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Gasch, C
Mueller, N.D
Miller, J
Morris, C
Beauchamp, E.G
Kaur, H
Stienstra, W.C
Carstens, G
Kachonoski, G
Sudduth, K.A
Killorn, R
Gardner, T
Below, F.E
Reeg, P.R
Singh, A
Karki, D
Lamczyk, A.J
Lange, D
Kovács, P
Lee, J
Behnke, G.D
Bereurter, A
Sadeghpour, A
Kaiser, D.E
Cook, K
Casteel, S
Sloan Veum, K
Heer, W.F
Paul, L.E
Graham, C
Still, S
Nieber, J.L
Lamond, R.L
Bisht, V
Fernandez, F
Woodward, L
Nelson, K
Bussan, A.J
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Bandura, C
Laboski, C
Camberato, J
Carter, P
Ferguson, R
Fernandez, F
Franzen, D
Kitchen, N
Nafziger, E
Sawyer, J
Shanahan, J
Clark, J
Sloan Veum, K
Fernandez, F
Camberato, J
Carter, P
Ferguson, R
Franzen, D
Kitchen, N
Laboski, C
Nafziger, E
Sawyer, J
Shanahan, J
Karki, D
Bly, A
Berg, S
Lee, J
Camberato, J
Nielsen, R
Shafer, M
Camberato, J
Carter, P
Ferguson, R
Fernandez, F
Franzen, D
Kitchen, N
Laboski, C
Nafziger, E
Nielsen, R
Sawyer, J
Shanahan, J
Caldwell, M
Nelson, K
Burdick, B
Bardella, G
Flaten, D
Lawley, Y
Heard, J
Lange, D
Grant, C
Kovacs, P
Casteel, S
Rosa, A.T
Ruiz Diaz, D.A
Gutierrez, M.N
Edwards, C.L
Gardner, T
Lorence, A
Zuber, S.M
Behnke, G.D
Nafziger, E.D
Villamil, M.B
Killorn, R
Voss, R
Carstens, G
McClenahan, E.J
Killorn, R
Hoeft, R.G
Ebelhar, S.A
Paul, L.E
Killorn, R
Kachonoski, G
Killorn, R
Beauchamp, E.G
Kachonoski, R.G
Bates, T.E
Killorn, R
Rehm, G.W
Stienstra, W.C
Wetterauer, D
Killorn, R
Sudduth, K.A
Drummond, S.T
Birrell, S.J
Kitchen, N.R
Kitchen, N.R
Sudduth, K.A
Drummond, S.T
Birrell, S.J
Kitchen, N.R
Sudduth, K.A
Drummond, S.T
Heer, W.F
Claassen, M.M
Janke, R.R
Carstens, D
Carstens, G
Hopkins, B.G
Jolley, V.D
Whitney, D.A
Lamond, R.L
Myers, D.B
Kitchen, N.R
Sudduth, K.A
Kaiser, D.E
Mallarino, A.P
Bermudez, M
Varsa, E.C
Ebelhar, S.A
Gerhard, E.A
Eberle, P.E
Wyciskalla, T.D
Lamczyk, A.J
Bailey, N
Motavalli, P
Udawatta, R
Nelson, K
Roberts, D.F
Kitchen, N.R
Scharf, P.C
Sudduth, K.A
Bergmann, N
Mallarino, A.P
Kaiser, D.E
Kaiser, D.E
Lamb, J.A
Rehm, G.W
Mallarino, A.P
Kaiser, D.E
Kitchen, N.R
Roberts, D.F
Sudduth, K.A
Drummond, S.T
Scharf, P.C
Pinney, M
Kaiser, D.E
Potter, B
Ostlie, K
Bereurter, A
Ferguson, R
Shanahan, J.F
Schlemmer, M
Kaiser, D.E
Lamb, J.A
Kim, K
Kitchen, N.R
Sudduth, K.A
Drummond, S.T
Sheridan, A.H
Heard, J
Bisht, V
Iverson, A
Mueller, N.D
Ruiz Diaz, D.A
Meyers, D.B
Kitchen, N.R
Sudduth, K.A
Sadler, E.J
Miles, R.J
Grunwald, S
West, J.R
Ruark, M.D
Bussan, A.J
Silva, E.M
Colquhoun, J.B
Kaiser, D.E
Kyveryga, P.M
Blackmer, T.M
Reeg, P.R
Ritchey, E
Cook, K
Gray, J
Miller, D
Casteel, S
Winans, E.T
Below, F.E
Sanyal, D
Wolthuizen, J
Karki, D
Clark, J
Bly, A
Clark, J.D
Bly, A
Karki, D
Sanyal, D
Wolthuizen, J
Kovacs, P
Bly, A
Berg, S
Gelderman, R
Rops, B
Sexton, P
Morris, C
Adler, R
Singh, G
Nelson, K
Bly, A
Berg, S
Karki, D
Franzen, D
Wick, A
Bu, H
Ressler, L
Bell, J
Berti, M
Gasch, C
Karki, D
Bly, A
Sadeghpour, A
Singh, G
Weidhuner, A
Lange, R
Clark, J.D
Bly, A
Karki, D
Kovacs, P
Ulrich-Schad, J
Keshavarz-Afshar, R
Jahanzad, E
Battaglia, M
Luo, Y
Sadeghpour, A
Adeyemi, O
Kaiser, D
Casteel, S
Franzen, D
Sadeghpour, A
Adeyemi, O
Hunter, D
Luo, Y
Armstrong, S
Harm Loman, M
Below, F.E
Singh , G
Nelson, K
Kaur, G
Sadeghpour, A
Weidhuner, A.M
Burkett, G
Zandvakili, O
Adeyemi, O
Kula, C
Berberich, J
Pike, J
Margenot, A.J
Sadeghpour, A
Kula, C
Sener, G
Vick, C
Kaur, H
Nelson, K.A
Singh, G
Kaur, G
Woodward, L
Below, F
Clark, J
Kovacs, P
Bly, A
Graham, C
Aanerud, Z.J
Fernández, F.G
Venterea, R.T
Pagliari, P.H
Cates, A.M
Nieber, J.L
Dorissant, L
Kovács, P
Clark, J
Sadeghpour, A
Adeyemi, O
Guzel, O
Kula, C
McGrath, J
Sener Guzel, G
Sadeghpour, A
Guzel, M
McGrath, J
Adeyemi, O
Arnall, B
Guzel, O
Sadeghpour, A
Ola, O
Guzel, O
Gage, K.L
Williard, K
Schoonover, J
Mueller, S
Sadeghpour, A
Burkett, G
Babaei, S
Adeyemi, O
Vaughn, K
Kula, C
Sadeghpour, A
Sener Guzel, G
Kula, C
Vick, C
Steinkamp, D.J
Nelson, K.A
Singh, G
Kaur, G
Kaur, H
Singh, A
Misar, C
Iqbal, J
Sadeghpour, A
Kula, C
Sener, G
Nain, A
Kaur , G
Nelson, K
Singh , G
Miller, J
Burkett, G
Vaughn, K
Adeyemi, O
Zandvakili, O
Battaglia, M
Babaei, S
Nair, J
Still, S
Sadeghpour, A
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Correcting sulfur deficiencies
Crop genetic and soil fertility interactions
Positive and negatives of cover crops
State Report
N Management with Cover Crops
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1. Agricultural Impact on Groundwater Qurlity

There has been an increasing awareness within Iowa of the impact of agriculture on groundwater quality. The data of Iowa Geologic Survey scientists from studies in northeast Iowa have focused attention on the Big Spring Basin area. A project to intensively study groundwater in the Big Spring Basin is underway. The project includes the active cooperation and participation of the following agencies: ISU Agricultural Experiment Station, Clayton County Soil Conservancy District ISU Cooperative Extension...

2. Can we Afford Not to Ridge Till?

A typical farmer response to ridge till is that it is just another method of tillage. My contention is that it is much, much more than that. In my career in this I have had three cbjectives. One is to attapt to create as much balance between famkq ad the enviroment as possible. ?he second is to rrake farming profitable. The third is to make farming easier and fun. I believe with the proper approaches in regards to fertility, chemicals and water management along with the ridge till technique the...

3. Corn Stem Nitrate N Content-Grain Yield Relationships and Their use as a Basis for Sidedress N Rate Recommendations

The objectives of this study were to confirm the relationship between nitrate nitrogen (NO3-N) content of basal corn steras and grain yield in Iowa, to establish crltical levels of stem NO3-N content for dtaining various levels of mximum yield, and to perform preliminary calibration of yield responses to sidedressed nitrogen (N) at various levels of st-Rm NO3-N content. Six sites across Iowa with a wide range of physical and environmental conditions were selected. N fertilizer was applied preplant,...

4. Effect of Ammonia Knife Spacing on Corn Yield

Experiments were conducted at DeKalb on a Drummer sicl, Dixon Springs on a Alford silt loam and Elwood on a Blaunt sicl to evaluate the effect of ammonia knife spacing at varying N rates and on different tillage systems on the yield of corn Nitrogen was awlied at 180 1bs N/acre at bath DeKalb and El& and at 210 lbs N/acre at Dixon Springs in the knife spacing by tillage study. In the rate by knife spacing by time of application study at DeKalb, the preplant nitrogen was placed under where the rows...

5. Effect of Time of N fertilizer Application on Corn Grain Yield in Iowa

The current concern about the impact of nitrogen (N) fertilizer use on the environment has caused a shift in the thinking about N management. Crop producers are interested in techniques (application methods) that will maximize the amount of N fertilizer harvested in the crop, and conversely minimize the amount remaining in the soil after harvest. Split applications or sidedress applications are common approaches currently being studied as a way to increase the efficiency of N fertilizer management....

6. Nitrogen Fertilizer Requirements for No-till corn

Conservation tillage is associated with higher surface crop residue levels, larger more stable soil aggregates, and generally higher surface soil water contents compared to conventional tillage. The changes in residue management and overall soil water regime under conservation tillage may result in different spatial distributions (laterally and with depth) of nutrients. In general, nitrogen fertilizer applied as broadcast urea is not recommended for no-till systems because of the possibility of ammonia...

7. Nitrate Soil Testing Correlation and Calibration Eastern Corn Belt

Current economic and environmental concerns have increased the interest in developing methods to help manage nitrogen (N) fertilizers as efficiently as possible. There is a concern that fertilizer N that remains in the soil following harvest may be leaching below the root zone of crops and eventually ending up in groundwater. Agronomists throughout the corn belt are actively evaluating methods to manage N fertilizer as efficiently as possible....

8. Nitrogen Soil Test for Corn in Ontario

It is generally believed that for high yielding crops such as corn. the N requirements are much larger than variations in the N supplying capacity of soil. In Ontario, fertilizer N recommendations are based on the requirements of the crop and, for some crops, the expected yield goal. Nitrogen credits are given for past management such as manure application and legumes in rotation. The credits are deducted from the economic rate of N. In a recent analysis of all existing fertilizer N crop response...

9. Trends in Soil Test P and K in Iowa

The Iowa State University Soil Testing Laboratory has provided soil test information to Iowa farmers since 1931 when Professor Firkins began the service for no charge. The predecessor of today's lab was initiated in February, 1946 (~ik~) . The lab's records provide us with valuable information on the trends in the plant nutrient status of Iowa's soils (Figure 1). During the period from 1960 to 1981, the consumption of nitrogen (N), phosphate (P), and potash (K) fertilizer materials rose from 7.5...

10. Reducing the Severity of Phyophthora Root Rot Damage in Soybeans with Selected Management Options

Phytophthora root rot of soybeans (PRR) is a major concern for soybean growers in south-central and southeastern Minnesota, where it can be responsible for major yield reductions. In these regions, PRR is generally a serious problem when soybeans are grown on poorly drained soils and/or there is a moderate amount of rainfall within 2 to 3 days of planting. Previous research has shown that PRR causes a reduction in the number of harvestable plants per acre and this is the major contributing factor...

11. Flooded Soil Syndrom and P Deficiencies on Four Iowa Soils

Several million acres of Midwest cropland were inundated during the floods of 1993. The length of inundation was from a few days to several months. In some areas growing crops were drowned out and other fields could never be planted. As the water receded and acres of barren ground were exposed, the reality of the disaster gave way to concerns for the 1994 crop and the development of Flooded Soil Syndrome. Flooded Soil Syndrome produces' symptoms similar to Fallow Syndrome which was originally identified...

12. Spatial Analysis of Yield-Limiting Factors

The spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters. ...

13. Spatial Prediction of Crop Productivity Using Electromagnetic Induction

An inexpensive and accurate method for measuring water-related, within-field soil productivity variation would greatly enhance site-specific crop management strategies. This paper reports on investigations to use an electromagnetic induction (EM) sensor to map claypan (Udollic Ochraqualfs) and alluvial (Typic and Aquic Udipsarnnlents, and Aeric Fluvaquents) soil conductivity variations and to evaluate the relationship of EM measurements to grain crop production. Grain yield measurement was obtained...

14. An Evaluation of Methods for Determining Site-Specific Management Zones

Numerous procedures have been examined for identifymg management areas within fields. Traditional soil surveys give a general understanding of the effects soil mapping units have on crop productivity. In the USA. county soil surveys report the average grain yield of major crops by soil series. Slope position and landform are topographic features thal also have been used to explain water and crop productivity relationships (Mulla et al., 1992; Sudduth et al., 1997). Generally, footslope positions...

15. Winter Annual Legume Cover Crops in a Wheat Grain Sorghum Rotation in South Central Kansas

Winter annual legumes in humid regions ofthe country can have a positive effect on subsequent corn (Zea mays) and grain sorghum (Sorghum bicolor) crops, mainly through N contribution of the legume and. in some cases, soil improvement. However, water use by the cover crop in drier regions has the potential to reduce yields in subsequent crops. This study was initiated in south-central Kansas to look at the agronomic implications of adding a winter annual legume cover crop to a winter wheat (Triticum...

16. Variable Seeding Rates in Twin Row Planting and Micro Management of Nutrients

A large scale study to determine if twin row planting, utilizing particular fertility concepts and conservational practices, out produces conventional methods of planting and fertilizing. The primary goal of the study was to increase fmer profitability and promote methods of conservational tillage. ...

17. Zinc Deficiency Response of Sorghum, Wheat, and Corn

Zinc (Zn) deficiency in corn (Zea mays L.) is more common than in sorghum (Sorghum bicolor (L.) Moench) or wheat (Triticum sp.). The ability of wheat to withstand low soil Zn conditions is related to increased release of phytosiderophore, a natural chelate, fiom its roots. The reasons for sorghum's ability to utilize low levels of soil Zn have not been adequately explored. The objective of this research was to: 1) ascertain if Zn deficiency can be induced with sorghum, wheat, and corn grown in a...

18. Assessing Spatial and Temporal Nutrient Dynamics with a Proposed Nutrient Buffering Index

Continued adoption of precision agriculture will lead to the accumulation of spatially and temporally dense soil fertility and yield data. Current soil fertility recommendation strategies use regional estimates of soil buffering properties to adjust application rates. A site specific nutrient buffering index (BI) is presented that uses accumulated yield maps and soil test data to locally estimate soil buffering properties relative to fertilizer additions and crop removal. BI is a quantity-intensity...

19. In-Furrow Starter and Broadcast Phosphorus and Potassium Fertilization for Corn

Increasing awareness of potential impacts of farming on the environment has renewed interest in further study of fertilizer management strategies that reduce nutrient inputs. Fertilizer recommendations for phosphorus (P) and potassium (K) usually are based on soil-test values and nutrient removal with crop harvest. Many Midwest fmers follow these recommendations. but many others apply removal-based P and K fertilizer rates even in high-testing soils. The typical farmer applies P and K fertilizer...

20. Utilizing Inhibitor Technology to reduce Ammonia Volatilization Losses from Urea Sources Applied to Conservation Tillage

A severe limitation to urea fertilizers and the ureacomponent in livestock wastes is the high potential for volatile loss of nitrogen (N) as ammonia. Losses are especially severe when the urea-containing materials are surface applied with no or only limited subsequent incorporation. Extensive losses are also observed when urea is applied to warm soils that are moist and undergoing rapid drylng. Soil pH, the presence of an active microbial population, and soil texture are also known to impact volatilization...

21. Soil Carbon and Nitrogen Distribution and Gaseous Flux Due to Landscape Position and Temperate Alley-Cropping Practices in an Agricultural Watershed

Soil NzO and COz efflux can be stimulated by agricultural practices whlch may contribute to an enhanced global warming effect. However, the efflux of these two gases in response to landscape position and soil conservation management practices such as contour strips in a temperate agoforestry alley cropping system has not been extensively studied. The objective of this study was to assess the effects of alley cropping and landscape position on soil total organic C and total N distribution and N20...

22. An Environmental Assessment of Sensor-Based Variable-Rate Nitrogen Management in Corn

In order to address the problem of nitrate contamination of surface and ground waters, various methods have been used to try to account for spatial variability of N within agricultural fields. One approach to account for this variability and thereby reduce nitrate pollution is in-season site- specific N application according to economic optimal N rate (EONR). Recently, active crop canopy sensors have been tested for mid-season, on-the-go N fertilizer application in corn. This 2004 and 2005 study...

23. Starter Potassium for Corn: Why and When

Starter 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...

24. Recent Perspectives for Starter Fertilizer Use on Corn in Minnesota

Application of fertilizer with the seed at planning has been a popular choice for Minnesota corn farmers to get their crop off to a fast start. Traditionally the salt index of a fertilizer has been important in farmers' management decisions. A research study was conducted at six locations on fine and coar se textured soils around Minnesota. Three fertilizer grades, 4-10-10, 10-34-0, and 3-18-18 were compared at two rates and in three placements relative to the seed. Nitrogen (N) and phosphorus (P)...

25. Foliar Fertilization and Fungicide Application for Soybean

Concerns over fungal diseases in soybean have renewed interest in applying pesticides for disease control with the goal of increasing grain yi eld. Interest has especially been sparked by discussions of the possibility of Asian Soybean Rust (Phakopsora pachyrhizi) spreading north to the North Central region. Because of increasing prices of soybean grain and traditional fertilizers, many Midwest grower s are considering mixing fluid fertilizers and fungicides for foliar application to soybean. Extensive...

26. Response Surface Models Of Subsoil K Concentration For Loess Over Till Soils In Missouri

Crop uptake of potassium (K) has demonstrated sensitivity to subsoil variation in K content. This fact has not been sufficiently considered in K management strategies in part due to logistical difficulties in sampling spatially variable subsoil K. We propose a simplified soil factorial model, a response surface, to enable site-specific accounting of whole root zone K supply for loess over till soils. We compared the performance of two peak functions and a non-parametric local regression procedure...

27. Organic Nutrient And Weed Management With Sweet Corn On Sandy Soil

The Central Sands region of Wisconsin is host to commercial-scale vegetable production, requiring intense nitrogen (N) fertilization. The limited nutrient holding capacity and minimal organic matter content of sandy soils in the Central Sands contributes to water nitrate contamination. Organic management may help to alleviate problems associated with leaching by increasing organic matter and nutrient retention in this soil. For organic agriculture to be feasible in this region, organic N inputs...

28. Sulfur Cycling from Corn in Corn-Corn and Corn-Soybean Rotations

Sulfur fertilizer requirements for corn grown on medium and fine textured soils have increased over the past ten years. The effect of sulfur rate and timing on the potential for sulfur cycling and carryover within a two year crop rotation, corn-corn and corn-soybean, were studied. Sulfur was applied as ammonium sulfate on the soil surface at planting and the V3-V5 growth stages at rates of 0, 10, 20, 30, and 40 lbs of S per acre during the first cropping year. Each plot was divided in two prior to...

29. Quantifying Risk in Nitrogen Management through On-Farm Evaluations

The process of nitrogen (N) management in corn (Zea mays L.) production is often reduced to finding ways to manage various risks. These risks include common difficulties of quantifying soil N availability, avoiding N fertilizer losses, and predicting the impact of weather before and after fertilizer applications. This poster provides a synopsis of several recent on-farm evaluation studies conducted across Iowa. These studies were designed and executed to identify management, soil, and weather factors...

30. The Use of Organic Soil Amendments for Winter Wheat Production in Kentucky

Most animal manures are land-applied in the fall and spring after crops have been harvested or prior to planting. Surface application of manures in the fall have more potential for nitrogen (N) loss when applied to fallow land compared to land cropped to winter wheat. This study was conducted to determine the N availability of fall applied organic fertilizers and resulting wheat grain yields compared to urea-N fertilizer. The effects of three organic fertilizer sources and rate on wheat yield and...

31. Comparison of Congranulated Fertilizer to Blends with S and Zn in Corn and Soybeans

High yielding corn and soybean production systems in Missouri have renewed an interest in micronutrient management such as sulfur (S) which is essential for protein formation and zinc. (Zn) which is important for enzymes and metabolic reactions. Yield increases due to sulfur applications are more likely to occur during cool, wet springs when mineralization and crop growth are slow as a result of a decrease in atmospheric sulfur deposition. Soil tests in 2010 indicated that over 60% of the samples... M. Caldwell, K. Nelson, B. Burdick

32. 4R Phosphorus Management for Soybeans in the Northern Frontier: Rate and Placement Effects on Plant Stand, Biomass and Seed Yield

Very little research has been conducted to determine the best rate, source, placement, and timing of P fertilizer for modern soybean cultivars grown in the Canadian Prairies. Preliminary results of the two years of field studies at 10 locations in Manitoba showed that typical agronomic rates of seed row P did not decrease plant stand and seed yield at any sites; nor was seed yield increased at any site, even with Olsen P concentrations as low as 3 ppm....

33. Changes in P Uptake and Partitioning in Soybean Cultivars Released in the Last 90 Years

Historical changes in nutrient uptake and partitioning of soybean [Glycine max (L.) Merr.] were not studied. Field studies were conducted in 2011 and 2012 to investigate phosphorus (P) uptake changes and partitioning through the growing season in 25 maturity group (MG) II, and 26 MG III cultivars. Plant samples were taken and partitioned at V4 (four trifoliates), R2 (full bloom), R4 (full pod), R6 (full seed), and R8 (physiological maturity) growth stages. In-season samples were partitioned into...

34. Fertilizer Placement and Tillage Interaction in Corn and Soybean Production

Different tillage systems can affect the availability of phosphorus (P) in the soil. The objective of this study was to evaluate the effects and interaction of fertilizer placement, tillage, and varieties/hybrids for corn and soybean. The experiment was established at two locations in Kansas in 2014. The experimental design was a factorial in a randomized complete block with four replications. Three fertilizer treatments were combined with two tillage systems and two varieties/hybrids of soybean...

35. Comparison of Soil Properties under Long-Term Crop Rotation and Tillage

Shifts in cropping systems from long-term rotations including forages to mostly annual crops has intensified tillage, but has also led to the development of conservation tillage practices such as no-till. There is a shortage of information about the interactive, long-term effects of rotation and tillage on soil quality. The objective of this study was to assess soil chemical and physical properties after 15 years of crop rotation and tillage treatments. Continuous corn (Zea mays L.) (CCC), corn-soybean...

36. Nutrient Deficiency Diagnostic Training with Field and Hydroponically Grown Crops

The Manitoba Crop Diagnostic School was initiated in 1995 and annually provides training for 350 - 400 field agronomists over a two week period in mid July. Symptons of nutrient deficiencies, other than Nitrogen (N), have proven difficult to demonstrate on the fertile high organic matter loam texturd soiles of the Carman Researh Station. The following techniques have been developed to demonstrate many of the macro and micronutient deficiencies which may occur in prairie crops....

37. Micronutrients as Starter and Foliar Application for Corn and Soybean

Corn and soybean production under high yield environments can benefit from the combined use of starter and foliar fertilization, including macro and micronutrients. The objective of this study was to evaluate corn and soybean response to starter fertilizers in combination with foliar application of macro and micronutrients to maximize yield s. Experiments were conducted in 2010 and 2011 at two locations for corn and soybean under irrigation. Starter and foliar fertilizer treatments were applied in...

38. Management Zone Delineation Techniques to Aid In-Season Sensor Based Nitrogen Application

The increased efficiency of nitr ogen fertilizer (N) use has been a long-term goal in reduction of nitrate contamination in the stat e of Nebraska. Preliminary rese arch has shown sensor based in- season application of nitrogen has the ability to be economic and environmentally viable. Although benefits have been published there is an opportunity for increased accuracy of N application through the integration of preprocesse d georeferenced management zones. In-season sensor based N application relies...

39. Response to Starter Applied Sulfur in Combination with Nitrogen and Phosphorus Across a Landscape

Corn ( Zea Mays L.) response to starter fe rtilizer combinations containing sulfur were studied using a replicated strip trial methodology. Combinations of ni trogen (20 lbs N), phosphorus (20 lbs P 2O5), and sulfur (25 lbs S) were applied two inches beside and below the seed with the planter and compared with a no-starter control a nd 25 lbs broadcast sulfur. Early plant growth was consistently increased by starter P and so metimes by starter N, while sulfur uptake was increased by S and P application....

40. What Do You Do When Your N-Rich Reference Fails?

In recent years, canopy reflectance sensing has b een investigated for in-season assessment of crop N health and fertilization. Typically, the procedure followed co mpares the crop in an area known to be non-limiting in N (the N-rich area) to the crop in a target area, which may be inadequately fertilized. Measurements from the two areas are used to calculate a relative reflectance to represent the potential need for add itional N fertilizer. Establishing N rich areas or strips is often inconvenient...

41. What are the Benefits of Canopy Sensing for Variable-Rate Nitrogen Corn Fertilization?

Canopy reflectance sensing for assessing crop N health has been proposed as a technology on which to base top-dress variable-rate N applicat ion. The objective of this research in Missouri was to evaluate the economic a nd environmental benefit of activ e-light crop-canopy reflectance sensors for corn N rate decisions. A total of 16 field-scale experiments were conducted over four seasons (2004-2007) in three major soil areas. Mu ltiple blocks of randomized N rate response plots traversed the length...

42. Early Season Nutrient Uptake from Combinations of N itrogen, Phosphorus, and Potassium Applies in Starter Fertilizer in Two Corn Hybrids

Conventional small plot field trials were establ ished to study the effect nitrogen (N), phosphorus (P), and potassium (K) applied as starter ferti lizer on early season growth and nutrient uptake of two corn hybrids with a nd without the Bt-rootworm gene. Ei ght locations were studied over two years comparing a non-starter check, N only, K only, NP, NPK, and NK starter fertilizer combinations on early season growth and nutrient uptake. Sites tested High initially in both P and K. One or more starter...

43. Nitrogen and Sulfur Application Effects on Soybean Quality and Yield

Sulfur deficiency is only becoming more prevalent in the Midwest across soybean fields with higher yields resulting in lower quality seed. Sulfur is a key component of methionine and cysteine, which are important amino acids in the nutrition in foodstuffs. The objective in this study is to explore the impact of N:S applications at different growth stages and rates on the soybean yield and seed composition and quality. In 2018 the trial was performed both in West Lafayette and Wanatah Indiana.... D. Miller, S. Casteel

44. Variation Among Commercial Corn Hybrids in Response to Agronomic Management

Strategic selection and utilization of corn (Zea mays L.) hybrids for a given yield environment and agronomic management system will require better understanding and documentation of the interactions between current commercial hybrids and agronomic factors that have sizeable impacts on yield. Therefore, this study evaluated the effects of N fertility, plant population, and row spacing on grain yield of corn and assessed the range in yield responses among commercial hybrids to these agronomic... E.T. Winans, F.E. Below

45. Cover Crops Influence Soil Health and Nutrient Cycling in a Multi-Location Study in South Dakota

Soil without living roots potentially loses mobile nutrients and retains excess water. Unprotected soil degradation and erosion enable the loss of carbon and nutrient rich top soil. Cover crops provide armor for the soil protecting from carbon and nutrient loss. Cover crop blends may influence soil health parameters and nutrient cycling. This multi-locational study depicts the influence of cover crop species blends with varying grass and broadleaf concentrations on established soil-health indicators... D. Sanyal, J. Wolthuizen, D. Karki, J. Clark, A. Bly

46. No-till and Cover Crops Influence Soil Health and Nitrogen Rate and Timing Recommendations: Early Results

The idea of improving soil health has become increasingly more talked about by researchers, agronomists, and farmers in the past five years. Management practices such as no- or reduced-tillage and planting cover crops are recommended to improve soil health because of their potential to improve organic matter and soil structure leading to a greater capacity to hold water and nutrients needed for plant growth. Research in South Dakota has been occurring these past two years to determine the influence... J.D. Clark, A. Bly, D. Karki, D. Sanyal, J. Wolthuizen, P. Kovacs

47. Cover Crops Impact on Biomass, Yield, Soil Health, and Nutrient Loss in a Tile-Terrace Field

Soil erosion by water can be the most important land degradation process on erodible to highly erodible soils. Therefore, different conservation practices can be implemented to address the issue including no-tillage, cover crops (CC), grass filter strips, riparian buffers, and terraces. A field trial was established at the University of Missouri Grace Greenley Research Center near Novelty to evaluate the impact of CC and no-CC (non-treated control, NTC) on crop yields, soil health, and water quality/quantity... R. Adler, G. Singh, K. Nelson

48. Nitrogen Source and Timing Effects on Corn

The 4R’s of nutrient management call for the right source, applied at right time, at the right rate at the right placement. Producers in South Dakota ask when the correct time to apply nitrogen fertilizers. Mean annual precipitation in the major South Dakota corn growing areas ranges from 16 to 26 inches. This is a relatively dry climate compared to other major corn growing regions and the effect of nitrogen timing might not be as important. Therefore, a research question that challenges... A. Bly, S. Berg, D. Karki

49. Nitrogen Non-Cycling from Cover Crops Grown Before Corn and Spring Wheat-Unexpected Early Project Results

Nitrogen credits in North Dakota State University fertilization recommendations include those anticipated from the previous year annual legume crops (field pea, lentil, soybean, chickpea) and from terminated alfalfa. In addition, it was established in the region that sugarbeet tops returned to the soil may have an N credit potential of up to 80 pounds of N per acre (Crohain and Rixhon, 1967; Moraghan and Smith, 1994a; Moraghan and Smith, 1995a; Moraghan and Smith, 1995b; Franzen et al.,... D. Franzen, A. Wick, H. Bu, L. Ressler, J. Bell, M. Berti, C. Gasch

50. Performance of Grain Oats at Different Nitrogen Regimes when Grown with and without Plant Growth Regulator (PGR)

Among small grains grown in the South Dakota (SD), oat is considered the most susceptible to lodging which can result to significant yield loss due to harvest difficulty. Although current South Dakota State University (updated 2005) recommends 1.3 pounds nitrate N per bushel of oats (minus soil test N and legume credit), producers have been using lesser than the SD recommended rate to avoid lodging. This study was initiated in 2016- i) to evaluate the response of oat grain yield at various nitrogen... D. Karki, A. Bly

51. Side-dressing Nitrogen Influence on Nitrogen Release Dynamics of Early and Late-Terminated Cereal Cover Crop

Termination date and nitrogen application of corn (Zea mays L.) can influence the decomposition rate of cover crops in a corn cropping system. Our objective was to evaluate (i) the biomass accumulation and nutrient uptake of wheat (Triticum aestivum L.) fertilized with 34 kg N/ha and (ii) decomposition rate of wheat terminated early (4 weeks prior to planting) and late (at corn planting time) with and without side-dressing N at 168 kg N/ha. Our preliminary data... A. Sadeghpour, G. Singh, A. Weidhuner, R. Lange

52. Manure and Fertilizer Management Influence on Soil Nutrient Levels and Grain Yields in Eastern South Dakota from 2003 to 2014

Concentrated animal feeding operations (CAFOs) are required to hold a manure management permit in South Dakota. The permit encompasses available nutrients from manure, crop nutrient use and removal, soil test nitrate-N, and phosphorus and land availability for approved nutrient application rates. The management plan determines if nitrogen or phosphorus based manure application rates are used. Most CAFO’s start out following the nitrogen based plan as soil test phosphorus (P) levels... A. Bly, S. Berg, R. Gelderman, B. Rops, P. Sexton, C. Morris

53. Post-Harvest Soil Nitrate Following Corn Production in Eight Midwestern States

Applying nitrogen (N) at economically optimal rates (EONR) and at times of rapid crop uptake are practices that are thought to minimize the amount of residual soil nitrate (RSN) in the profile that may be susceptible to loss. The objective of this study was to evaluate the effects of rate (0 to 280 lb N/a in 40 lb increments) and timing (pre-plant (PP) or PP plus V9 sidedress (PP+SD)) of N application on corn grain yield and RSN in the top 3 feet of soil relative to the calculated EONR. Thirty-two... C. Bandura, C. Laboski, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, E. Nafziger, J. Sawyer, J. Shanahan

54. The Anaerobic Potentially Mineralizable Nitrogen Test as a Tool for Nitrogen Management in the Midwest

The anaerobic potentially mineralizable nitrogen (PMNan) test is a tool that can improve estimations of mineralizable nitrogen (N) and enhance nitrogen use efficiency. This tool may also help improve predictions of N uptake, grain yield, and the economic optimum nitrogen rate (EONR) of corn (Zea mays L.). A 32 site-year study across eight US Midwestern states was conducted to 1) compare the effect of incubation length (7-, 14-, 28-d), soil sampling timing, N fertilizer rate, and their... J. Clark, K. Sloan veum, F. Fernandez, J. Camberato, P. Carter, R. Ferguson, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, J. Sawyer, J. Shanahan

55. Effects of Applied Soil Micronutrients on Corn and Soybean Yields in Eastern South Dakota Environments

Micronutrients although taken up by plants in small quantities, their deficiencies can have significant detrimental effects on grain yield. As growers aim for maximum corn and soybean yields, availability of micronutrients in agricultural market both as individual source or combined with other secondary nutrients have also increased. However, effects of micronutrients on corn and soybean grain yields are not well documented for South Dakota (SD) soils, and growers seem to be concerned if application... D. Karki, A. Bly, S. Berg

56. Starter Fertilizer Slows the Movement of Corn Roots Across the Row

Applications of starter fertilizer may alter the root morphology of young developing plants by causing lateral roots to proliferate when the root system enters the highly concentrated fertilizer band. This may affect the timing of root movement across the row when starter fertilizer is used. The timing of root movement across the row was determined by placing 20 12-inch-long perforated cylinders vertically in the soil at the V2 leaf stage. The cylinders were placed approximately every 15”... J. Lee, J. Camberato, R. Nielsen

57. Variation in Internal N Efficiency of Corn and Impact on Yield-Goal Based N Recommendations

Internal N efficiency (IE) is defined as bushels per acre (GY) produced per pound of N per acre (PMN) in the plant at physiological maturity (R6). Internal N efficiency defines the required amount of plant N content at R6 in a yield-goal based N rate recommendations (currently used in 30 U.S. states) and several commercial N recommendation models. Commonly IE is assumed to be constant at an approximate value of 0.8 bu lb-N-1 in yield-goal based recommendations. Our research objective was... M. Shafer, J. Camberato, P. Carter, R. Ferguson, F. Fernandez, D. Franzen, N. Kitchen, C. Laboski, E. Nafziger, R. Nielsen, J. Sawyer, J. Shanahan

58. South Dakota Producers Use of Soil Testing to Make Soil Fertility Decisions

Soil fertility guidelines in South Dakota are primarily based on soil testing results. There are several possible soil sampling procedures regarding timing, frequency, and type of soil sampling that can be followed by producers. Survey information collected from South Dakota producers can inform us what soil sampling procedures they are commonly using. We distributed a survey to 3,000 South Dakota producers based on crop reporting district, crops grown, and farm size. We reminded producers three...

59. CORN YIELD AND NITROGEN USE EFFICIENCY RESPONSE TO WHEAT COVER CROP AND SPLIT NITROGEN APPLICATION

Corn (Zea mays L.) grain is a major commodity crop in Illinois and its production largely relies on timely application of nitrogen (N) fertilizers. Currently, growers in Illinois and other neighboring states in the U.S. Midwest use the maximum return to N (MRTN) decision support system to predict corn N requirements. However, the current tool does not factor in implications of integrating cover crops into the rotation, which has recently gained attention among growers due to several... R. Keshavarz-afshar, E. Jahanzad, M. Battaglia, Y. Luo, A. Sadeghpour, O. Adeyemi

60. Oh, K? When is Too Much K Too Much?

Potassium is required in large amounts by crop plants and is a staple fertilizer, mainly as KCl.  Recent data across three midwestern states suggests that sometimes, especially at high rates and shortly before planting, KCl may have negative impacts on corn and/or soybean yields.  Three researchers will briefly describe their research in this area and then field questions from the audience. - Kaiser Twenty-nine potassium (K) fertilizer trials were conducted in eastern... D. Kaiser, S. Casteel, D. Franzen

61. Precision planting impacts on winter cereal rye growth, nutrient uptake, spring soil temperature, and adoption cost

Growing winter cereal rye (Secale cereale) (WCR) has been identified as an effective in-field practice to reduce nitrate-N and phosphorus (P) losses to Upper Mississippi River Basin (UMRB), USA. In the Midwestern USA, growers are reluctant to plant WCR especially prior to corn (Zea mays L.) due to N immobilization and establishment issues. Precision planting of WCR or “Skipping the corn row” (STCR) can minimize some issues associated with WCR ahead of corn while reducing...

62. Synergism Between Lime and Phosphate Fertilizer Application Enhances Soil Phosphorus Availability

Because phosphorus (P) is a non-renewable resource and an essential mineral element for plant development, understanding factors that affect soil phosphorus bioavailability is crucial for sustainable food production. Soil organic P can account for a large fraction of the total soil P, and its mineralization can replenish the soil solution with plant-available P. Raising the soil pH with a liming agent can enhance soil biological activity and increase soil P availability in acidic soils, but it... M. Harm loman, F.E. Below

63. Landscape Position Affects Management Decisions for Crop Production

Landscape attributes including topographic positions, slope, curvature, elevation, water flow direction and water flow accumulation are well documented in the literature for their effects on crop productivity. Topography influences crop growth and yield by impacting water and nutrient movement in the soil. Under dryland crop production systems, water availability generally depends on topsoil depth, soil organic matter, and curvature of the micro-topography. To improve overall productivity of a... G. Singh , K. Nelson, G. Kaur

64. Carbon Credit and Sequestration in Agroecosystems; Lessons from Trials in Southern Illinois

A carbon (C) credit is the attribution of net CO2-C equivalent which can be used to decrease climate forcing through a given practice or farming system for a given unit time. Carbon credits allow industries to purchase C that is produced on a farm (i.e., offsets). Carbon can be captured in two ways; (i) by capturing and reducing greenhouse gasses (on a CO2-C equivalent basis), and/or (ii) by increasing soil organic C stocks. Therefore, to enable C credits in the agricultural... A. Sadeghpour, A.M. Weidhuner, G. Burkett, O. Zandvakili, O. Adeyemi, C. Kula, J. Berberich, J. Pike, A.J. Margenot

65. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern Illinois

It is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, C. Kula, G. Sener, C. Vick

66. Drainage and Nitrogen Management Affects Soil Health and Soil Properties

Midwestern United States farmers rely on key fertilizer inputs and management of soil drainage to maintain productivity and profitability. Subsurface tile drainage is used extensively throughout the Midwest U.S. to lower the water table and drain waterlogged soils. To improve nutrient use efficiency and sustainable crop production, best management practices such as 4R nutrient stewardship framework is being promoted in conjunction with drainage water management technology. The 4R nutrient stewardship... H. Kaur, K.A. Nelson, G. Singh, G. Kaur

67. Versatility of Mycorrhizal Fungi Applications to Increase Maize Productivity

With rising fertilizer prices and continual water contamination issues, it is vital to establish management factors that maximize productivity, while minimizing nutrient losses to the environment. One potential practice for improving nutrient use and grain yields includes utilizing mycorrhizal fungi. The objectives of this research were to determine the efficacy of various mycorrhiza applications on root colonization and the subsequent grain yield responses of maize (Zea mays... L. Woodward, F. Below

68. Comparing Yield Goal and Maximum Return to N Based Methods in Predicting Corn Economic Optimal Nitrogen Rates

There are two main N rate recommendation systems used in the U.S.–Yield goal and maximum return to N (MRTN). The current yield-goal based system for calculating corn N rate recommendations in SD has not been evaluated for accuracy since 2013. Therefore, the objective of this project was to 1) evaluate the accuracy of the current yield goal-based equation and 2) create a database of N response trials and evaluate the accuracy of using the MRTN approach for predicting N rate requirements.... J. Clark, P. Kovacs, A. Bly, C. Graham

69. Effects of Variable Nitrogen Fertilizer Rates on Corn Grain Yield, Profitability, and Nitrogen Losses in Southwestern Minnesota

Global crop production heavily relies on the application of nitrogen (N) fertilizers, which unfortunately comes with environmental concerns. The primary pathways N is lost to the environment is through nitrate leaching into groundwater, ammonia volatilization, and nitrous oxide emissions to the atmosphere. This ongoing study started in 2021 at the University of Minnesota Southwest Research and Outreach Center in Lamberton, MN, to comprehensively assess the effects of varying N fertilizer rates... Z.J. Aanerud, F.G. Fernández, R.T. Venterea, P.H. Pagliari, A.M. Cates, J.L. Nieber

70. Exploring the Impact of Temporal Variability in Emergence on Corn Grain Yield and Development Patterns

Concerns have raised among farmers in the Midwest regarding the impacts of uneven emergence of corn (Zea mays L.) seedlings. Research has showed that even a minor delay in emergence of a few hours could have a substantial influence on plant performance and ear weight; and one of the contributing factors to uneven seedling emergence in corn is the application of starter fertilizer. Placing fertilizers in the seed furrow increases the salt concentration surrounding the seed and as a result, delays... L. Dorissant, P. Kovács, J. Clark

71. Corn Nitrogen Requirement in Winter Cereal Cover Crop Trials in Southern Illinois

Winter cereal cover crops, including wheat (Triticum aestivum L.) and winter rye (Secale cereale L.) are recommended as the best in-field management strategy by the Illinois Nutrient Loss Reduction Strategy (INLRS) to minimize nitrate-N leaching to the Mississippi River Basin and the Gulf of Mexico. We evaluated the effect of wheat and winter rye on corn grain yield, and nitrogen (N) requirement. Treatments were laid out in a randomized complete block design with four replicates... A. Sadeghpour, O. Adeyemi, O. Guzel, C. Kula, J. Mcgrath, G. Sener guzel

72. Does Sensor-based Nitrogen Management Maintain Crop Production and Decrease Nitrate-N Leaching?

To improve water quality, nitrogen (N) management in corn production systems should shift from current N decision support system [maximum return to N (MRTN)] which suggests a single rate N addition to sensor-based (GreenSeeker) active N management (variable N rate approach). Single rate N recommendations often result in under- and over-N addition and either increase environmental N losses or cause corn yield penalty. Our objectives were to evaluate corn optimum nitrogen N requirement (EORN) in... A. Sadeghpour, M. Guzel, J. Mcgrath, O. Adeyemi, B. Arnall, O. Guzel

73. Does Nitrogen Management in Winter Wheat Affects Its Yield and Nitrate-N Leaching in a Wheat-Soybean Double Cropping System?

Conventional corn (Zea mays L.)-soybean (Glycine max L.) rotation contributes to nitrate-N and phosphate leaching to waterbodies causing water quality concerns. Two strategies that could minimize N and P losses include (i) incorporating winter rye (Secale cereale L.) (WR) as a cover crop to capture residual nutrients or (ii) intensifying the corn-soybean rotation with winter wheat (WW) (Triticum aestivum L.) (Double cropping). Double cropping WW at a right N... A. Sadeghpour, O. Ola, O. Guzel, K.L. Gage, K. Williard, J. Schoonover, S. Mueller

74. Does Nitrogen Fertilization with Manure Injection Versus Surface Application Influence Corn for Silage and Winter Rye Yield, Quality, Phosphorus Balance and Soil Test Phosphorus Over Three Years?

Switching from nitrogen (N)-based to phosphorus (P)-based manure management has been shown to decrease P loss to the environment allowing for sustainable P management in dairy farms. At high P soils, dairy farmers often surface apply the liquid manure to corn (Zea mays L.) for silage at the P-based rates and supplement the limited N to corn with N fertilizers to ensure optimum crop production. With high fertilizer prices, one solution to reducing the N requirement of corn could be to... A. Sadeghpour, G. Burkett, S. Babaei, O. Adeyemi, K. Vaughn, C. Kula

75. Response of Corn to Planting Methods of Cover Crop Species and Nitrogen Rate in Southern Illinois

It is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, G. Sener guzel, C. Kula, C. Vick

76. Corn Response to Nitrogen Fixation Technology in Upstate Missouri

Nitrogen is one of the most expensive corn input costs and is critical for grain production. Nitrogen (N) fixing bacteria convert atmospheric N into organic forms that can be utilized by the plant are common with legumes. The symbiosis between Rhizobia and legumes is a critical plant–microbe mutualism that is essential for high yielding soybean. Recently, an emphasis on developing technology to supply corn with additional N through biological processes has been a focus of several agribusinesses... D.J. Steinkamp, K.A. Nelson, G. Singh, G. Kaur, H. Kaur

77. Evaluating the Effects of Nitrogen Source, Placement, and Timing on Corn Yield and Nitrogen Losses in the Sandy Soils of Northeast Nebraska

The impact of nitrogen sources, placement, enhanced efficiency fertilizers (EEFs), and application timing on improving groundwater quality in groundwater management areas remains unclear. This study assessed the effects of various N fertilizer sources, EEFs, application timing, and placement on corn yield and nitrogen losses via nitrate (NO3- ) leaching and ammonia (NH3) volatilization. The experiment was conducted in 2023, a notably dry year, at a farmer’s... A. Singh, C. Misar, J. Iqbal

78. Cover Crop Species and Planting Methods Influence on Corn N Requirement in Southern Illinois

It is well established that planting cover crops prior to corn (Zea mays L.) can influence soil temperature, moisture, and nitrogen (N) dynamics. These changes in soil along with the effects of cover crop on corn plant population can influence corn grain yield and N requirement. Two strategies to facilitate corn establishment and avoid N immobilization especially in winter cereal cover crops is by mixing cover crop species or skipping the corn row (precision planting). A randomized complete... A. Sadeghpour, C. Kula, G. Sener

79. Industrial Hemp Response to Nitrogen Applications

With the increasing interest in industrial hemp (Cannabis sativa L.) as a versatile crop for both fiber and grain production, optimizing nitrogen (N) management has become critical for maximizing its productivity. Field experiments were conducted at two locations (Novelty, Albany) in northern Missouri to evaluate the effects of N application rates on industrial hemp growth, biomass, and grain yield. The experiment was set as a randomized complete block design with a split-plot arrangement... A. Nain, G. Kaur , K. Nelson, G. Singh , J. Miller

80. Nitrogen Rate and Harvesting Time Based on Growing Degree Days Influenced Winter Cereal Rye Morphological Traits, Forage Yield, Quality, and Farm Profit in Poorly Drained Alfisols

Winter cereal rye (Secale cereale L.) (WCR) is often double cropped with maize for silage (Zea mays L.) to increase farm forage supply and profit. Spring nitrogen (N) fertilization to WCR could influence its production and quality at different harvesting times. Therefore, two on-farm trials were conducted in the 2019-2020 and 2020-2021 growing seasons to evaluate the effect of harvesting time (late-March to end-of-April considering the growth stage) and spring N fertilization... G. Burkett, K. Vaughn, O. Adeyemi, O. Zandvakili, M. Battaglia, S. Babaei, J. Nair, S. Still, A. Sadeghpour