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Showing posts from July, 2023

Making sense of Minnesota’s corn fertilizer guidelines: Frequently asked questions and answers

Dan Kaiser, University of Minnesota Extension nutrient management specialist, recently updated the publication Fertilizer Guidelines for Agronomic Crops in Minnesota for the first time since 2011. Here are some common questions he gets about the guidelines for corn and his answers. How should growers use the fertilizer rate guidelines? We know there can be variability from field to field, and even within a field, in terms of fertility requirements. What our fertilizer rate guidelines provide is a starting point for growers and advisors, backed up by real world data. One of the main focuses of our Nitrogen Smart program is to start with the university-suggested rate and adjust a little bit up or down based on what you know about your field. For example, this year , following a dry 2021 growing season, would have been a good year to take a pre-plant  nitrate test (PPNT)  to see if there’s some carryover nitrogen (N) left in the soil that you could credit for this year’s crop. Then, you

A Tale of Two Crops

While the title is a not-so-subtle reference to Charles Dicken's novel, there is a lot less intrigue in this case.  The results of the very dry seedbed combined with a lack of meaningful precipitation in the week or weeks following seeding have become very visible in wheat, barley, and oat fields in the last week or so (Photo 1). At first glance, this may look like a mix of two different varieties of wheat. A closer inspection makes you realize that this is the same variety at completely different growth stages rather than two different varieties.   Photo 1 - A field of spring wheat near Crookston with two crops that are more than a week apart in their growth and development The challenge ahead is how to harvest these two crops without either an increase in dockage, a loss of quality, or both. The published data on the effect of swathing grain prior to physiological maturity (the point in the development of the crop where the maximum dry weight has been accumulated in the kernel an

Management of soybean aphids and twospotted spider mites in soybean: Scouting, thresholds, and insecticide/miticide considerations

by Robert Koch, Extension entomologist, and Bruce Potter, Extension IPM specialist Revised from a July 27, 2022 MN Crop News Article Scouting of soybean for soybean aphids (SBA) and twospotted spider mites (TSSM) should be underway. However, do not just assume you have significant infestations of either or both pests. This year, infestations of these pests are variable across the state, due to variable plant development and weather conditions. In addition, populations of both pests can rapidly change (increase or decrease). This is why scouting is particularly important. Below, we provide an overview of scouting and thresholds for these pests in soybean and a table listing the insecticides/miticides available for the management of these pests, along with notes to help determine which products to use for each pest alone or in combination. Soybean aphids Predators and parasites have been keeping soybean aphid populations in check in many fields; while in others, populations are approachi

2023 Fertilizer Guidelines for Agronomic Crops in Minnesota publication now available

While the University of Minnesota’s crop-specific fertilizer guidelines are updated often on Extension’s website, this is the first time since 2011 that the official publication, Fertilizer Guidelines for Agronomic Crops in Minnesota, has been updated. Download the free publication: (PDF) The publication features fertilizer guidelines for 21 crops and cropping systems, a chapter on how to understand your soil test report, and a chapter on lime needs. Each chapter includes everything you need to know about fertilizing the crop, from optimal N-P-K rates to rotation management considerations. Funding for the development of this publication was provided by Minnesota's Agricultural Fertilizer Research and Education Council (AFREC). Learn more about AFREC at --- For the latest nutrient management information, subscribe to the Nutrient Management Podcast wherever you listen and never miss an episode! And don't forget to subscr

Sign up for Soil Solutions Field Day in September

Farmers and agricultural experts from across the region are invited to the UMN Extension Soil Solutions Field Day: Improving farm productivity through healthy soil on September 7. Come and explore innovative methods to enhance farm productivity through the promotion of healthy soil. Taking place at the West Central Research and Outreach Center, located at 46352 W Hwy 329, Morris, MN 56267, the field day promises to offer valuable insights for attendees. One of the main challenges faced by farmers is the dilemma between long-term soil health goals and the immediate benefits of tillage for residue management and seedbed preparation. This predicament is particularly prominent in the west-central region of Minnesota, where the planting window is already narrow. The Soil Solutions Field Day will address this issue by discussing management tweaks that can be tailored to each farm's unique soil content. The aim is to help farmers strike a balance between building soil health and profitabi

Field Notes session talks corn rootworm challenges and solutions

Angie Peltier, UMN Extension educator, Fei Yang, UMN Extension corn entomologist and Bruce Potter, UMN Extension IPM specialist The following information was provided during a 2023 Strategic Farming: Field Notes session. Read further to learn more about this free program that takes place each Wednesday morning throughout the growing season. Corn rootworm milestones At this time of the year, rootworm management should be focused on how to manage rootworms in the next corn crop. Beetles are currently mating and laying eggs and the eggs must go through a period of rest (also known as a diapause) over the winter. Larvae hatch next year in early June, feed for a few weeks and then pupate. Beetles emerge in mid-July. Both egg hatch and beetle emergence happen over an extended period of time. Two corn rootworm species differ in ability to resist management strategies Two species of corn rootworm occur in Minnesota – western and northern (Figure 1). While both feed on corn roots, they have evo

Measuring and building soil carbon: Challenges and solutions for farmers and researchers

In this episode of the Nutrient Management Podcast, we’re talking about measuring and building soil carbon, and some challenges and solutions for farmers and researchers. Why is carbon in the soil being considered as a credit in the global carbon cycle? What practices change soil carbon? What makes soil carbon complicated to measure? What do you think is the ideal or is there an ideal carbon measurement scheme and what would it look like? What new research exists to address some of these challenges? Is Minnesota uniquely positioned in any way to contribute to solving these issues? Transcript Guests: Anna Cates, Extension soil health specialist (St. Paul) Jessica Gutknecht, faculty, U of M Department of Soil, Water, and Climate (St. Paul) Gregg Sanford, research scientist, U of Wisc Department of Plant and Agra Ecosystem Sciences (Madison) Additional resources: Contact information for Anna Cates: Contact information for Gregg Sanford: SOCNET MN Farmers

Minnesota CropCast: Plant breeding for tomorrow with Dr. Kevin Smith

Dr. Kevin Smith is best known for leading the U of MN's barley breeding program. He has been forced to react to changes in plant diseases, economic challenges from other crops, and evolving demands of the brewing industry, but has new varieties that will be in your beer soon. In this episode, he talks with David and Seth about the opportunities to develop varieties for a changing beer industry in the US. Kevin also leads the breeding efforts for another traditional Minnesota crop, oat. He talks about oat’s unique challenges and the opportunity to compete with Canadian production. Finally, Dr. Smith is working to domesticate a crop for tomorrow, Silphium ( Silphium integrifolium),   a native perennial plant in the sunflower family. Kevin speaks briefly of the challenges in crop domestication.  Listen to the podcast What is Minnesota CropCast? Hosts David Nicolai and Seth Naeve discuss the progress and challenges of Minnesota's agronomic crops in this new podcast. They are joi

Northern corn rootworm and extended diapause problems increase in areas of Minnesota

Dr. Fei Yang, Extension corn entomologist, and Bruce Potter, Extension IPM specialist A new old problem Northern corn rootworm beetle. In southern Minnesota, western corn rootworm (WCR) tends to be the dominant species in continuous corn. Likely due to greater cold tolerance of overwintering eggs, the northern corn rootworm (NCR) increasingly becomes the dominant species as one moves north within the state.  While significant Minnesota WCR populations have been limited to continuous corn, a portion of NCR has adapted to short corn rotations with an extended diapause genetic trait. Most recently, rotation-resistant NCR issues have arisen in the early to mid-1980s, early-2000s. These past events have been geographically limited in scope, rising and falling with overall NCR population densities. Minnesota’s NCR populations have been generally low since 2005. In recent years, most corn rootworm management has focused on WCR in continuous corn in the southern part of Minnesota. Meanwhil

Field Notes talked soybean conditions and crop diseases

Phyllis Bongard, Educational content development and communications specialist Iron deficiency chlorosis. Photo: Angie Peltier The drought is affecting not only crop conditions but the potential for disease development. Drs. Seth Naeve, Extension soybean agronomist, and Dean Malvick, Extension plant pathologist, addressed how soybeans are faring in the state and disease concerns during the July 19 Field Notes session. They were joined by moderator Liz Stahl, Extension crops educator, for the wide-ranging discussion. Soybean update Naeve travelled around Minnesota these past two weeks assessing the soybean crop. Despite the drought, soybeans are looking reasonably good. However, we are living “paycheck to paycheck” in terms of soil moisture and need timely rain for the crop to develop and yield. After an early, dry spring in southern Minnesota, excessive rain at planting was followed by an early shut down of rain. These conditions have resulted in a perfect storm of challenges. The pr

Research shows precision irrigation technology can improve irrigation water productivity in corn

By: Vasudha Sharma, Extension irrigation specialist, and Taylor Herbert, Extension educator A recent on-farm study conducted in the Central Sands region of Minnesota shows that variable rate irrigation technology could help save farmers water and reduce irrigation-induced nutrient loss to the environment without impacting farm profitability. Minnesota’s Central Sands region More than 25% of groundwater in Minnesota is pumped for irrigating crops. This makes irrigation the second-largest user of groundwater in the state. Minnesota has over 600,000 acres of irrigated cropland, and many of these irrigated acres are in the state’s Central Sands region. The coarse textured or sandy nature of the region’s soils means that they do not hold large quantities of water and have a rapid drainage rate to groundwater compared to high clay soils. These soils present challenges in agricultural irrigation and nutrient management. It takes less precipitation to saturate these soils, and they hold less p