Locations In Kansas Research Articles

Early Season Environmental Indicators of Wheat Stripe Rust Epidemics in Kansas and the Central Great Plains Region of United States.

During the past two decades, the wheat producing areas of the Great Plains region in North America experienced frequent, severe yield losses to stripe rust (Puccinia striiformis f.sp.tritici). In general, outbreaks of rust diseases in the Southern Great Plains region often precede disease problems in the Central and Northern Great Plains. However, these generalizations provide little information and our objective for this study was to identify weather variables, geographical areas and time periods that influence the early stages of stripe rust epidemics in the Great Plains. Data used in this analysis consisted of monthly summaries of temperature, precipitation and soil moisture from 10 climate districts in the US state of Texas. These environmental variables were paired with estimates of wheat yield losses to stripe rust in Kansas, 2000-2019 with yield loss coded as a binary variable (1 = >4% statewide yield loss). An ensemble of simple models representing weather variables, time periods and geographical locations hypothesized to be influential in the development of stripe rust epidemics. Model performance were verified with observations not used in model development. Results of this study indicated that soil moisture within 2 to 3 climate districts in Texas were particularly influential in regional disease development. These areas of Texas were 700-1000 km away from locations in Kansas where the disease related yield losses were observed, and often preceded disease losses by 3-6 months. In the future, these models could help establish priority locations and time periods for disease scouting, and inform regional estimates of disease risk.

Impact of simulated hail damage at different growth stages and canopy positions on rainfed and irrigated winter wheat

AbstractProducers and crop insurance providers will benefit from an accurate assessment of yield reduction after hailstorms that considers crop management, weather, growth stage, and impacted part of crop (hail affected canopy position). But, limited information is available. The main objectives of this study were to quantify wheat (Triticum aestivum L.) yield losses associated with simulated hail damage timing and canopy position. The study was conducted in two locations (Garden City [irrigated], and Manhattan [rainfed]) in Kansas, from 2018 to 2020 and 2016 to 2018, respectively. Treatments were an incomplete factorial combination of stem bending at seven flowering stages, above or below the flag leaf and a nontreated control. Results of the study indicated 11%–22% wheat yield reduction due to simulated hail damage above the flag leaf and 32%–52% due to hail impact below the flag leaf under irrigated conditions. Within the high‐yielding rainfed environment, hail damage caused up to 20% yield reduction compared with the control. In rainfed and low‐yielding environments, the impact of hail damage was mainly dependent on the growth stage of wheat at hail occurrence. Hail damage at Feekes 11.2–11.4 stages decreased yield by 20%–50% from the rainfed control. Hail damage at Feekes 10.0–10.5.4 decreased yield by 50%–70% from the rainfed control. We provide empirical evidence that indicates hail damage on wheat is dependent on the interaction effect of in‐season crop water management, weather, canopy position and crop growth stage, and estimates of yield loss due to hail should consider these factors.

Changes to Water Table Elevation Across Kansas Wells

Ground water is a valuable resource for all aspects of society whether used for agriculture, commerce, industry, and more. Monitoring the depth of the water table is crucial when determining accessibility and use of this resource, especially in agriculture-heavy regions like Kansas. By subtracting the altitude of the surface from the depth of water in a well, the depth of the local water table can be determined. Using this well data gathered from various locations in Kansas at different can be used to observe past behavior of the water table as well as help predict future behavior.

Biomass and Nutrient Accumulation by Dual-Purpose Hemp and Concurrent Soil Profile Water Depletion at Three Locations in Kansas in 2022

Hemp has garnered interest as a potential crop that is not constrained by the typical food, feed, and fuel market channels. Although hemp varieties are available for either grain, fiber, or both (dual-purpose: both grain and fiber) markets, little information is available on hemp growth and water use in Kansas environments. Experiments were conducted at three locations representing the precipitation gradient across Kansas in 2022 to characterize hemp growth, nutrient uptake, and soil water depletion. One fiber and one grain variety were evaluated with and without fertilizer nitrogen at Manhattan, Haysville, and Scandia, KS. Both non-irrigated and fully irrigated plots were evaluated at Scandia. Soil water content and biomass accumulation were monitored in plots with full nitrogen fertilizer. Results from the 2022 season confirmed the benefit of nitrogen fertilizer. Although total biomass yield was similar for the two varieties, more of that yield was partitioned to grain in the grain variety and to stalks in the fiber variety. Nutrient uptake patterns were similar to those observed for hemp in previous years and documented in other crops. Nitrogen and potassium accumulation occurred at a faster rate than dry matter, and phosphorus accumulation lagged that of dry matter. Carbon accumulation closely followed total dry matter accumulation. The sum of net depletion of the soil profile water plus precipitation averaged 17.3 inches across the three locations in 2022, but some of the precipitation came in intense events that resulted in runoff. Relatively stable stalk yield coupled with more variable grain yield reveals hemp’s ability to adjust growth to match the inconsistent growing conditions typical of Kansas.

2022 Kansas State University Industrial Hemp Dual-Purpose Variety Trials

Hemp is a broad term used to describe the many varieties of Cannabis sativa L. that produce less than 0.3% tetrahydrocannabinol (THC). The crop is globally significant and has recently been approved in the United States. There are many uses for industrial hemp, and the market for industrial hemp is rapidly growing as more states are legalizing its production. Industrial hemp is marketed for oil, grain, and fiber. Varieties have been selected for improved fiber and grain production that can service these markets. However, little research-based information is available regarding adaptability or production of these varieties in Kansas. The objectives of this research were to evaluate commercially available varieties of industrial hemp at two locations in Kansas.

Nutrient Management Strategies to Control Broomsedge Infestation and Improve Yield and Quality of Tall Fescue Hayfields

A study in tall fescue hayfields infested with broomsedge and bluestem was conducted at four locations in southeast Kansas. The purpose of this study was to evaluate how phosphorus, nitrogen, and potassium fertilization affect yield, forage quality, and broomsedge/bluestem control in tall fescue hayfields. This trial will be repeated in 2023.

Winter wheat light interception measured with a quantum sensor and images

AbstractLight interception (LI) measurements are essential for modeling crop biomass and grain yield. Canopy LI is often measured with linear quantum sensors, but the need for unobstructed sunlight near solar noon can make field measurements impractical. We aimed to evaluate the use of the fraction of green canopy cover (FGCC) as a surrogate for LI in winter wheat (Triticum aestivum L.) canopies. A linear quantum sensor and a camera were used to collect 930 observations during the 2021 growing season across three locations in Kansas. Images were analyzed with the Canopeo application. The quantum sensor was also used to estimate the LI and leaf area index (LAI) in different canopy strata. Growing season shoot dry biomass was modeled with LI values from images and the quantum sensor. The LI estimated by the quantum sensor and images resulted in a strong positive linear correlation (r = 0.97). During the vegetative stages, LI values from images were generally greater than the LI values from the quantum sensor. During the reproductive stages, LI values from images were generally lower than those obtained by the quantum sensor, which was partly attributed to the better discrimination of FGCC for senescing vegetation. Using images to measure LI was easier and faster in prostrate canopies, and less sensitive to soil microrelief and changing sky conditions. The quantum sensor was useful for quantifying LI and LAI nondestructively in different canopy layers. Final growing season shoot dry biomass determined by either method was within 5% of the observed biomass.

Soybean Seed Yield Productivity and Biological Nitrogen Fixation in Kansas

Soybean [Glycine max (L.) Merr.] productivity (seed yield) and biological nitrogen fixation (BNF) were evaluated in response to different fertilization strategies. The study comprised four different locations in Kansas during the 2021 growing season, two irrigated (Topeka and Scandia) and two dryland (Kiro and Ashland Bottoms) sites. Greater seed yields were recorded in Topeka and Kiro (80 bu/a) relative to Scandia (55 bu/a) and Ashland Bottoms (51 bu/a), without observing fertilizer effects on yields. Overall, the relative abundance of ureides (% RAU), an indicator of the level of BNF, increased as the crop matured and showed a negative association with the soil N level. The main objective of this study was to identify how different levels of nitrogen (N) and sulfur (S) fertilization affect the seed yield and the biological nitrogen fixation (BNF) in soybean.

Increasing Winter Wheat Grain Yield by Replicating the Management Adopted in High-Yielding Commercial Fields

Large winter wheat yield gaps between farmer yields and yield potential in the southern Great Plains indicate the need to improve recommendations of best management strategies to profitably bridge this gap. Many studies have been completed on individual management factors pre-determined by the individual researcher, but we are not aware of studies comparing combination of practices that producers are currently using, which would be more relevant for real-world scenarios. Our objective was to determine the yield gains resulting from management intensification using combination of practices currently adopted in commercial wheat fields. Four management intensities (i.e., Low, Average, High, and Top) were derived from a survey of 656 commercial fields, and replicated in trials conducted in four and six locations in western and central Kansas. Management intensities were tested factorially on two adapted varieties. Grain yield in central Kansas ranged from 45.5 bu/a in the Low management intensity to 69.3 bu/a in the High and Top intensities, with the Average management increasing yields by 30% as compared to the Low intensity, and the High management increasing yields 18% from the Average. The variety WB4269 outyielded Zenda (63.2 and 58.7 bu/a) across central environments. In western Kansas, there was a significant variety by management interaction, where wheat yield increased from the Low and Average intensities to the High and Top intensities (72.8–78.9 to 90.7–96.0 bu/a). The WB-Grainfield and KS Dallas varieties produced similar yields in the western environments. Using similar management practices as the producers with high-yield results in central and western Kansas narrowed the yield gap, and further increases in management intensification were not warranted. Variety selection played an important role either by increasing attained yields or by interacting with management practices.

Biomass and Nutrient Accumulation by Dual-Purpose Hemp and Concurrent Soil Profile Water Depletion at Two Locations in Kansas in 2020

Biomass and Nutrient Accumulation by Dual-Purpose Hemp and Concurrent Soil Profile Water Depletion at Two Locations in Kansas in 2020

Cation Exchange Resins as Indicator of In-Season Potassium Supply for Soybean in Kansas

The use of ion-exchange resins to measure soil nutrient availability has potential applications for fertilizer recommendations. The objective of this study was to evaluate the relationship between potassium (K) adsorption by cation exchange resins (CER) and K uptake by soybean in field conditions. The study was conducted at two locations in Kansas during 2019. Two treatments were selected to evaluate the CER. Treatments included a check (0 lb K2O/a) and a high K rate with 150 lb K2O/a applied pre-plant and incorporated. The Plant Root Simulator (PRS, Western Ag Innovations, Saskatchewan, Canada) was used as an indicator of in-season K supply to soybean. In addition, whole plant samples were collected at V4, R2, R4, and R6 stages to measure plant K uptake. Soil moisture content was calculated based on soil samples collected at the beginning and end of each burial period. The CER was able to adsorb more K (measured as cumulative adsorption) when K fertilizer (150 lb K2O/a) was applied. Data showed a positive relation between CER values and soil moisture content. Preliminary results from this study suggest that CER can be used as an indicator of K supply, particularly in soils with low soil test K levels.

Corn Response to Long‐Term Phosphorus Fertilizer Application Rate and Placement with Strip‐Tillage

Core Ideas Results showed a significant effect of P fertilizer rate and placement in early season whole plant P uptake, ear leaf P concentration, grain P concentration, and yield over the course of this study but particularly after multiple years of treatment application. Early P uptake in corn was consistently higher with deep band P fertilizer applications and with starter fertilizer with the planter. The long‐term evaluation of P fertilizer placement showed that deep‐band P placement only seldom resulted in higher yields. The use of starter fertilizer increased average grain yield, particularly for high‐yielding systems. Multiple years of phosphorus (P) fertilizer application may be needed before the agronomic and environmental effect of P fertilizer placement and application rate become noticeable. The objective of this study was to evaluate the long‐term effects of P placement on corn (Zea mays L.) with strip‐tillage. The study was conducted for 10 yr at two locations in Kansas in a corn and soybean (Glycine max L.) rotation from 2006 to 2015. Strip‐tillage was conducted before corn and soybean were planted without previous tillage. Phosphorus fertilizer placement and rate treatments included a control, broadcast at 20 kg P ha−1 and 39 kg P ha−1, deep‐band at 20 kg P ha−1, and 39 kg P ha−1, in a factorial combination with two starter fertilizer treatments (with and without starter fertilizer). Response parameters included V6 whole plant P uptake, ear leaf P, grain P concentration, and yield. Phosphorus fertilizer increased crop response parameters when compared to the control including yield for some years or across years at the two locations. However, corn response was similar among the P rate‐place treatments with generally higher values for the P rate of 39 kg P ha−1. The use of starter fertilizers in combination with broadcast or deep‐band P fertilizer resulted in greater P uptake, ear leaf P and grain P; however only increased yield at one location. Results from this study showed similar corn yield for deep‐band and broadcast P fertilizer under strip‐tillage and starter fertilizer increased yield for a high‐yielding, low soil test P location.

Geographic variation in thermal sensitivity of early life traits in a widespread reptile.

Taxa with large geographic distributions generally encompass diverse macroclimatic conditions, potentially requiring local adaptation and/or phenotypic plasticity to match their phenotypes to differing environments. These eco‐evolutionary processes are of particular interest in organisms with traits that are directly affected by temperature, such as embryonic development in oviparous ectotherms. Here we examine the spatial distribution of fitness‐related early life phenotypes across the range of a widespread vertebrate, the painted turtle (Chrysemys picta). We quantified embryonic and hatchling traits from seven locations (in Idaho, Minnesota, Oregon, Illinois, Nebraska, Kansas, and New Mexico) after incubating eggs under constant conditions across a series of environmentally relevant temperatures. Thermal reaction norms for incubation duration and hatchling mass varied among locations under this common‐garden experiment, indicating genetic differentiation or pre‐ovulatory maternal effects. However, latitude, a commonly used proxy for geographic variation, was not a strong predictor of these geographic differences. Our findings suggest that this macroclimatic proxy may be an unreliable surrogate for microclimatic conditions experienced locally in nests. Instead, complex interactions between abiotic and biotic factors likely drive among‐population phenotypic variation in this system. Understanding spatial variation in key life‐history traits provides an important perspective on adaptation to contemporary and future climatic conditions.

Agricultural management effects on soil health across the US Southern Great Plains

Improving soil health is commonly suggested as a way to “buffer” agricultural systems against climate change impacts such as increases in drought, storm severity, and annual temperature. A number of producers in the US Southern Great Plains (SGP) and elsewhere have begun to manage their systems with an emphasis on improving soil health, but adoption of these practices is not yet widespread. There is evidence that soil health management (SHM) has positive effects on soil health that conventional management (CM) does not, but the effects have not been compared to sustainability managed conventional systems, nor have they been quantified using a standard method across regional climatic gradients such as those that characterize the SGP. In this study, we used a network of three pairs of SHM and CM sites at 12 locations in Kansas, Oklahoma, and Texas to test a suite of biological, chemical, and physical soil health indicators. We analyzed differences among these indicators to better understand how SHM and CM fields compared across the region, and to identify potential effects of precipitation and temperature on these differences. We found that responses to management were not uniform across the SGP and that soil health indicators responded primarily to climate, rather than to management practices. These results suggest that soil health responses as a result of SHM may be constrained by other factors, resulting in variations across the landscape that make soil health assessments challenging. Our findings underscore the importance of understanding management and other impacts on soil health when developing realistic land management goals.

Influence of Genotype × Location Interaction on Grain Sorghum Grain Chemistry and Digestibility

Grain sorghum is an important cereal crop for both human food, animal feed, and biofuel production in the United States. A diverse set of 19 grain sorghum genotypes was grown in three locations in Kansas to evaluate the genotype, location, and genotype × location effect on grain quality attributes. The physical characteristics of the grain (size and hardness) were greatly affected by genotype, location, and their interaction. The chemical components and functional properties were affected by genotype and location. The amylose content varied from 19.2 to 30.7% and was variable due to growing location. The starch granule size distribution exhibited little variation due to location, but was affected by the genotype. Protein content ranged from 11.1 to 15.2% and digestibility ranged from 45.6 to 62.1% due to genotype. The small amount of interaction between genotype and location for the protein content and digestibility allows for selection of the desired genotype and location without a wide variation due to their combination. Among the nine traits studied, maximum variation was explained by kernel diameter (20.0%), followed by kernel weight (19.3%), ash (14.6%) and protein content (LECO) (10.8%). Principal component analysis identified SC628, SC489, SC1104 and BTx399 with good and SC391 and SC11277 with poor grain quality. The diverse set of grain sorghum genotypes and variation in growth conditions led to differences in both the physical and chemical components in the grain. Thus, the variation due to genotype and location will allow for the ability to select the most desirable trait at a specific location.

Emergence Dynamics of Kochia (Kochia scoparia) Populations from the U.S. Great Plains: A Multi-Site-Year Study

Evolution of kochia biotypes resistant to multiple herbicide sites of action is an increasing concern for growers across the U.S. Great Plains. This necessitates the development of integrated strategies for kochia control in this region based on improved forecasting of periodicity and patterns of kochia emergence in the field. Field experiments were conducted near Huntley, MT, in 2013 and 2014, and in Manhattan and Hays, KS, in 2013 to characterize the timing and pattern of emergence of several kochia populations collected from the U.S. Great Plains’ states. The more rapid accumulation of growing degree days (GDD) resulted in a shorter emergence duration (E90–E10) in 2014 compared with 2013 in Montana. Kochia populations exhibited an extended emergence period (early April through mid-July). Among all kochia populations, in 2013, Kansas-Garden City (KS-GC), Kansas-Manhattan (KS-MN), Oklahoma (OK), and Montana (MT) populations began to emerge earlier, with a minimum of 151 cumulative GDD to achieve 10% cumulative emergence (E10values) in Montana. The New Mexico-Los Lunas (NM-LL) population exhibited a delayed onset but a rapid emergence rate, while the North Dakota (ND) and Kansas-Colby (KS-CB) populations emerged over a longer duration (E90–E10of 556 and 547 GDD, respectively) in 2013 in Montana. In 2013 at the two locations in Kansas, kochia populations exhibited a similar emergence pattern, with no differences in the time to initiate germination (E10), rate of emergence (parameterb), or duration of emergence (E90–E10). At Hays, KS, the GDD for E50and E90were less for ND compared with KS-MN and KS-GC local populations. In 2014 the KS-MN kochia population exhibited an early (ED10value of 215 GDD) but a more gradual emergence pattern (E90–E10=526 GDD) in Montana. In contrast, OK and New Mexico-Las Cruces (NM-LC) populations had an early and a more rapid emergence pattern (E90–E10=153 and 154 GDD, respectively). Kochia in Montana exhibited two to four emergence peaks. This differential emergence pattern of kochia populations reflects the occurrence of different emergence “biotypes” and emphasizes the need to adopt more location-specific and diversified weed control tactics to manage kochia seedbanks.

Fungus and Frogs: Preliminary Analysis of a Survey of Chytrid in Kansas

Amphibians are one of the most threatened groups of organisms worldwide, per the International Union for Conservation of Nature. A disease known as chytridiomycosis has been linked to population declines worldwide. Incidence of the fungus has recently been reported at three locations in south-central Kansas. The objective of our study was to assess the status of chytrid throughout the state of Kansas. In 2015-2016 we conducted surveys at multiple locations. We used real-time PCR to analyze swabs collected at each location. Preliminary results show chytrid present at 4 locations in Kansas. We will continue to analyze samples to determine aspects of life history that might increase the potential for infection.

Speed Reduction Mitigation Strategies on Rural Highways at Two-Way Stop Control Intersections and Curves

Studies conducted on crashes at rural intersections of state highways and local roads/streets with two-way stop control have proved that the problem was likely poor judgment by the stopped driver on the minor approach of the speed of an oncoming vehicle and/or safe gap in traffic on the major highway. Several mitigating strategies have been suggested and studied in various studies to improve safety at the two-way stop control rural intersections and at other rural highway segments. There are also several low-cost techniques used, mostly in foreign countries, to slow drivers on major highways as they enter small towns and villages, e.g., narrowing pavement lines, establishing visual gateways, etc. Lowered speeds would decrease crash severity. In this study, four strategies including solar speed display units, mobile speed trailers, optical speed bars, and colored pavement were tested and assessed in some locations in Kansas. The results of this research indicate that both solar speed display units and mobile speed trailers are effective in speed reduction at the desired points, but optical speed bars and colored pavements do not yield reliable results. Additional studies and longer term studies, should be conducted.

Microclimate and Scion Leaf Removal to Improve the Success of Grafted Tomato Seedlings

The utilization of grafted tomato (Solanum lycopersicum) plants in the United States shows significant promise, particularly as intensively managed production systems like high tunnels and greenhouses become more popular. However, the availability of grafted plants in the United States is currently a major barrier and a large portion of farmers who would like to use grafted plants would prefer to propagate their own. The objectives of this study were to determine how healing chamber design affects graft survival and microclimate, and to investigate how scion leaf and shoot removal affects graft survival in various healing chambers. Similar experiments were repeated at two locations in Kansas and a split-plot, randomized complete block design (RCBD) was used in each, with three and four replications being conducted over time at each of the locations. Five chamber treatments were tested including a negative control (none) as well as shadecloth alone, white vinyl mesh, polyethylene film and shadecloth, and polyethylene film with shadecloth and a cool-mist humidifier. No statistically significant effects of chamber design were seen on grafted plant success. However, microclimate data from the various healing chambers offer valuable data toward determining the best management practices for grafted plants. Shadecloth alone showed significant promise as this covering provided cooler temperatures during the afternoon when the healing chambers were prone to excessive heat buildup. Three tube-grafting methods were tested, including standard tube-grafted plants (no leaves removed), leaf removal (LR) plants (≈75% of the leaf surface area was removed from the scion), and shoot removal (SR) plants (the apical meristem and all true leaves were removed). The SR method did not affect graft survival, but the LR method increased grafting success from 78% to 84% and was significant as compared with the other methods (P < 0.05). The long-term goals of this work are to develop successful propagation systems that can be used by small-acreage growers with limited greenhouse facilities. The data presented here indicate that high-humidity healing chambers (>85% relative humidity) may not be necessary for tomato, and LR can increase the grafting success rate.

Broadleaf Weed Control in Sunflower (<i>Helianthus annuus</i>) with Preemergence-Applied Pyroxasulfone with and without Sulfentrazone

A field study was conducted at two locations in Kansas, USA in 2011 and 2012 to test weed control efficacy and crop response to preemergence-applied pyroxasulfone alone and in combination with sulfentrazone in sunflower. Treatments included three rates of pyroxasulfone (100, 200 and 400 g·ha-1) applied alone and tank-mixed with sulfentrazone at 70, 140 and 280 g·ha-1. Commercial standards sulfentrazone at 140 g·ha-1 + pendimethalin at 1390 g·ha-1 and sulfentrazone at 140 g·ha-1 + S-metolachlor at 1280 g·ha-1 were also included. Pyroxasulfone at 100 g·ha-1 controlled Palmer amaranth 87% at 3 weeks after application (WAA), but control decreased to 76% at 6 WAA. Increasing pyroxasulfone rate to ≥200 g·ha-1 or tank mixing with sulfentazone at 140 g·ha-1 provided ≥90% Palmer amaranth control for at least 6 WAA. Sulfentrazone alone at 70 g·ha-1 controlled Palmer amaranth 77% at 3 WAA, but control dropped to 69% at 6 WAA. Increasing sulfentrazone rate from 70 to 140 or 280 g·ha-1 increased control to >90% at 3 WAA, but did not maintain acceptable control at 6 WAA. Tank mixing sulfentrazone at 140 g·ha-1 with pendimethalin at 1390 g·ha-1 or S-metolachlor at 1280 g·ha-1 controlled Palmer amaranth ≥90 and 84% at 3 WAA and 6 WAA, respectively. The lowest rate of pyroxasulfone (100 g·ha-1) controlled kochia 98% and the control was complete with all other treatments. However, no treatment provided as much as 90% puncturevine control at 3 WAA and the control was commercially unacceptable (<75%) at 6 WAA. No treatment visibly injured sunflower anytime during the season or reduced sunflower plant population.