Minnesota Crop News

By Lizabeth Stahl, Natalie Hoidal, and Kerry Richards The Environmental Protection Agency (EPA) recently announced certified applicators must successfully complete an EPA-approved training program before mixing, loading, and/or applying paraquat dichloride, an herbicide commonly referred to as paraquat.  Paraquat is a restricted use pesticide sold under brand names such as Blanco, Bonfire Herbicide, Devour, Firestorm, Gramaxone, Helmquat, Para-SHOT, Paraquat, Parazone, and Quik-Quat.  Why is additional training being required to use paraquat? Paraquat is highly toxic to humans:  Just one small sip can be fatal and there is no antidote.  Additionally, several deaths and many severe injuries have been caused by paraquat getting onto the skin or into the eyes of those working with the product. From an EPA Press release (dated March 8, 2019): Since 2000, 17 deaths have been caused by accidental ingestion of paraquat. Many of these deaths resulted from people illegally transferring

Graphic courtesy of the IPNI By: Anna Cates, Extension soil health specialist Predicting the amount of nitrogen (N) that will be available to a crop in the upcoming year is difficult. Crops need N at different physiological stages. The timing of those stages depends on growing degree days and available moisture and nutrients. Soil microbes transform organic N into plant-available nitrate (NO3—) or ammonium (NH4+). The pace of those transformations is also dependent on the weather. Most microbes need both water and oxygen, so overly dry or moist conditions slow things down. (Saturated soils will lose N as nitrogen dioxide (NO2) because a different group of microbes that do not need oxygen takes over.) So predicting N availability comes down to being able to predict the weather, and taking into account both plant and microbial responses to temperature and moisture. The tools we use now for predicting crop-available N are based on measuring how much N is in the soil. This makes s

In this episode of the Nutrient Management Podcast, University of Minnesota Extension specialists and educators discuss  agricultural drainage and nutrient management . What happens when we drain soils? How does drainage impact crop production and water quality? How can we minimize nutrient loss through drainage systems? Thank you to the Minnesota Agricultural Fertilizer Research and Education Council (AFREC) for their support of this podcast.

Vasudha Sharma, Extension irrigation specialist and Anne Nelson, Extension educator Measuring soil moisture and electrical conductivity in a corn field. Efficient irrigation management can improve yields, grain quality, conserve water and energy, and reduce nutrient leaching. One of the easiest and most effective ways to improve irrigation efficiency is to implement soil sensor technology in irrigation scheduling. This article provides basic knowledge and practical recommendations for using soil moisture sensors for irrigation scheduling. Types of soil moisture sensors Soil moisture sensors are divided into two categories depending on the technology they use: 1) Sensors that measure volumetric water content and 2) Sensors that measure soil tension when placed in the soil profile (Figure 1). Figure 1. General categorization of soil moisture sensors. Volumetric water content (VWC) soil moisture sensors Volumetric water content is the volume of liquid water per volume of

Bruce Potter, Integrated pest management specialist Figure 1. Black cutworms and damage to soybean. The black cutworm can be a significant pest of corn, sugarbeets and other crops. Because they cannot survive our Minnesota winters, the risk of economic crop loss depends on how many moths arrive and when they arrive with respect to crop development. In some areas of Minnesota, planned fall tillage that did not happen and the later start to 2019 spring fieldwork both increase the proportion of fields that are attractive egg-laying sites for early-arriving migrant moths. Additionally, more corn acres are expected to be planted to hybrids susceptible to black cutworm damage. To help predict risk of economic damage and help time scouting efforts, the UMN Cooperative Black Cutworm Trapping Network is once again operating during 2019. Each day, cooperators check their pheromone traps to look for moths that have migrated into the state. The timing of arrivals of large numbers of mot

By: Jared Spackman, graduate student, and Fabian Fernandez, Extension Specialist Wet conditions last fall and this spring have limited the number of acres that received nitrogen in preparation for the upcoming growing season. This creates the challenging dilemma of whether to delay planting in order to get fertilizer down. Most Minnesota soils can supply sufficient nitrogen to meet early corn growth without a yield reduction. The best bet is to plant corn on time to optimize yield potential and come back later to apply nitrogen. Which fields should I focus on early fertilization? Minnesota typically receives about a third of its annual precipitation in the months of April through June. Early applications of nitrogen may be subject to significant losses, especially if it converts to the nitrate form. During this time, corn demand for nitrogen is low, with only about 10% of the total N taken up by mid-June. Fields that are on hilltops or less prone to water-saturated conditions

Jared Goplen, Extension educator - crops and Brian McNeill – Extension educator - youth development Crop scouting skills are essential for any farming operation to maximize crop production and economic returns. The University of Minnesota Extension 4-H program is excited to announce an all-new crop scouting event kicking off this summer. This crop scouting event aims to equip the next generation of farmers and ag-industry specialists with basic crop scouting and pest management skills helpful for any career in agriculture, environmental sciences, or food production. The 4-H Crop Scouting event is designed as a competition, where teams will compete by testing their skills in troubleshooting agronomic issues and weed, insect, and disease identification at hands-on field stations. Who:  4-H and FFA teams in grades 7-12 at any skill level are invited to participate.  When: Monday, July 29  Where: Near Benson, MN at a crop research farm.  The top two teams will qualify for the

By: Greg Klinger, Extension educator I was recently asked how growing cover crops can impact the nitrogen credit we give to corn grown after soybeans. This credit, which is often incorrectly assumed to be based on soybean adding nitrogen to the soil, is mostly related to the carbon-to-nitrogen ratio of soybean residue. The main issue to consider is: what is happening to soil nitrogen as that cover crop is decomposing? A lot of this comes down to what the cover crop is, how much biomass is out there, and what stage of growth it is at. Legume cover crops Legume cover crops, like vetch or clover, have the advantage of both fixing some amount of nitrogen and having a low carbon-to-nitrogen ratio regardless of their stage of growth. They will quickly decompose after termination, and release more nitrogen than they tie up. However, because there is usually so much more residue left over from the previous year’s cash crop than there is from the cover crop, the effects on nitrogen dem

by Jared Goplen – Extension Educator, Crops Can you identify these weeds? It really can be that simple. Last summer I was introduced to an app / website called iNaturalist, a tool commonly used by those working in natural resources. While it can be used to help identify nearly any species, it works especially well to identify weeds. Best of all it is free! The app / website works by using facial recognition software and machine-learning to provide an instantaneous “likely” ID based on what the software matches the picture to. The app then provides descriptions and pictures of the “likely” matches to help determine what the species might be. Finally, you can upload the photo so other users can confirm your ID or provide other suggestions via crowdsourcing. At first I was skeptical that an app like this would actually be useful. In trying it last summer, however, even difficult identifications would at least key to the genus-level with the photo-recognition aspect. This at leas

By Lizabeth Stahl, Extension Educator in Crops and Bruce Potter, Integrated Pest Management Specialist Treated seed should be cleaned up or covered with soil to prevent exposure to birds and other wildlife. Photo: Liz Stahl A significant amount of seed planted this year will have been treated with one or more fungicide, insecticide, nematicide, or biological seed treatments. The following are some key precautions and reminders to follow when working with treated seed to help prevent pesticide exposure to handlers, non-target organisms, and the environment. Read the seed tag label.  This is a basic, but key first step in understanding what steps and precautions to take when working with seed that has been treated with a particular product(s).  Be familiar with any restrictions listed on the seed bag label before you use the seed.  Wear the proper personal protective equipment (PPE) when handling treated seed. Most seed tag labels will state that at minimum, a long-sleeve

By: Dan Kaiser, Extension Specialist Changes were recently made to the University of Minnesota’s potassium (K) fertilizer guidelines for corn and soybean. These changes were made to reflect research evaluating critical soil test levels and primarily centers on medium and fine textured soils. How are the new guidelines different? The new guidelines follow the same fertilization strategy used in Minnesota for many years. The guidelines differ in that the ranges for the soil K classes have been adjusted to reflect current research which has shown the need for slightly higher critical soil test K levels for poorly drained medium to fine textured soils. Changes in the ranges were made for both corn and soybean, putting the critical level at 200 parts per million (ppm). These changes reflect the use of the dried ammonium acetate K test, which is recommended in Minnesota. In addition, suggested K application rates for soybean have been increased for the Medium and High soil test K cla

Angie Peltier and Jared Goplen, Extension educators and Seth Naeve, Extension soybean agronomist Soybean cyst nematode on soybean roots. Arrows point to cysts (swollen female nematodes filled with eggs). Sampling program results Samples submitted through the Minnesota SCN sampling and education program originated from 28 Minnesota counties, with the majority of the 363 samples coming from the most newly infested northwest region (Figure 1). While 49.6% of samples had SCN population densities below the limit of detection of 50 eggs per 100 cubic cm of soil, the remaining 50.4% tested positive. One sample submitted through this survey included the first documented infestation in Beltrami County. Among samples testing positive: Figure 1. SCN population density estimates from soil samples analyzed on behalf of the MSRPC-sponsored 2018 sampling and education program. 43% had egg densities high enough to cause some yield loss on SCN susceptible varieties. 38% had egg

Lisa Behnken, Fritz Breitenbach, Ryan Miller and Jeff Gunsolus Soybeans were no-till planted into an existing alfalfa stand. Plans change. Perhaps you planned to terminate an alfalfa stand last fall but the weather made tillage impossible to complete. Or, the winter weather has severely damaged your alfalfa stand. In either situation, is planting soybean after alfalfa when it's terminated in the spring a viable option? Spring termination of an alfalfa stand due to planned rotation or winter injury can increase the probability of volunteer alfalfa in the subsequent crop. Volunteer alfalfa becomes even more challenging to control if it is a glyphosate tolerant variety. Our studies show that soybean technologies (dicamba-, 2,4-D-, and glufosinate-tolerant) offered herbicide choices that controlled volunteer alfalfa well after spring termination, making soybean a viable crop option. Planting decision Corn is the preferred crop to plant in rotation after alfalfa, due to

By: Brad Carlson, Extension educator With planting season right around the corner, many farmers are looking at designing on-farm trials in some of their fields. Here are a few pointers to help ensure that you are able to answer the questions you are trying to evaluate: 1. Choose a uniform site Avoid fields that have areas of poor drainage, or sandy spots. Also, make sure that the field received consistent management in the recent past. Some things that could cause problems include: old field boundaries, uneven manure applications or partial residue removal (like baling corn stalks from only half of the field). Variability in the soil that you cannot see can cause yield variability, so controlling what you can see is critical. 2. Use replication and randomization Simply splitting a field, or comparing one field to another, cannot provide reliable answers to agronomic questions. Even with no differences in management, you will find a higher yield in one field versus a

By: Daniel Kaiser, Extension specialist Decisions on optimal fertilizer management can be challenging in years with low commodity prices. Work is underway to overhaul the corn and soybean potassium (K) guidelines in Minnesota. When making decisions for applying K for corn and soybean, here are a few things that you should consider: 1. Focus on rate, not timing Applying the correct rate that is needed over one or two years in a crop rotation has been shown to be more important than the time when the fertilizer is applied. Much of our current data has demonstrated that timing of application in a multi-year cropping rotation is not important. Applying ahead of the crop that will get the greatest advantage from the K is the best way to get the most bang for your buck. 2. Focus on a proven yield, not a yield goal When making decisions about how much K to apply, it can be difficult to determine what yield should be used for both a sufficiency-based or build and maintenance st

Figure 1. Project management dilemma of picking two priorities (left), and alfalfa tradeoff priorities (right). Adapted from the Developer Society (April 5, 2018) M. Samantha Wells – forage and cropping system agronomist Balancing alfalfa tradeoffs between yield, quality and persistence reminds me of the "Good, Fast, and Cheap" paradigm where only two can be selected (Figure 1; Dev. 2018). Cheap and fast typically corresponds to lower quality work whereas fast and good tends to be expensive. But wait, what about good and cheap? From my experiences, good and cheap are seldom in alignment. Now substitute good, fast and cheap with alfalfa yield, quality, and persistence (Figure 1). It is easy to see that alfalfa management priorities also fit the project management paradigm with a few caveats. Optimizing alfalfa production Optimizing alfalfa tradeoffs is a bit more challenging than picking project management priorities. In the management paradigm, we are assured tha

Jeff Coulter, Extension corn agronomist Successful corn stand establishment is the foundation for high yield and profitability. It is driven by soil conditions during preplant tillage and planting, along with the date, depth, and rate of planting. Consider the following guidelines to reduce risk and maximize economic net return. Soil conditions Avoid preplant tillage and planting when soils are wet. A field is ready for seedbed preparation when soil in the depth of tillage crumbles when squeezed. Tillage in wet soil causes clods, which reduce seed-to-soil contact. Excellent seed-to-soil contact is essential for rapid imbibition of moisture by seeds and uniform emergence. Tillage in wet soil also creates a compacted layer below the depth of tillage, which can restrict root development. Sidewall compaction can occur when planter disc openers cut through wet fine-textured soil, resulting in compacted soil around the seed that is difficult for roots to penetrate. Seed furrows can

This article detailing the Palmer Amaranth Summit was written by Communications specialist Dana D'Amico was originally posted on the Minnesota Invasive Terrestrial Plants & Pests Center website . Palmer amaranth in southern Illinois. Photo: Robert Bellm Tracking Palmer amaranth in Minnesota Palmer amaranth in Minnesota started with just one pathway of spread – a single company selling contaminated native seed mix for conservation plantings. Nearly two years later, Palmer continues to spread by other means, including via humans, equipment, livestock, hay, forage and feed. In 2018, Palmer was reported at 44 sites across 6 counties. This includes the first sightings of Palmer in soybean fields. MDA's Noxious Weed and Hemp Unit Supervisor Tony Cortilet discusses Minnesota's response to date. How can you help slow the spread? Learn how to identify Palmer and how it differs from other common pigweeds and waterhemp. If you suspect a Palmer plant, record its locat