SRP1142

Spring field peas are a cool-season, grain legume crop that has emerged in recent years as a potential cash crop in northern Kansas. An official field pea variety testing program was established in 2014 to provide Kansas growers with unbiased performance comparisons of spring field pea varieties. From 2014-2016, the entries consisted entirely of yellow cotyledon type varieties. In 2017, several varieties of green field peas were entered, including CDC Greenwater, PSTSP28, and PSTSP29. Companies enter varieties of their choice and pay entry fees, which are used to cover the expenses of the testing program

Effects of spatially variable plant available water on optimal corn seeding rate – field scale and site-specific approaches

Master of ScienceDepartment of AgronomyScott A. StaggenborgSpatial variability in plant available water can be caused by uncontrollable factors such as topography and soil texture as well as controllable factors such as residue management. Research located on the High Plains evaluated the impact of wheat (Triticum aestivum L.) stubble height on snow catch, plant available water at seeding, and optimal corn seeding rates. Treatments consisted of stripper harvest height of 71 cm (28 in.), cut heights of 25 cm (10 in.), and 10 cm (4 in.) Measured snow depths were significantly different among treatments (p<0.0001) with equivalent precipitation of 5.77 (2.27), 3.25 (1.28), and 1.73 cm (0.68 in.) for the stripped, 25 cm, and 10 cm heights respectively. Available soil water at planting increased 24% as stubble height increased from 10 to 71 cm (4 to 28 in) in one year of the study. Two corn hybrids of varying maturity (97 and 108 days) were planted into the stubble treatments at seeding rates ranging from 2.47 to 5.43 plants m[superscript]-2 (10 to 22 000 plants ac[superscript]-1). In the dry year, the long season hybrid responded positively to increasing population in tall stubble and negatively in short stubble. Yield of the short season hybrid increased with increasing stubble height and was mostly unresponsive to population. Grain yields of both hybrids responded positively to increasing plant population in a wet year. Treatments also affected the yield components of yield plant[superscript]-1, kernel weight, and kernels plant[superscript]-1. Managing seeding rates for uncontrollable factors was attempted with small-plot and field scale research across 3 fields in northeast Kansas. A relationship between soil electro-conductivity (EC) and measured water holding capacity values was developed for one study field. This quadratic relationship was significant (p<0.0001) and explained variability in water holding capacity with respect to EC quite well (R[superscript]2=0.6239). Responses from small plots showed that sites differing in population response characteristics could be identified. Field scale data was used to derive a function describing optimal seeding rate with respect to soil EC. In the field under study, optimal seeding rates varied from 3.08 to 8.74 plants m[superscript]-2 (12 500 to 35 375 plants ac-1)

2019 Kansas State University Industrial Hemp Dual-Purpose and Fiber Trial

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, but only recently allowed to be grown again in the United States. Varieties that have numerous industrial uses have been selected for improved fiber and grain production. However, there is no information available regarding adaptability or production of these varieties in Kansas. In 2019, Kansans were allowed to apply for research licenses to grow industrial hemp. It was assumed the crop would grow well throughout Kansas since there are wild remnant populations of C. sativa flourishing at numerous locations across the state. However, controlled variety trials are necessary to determine which varieties are best adapted to the state. Currently, farmers must rely on information generated from other states with vastly different growing conditions than Kansas. Variety selection is vital in hemp production considering latitude (day length) and length of growing season influence planting time, number of days to harvest, and ultimately yield. The objective of this study was to evaluate commercially available varieties of industrial hemp in south central Kansas

Using Yield Monitors to Assess On-Farm Test Plots

Farmer test plots have become a staple for production agriculture. These plots can range from simple side-by-side demonstration plots to a replicated research study. The rush of harvest often creates a challenge for harvesting these plots. Yield monitor data were collected from field scale plots in multiple states to assess ability to measure on-farm research. Grain mass was also measured for each plot with a weigh wagon or certified scale. The variability of yield monitor error (standard deviation) was not correlated with the magnitude of the error (mean). Thus calibration in and of itself will likely not result in more consistent yield monitor error. Determining if treatments or observations from non-replicated studies are different will be challenging. Depending on the chosen probability level, this data indicate that distinguishing a 3 to 9 percent difference was possible. Statistical analysis of replicated trials results in similar conclusions with reference and yield monitor data. Mass flow rate is one factor impacting yield monitor error

Tillage Intensity in a Long-Term Wheat-Sorghum-Fallow Rotation

This study was initiated in 1991 at the Kansas State University Southwest Research-Extension Center near Tribune, KS. The purpose of the study was to identify the effects of tillage intensity on precipitation capture, soil water storage, and grain yield in a wheat-sorghum-fallow rotation. Grain yields of wheat and grain sorghum increased with decreased tillage intensity in a wheat-sorghumfallow (WSF) rotation. In 2022, available soil water at sorghum planting was greater for no-tillage (NT) than reduced tillage (RT), which was greater than conventional tillage (CT). For wheat there was a similar pattern as sorghum, with available soil water at wheat planting being in the order of NT\u3eRT\u3eCT. Averaged across the most recent 22 years of the study, available soil water at wheat planting was 0.60 inch greater for NT than RT and approximately 1.7 inches greater than CT. Average available soil water at sorghum planting was greater in the order RT=NT\u3eCT averaging 7.9 inches for RT and NT and 5.9 inches for CT. Averaged across the past 22 years, NT wheat yields were 6 bu/a greater than RT and 10 bu/a greater than CT. Averaged across the past 22 years, sorghum yields with long-term NT have been 57% greater than with RT (82 vs. 52 bu/a)

Wheat and Grain Sorghum Sequencing for Three Crops in Four-Year Rotations

In 1996, an effort began to quantify soil water storage, crop water use, and crop productivity on dryland systems in western Kansas. Research on 4-year crop rotations with wheat and grain sorghum was initiated at the Southwest Research-Extension Center near Tribune, KS. Rotations were wheatwheat- sorghum-fallow (WWSF), wheat-sorghum-sorghum-fallow (WSSF), and continuous wheat (WW). Soil water at wheat planting averaged about 9.1 in. following sorghum, which is about 3.8 in. more than the average for the second wheat crop in a WWSF rotation. Soil water at sorghum planting was only about 1.5 in. less for the second sorghum crop compared with sorghum following wheat. Sorghum grain yield in 2022 was near average for first crop sorghum after wheat, above average for recrop sorghum, and below average for sorghum after recrop wheat. Wheat yields in 2022 were near zero due to hail. Wheat yields, when averaged across years, have been 2 bu/a greater following two sorghum crops than following one sorghum crop. Average sorghum yields were the same following one or two wheat crops. Yield of the second sorghum crop in a WSSF rotation averages ~66% of the yield of the first sorghum crop

Occasional Tillage in a Wheat-Sorghum-Fallow Rotation: 2022 Growing Season

Beginning in 2012, research was conducted near Garden City and Tribune, KS, to determine the effect of a single tillage operation every 3 years on grain yields in a wheat-sorghum-fallow (WSF) rotation. Treatments included no-till, single tillage post wheat harvest in mid-August, and single tillage mid-June during the fallow phase. This study was revised with two additional more intensive tillage treatments since 2019. The two additional treatments were 1) two tillage operations during the fallow phase and 2) one tillage during fallow phase and one tillage post wheat harvest. Grain yield varied greatly by year and location. Wheat yields ranged across years from mid-20s to 90 bu/a at Tribune and less than 10 to 100 bu/a at Garden City. Grain sorghum yields ranged from 40 to greater than 140 bu/a, depending upon year and location. Wheat yields tended to be greater with a single or two tillage operations during the fallow phase, and less with single tillage post wheat harvest at Garden City. Grain sorghum yield was less at Tribune when tilled post wheat harvest. This indicates that if a single tillage operation is needed to control troublesome weeds, that tillage during fallow prior to wheat planting may be better than tillage after wheat harvest. This study supports the hypothesis that if herbicide-resistant weed populations are high enough to cause yield reductions, then tillage might improve yields

Palaeomagnetism and magnetostiatigraphy of Triassic strata in the Sangre de Cristo Mountains and Tucumcari Basin, New Mexico, USA

We report palaeomagnetic data and a composite magnetic polarity sequence for Middle and Upper Triassic rocks assigned to the Anton Chico Member of the Moenkopi Formation and Chinle Group, respectively, exposed along the eastern flank of the Sangre de Cristo Mountains and in the Tucumcari Basin of eastern and northeastern New Mexico. Thermal demagnetization isolates a well-defined, dual polarity, characteristic magnetization, carried in most cases by haematite and interpreted as an early acquired chemical remanent magnetization (CRM). Characteristic magnetizations from 74 palaeomagnetic sites (one site = one bed) are used to define a magnetic polarity sequence, which we correlate with previously published Triassic data obtained from both marine and non-marine rocks. Preliminary correlation suggests that the resolution of magnetostratigraphic data derived from continental strata is not necessarily of lesser quality than that from marine rocks. On the basis of the magnetostratigraphic data, a profound unconformity is believed to separate lower-middle Norian and upper Norian-Rhaetian strata of the Chinle Group. Palaeomagnetic poles derived from selected sites in steeply dipping (> 85°) strata for the Middle Triassic (Anisian, ∼240 Ma: 50°N 121°E; N = 8), late Carman-early Norian (∼225 Ma: 53°N 104°E; N = 16), and late Norian-Rhaetian (∼208 Ma: 59°N 77°E; N = 8) are in relatively good agreement with previously published data for the Moenkopi Formation and Chinle Group and related strata in southwest North America. None the less, comparison with palaeomagnetic poles obtained from gently dipping or flat-lying Triassic strata from this study (Anisian, 46°N 112°E; N = 13; late Carnian, 54°N 87°E; N =12) and previously published Triassic poles in southwest North America suggest that a modest ‘apparent rotation’ not greater than about 5° affects declinations from steeply dipping rocks. The distribution of palaeomagnetic poles indicates ∼25° (angular distance) of apparent polar wander between about 240 and 208 Ma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73972/1/j.1365-246X.1996.tb05646.x.pd

Field Evaluations of Nitrogen-Fixing Products in Grain Sorghum

Nitrogen fertilizer is one of the largest input expenses for grain crops. Biological prod­ucts are currently available that contain nitrogen-fixing bacteria to supply nitrogen to a crop throughout the growing season. Pivot Bio PROVEN (developed for corn), RETURN (developed for sorghum) and experimental product versions were evaluated in grain sorghum at Manhattan, KS, in 2020, 2021, and 2022. Products were compared with an untreated check at five rates of nitrogen fertilizer. Products were applied at planting in-furrow in a volume of five gallons of water solution per acre. Crop response was characterized by several in-season parameters plus grain parameters and yield. In all years, the interaction of the product with nitrogen fertilizer was not significant for any parameter, indicating that neither version of the product affected how sorghum responded to nitrogen rates. However, most parameters significantly responded to nitrogen fertilizer, indicating that grain sorghum responded to nitrogen supply in all years. In 2020 and 2021, the product did not affect any of the response parameters. In 2022, the experimental product increased canopy normalized vegetative differ­ence index (NDVI) by 8%, biomass by 21%, and nitrogen uptake by 20% early in the growing season compared to the untreated check. Biomass, nitrogen concentration, nitrogen uptake, grain yield, and other parameters quantified at late vegetative stages or later did not differ from the untreated check for either version of the product. Although one product had a positive effect on early-season growth in one year, mid- to late-season biomass and grain yield were not affected