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Agronomy and Crop Sciences Commons

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2017

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Articles 61 - 90 of 340

Full-Text Articles in Agronomy and Crop Sciences

Corn Grain Yield Trends From 2012 To 2016: A 26-Year Long-Term Experiment, J. Rivera-Zayas, Charles Rice Jun 2017

Corn Grain Yield Trends From 2012 To 2016: A 26-Year Long-Term Experiment, J. Rivera-Zayas, Charles Rice

Kansas Agricultural Experiment Station Research Reports

Long-term research trials provide an understanding of long-term effects on crop production. This long-term research studied the effect of conventional tillage (CT) and no-tillage (NT) systems. Factors of this 22-year study of corn (Zea maysL.) production also included the application of nitrogen (N) in the forms of ammonium nitrate and manure at rates of 150 lb/N/a. Corn grain yield trends during 2012 to 2016 were affected by the interaction between N source and year (P<0.05). The interaction between tillage practices and N source and the overall interaction between the last 5 years did not yield performance (P>0.05). Under the studied conditions the 75 lb/N/a as N fertilizer or manure achieved high corn yields.


Agricultural Bio-Stimulant Application To Enhance Phosphorus Availability In Grain Sorghum, A. Obour Jun 2017

Agricultural Bio-Stimulant Application To Enhance Phosphorus Availability In Grain Sorghum, A. Obour

Kansas Agricultural Experiment Station Research Reports

This study was conducted to determine the effectiveness of AgZyme and SuperHume (both products of Ag Concepts Corp) application on phosphorus (P) uptake and utilization efficiency in grain sorghum. Treatments were a control, 30 lb P2O5/a, 20 oz/a AgZyme, 20 oz/a AgZyme + 30 lb P2O5/a, 20 oz/a AgZyme + 30 lb P2O5/a + 6 qt/a SuperHume, which were arranged in a randomized complete block design with four replications. Preliminary results in 2016 showed grain sorghum aboveground biomass, grain moisture content, and test weight were not affected by …


Impact Of Cover Crops And Phosphorus Fertilizer Management On Nutrient Cycling In No-Tillage Corn-Soybean Rotation, R. E. Carver, N. O. Nelson, D. S. Abel, K. Roozeboom, G. J. Kluitenberg, P. J. Tomlinson, J. R. Williams Jun 2017

Impact Of Cover Crops And Phosphorus Fertilizer Management On Nutrient Cycling In No-Tillage Corn-Soybean Rotation, R. E. Carver, N. O. Nelson, D. S. Abel, K. Roozeboom, G. J. Kluitenberg, P. J. Tomlinson, J. R. Williams

Kansas Agricultural Experiment Station Research Reports

The objective of this study was to quantify the effects of cover crops and different fertilizer management techniques on the amount of nutrients being removed and recycled in the soil system. This study was conducted at Ashland Bottoms, KS, from 2014-2016. A 2 × 3 factorial design with three replicates was utilized in this study. The fertilizer management treatments included a control of 0 lb/a P2O5, along with fall broadcast and spring injected applications of P2O5based on a build and maintain recommendation system. Results show that total uptake of K2O …


Biochar And Nitrogen Effects On Winter Wheat Growth, T. E. Zee, N. O. Nelson, G. Newdigger Jun 2017

Biochar And Nitrogen Effects On Winter Wheat Growth, T. E. Zee, N. O. Nelson, G. Newdigger

Kansas Agricultural Experiment Station Research Reports

Biochar, a co-product of thermochemical bioenergy production, may be a valuable soil amendment, but little is known about its potential long-term effects on plant growth and soil fertility. In order to gain more information, this experiment was performed to see if the addition of biochar, in comparison to lime and fertilizer treatments, has the potential to return key nutrients back to the soil or increase crop yield. A field study to investigate the effects of biochar on plant growth was initiated in 2011 near St. John, KS. Treatments included biochar applied at 16.6 ton/a (biochar), lime and annual applications of …


Long-Term Nitrogen And Phosphorus Fertilization Of Irrigated Grain Sorghum, A. Schlegel, H. D. Bond Jun 2017

Long-Term Nitrogen And Phosphorus Fertilization Of Irrigated Grain Sorghum, A. Schlegel, H. D. Bond

Kansas Agricultural Experiment Station Research Reports

Long-term research shows that phosphorus (P) and nitrogen (N) fertilizer must be applied to optimize production of irrigated grain sorghum in western Kansas. In 2016, N applied alone increased yields 71 bu/a, whereas N and P applied together increased yields up to 93 bu/a. Averaged across the past 10 years, N and P fertilization increased sorghum yields up to 77 bu/a. Application of 80 lb/a N (with P) was sufficient to produce 89% of maximum yield in 2016 which is slightly less than the 10-yr average. Application of potassium (K) has had no effect on sorghum yield throughout the study …


Long-Term Nitrogen And Phosphorus Fertilization Of Irrigated Corn, A. Schlegel, H. D. Bond Jun 2017

Long-Term Nitrogen And Phosphorus Fertilization Of Irrigated Corn, A. Schlegel, H. D. Bond

Kansas Agricultural Experiment Station Research Reports

Long-term research shows that phosphorus (P) and nitrogen (N) fertilizer must be applied to optimize production of irrigated corn in western Kansas. In 2016, N applied alone increased yields 85 bu/a, whereas P applied alone increased yields only 12 bu/a. Nitrogen and P applied together increased yields up to 164 bu/a. This is 20 bu/a greater than the 10-year average, where N and P fertilization increased corn yields up to 144 bu/a. Application of 120 lb/a N (with highest P rate) produced about 94% of maximum yield in 2016, which is similar to the 10-year average. Application of 80 instead …


Palmer Amaranth (Amaranthus Palmeri) Suppression With Half Rates Of Dicamba And Atrazine With Increasing Sorghum (Sorghum Bicolor) Density And Nitrogen Rate, I. B. Cuvaca, R. Currie, A. J. Foster Jun 2017

Palmer Amaranth (Amaranthus Palmeri) Suppression With Half Rates Of Dicamba And Atrazine With Increasing Sorghum (Sorghum Bicolor) Density And Nitrogen Rate, I. B. Cuvaca, R. Currie, A. J. Foster

Kansas Agricultural Experiment Station Research Reports

Palmer amaranth (PA) competition can result in severe yield loss in grain sorghum. Increasing sorghum density and nutrient supply could promote early/rapid canopy closure and therefore reduce the amount of light that could otherwise penetrate the canopy and promote PA growth in sorghum. A study was conducted at the Southwest Research-Extension Center near Garden City, KS, to determine if PA could be suppressed with dicamba and atrazine applied as PRE at half rates combined with increasing sorghum density (60,000, 90,000, and 120,000 seeds/a), and nitrogen rate (0, 100, 200 lb/a). Preliminary results indicate that increasing plant density and nitrogen rate …


Nitrogen And Phosphorus Application Effects On Pearl Millet Forage Yield And Nutritive Value, D. D. Serba, A. Obour Jun 2017

Nitrogen And Phosphorus Application Effects On Pearl Millet Forage Yield And Nutritive Value, D. D. Serba, A. Obour

Kansas Agricultural Experiment Station Research Reports

There is limited information on the nitrogen (N) and phosphorus (P) fertilizer requirement of pearl millet forage in dryland systems. Determination of optimum N and P rates for pearl millet forage production in dryland environments of the Great Plains will have economic advantage for farmers and ranchers growing pearl millet for forage. A field experiment was conducted in 2016 at the Agricultural Research Center-Hays, KS, to investigate N and P fertilizer application effects on forage yield and nutritive value of pearl millet. Factorial combinations of five levels of N (0, 30, 60, 90, and 120 lb/a) and three levels of …


Interaction Of Seeding And Nitrogen Rate On Grain Sorghum Yield In Southwest Kansas, A. J. Foster, A. Schlegel, J. D. Holman, I. A. Ciampitti, C. Thompson, D. Ruiz Diaz Jun 2017

Interaction Of Seeding And Nitrogen Rate On Grain Sorghum Yield In Southwest Kansas, A. J. Foster, A. Schlegel, J. D. Holman, I. A. Ciampitti, C. Thompson, D. Ruiz Diaz

Kansas Agricultural Experiment Station Research Reports

This study compared drilled planted sorghum at four seeding rates to planted sorghum at three different nitrogen (N) fertility levels at two locations in southwest Kansas (Garden City and Tribune). At the Garden City location, no difference was observed in yield among the drilled seeded sorghum populations greater than 27,000 seeds/a compared to the standard planted sorghum (sorghum planted at 27,000 seeds/a with a planter at 30 in.-row spacing). At Tribune, there was no difference in yield between the drilled sorghum and the standard planted sorghum (sorghum planted at 40,000 seeds/a with a planter at 30 in.-row spacing) regardless of …


Geometry-Based Mass Grading Of Mango Fruits Using Image Processing, M. A. Momin, Md Towfiqur Rahman, M. S. Sultana, C. Igathinathane, A. T. M. Ziauddin, T. E. Grift Jun 2017

Geometry-Based Mass Grading Of Mango Fruits Using Image Processing, M. A. Momin, Md Towfiqur Rahman, M. S. Sultana, C. Igathinathane, A. T. M. Ziauddin, T. E. Grift

Department of Biological Systems Engineering: Papers and Publications

Mango (Mangifera indica) is an important, and popular fruit in Bangladesh. However, the post-harvest processing of it is still mostly performed manually, a situation far from satisfactory, in terms of accuracy and throughput. To automate the grading of mangos (geometry and shape), we developed an image acquisition and processing system to extract projected area, perimeter, and roundness features. In this system, images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting. An image processing algorithm based on region based global thresholding color binarization, combined with median filter and morphological analysis was developed …


Kansas Fertilizer Research 2017 Jun 2017

Kansas Fertilizer Research 2017

Kansas Agricultural Experiment Station Research Reports

Reports on fertilizer and related topics from Kansas State University.


Transcriptomic Resources For The Medicinal Legume Mucuna Pruriens: De Novo Transcriptome Assembly, Annotation, Identification And Validation Of Est-Ssr Markers, N. Sathyanarayana, Ranjith Kumar Pittala, Pankaj Kumar Tripathi, Ratan Chopra, Heikham Russiachand Singh, Vikas Belamkar, Pardeep Kumar Bhardwaj, Jeff J. Doyle, Ashley N. Egan May 2017

Transcriptomic Resources For The Medicinal Legume Mucuna Pruriens: De Novo Transcriptome Assembly, Annotation, Identification And Validation Of Est-Ssr Markers, N. Sathyanarayana, Ranjith Kumar Pittala, Pankaj Kumar Tripathi, Ratan Chopra, Heikham Russiachand Singh, Vikas Belamkar, Pardeep Kumar Bhardwaj, Jeff J. Doyle, Ashley N. Egan

Department of Agronomy and Horticulture: Faculty Publications

Background:

The medicinal legume Mucuna pruriens (L.) DC. has attracted attention worldwide as a source of the anti-Parkinson’s drug L-Dopa. It is also a popular green manure cover crop that offers many agronomic benefits including high protein content, nitrogen fixation and soil nutrients. The plant currently lacks genomic resources and there is limited knowledge on gene expression, metabolic pathways, and genetics of secondary metabolite production. Here, we present transcriptomic resources for M. pruriens, including a de novo transcriptome assembly and annotation, as well as differential transcript expression analyses between root, leaf, and pod tissues. We also develop microsatellite markers …


A Comprehensive Analysis Of Alternative Splicing In Paleopolyploid Maize, Wenbin Mei, Sanzhen Liu, James C. Schnable, Cheng-Ting Yeh, Nathan M. Springer, Patrick S. Schnable, William Brad Barbazuk May 2017

A Comprehensive Analysis Of Alternative Splicing In Paleopolyploid Maize, Wenbin Mei, Sanzhen Liu, James C. Schnable, Cheng-Ting Yeh, Nathan M. Springer, Patrick S. Schnable, William Brad Barbazuk

Department of Agronomy and Horticulture: Faculty Publications

Identifying and characterizing alternative splicing (AS) enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level …


Using Ancient Practices To Fix Modern Problems: The Effect Of Biochar On Einkorn Wheat And Soil Quality, Sarah L. Miller May 2017

Using Ancient Practices To Fix Modern Problems: The Effect Of Biochar On Einkorn Wheat And Soil Quality, Sarah L. Miller

Senior Honors Projects, 2010-2019

As farmland soils become more and more depleted, the importance of effective soil amendments grows. Biochar is a potential soil and carbon amendment that could improve water and nutrient holding capacity and foster growth of beneficial microbes and fungi. Biochar does not contain nutrients but acts like a sponge, absorbing nutrients around it. It is so effective at holding nutrients that in the first year, if applied alone, it can make the nutrients unavailable to plants and lowers crop yields. To get the best results biochar must be saturated, also referred to as inoculated or charged, with nutrients. Once the …


Precision Drought Stress In Orchards: Rootstock Evaluation, Trunk Hydration And Canopy Temperature, Lance V. Stott May 2017

Precision Drought Stress In Orchards: Rootstock Evaluation, Trunk Hydration And Canopy Temperature, Lance V. Stott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tree fruit crops are of high value, but use a lot of water. Precision irrigation has the potential to save water while simultaneously improving crop quality. The timing and method of precision water stress in various tree fruit crops has been widely studied. However, in order to successfully employ precision irrigation methods in orchards, an accurate measurement of tree water status is required. Currently, stem water potential is the preferred indicator. However, this measurement is tedious and cannot be automated. Because measurements must be taken near solar noon (approximately 1:30 PM MDT in the summer in northern Utah), the number …


Efficiency And Competitiveness Of Kosovo Raspberry Producers, Rina Vuciterna May 2017

Efficiency And Competitiveness Of Kosovo Raspberry Producers, Rina Vuciterna

Graduate Theses and Dissertations

Raspberry production is a growing industry in Kosovo. In addition to private investments, this growth has been supported by grants, subsidies, and direct investment from international donor organizations and governmental institutions. At present, most of the commercially produced raspberries in Kosovo are produced on small farms, harvested by farmers and packed manually by collection centers, and then sold in frozen form for the export market. The long-term viability and continued growth of raspberry production in Kosovo depends on the industry being able to compete in export markets and hold its own against production regions in Poland, Serbia, and Russia. Our …


The Effect Of Spray Parameters On The Application Of Enlist Duo, Matthew R. Nelson May 2017

The Effect Of Spray Parameters On The Application Of Enlist Duo, Matthew R. Nelson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The emergence of new weed control challenges, along with shifts in weed management strategies and cultural practices, has resulted in an increased reliance on chemical weed control in United States (US) cropping systems. As a result, numerous weed species have evolved resistance to herbicides such as glyphosate, thus prompting the development of new weed control systems designed to aid growers in managing resistant weeds. While these new weed control options may give growers additional management options, the high sensitivity of broadleaf crops, fruits, and vegetables to products containing 2,4-D or dicamba increases the potential for herbicide drift resulting from application …


Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi May 2017

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Graduate Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied …


Evaluation Of Benzobicyclon For Use In Midsouthern Rice (Oryza Sativa) Systems, Mason Luke Young May 2017

Evaluation Of Benzobicyclon For Use In Midsouthern Rice (Oryza Sativa) Systems, Mason Luke Young

Graduate Theses and Dissertations

A new herbicide site of action (SOA) is needed by rice (Oryza sativa L.) producers in the Midsouth for the control of problematic and herbicide-resistant weeds. Currently, six problematic weeds are relevant to Midsouthern rice producers because of resistance to at least one SOA, if not more. Gowan Company is in the process of commercializing benzobicyclon for use in Midsouthern rice systems. Benzobicyclon, a Group 27 post-flood herbicide, controls a broad spectrum of aquatics, broadleaves, grasses, and sedges, including those currently resistant to Group 2 herbicides. This will be the first 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicide commercially available in US rice …


Effects Of Drought Conditions On Microbial Communities In Native Rangelands, Abbie L. Lasater, Tiffany Carter, Charles Rice May 2017

Effects Of Drought Conditions On Microbial Communities In Native Rangelands, Abbie L. Lasater, Tiffany Carter, Charles Rice

Chemical Engineering Undergraduate Honors Theses

Climate change is a result of greenhouse gases released into the atmosphere. These changes are expected to cause extreme weather conditions, including severe storms. Large amounts of rain will fall in shorter periods of time, leading to heavy runoff, and increasing the severity of drought conditions within the soil (Zeglin et al. 2013).

Native grasslands occupy almost a quarter of the earth’s land surface and are valuable ecological resources. They contain soils with high concentrations of organic matter and play a key role in mitigating greenhouse gas emissions through carbon sequestration. There are a variety of grassland management techniques including …


Value Of Cover Crops In Suppressing Weeds And Protecting Cotton Yields And Likelihood Of Residual Herbicide Carryover To Cover Crops, Matheus Gabriel Palhano May 2017

Value Of Cover Crops In Suppressing Weeds And Protecting Cotton Yields And Likelihood Of Residual Herbicide Carryover To Cover Crops, Matheus Gabriel Palhano

Graduate Theses and Dissertations

Weed-resistance management has become a topic of concern for modern agriculture. Cost related to herbicide usage has increased greatly due to evolution and proliferation of resistant weeds. Therefore, experiments were conducted to investigate the potential for using cover crops to suppress problematic weeds in cotton as well as chemical options for cover crop dessication, and sensitivity of cover crops to residual herbicides were evaluated. No differences were observed for cereal rye biomass production and consequently weed suppression between broadcast and drilled planting methods. Total amount of cover crop biomass was vital to effectively suppress weeds. Hence, of the cover crops …


Characterization Of Candidate Compound For Control Of Barnyardgrass And Other Troublesome Weeds In Rice, Michael Ryan Miller May 2017

Characterization Of Candidate Compound For Control Of Barnyardgrass And Other Troublesome Weeds In Rice, Michael Ryan Miller

Graduate Theses and Dissertations

Barnyardgrass remains one of the most difficult weeds to manage in rice. As herbicide resistance in this species, as well as others, continues to increase new control options are needed. Dow AgroSciences recently discovered and is developing a new herbicide for rice which is the primary focus of this research. Experiments were conducted to characterize this new herbicide for its use and effectiveness in midsouthern U.S. rice systems. The research conducted herein covers various aspects of herbicide characterization including: barnyardgrass dose response, accession testing, spectrum of control and tank-mix capability, application optimization, soil carryover and plant back determination, drift onto …


Evaluation Of Safening Effects To Herbicides Conferred Via Insecticide Seed Treatments In Soybean (Glycine Max) And Grain Sorghum (Sorghum Bicolor), Nicholas Robert Steppig May 2017

Evaluation Of Safening Effects To Herbicides Conferred Via Insecticide Seed Treatments In Soybean (Glycine Max) And Grain Sorghum (Sorghum Bicolor), Nicholas Robert Steppig

Graduate Theses and Dissertations

Interactions between herbicides and insecticides in crop production have been documented for a number of years. Research has shown that applications of some organophosphate insecticides at planting can reduce cotton injury following applications of the soil-applied herbicide clomazone. Additionally, recent research has shown that, when applied as seed treatments prior to planting, some neonicotinoid insecticides can safen rice to drift from both glyphosate and imazethapyr. Since insecticide seed treatments are commonly used in many crop production systems throughout the Midsouth, exploring their ability to reduce injury from herbicides in other crops besides rice is of great interest. Presently no research …


Evaluation And Association Analysis Of Cowpea Salt Tolerance, Waltram Second Ravelombola May 2017

Evaluation And Association Analysis Of Cowpea Salt Tolerance, Waltram Second Ravelombola

Graduate Theses and Dissertations

Cowpea [Vigna unguiculata (L.) Walp.] (2n=2x=22) is a leguminous crop providing inexpensive protein for human consumption that can be grown worldwide. Salinity is one of the major threats to cowpea production, particularly in semi-arid regions of Africa. Salinity significantly affects seed germination and decreases pod yield in cowpea. However, little has been done to provide farmers salt-tolerant cowpea cultivars. Knowledge on the genetics of cowpea salt tolerance is very limited. This study aimed to:(1) evaluate cowpea salt tolerance at germination stage, (2) evaluate cowpea salt tolerance at seedling stage, (3) conduct an association study for cowpea salt tolerance at germination …


Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening Apr 2017

Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening

Theses and Dissertations

Nutrient pollution originating from agricultural regions in the Midwest is a serious issue, leading to pollution of drinking water sources as well as large hypoxic zones in the Gulf of Mexico. The source of much of this contamination has been shown to be runoff from agricultural fields in the Upper Mississippi River Basin. One method that has been shown to reduce this pollution from the Upper Mississippi River Basin is the planting of winter cover crops. Winter cover crops such as rye and tillage radish have been shown to significantly reduce nitrate exported from agricultural fields, even in tile-drained watersheds …


Determining The Effects Of Sulfur Fertility Levels On Edamame Soybean [ Glycine Max ( L. ) Merrill ] Protein Components, Theoneste Nzaranyimana Apr 2017

Determining The Effects Of Sulfur Fertility Levels On Edamame Soybean [ Glycine Max ( L. ) Merrill ] Protein Components, Theoneste Nzaranyimana

Theses and Dissertations

Edamame [Glycine max (L.) Merr.] a vegetable type soybean is harvested and consumed before reaching its maturity stage (R6). Its health properties drew attention to U.S. consumers because of its high protein content. Proteins are the major structural component of all cells in the living organisms. They are made of essential and non-essential amino acids which play a big role in growth and development and are source of energy. Proteins act as enzymes, antibodies, and hormones and blood protein. Sulfur (S) is a component of the amino acids cysteine (Cys) and methionine (Met) which are the building blocks for proteins. …


Winter Rye Cover Crop Biomass Production, Degradation, And N Recycling, J. L. Pantoja, J. E. Sawyer, D. W. Barker Apr 2017

Winter Rye Cover Crop Biomass Production, Degradation, And N Recycling, J. L. Pantoja, J. E. Sawyer, D. W. Barker

John E. Sawyer

Winter rye (Secale cereale L.) as a cover crop can take up residual inorganic N between annual row crops and therefore be used to help reduce NO3 -–N loss from fields and movement to water systems. However, does the rye N uptake affect N recycling to soil and add to plant available N? The rye carbon:nitrogen (C:N) ratio could also influence N recycling. The objectives of this study were to evaluate rye biomass degradation and N recycling after spring rye termination in a no-till corn (Zea mays L.) - soybean [Glycine max. (L.) Merr.] rotation. A two year experiment (2010-2011) …


In-Season Nitrogen Fertilization Of Soybean, J. E. Sawyer, D. W. Barker Apr 2017

In-Season Nitrogen Fertilization Of Soybean, J. E. Sawyer, D. W. Barker

John E. Sawyer

Nitrogen (N) fertilization is not a traditional nutrient management practice for soybean production in Iowa. Soybean is a legume plant and is assumed to adequately obtain needed N through symbiotic fixation. However, there has been interest over the years in using N fertilization to increase yield and grain protein due to the recognition of the large N requirement associated with high yields. Depending on the soil residual inorganic N level and soil N mineralization characteristics, approximately 40 to 75% of the N in a mature soybean plant is derived from the soil (Shibles, 1998). Also, soybean seems to require this …


Corn And Soybean Response To Sulfur Application On Iowa Soils, J. E. Sawyer, D. W. Barker Apr 2017

Corn And Soybean Response To Sulfur Application On Iowa Soils, J. E. Sawyer, D. W. Barker

John E. Sawyer

Historically sulfur (S) application has not been recommended on Iowa soils for com and soybean production. Prior research has not determined a consistent need for S fertilization in Iowa, with field research indicating no com or soybean yield response to applied S at virtually every site studied (Thorup and Leitch 1975; Webb, 1978; Alesii 1982; Killorn, 1984; Sexton et al., 1998; Mallarino et al., 2000). The soil supply, in combination with sources such as manure and atmospheric deposition has apparently met com and soybean S needs. Sulfur deficiencies have been reported over the years in various areas of the Midwestern …


Corn Nitrogen Rate Response And Crop Yield In A Rye Cover Crop System, John E. Sawyer, Jose L. Pantoja, Daniel W. Barker Apr 2017

Corn Nitrogen Rate Response And Crop Yield In A Rye Cover Crop System, John E. Sawyer, Jose L. Pantoja, Daniel W. Barker

John E. Sawyer

Water quality impairment related to N loss from crop production fields continues to be a concern in Iowa, including meeting the USEPA nitrate-N drinking water standard and reducing N export to the Gulf of Mexico. Therefore, in-field production practices would be helpful to aid in reduction of nitrate leaching and movement to water systems. One practice identified in the science assessment for the Iowa Nutrient Reduction Strategy is use of a winter cereal rye (Secale cereal L.) cover crop, where a mean 31% (29% standard deviation) nitrate-N reduction would be expected, but with a 6% (22% standard deviation) corn yield …