://marketjournal.unl.edu/roadshow
Dec. 2:  Market Journal Road Show, 9 a.m.-Noon, Nebraska Innovation Campus Conference Center 2021 Transformation Drive Lincoln, http://marketjournal.unl.edu/roadshow
Dec. 5:  Cover Crop and No-Till Conference featuring Gabe Brown, 9:30 a.m.-3:00 p.m., Trotter Event Center, Ord, RSVP 308-346-3393
Dec. 5:  Field to Market Workshop, 4-H Building, York, Please RSVP to 402-362-5508 or jrees2@unl.edu
Dec. 6:  Grain Marketing Workshop, 9:30 a.m.-3 p.m., Webster County Fairgrounds on the west side of Crescent Street between Helen and Mariel streets, RSVP go.unl.edu/marketingworkshops <http://cropwatch.unl.edu/go.unl.edu/marketingworkshops>  or by calling Robert Tigner at 308-345-3390.
Dec. 8:  Solar Energy in Ag Workshop, 1-3 p.m., Norfolk, NE at the Lifelong Learning Center Preregister at 402-370-4040.
Dec. 14:  Farmers/Ranchers College Dr. David Kohl, 1-4 p.m., Bruning Opera House, Bruning

Farm Finance Clinic Sites and Dates To sign up for a clinic or to get more information, call Michelle at the Nebraska Farm Hotline at 1-800-464-0258.

• Grand Island — Thursday, Nov. 3
• Fairbury — Thursday, Nov. 3
• Valentine — Tuesday, Nov. 8
• North Platte — Thursday, Nov. 10
• Norfolk — Tuesday, Nov. 15
• Lexington — Thursday, Nov. 17
• Norfolk — Wednesday, Nov. 30

Grazing Corn Residue:  With harvest completed or rapidly nearing completion, some may be interested in residue management.  Grazing can remove corn kernels lost during the harvest process reducing volunteer corn for the following year and reduces residue while benefiting cattle as livestock feed.  However, 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.   

Grazing Frosted Sorghums:  With at least one night of frost in this area of the state, there’s been regrowth on some sorghums due to warmer temperatures.  I’ve received a few questions regarding any danger of the regrowth.  Dr. Bruce Anderson and Dr. Darren Redfearn our Extension Forage Specialists share that the hydrocyanic acid (or prussic acid) in this new growth can be highly toxic to grazing cattle.

Prussic acid toxicity is considered to be more problematic during the summer months, but any new fall growth following a frost that kills only the plant tops can be toxic. Risk of prussic acid poisoning can be mitigated several ways. Prussic acid poisoning is dose-dependent — both the amount and concentration of prussic acid in the diet as well as how rapidly it’s consumed will influence the likelihood of toxicity.  Important questions to ask include:  ‘How long has it been since the freeze/frost?’ and ‘Can they consume enough of the new regrowth so rapidly that it will cause an issue?’

When in doubt, wait at least seven days after a killing frost before grazing to allow adequate time for the chemicals to be eliminated from the plants.  Another key is to not turn cattle out hungry into forages that may be high in either prussic acid or nitrates. 

They share if the new growth of a previously frosted plant is short and consists of only 1 or 2 new tillers, the likelihood of prussic acid poisoning is minimal. However, if there are 5 or more new tillers with growth of 4 to 5 inches, then the possibility of prussic acid poisoning increases markedly. The reason is that with the increased amount of new growth, grazing cattle could consume enough new growth to receive a lethal dose of prussic acid.  In that case, it may be wise to wait for another hard freeze and wait at least seven days before grazing to reduce risk of prussic acid poisoning.

Mulching Tender Plants:  November may be the month to protect tender plants with winter mulch but wait until plants are fully dormant and air temperatures are dropping into the lower 20s each night before applying winter cover. Tender plants such as hybrid tea roses, strawberries and Chrysanthemums benefit from winter protection. Winter injury occurs from plants or soil freezing and thawing over winter and from winter drying, as well as from cold temperatures. It is important not to put mulch or covers like rose cones in place too early or winter injury may increase from delayed dormancy, smothering, or promotion of crown rots. Wait until after a number of killing frosts to ensure plants are fully dormant. This is typically in late November or early December. Once plants are fully dormant, cover the plants or their bases with a 10 to 12 inch layer of straw, wood chips or coarse leaves.