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Showing posts from July, 2021

Feeding weedy forages

 Craig Shaeffer, Professor, Department of Agronomy and Plant Genetics, Krishona Martinson, Extension equine specialist, and Jared Goplen, Extension educator-crops Weeds generally compete with crops for water, light, and nutrient resources, and may affect human and animal health. While the goal of harvesting forages usually includes minimal weed infestations, weeds can provide valuable forage during a drought. Key Points Weeds can provide nutrients and contribute to the needs of some livestock. Proper weed ID is essential to ensure weeds are not toxic to livestock. Weeds may also have antiquality traits, including plant chemicals, thorns, or plant hairs that affect palatability. Nitrates can accumulate in drought stressed weeds. Forages suspected of being high in nitrates should be tested before feeding. Before feeding forages containing weeds, test to determine nutritive value to allow adjustment of the ration. Weedy forage should be introduced slowly to livestock rations to allow for

Join us August 4 for Field Notes when we discuss late-season insect and mite issues

  An all-new weekly crops program from the University of Minnesota Extension Crops Team Two-spotted spider mites adults and eggs. Photo: David Cappaert, Michigan State University, Bugwood.org Join us Wednesday, August 4 for Field Notes when we welcome Dr. Ken Ostlie, Corn Extension Entomologist, and Dr. Bob Koch, Soybean Extension Entomologist, both with the University of Minnesota Department of Entomology. Drought conditions during the growing season have exacerbated some pest issues, such as spider mites. Corn rootworm adults have been a concern at noticeable densities for some growers. Soybean aphid so far has only been found at low densities in most fields across the state, but there is still potential for aphid populations to reach damaging levels in August. In addition to conversations on corn and soybean insects, we will also discuss alfalfa insect management and what IPM scouts in western Minnesota have been finding in soybeans. What is Field Notes? The Field Notes program is

Navigating nitrate toxicity in feedstuffs

 Dana Adams, Extension educator This article was originally published in Dairy Star This summer in the Upper Midwest is exceptional. It’s exceptional because we are battling our way through a remarkable lack of rain, early in the season, for a prolonged period. Naturally, this has many producers taking off ball caps and kicking the dirt in frustration. Fast-forwarding several hours, many livestock producers will look their animals in the eye and ponder,” what am I going to feed you?" Any producer can tell you not every bale of hay, pasture, or bunker of corn silage is the same. This difference in small grains or forage quality becomes even more evident when feedstuffs withstand drought stress. Under normal conditions, plants uptake nitrogen from the soil as nitrate. However, little nitrate accumulates in the plant due to its conversion of nitrate into amino acids and proteins. Under drought stress, the plant takes up more nitrate than it converts to protein, resulting in abnormall

Two-spotted spider mites in 2021 in Minnesota crops?

Bruce Potter, IPM specialist, Bob Koch, Extension entomologist and Ken Ostlie, Extension entomologist Lower leaf loss on plants severely infested with two-spotted spider mites. The hot, dry growing season has led to infestations of two-spotted spider mites in many areas of Minnesota. Over the past two weeks, increasing numbers of fields with economic infestations have been observed. Most, but not all, have been in areas with obvious drought stress. Soybeans appear to have the heavier infestations although spider mites also be found in corn and other crops. Complicating these developments are reports of inconsistent performance of chlorpyrifos (e.g., Lorsban), presumably due to populations of resistant mites, which were first documented in Minnesota in 2012. Since then, chlorpyrifos applications to soybean and other crops have continued selection for resistant populations. Close-up of two-spotted spider mites and eggs. Two-spotted spider mite populations are typically kept in check by p

Crop water use and irrigation timing

Vasudha Sharma, Extension irrigation specialist Good understanding of crop water use or crop evapotranspiration (ET) is essential for managing irrigation efficiently, especially during the periods of water scarcity. Information on how much and when crop uses the water and what are the different factors that derive the crop water use would help growers in avoiding over- and under-irrigation that helps in reducing nitrate leaching and maintaining good crop yield. What is Evapotranspiration (ET)? Evapotranspiration (ET) includes two terms: evaporation (E) from the soil surface and transpiration (T) from the leaves. It is very difficult to estimate or measure these two components independently, so they are often calculated and measured together. Over a growing season, 70% to 80% of all ET is used up as transpiration and remaining 20% to 30% of ET is direct evaporation from the soil.  For transpiration, water moves from the soil through the crop’s root system and comes out from the leaves.

Crop Pest Management Plot Tour at SWROC August 10

The University of Minnesota Southwest Research & Outreach Center near Lamberton welcomes visitors on-site for a crop pest management plot tour on Tuesday, August 10th from 1:00 to 4:00 p.m. This tour of research and demonstration plots will feature Extension entomologist Ken Ostlie discussing corn rootworm management and Extension weed scientist Debalin Sarangi discussing corn and soybean weed management approaches. Extension IPM Specialist Bruce Potter will also highlight other current pest management issues. This plot tour is free but participants are encouraged to pre-register. CEUs for certified crop advisors have been applied for. In the event of rain, the plot tour will be modified and moved indoors. Register for the tour For more information or to request special accommodations, email eneperma@umn.edu or visit swroc.cfans.umn.edu . 

Drought stress on corn

Jeff Coulter, Extension corn agronomist Many people are concerned about how the continued dry conditions and recent hot weather are affecting the corn crop. This article discusses how corn growth and development are influenced by dry and hot weather before, during, and after pollination. Currently, most of the corn in Minnesota has finished pollination and its kernels are well into the blister stage of development. The most critical period for the formation of corn grain yield begins about 10 days before the start of silking and lasts for about 24 days. Drought and other stresses during this period will reduce corn grain yield more than at any other time. From about the eight leaf collar stage through the 15 leaf collar stage (which is about eight days before the start of silking), the number of potential kernels per row is determined. Therefore, drought stress during this time can reduce potential ear length. Drought stress during the week before tasseling that lasts through the si

Summer re-seeding (or seeding) of alfalfa

 Craig Sheaffer, Professor, Department of Agronomy and Plant Genetics, Krishona Martinson, Extension equine specialist, and Jared Goplen, Extension educator-crops. Figure 1. An alfalfa field seeded in early May with an oat companion crop. Forage was cut and baled in mid-July. The green vegetation in the field is lambsquarters and regrowth from the oats, whereas the alfalfa has failed to establish (Photo taken late July). The drought in many regions of Minnesota caused significant problems with alfalfa establishment this spring (Figures 1 & 2). Although periodic rainfall has occurred, most of the state continues under moderate to severe drought ( https://www.drought.gov/states/minnesota ).  On some farms, alfalfa seeds germinated this spring but failed to thrive due to limited moisture. This has resulted in thin or uneven stands in many fields.  In some cases, areas of fields with heavier soils produced partial alfalfa stands while lighter, sandy soils have no alfalfa. Drought-toler

How to calculate a nitrogen credit from irrigation water

By: Vasudha Sharma, Extension irrigation specialist & Fabian Fernandez, Extension nitrogen management specialist Nitrate (nitrate-N) is commonly found at some level in irrigation water. For corn in Minnesota in a normal irrigation year, when nitrate concentrations in irrigation water are below 10 parts per million (ppm), or 10 milligrams per liter (mg/L), we don’t recommend making adjustments to your fertilization plan. This is because the University of Minnesota’s corn fertilizer guidelines already account for this. If nitrate concentrations are greater than 10 ppm or the amount of irrigation during the season is substantially greater than normal, the nitrogen added through irrigation should be accounted for because: Excess nitrogen in some crops can result in vigorous and excessive vegetative growth, leading to uneven or delayed maturity and reduced quality. The nitrogen credit from irrigation water means you can save money on nitrogen fertilizer costs, especially in dry years l

Should you apply sulfur fertilizer for alfalfa?

Photo credit: Jared Goplen/University of Minnesota Extension By: Dan Kaiser, Extension nutrient management specialist Did you know that alfalfa can remove more sulfur from the soil in a year than a corn crop? However, past research on forage crops has been inconclusive as to whether sulfur fertilizer is required for highly productive alfalfa fields with organic matter (OM) concentrations greater than 4%. In addition, most of the research out there on this topic is based on one-year trials, which may not be long enough to establish the benefits of sulfur for growers pushing for higher tonnage in their alfalfa production systems. That’s why we sought funding from Minnesota’s Agricultural Fertilizer Research and Education Council (AFREC) for a multi-year study on sulfur fertilizer sources and application rates. The project, at the Rosemount Research and Outreach Center, is currently in its third year. Combined with another trial in Rosemount from the 2019 growing season, Minnesota-based s

Sand Plain Research Farm Irrigation and Nutrient Management Field Day

University of Minnesota Extension’s 2021 Sand Plain Research Farm Irrigation and Nutrient Management Field Day will take place on Monday, August 30th from 4pm to 7:30pm . This event is free and dinner will be provided . Registration is required. Please register by August 20th. Register now The Sand Plain Research Farm (SPRF) is a unique coarse textured-soil site in central Minnesota featuring irrigated and non-irrigated agronomic research. The current SPRF research site includes 345 acres of cropland. Of that, 290 acres are irrigated. The farm is outfitted with eight irrigation systems (three laterals and five center pivots). All three of the lateral irrigation systems and one of the center pivot systems are equipped with variable rate irrigation (VRI) technology. Presentations Vasudha Sharma, Ph.D. - Irrigation management strategies for profitable corn production and water quality protection in Minnesota Central Sands Yuxin Miao Ph.D. - Proximal and remote sensing technologies for cor

Recent findings of the Western Minnesota IPM Survey

By Angie Peltier, Anthony Hanson and Jared Goplen, UMN Extension educators. UMN Extension soybean IPM scouts traveled across northwest and west central Minnesota completing another week of data collection on July 16. When visiting each soybean field, scouts first sweep for grasshoppers in the grassy area next to the field and then begin walking in a zig-zag pattern throughout the field, stopping along the way to growth stage the crop and examine 31 plants for soybean aphids, aphids that have been colonized by parasitic wasps, bean leaf beetles and spider mites. Growth stages. For the most part, soybeans in northwest counties were either just beginning to bloom or had reached full bloom ( Figure 1 ). Further south, soybeans had all reached full bloom with some crops reaching the full pod growth stage. Figure 1 . Growth stages of soybeans scouted between July 5 and 16 as part of the UMN Extension 2021 soybean IPM survey. Map source: NDSU IPM program. Grasshoppers. Scouts us