Charles Wortmann - Extension Soil and Nutrient Management Specialist

Charles Wortmann

faculty
Work Keim Hall (KEIM) 369
Lincoln NE 68583-0915
US
Work 402-472-2909 On campus, dial 2-2909

Faculty Bio

Research Cited in CW
How Manure Impacts Soil Aggregation

Taking CO2 measurements in plots where residue has been baled
Taking CO2 measurements in plots where residue has been baled

Corn Residue Removal and CO2 Emissions

February 26, 2018
University research looking at CO2 emissions from two types of residue removal (baling and grazing) compared with a control treatment found little day-to-day impact; however, when looking at cumulative data for the whole year, grazing did appear to affect cumulative CO2 emissions in irrigated crop-livestock systems. This data represents the first year of this study.

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Figure 1. Land-applied manure from finishing 5 million beef cattle per year in Nebraska contains the equivalent of 150 lb/ac/yr N applied to 1.2 million acres.
Figure 1. Land-applied manure from finishing 5 million beef cattle per year in Nebraska contains the equivalent of 150 lb/ac/yr N applied to 1.2 million acres.

Fertilizer N Substitution Values of Land-Applied Organic Materials

January 8, 2018
An article from the Proceedings of the 2018 Nebraska Extension Crop Production Clinics on accounting for nitrogen from land-applied manure when determining soil nutrient needs for crop production.

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Land-applied manure
Research to validate or adapt canopy sensor-guided in-season N application practices for manured fields was evaluated in two trials.

Adaptation of Canopy Sensor-Guided In-Season Nitrogen Application for Manured Fields

January 8, 2018
An article from the Proceedings of the 2018 Nebraska Extension Crop Production Clinics on research on land application of manure to enhance soil nutrients for crop production.

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Chart

Improved Use Efficiency of Applied Organic Nitrogen

January 8, 2018
An article from the Proceedings of the 2018 Nebraska Extension Crop Production Clinics about recent research to validate or adapt canopy sensor-guided in-season N application practices for fields with manure or other organic material applied and to improve the predictionof fertilizer N substitution for organic materials.

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Figure 1. Based corn stalk residue.
Figure 1. Where moisture is not limited, research shows that removing some corn residue from a field may benefit yield in the following crop. However, if residue is removed for more than three years, research showed longer term impacts to the soil.

Crop Residue Removal: Impacts on Yield

December 8, 2017
A review of multiple research studies indicates that where moisture is not limited, residue removal can result in no yield reduction to yield increases for the subsequent crop. However, long-term residue removal has been shown to affect other production factors and it's recommended that even in minimal erosion areas, removing residue does impact other production factors and it's recommended that 2.4 tons/acre of residue be left in the field.

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Figure 1. Corn stalk residue with downed ears, baled and ready to use. (Photo by Jenny Rees)
Figure 1. Corn stalk residue with downed ears baled and ready to use. (Photo by Jenny Rees)

Corn Stover Removal: Nutrient Value of Stover and Impacts on Soil Properties

December 7, 2017
Corn residue has a number of uses and thus its value as well as its impact on other systems may need to be estimated when evaluating post-harvest options. This article looks at how to estimate the nutrient value of the residue and potential impacts to the soil from removing the residue, based on Nebraska research.

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Amelioration Strategies after Corn Residue Removal

December 7, 2017
The authors review three research studies on how amelioration practices such as adding cover crops and/or manure may offset any effects of removing crop residue.

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Fertilizer Management for Winter Wheat

August 29, 2017
With winter wheat planting drawing near, it's time to collect soil samples and determine fertilizer needs. Use the nitrogen and phosphorus information to guide your strategy.

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