Locations In Nebraska Research Articles

Irrigated Corn Yield and Nitrogen Accumulation Response in a Comparison of No‐till and Conventional Till: Tillage and Surface‐Residue Variables

AbstractComparisons between no‐till and conventional‐till management are often confounded by variation in both tillage and residue placement. The objective of this research was to separate the tillage variable from the surface‐residue variable associated with no‐till and conventional‐till management comparisons in irrigated continuous corn (Zea mays L.) production. Two Nebraska locations (Mead and Clay Center) with differences in soil types and climate were selected. Four tillage‐residue treatments [NT‐NR (no‐till, residue removed), NT‐R (no‐till, surface residue), T‐NR (till, residue removed), T‐R (conventional till, surface residue)] were fertilized by either broadcasting at planting or sidedressing at the 6‐leaf stage with rates of 0, 56, 112, and 168 kg N ha−1. At Clay Center, grain yields and total N accumulation were similar for all tillage‐residue treatment combinations in all years when the highest fertilizer N rate was used. In 2 of 3 yr at Mead, grain yields and total N accumulation were less for no‐till than conventionaltill treatments, but in 1 yr the yields and total N accumulations were greater in no‐till than conventional‐till treatments. At Mead, surface residue resulted in lower grain yields and total N accumulation compared with bare soil at lower N rates, but not at greater N rates, in 2 of 3 yr. Sidedressing fertilizer N was generally a more efficient N placement than broadcasting. Differences between tillage and residue effects at Clay Center and residue effects at Mead were overcome with higher rates of fertilizer N. Tillage effects at Mead did not appear to be N‐related. The data suggest that tillage may be necessary to maintain optimum production levels on finer‐textured soils when spring soil temperatures are cool and slow to warm. When spring soil temperatures are warm, no‐till strategies can be used for optimum production levels on these soils.

Variation in Polyphenol Oxidase Activity and Quality Characteristics Among Hard White Wheat and Hard Red Winter Wheat Samples

ABSTRACTPolyphenol oxidase (PPO) has been related to an undesirable brown discoloration of wheat‐based end products. Consumer acceptance and product quality are generally decreased by the darkening phenomena. Two sets of wheat samples (Triticum aestivum L.) were investigated for variation in grain and flour PPO levels. Samples included 40 advanced experimental hard white winter wheat lines grown at two Kansas locations and 10 hard red winter wheat genotypes grown at three Nebraska locations. The variability in grain and flour PPO activities was influenced by growing location and population for the hard white wheat samples. There also was a significant influence of population by growing location interactions on PPO activity in both grain and flour. Genotype and growing location both contributed to variability in flour PPO activity among the hard red wheat samples. The variation in flour PPO activities among growing locations appeared larger than variation produced by genotypes tested for the hard red wheat samples. Quality parameters, such as wheat physical properties, flour protein and ash contents, grain color, and milling yield significantly correlated with grain and flour PPO activities. Among red wheat samples, flour PPO activity was related to 100 kernel weight, first reduction flour yield, and flour ash content. Grain PPO activity was related to variation in grain color observed among hard white samples. The relationship of quality characteristics with grain and flour PPO activities varied among white and red wheat samples.

A space-time stochastic climatological approach to daily global solar radiation

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 07:11-20 (1996) - DOI: https://doi.org/10.3354/cr007011 A space-time stochastic climatological approach to daily global solar radiation Matyasovszky I, Bogardi I A stochastic climatological model is presented to describe the space-time behavior of daily global solar radiation measured by pyranometers. Due to the difficulty of describing daily global radiation by common probability distributions, a nonparametric technique, the Abramson kernel estimator, is used. The space-time climatological model of daily global radiation consists of a transformed multivariate autoregressive (AR) process conditioned on large-scale atmospheric circulation patterns. The transformation is necessary to establish a relationship between the probability distribution of global radiation and a normal variable used in the AR model. In order to check the stochastic model a simulation study was performed for 7 locations in Nebraska, USA. Although a split sampling approach could not be used due to the relatively small sample size the simulated probability distributions reproduced the empirical distributions quite correctly. Also, the space-time dependency was maintained. The methodology may be a useful tool to estimate local/regional radiation under climate change. Global solar radiation · Probability distribution · Kernel estimator · Space-time model · Circulation patterns · Downscaling Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 07, No. 1. Publication date: August 22, 1996 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 1996 Inter-Research.

Traffic Effects on Water Infiltration in Chisel‐Plow and No‐till Systems

AbstractTraffic effects on pore structure and hydraulic properties of soils may be affected by site‐specific factors. The objective of this study was to determine if the effects of wheel traffic on infiltration rates in chisel‐plow and no‐till tillage systems differed among five Midwestern locations. Ponded and unsaturated (30‐, 60‐, and 150‐mm water tension head) infiltration rates were measured sequentially using infiltrometers after removing surface residues and the upper 2 cm of soil. Wheel traffic reduced ponded infiltration rates in both tillage systems at all locations, ranging from 95% in the chisel‐plow system in Iowa to approximately 55% in the chisel‐plow system in Missouri. Tillage systems significantly affected ponded infiltration rates at only two of the locations. At the Minnesota and Nebraska locations, no‐till reduced ponded infiltration rates in untrafficked interrows by 33 and 64%, respectively, compared with those in the chisel‐plow system. Ponded infiltration rates of trafficked interrows did not differ between tillage systems at any location. At the Iowa and Nebraska locations, the decrease in infiltration rate with an increase in tension head was greater for untrafficked interrows than for trafficked interrows in the chisel‐plow system. The large pores that drain at 30 mm of tension head accounted for a lower percentage of the water flow with ponding in trafficked interrows (73%) than in untrafficked interrows (88%). Infiltration rate comparisons between tillage systems should consider wheel traffic patterns.

Removing Spatial Variation from Wheat Yield Trials: A Comparison of Methods

Most cultivar evaluation trials use blocked designs and are analyzed using classical analysis of variance; however, a standard analysis for blocked designs often does not adequately account for spatial variability. Recent advances in spatial statistics suggest that there are better alternatives. The primary objective of this research was to compare randomized complete block (RCB) analysis with two nearest neighbor adjustment (NNA) methods; a random field procedure was also examined, as another way to remove spatial variability. Yield data from three replicated breeding nurseries involving diverse adapted and unadapted germplasm, each grown at four locations in Nebraska during 1988–1989, were used for the comparisons. The NNA approach was superior for all nurseries at all locations, on the basis of lower coefficient of variation and greater ability to distinguish cultivar differences. For 9 of 12 trials, RCB cultivar means were highly correlated with NNA cultivar means, indicating that both procedures would identify similar elite lines. For three trials, however, the estimated cultivar yield and cultivar rank from RCB and NNA procedures were different, and so different lines would be selected. The random field analysis was applied to the trial for which the discrepancy between the RCB and NNA analysis was greatest; this yielded results similar to the nearest neighbor analysis. Our results suggest that spatial trends are common in Nebraska and compromise the accuracy and precision of standard analysis of blocked designs. Therefore, NNA or random field analysis should be used to improve the analysis of breeding trials.

INFLUENCE OF TEMPERATURE ON STABILITY OF PLANT ARCHITECTURE OF DRY BEANS (PHASEOLUS VULGARIS L.) AND IMPLICATIONS FOR SELECTION

Upright, unstable Great Northern (GN) and Pinto (P) dry bean lines (Type IIb) have been developed in Nebraska (NE). The influence of temperature (T) under a long photoperiod (PH) on architype was investigated. A split-plot design, with 3 T regimes (PH, 15 hrs. light, 9 hrs. dark) as main-plots and 5 lines as sub-plots, with 3 replications, were used in growth chambers (GCs). Twenty-two bean lines were planted in a RCBD with 4 replications at each of 3 field locations in NE (1991, 1992). A significant interaction of lines × T regimes for branch number was observed in the GCs. Some lines developed more branches under 28C light/20C dark than under lower T regimes. Significant interactions between lines × locations, lines × years were detected for branch number, plant uprightness, plant height and days to flowering and maturity. Most lines had less branches and were more upright at lower T. Lines need to be screened under high T and long PH to select for architectural stability.

Simulation of crop productivity and responses to climate change in the year 2030: the role of future technologies, adjustments and adaptations

Advances in agricultural technology may affect the response of crop yields to a future climate change induced by greenhouse warming. We illustrate a methodology for simulating these effects by manipulating the parameters of a crop simulation model erosion productivity impact calculator (EPIC) to represent a set of proposed future technologies. Sensitivity analyses were first performed to test the effect of changes in each of the parameters individually. Crop yields were then simulated with a set of these future technologies under the climate of the 1951–1980 period (the ‘control’ climate) and under the climate of the 1930s (used as an analog of climate change), for locations in Missouri, Iowa, Nebraska and Kansas (MINK). The future technologies increased yields by an average of 72% above current levels, but had little effect on the sensitivity of crop yields to climate change. Next, realizing that attempts will probably be made to adjust farming practices to a changed climate, we implemented a set of changes which represent both currently available strategies for coping with the analog climate as well as new techniques which might be developed in response to a hotter, drier climate. With these changes in place, both yields and water use were less affected by the analog climate. If the direct effects of increased CO 2 are also considered, yields of all crops but corn were equal to or greater than those that occur with no climate change. We also considered the economic feasibility of crop substitutions and shifts in the location of irrigated agriculture as adjustments to the analog climate. The final step in this analysis was to scale farm-level results to the regional level.

Genotype and Environment Effects on Quality Characteristics of Hard Red Winter Wheat

Improvement of end‐use quality in wheat (Triticum aestivum L.) depends on thorough understanding of the influences of environment, genotype, and their interaction. Our objectives were to determine relative contributions of genotype, environment, and G × E interaction to variation in quality characteristics of hard red winter wheat. Eighteen winter wheat genotypes were grown in replicated trials at six locations in Nebraska and one site in Arizona in 1988 and 1989. Harvested grain was micromilled to produce flour samples for evaluation of protein concentration, mixing characteristics, and sodium dodecylsulfate (SDS) sedimentation. Kernel hardness was determined by microscopic evaluation of individual kernels. Genotype, environment, and interaction effects were found to significantly influence variation in all quality parameters. Variances of quality characteristics associated with environmental effects were generally larger than those for genetic factors. The magnitude of G × E effects were found to be of similar magnitude to genetic factors for mixing tolerance and kernel hardness, but were smaller for flour protein concentration, mixing time, and SDS sedimentation value. Significant differences among genotype responses (b‐values) were observed in the regressions of genotype mean on location means for each quality parameter. There were few instances of significant deviations from regression. Positive correlations between genotype grand mean and genotype b‐values for flour protein, mixing time, and mixing tolerance suggest that simultaneous improvement in both mean and stability for these traits may be difficult. Based on these results, environmental influences on enduse quality attributes should be an important consideration in cultivar improvement efforts toward enhancing marketing quality of hard red winter wheat.

Sand Bluestem and Prairie Sandreed Establishment

Sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern,] and prairie sandreed (Calamovitfa longifolia Hook.) are native warm-season grasses used to revegetate cropland and degraded rangeland on highly erodible sandy soils in the central Great Plains. The objectives of this study were to compare establishment success of the 2 grasses and to determine if application of atrazine at time of planting enhanced grass establishment. Eight plantings, including 'Goldstrike' and 'Garden' sand bluestem and 'Goshen' and 'Pronghorn' prairie sandreed, were made from 1985 to 1987 at locations in eastern, northcentral, and western Nebraska. Three plantings were established under irrigation and 5 under dryland conditions. Atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] was applied at a rate of 2.2 kg a.i./ha at planting at 3 of the dryland sites. Grasses were planted at a rate of 430 pure live seed/M2 in clean tilled seedbeds. Establishment of sand bluestem, as measured by herbage dry matter yield and/or grass frequency, was generally superior to that of prairie sandreed. Goshen prairie sandreed failed to establish adequate stands in 6 of the 8 plantings. Atrazine, applied at time of planting, increased sand bluestem stand frequency on sites with high weed interference but did not affect that of prairie sandreed. Based on these results, sand bluestem should be a dominant component in seed mixtures used to revegetate and stabilize sandy soils in the central Great Plains.

Role of nitrogen mineralization in fertilizer recommendations

Abstract Efficient use of nitrogen (N) fertilizer is important to achieve optimum crop yields while avoiding potential contamination of surface and ground water. A major obstacle in achieving optimum N fertilization is the difficulty of predicting soil organic N mineralization under field conditions. Since soils differ in their N‐supplying capacity, there is need for a testing procedure that will enable producers to make an accurate assessment of soil N availability. The purpose of this study was to evaluate electro‐ultrafiltration (EUF) and autoclave techniques to estimate soil N mineralization relative to N uptake by corn from unfertilized plots. Five different geographical locations in Nebraska were selected to encompass climatic conditions and soil types typically encountered throughout the state. Soil organic N mineralized determined by plant N uptake varied between geographical locations and ranged from 13 to 131 kg ha‐1. Data from both laboratory procedures were poorly correlated with crop N uptake across geographic locations. However, multiple regression including potentially mineralizable N (PMN), residual soil N, and growing degree days as independent variables resulted in a high correlation (R2 ≥ 0.93) with total N uptake. The results indicated that mineralization of organic matter (OM) can represent an important source of N and that it may be feasible to quantify soil organic matter mineralization by laboratory testing procedures for a broad range of climatic conditions.

Estimating potential evapotranspiration: the effect of random and systematic errors

Random and systematic errors, inherent in meteorological measurements, affect the values of variables used to estimate potential evapotranspiration ( ET p). A simulation approach was used to study the effect of the magnitude of those errors on daily ET p estimates over the course of a growing season. Previous attempts to quantify the effect of errors in those variables have been conducted using only 24 h of data. In this study, daily ET p was calculated with the Penman method using data collected at four locations in Nebraska during the 1985 growing season. These ET p values were compared to estimates made after introducing random and systematic errors to the input data. Errors in ET p estimates were progressively larger for errors introduced into the wind run, temperature, humidity, and radiation data leading to the conclusion that accuracy and calibration of humidity and radiation sensors is more critical than wind run and temperature in the Central High Plains of the U.S.

Preseason precipitation probabilities as an aid to corn planting decisions

An analysis of corn yield data from 5 countries and precipitation data from 5 representative locations in eastern Nebraska from a 58-year period 1925–1983 show that yields are above normal when the preseason season precipitation (1 September–15 May) is above average. Long term precipitation records of 80 or more years were used to determine the probability, at different times during a 75-day period prior to planting, that the preseason precipitation at planting time would be average or higher.

Persistence, Germinability, and Distribution of Jointed Goatgrass (Aegilops cylindrica) Seed in Soil

The persistence and germinability of jointed goatgrass (Aegilops cylindricaHost. # AEGCY) seed (caryopses) were studied over a five-year period between 1979 and 1984 at five locations in Colorado, Kansas, and Nebraska. Seed were buried in open-mesh packets and the sites were not disturbed for the duration of the study. Seed survival at burial depths of 5, 15, or 30 cm decreased rapidly over the first three years at all locations. By the third year, less than 7.4 ± 6.5% (mean ± SD) of the seed remained at 5 cm in the soil at all locations. By the third, fourth, and fifth year there was total loss of seed at one, two, and four sites at the 5-cm burial depth. Only three of five sites had total loss of seed at 30 cm after five years. The proportion of surviving seed that were germinable increased with time and was almost 100% after three years of burial. Because jointed goatgrass seed were relatively transient in the soil profile, fallowing of infested areas for a three-year period may significantly reduce populations of this weed or eradicate it, depending upon location.

Weed Seed Demise in Soil in Weed-Free Corn (Zea mays) Production Across Nebraska

An experiment was conducted at five locations in Nebraska to determine the extent of demise of weed seed in soil when seed production was eliminated from 1975 through 1979 in corn (Zea maysL.). Weed yields, weed seed production, and corn yields were determined under four weed management levels in 1980. Annual broadleaf weed seed were more prevalent than grass seed in cultivated soil throughout the study. The population of viable weed seed in soil declined 95% during the 5-yr period that weed seed production was eliminated. Weed seed buildup recovered to within 90% of the 1975 level during 1980 at Concord and Clay Center but remained low at Lincoln, North Platte, and Scottsbluff. Thus, seed longevity in soil was sometimes sufficient to withstand modern weed control methods and still reinfest a field after 5 yr of eliminating weed seed production. Corn yields were maintained 1 yr with minimum weed management effort following 5 yr of no weed seed production.

Effect of Fertilizer Phosphorus Placement Depth on Winter Wheat Yield

AbstractField studies were conducted with winter wheat (Triticum aestivum L. ‘Centurk 78’) at nine locations in southwestern, central, and eastern Nebraska in 1982 and 1983 to determine the effect of phosphorus (P) placement depth (0, 5, 10, and 15 cm). As a comparison to these depths, seed placed P, soil surface placed P, and no P treatments were used. A rate of 11 kg P ha−1 was applied. Soil great groups were either Argiustolls or Argiudolls with surface soil Bray and Kurtz no. 1 P levels ranging from 4 to 9 mg kg−1 and pH values ranging from 5.5 to 7.5. Grain yield was increased by added P in both years though magnitude of response varied at different locations. A linear and quadratic response to depth was evident in both years, though variation occurred between locations. Optium depths of P placement for maximum grain yield occurred at 11.9 cm in 1982 and 10.4 cm in 1983. No differences between either the best depth (10 cm) and seed treatments or the surface and seed treatments were found, indicating that, depending on management situations, these methods of P application could be used interchangeably. Total P uptake was increased by P applications in a manner similar to grain yield. Phosphorus uptake of the seed treatment and the best depth treatment at several growth stages (Feekes' stages 2.0, 6.0, 10.0, 10.5, and 11.4) was compared. An early advantage (stage 2.0) of the seed treatment was not evident at harvest, indicating that early P uptake is not necessary for maximum yield. The number of heads and seed weight were both increased due to applied P in both years and seed weight responded linearly to depth in 1982. No effect on the seed number per head was found.

Effect of Solar Azimuth and Infrared Thermometer View Direction on Measured Soybean Canopy Temperature1

AbstractMeasurements of radiative canopy temperature taken with infrared thermometers (IRTs) are strongly influenced by amount of crop cover and amount of viewed soil background. This influence can be minimized by making off‐nadir measurements so that mostly vegetative surface is viewed. But off‐nadir measurements vary with the relative azimuthal positions of the sun and the IRT due to the measurement of true variations in the individually sunlit and shaded canopy elements. The geometrical relationship between solar azimuth and IRT view azimuth on measured canopy temperatures was investigated for soybeans grown at two Nebraska locations in 1982. Soils at the two locations were a Typic Argiudoll and a Typic Ustipsamment. Canopy temperature as measured by the IRT declined linearly as the difference between the solar azimuth and IRT view azimuth increased from 0° to about 110°. As this difference increased to angles greater than 110°, the viewed canopy temperature remained fairly constant at about 0.30°C below the average of the canopy temperatures measured at the four cardinal directions. The declining linear relationship seen for angles between 0° and 110° was found to be more strongly defined during the vegetative growth stages than during the reproductive growth stages. This was attributed to declining heliotropic response of soybean [Glycine max (L.) Merr.] leaves as the canopy ages.

Field Corn, Corn Rootworm Larval Control, 1983

Abstract Soil insecticides to control larvae of the corn rootworm were evaluated at two locations in northeast Nebraska. Corn was planted on 9 and 13 May, Belden and Royal respectively. The Belden plots were nonirrigated and the Royal plots were irrigated with an overhead center pivot irrigation system. All treatments were applied in a 7-in. band over the row (1.2 oz (AD/1,000 ft row). Planting time treatments were incorporated with a six-prong harrow mounted on rear of applicator. Cultivation treatments were incorporated immediately by a tractor mounted cultivator. Each treatment consisted of one row 75 ft long replicated four times. Insecticide treatments were evaluated for root damage in late July by digging five equally spaced plants from each row (20 plants total per treatment) and rating the roots for rootworm feeding damage using a 1 to 6 damage scale (1, no damage; 6, three or more nodes of roots destroyed).

Protection of Grain Sorghum (Sorghum bicolor) from Chloroacetanilide Herbicide Injury

CGA-43089 [α-(cyanomethoximino)-benzacetonitrile] seed treatment was evaluated at three Nebraska locations during 1979 and 1980 for grain sorghum [Sorghum bicolor(L.) Moench] protection from injury by metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], four other chloroacetanilide herbicides, and three metolachlor +s-triazine combinations. Acetochlor [2-chloro-N-(ethoxymethyl)-6′-ethyl-o-acetotoluidide] caused the most frequent and severest injury to unprotected and protected sorghum. Soilincorporated metolachlor produced more consistent injury than preemergence application to unprotected sorghum, but placement did not affect CGA-43089 protection. Sorghum-stand reduction was the type of injury most frequently encountered, but crop yield was least affected. CGA-43089 always protected the grain sorghum from yield reduction with these herbicides.

Layby Herbicide Application for Season - Long Weed Control in Irrigated Corn (Zea mays)

Combinations of herbicides applied preplant incorporated and preemergence plus at layby were evaluated in corn (Zea maysL.) at three Nebraska locations in 1977 through 1980 for their effectiveness in providing season-long weed control. Pendimethalin [N-(1 -ethylpropyl) - 3,4-dimethyl - 2,6 - dinitrobenzenamine], pendimethalin + atrazine [2- chloro - 4 - (ethylamino) -6 - isopropylamino) -s- triazine ], metolachlor [2 - chloro -N- (2 - ethyl - 6 - methylphenyl) -N- (2 - methoxy -1 - methylethyl) acetamide], alachlor [2 - chloro -2′,6’ - diethyl -N- (methoxymethyl)acetanilide], cyanazine {2 -[[4 - chloro- 6 - (ethylamino) -s- triazin-2 - yl] amino] -2 -methylpropionitrile}, and cyanazine + atrazine were shown to be selective to corn and effective in controlling late - germinating weeds. Irrigated - corn yield was not increased by layby herbicide applications on the weed species and weed densities present in these experiments.

Housing Types in Webster County, Nebraska 1870–1920

Editor's Note: Due to the length of the article “Housing Types in Webster County, Nebraska 1870–1920,” and the decision by the editorial committee to publish it in its entirety, the introduction and section I & II are being printed in this issue. Part III and the conclusion will be printed in Vol. 8, Number 2, Fall 1982, of JIDER. We regret any inconvenience that this decision may bring to our readers. The first settlers arrived in Webster County, Nebraska in the spring of 1870. In recent years due to the current recognition of the early writings of Willa Cather (1873–1947), Webster County has come to stand as the prototype of the pioneer settlement of the plains. However, a casual look by the traveler at other Nebraska locations indicates that housing in Webster County is typical of early housing in other parts of the state. The original study of Webster County housing was partially funded by the Nebraska State Historical Society, The Center for Great Plains Studies and the patrons of the Webster County Historical Museum.