Proceedings
Authors
| Filter results13 paper(s) found. |
|---|
1. In-Season Soil Nitrogen as a Predictor of Corn Grain YieldCorn (Zea mays L.) grain yield is closely linked to plant available soil nitrogen (N). Our objectives were to (i) examine the influence of N rate, source, and time of application on N use efficiency with relation to grain yield and total plant N uptake, and (ii) evaluate in-season soil N testing as a tool to determine N rate needs and predict grain yield. During the 2014-2015 growing seasons, 12 fields across Minnesota varying in soil and climate conditions received 1) pre-plant urea (0 to 204... J. Spackman, F. Fernandez |
2. Comparison of Canopy Sensing Technologies for Corn Nitrogen Management in MinnesotaVarious crop canopy sensing tools are being used to manage nitrogen, but their utility to predict N needs in Minnesota remains unclear. The objectives of this study are to compare the effectiveness of different canopy sensing technologies at predicting corn (Zea mays L.) yield at different development stages, and compare their capability to determine in season N deficiency. Six to seven N rates at 35 to 45 kg N ha -1 increments were pre-plant applied in six fields throughout Minnesota and a rate... |
3. Phosphorus and Water Quality Issues in Lake ErieWhat are harmful algae blooms? Harmful algal blooms (HABs) are so named because they can produce toxins (or poisons) that can cause illness or irritation sometimes even death in pets, livestock, and humans. The term algae is somewhat misleading since HABs are actually cyanobacteria, which are commonly referred to as blue-green algae, and are not true algae. These organisms act like many other plant and use photosynthesis to capture sunlight but unlike most plants and algae some can fix their own... |
4. Active Sensor Orientation Over Corn Rows and Effect on Assessment of BiomassOur long-tern mresearch goal is to develop practical N application systems that use on-the-go remote sensing as a nleans to assess crop N status and only apply N where needed at times when the crop can most efficiently utilize N. Our preliminaty testing of two active sensor systems has shoxl-11 considerable promise for rapid and accurate assessment of canopy N status and crop biomass. In this work, the effect of sensor positioning and orientation over the canopy and their effects on assessment of... |
5. Comparison of Nitrogen Recommendation Models for Corn in Two Cropping SystemsSeveral lnodels exist to generate N recommendations, and the model selected can have both economical and environmental implications. A study was initiated in 1998 to compare the response of corn to N in two ci-opping systenls (corn following corn and corn following soybeans). All plots received a starter N rate of 45 kg N ha-' (2 x 2 placement). and five rates of sidedress N (0, 22, 90, 157, and 224 kg N hi') were applied at gro~vth stage V6 either as anhydrous arnmonia or urea-ammonium rli trate... |
6. In Season RecommendationsWe are testing a prototype high-clearance tractor configured with active crop canopy sensors, drop nozzles with electronic valves, and a variable rate controller as means to deliver in-season variable rates of liquid N fertilizer based on crop needs as an alterative to preplant uniform applications of N. The active sensor we're evaluating is the model ACS-210 Crop Circle made by Holland Scientific. It generates it's own source of modulated light in the amber and near infrared (NIR) bands and then... |
7. Field Measurements of Nitrous Oxide Emissions across a Nitrogen Fertilizer Gradient for Corn Cropping SystemsSignificant reductions in nitrous oxide (N 2O) emissions from corn (Zea maize L.) cropping systems may be possible by reducing N fertilizer i nputs with relatively little impact on crop grain yield or economic return. To te st this hypothesis, experiments we re conducted at 4 locations in corn production in Michigan in 2007. All sites were under a corn-soybean rotation. Prior to planting, six rates of urea fertilizer (0-200 lb ac -1) were broadcast and incorporated into four replicate plots (RCBD)... |
8. Starter Potassium for Corn: Why and WhenStarter fertilizer application can complement broa dcast P and K fertilization for corn and other crops. Questions about its use relate mainly to the conditions in which it is most effective (such as soil-test level, tillage syst em, and broadcast fertilization rates among others), application methods and rates that do not damage seedlings, and nutrient ratios. Many studies in Iowa and the Midwest have shown that starter mixtures (usu ally N-P or N-P-K) often increase early corn growth. Corn yield... |
9. Crop Sensor-Based N Rates Out-Performed Producer-Chosen N RatesOptimal N fertilizer rate for corn (Zea mays L.) and other crops can vary substantially within and among fields. Current N management practices do not address this variability. Crop reflectance sensors offer the potential to diagnose crop N need and control N application rates at a fine spatial scale. Our objective was to evaluate the performance of sensor-based variable-rate N applications to corn, relative to constant N rates chosen by the producer. Fifty-five replicated on- farm demonstrations... |
10. 4R Nutrient Management for Corn Production on Upper Midwest SoilsCorn (Zea mays L.) demand for nitrogen (N) is often met using inorganic fertilizer on Upper Midwest soils. While applying the right rate of fertilizer N normally has the greatest impact on yield and N use efficiency (NUE), selection of the right fertilizer source, placement, and application timing can fine-tune rate recommendations, improve NUE by matching soil N availability to corn demand, and minimize loss to the environment. Given the diversity of corn production environments, the... J. Spackman, F. Fernandez, K. Fabrizzi |
11. Relating Soil Properties to Spatial Variation of Phosphorus Critical LevelVariable rate (VR) fertilizer application has increased with proliferation of VR capable equipment. Current recommendations for VR phosphorus (P) application often assume that critical level is constant across a field adjusting only for spatial variation of soil P concentration. We conducted this study to determine whether variation in critical level, identified by relative yield of unfertilized to fertilized plots, could be explained by soil properties. In 2016, plots, measuring... J. Bowen |
12. Soil Nitrogen Management is Impacted by Soil Texture and WeatherNitrogen (N) is an important nutrient for corn production that is often supplied as inorganic fertilizer, but its use can also lead to environmental degradation. The 4R (right rate, source, time, and placement) approach has been suggested as a framework for N management to improve crop yield and nutrient use efficiency while minimizing environmental contamination. There is not a universal 4R best management strategy, nor should there be because many variables impact N... J. Spackman |
13. Fertilizer Derived Nitrogen Dispersion in Minnesota Corn with Rye and Kura Clover Cover CropsWhile ideally all fertilizer nitrogen (N) is utilized by crops, much can be lost to the environment as nitrate (NO3), nitrous oxide (N2O), or ammonia (NH3). To enhance agronomic systems and mitigate environmental N dispersion, best management practices can be utilized. Here, urea was applied to continuous corn at 250 kg N/ha or a 0 kg N/ha control, and with select cover crops (no cover, winter rye, kura clover) to assess practices that may result in optimal fertilizer... J. Kastenbauer, F. Fernández, V. Sharma, R. Venterea, J. Spackman |