bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corn and Soybean Yield Response to Crop Residue Management Under No‐Tillage Production Systems1
Authors: Wilhelm W. W. , Doran J. W. , Power J. F. 
Published: July 2010

AbstractCrop residues (stover) have many potential uses by society: food, feed, shelter, fuel, and soil amendment. Use of residues for purposes other than as a soil amendment may have serious negative consequences on crop productivity. This study was conducted to investigate the yield response of continuous corn (Zea maysL.) and continuous soybean [Glycine max(L.) Merr.] to removal or addition of crop residues under no‐tillage management. The study was conducted near Lincoln, NE, on a Crete‐Butler silty clay loam (fine, montmorillonitic, mesic Pachic Arguistoll‐Abruptic Argiaquoll) with 1 to 2% slope. Crop residue was collected and weighed immediately after harvest in autumn. Quantity of residue to be returned to each treatment (0, 50, 100, or 150% of that produced) was calculated and uniformly spread over the plot area (12.2 by 12.2 m) by hand. Corn and soybean were planted into the established residue levels with no tillage the following spring. Data were collected on soil water, soil temperature, and grain and residue yield. A positive linear response was found between grain and stover yield and amount of residue applied to the soil surface. Each Mg ha−1of residue removed resulted in about a 0.10 Mg ha−1reduction in grain yield and a 0.30 Mg ha−1reduction in residue yield. Quantity of applied residue accounted for 81 and 84% of the variation in grain yield of corn and soybean, respectively, and 88 and 92% of the variation in residue yield. Amounts of stored soil water at planting were closely associated with quantity of residue applied the previous year. Differences in total available water (soil storage at planting plus rainfall) accounted for approximately 70% of the yield variation associated with the residue treatments. Soil temperature (50‐mm depth) and total available water accounted for nearly the same amount of variation in yield (80 to 90%) as quantity of residue, emphasizing the importance of these factors in evaluating response of crops to residue‐management practices. Residue removal reduced grain and residue yields by amounts equal to 10 and 30%, respectively, of the quantity of residue removed. Residue effects on crop yield were induced mainly through changes in soil water and soil temperature.
Interactive Effects of Nitrogen and Water Stresses on Water Relations of Field‐Grown Corn Leaves1
Authors: Bennett J. M. , Jones J. W. , Zur B. , Hammond L. C. 
Published: July 2010

AbstractWater and N stresses often limit corn (Zea maysL.) grain yields. Although the effects of either water or N stress on crop growth and development, physiology, and yield have been widely studied, relatively little information is available on the interactive effects of these stresses when imposed in combination. The objective of this study was to define and evaluate the interactive effects of water and N stresses on leaf water potential components, transpiration rate, and stomatal resistance of field‐grown corn leaves. Corn grown on a Kendrick fine sand soil (loamy, siliceous, hyperthermic Arenic Paleudult) was subjected to two water management treatments (optimal irrigation, and a 10‐day water stress period, which immediately preceded 50% silking). Within each water management treatment, two N levels (low, 62 kg ha−1; high, 275 kg ha−1) were imposed. During the water stress period, both midday and diurnal measurements of leaf water potential (ΨL)leaf osmotic potential (Ψτ), leaf turgor potential (ΨP), leaf transpiration, and leaf diffusive resistance were determined on combinations of the water and N stress treatments. Although high‐N plants attained similar or slightly lower ΨLthan low N plants as a result of the water stress, high‐N plants maintained lower stomatal resistances at the lower ΨL. High‐N plants also extracted more water from depths below 0.3 m in the soil profile compared with the low‐N plants. Lower Ψτas ΨLdeclined resulted in higher ΨPin high‐N plants, which was probably responsible for the lower stomatal resistances and higher rates of transpiration that were observed. Lower Ψπof the water‐stressed, high‐N plants could have resulted in the more efficient extraction of water from the soil profile. We conclude that the high‐N plants were affected less by the water stress than low‐N plants as evidenced by the maintenance of ΨPopen stomata, and higher rates of individual leaf transpiration despite similar reductions in ΨLduring periods of low soil water availability.
Plant Height and Yield Responses of Rice to Paclobutrazol1
Authors: Street J. E. , Jordan J. H. , Ebelhar M. W. , Boykin D. L. 
Published: July 2010

AbstractLodging of rice decreases speed and efficiency of mechanical harvest of rice (Oryza salivaL. ‘Starbonnet’). A 3‐yr field study was conducted at Stoneville, MS, on a Sharkey clay soil (Vertic Haplaquept) to determine if rice height and lodging could be reduced with a growth regulator. Paclobutrazol [(2RS,3RS)‐1‐(4‐chlorophenyl)‐4,4‐dimethyI‐2‐1,2,4‐triazol‐1‐yl‐)penta‐n‐3‐ol)] was applied at 0.14 and 0.28 kg a.i./ha 2 weeks before or 2 weeks after panicle initiation, and at 0.07, 0.14, and 0.28 kg a.i./ha at panicle initiation. Application of 0.28 kg a.i./ha of paclobutrazol 2 weeks after panicle initiation reduced rice height each year and increased rough rice yield in 2 of 3 yr. Lodging, which occurred in only 1 of 3 yr, was significantly decreased with 0.28 kg a.i./ha of paclobutrazol applied either at panicle initiation or 2 weeks after panicle initiation. Increasing preflood N rates to 168 kg N/ha plus applications of paclobutrazol did not consistently increase yields
Estimation of Aerodynamic and Crop Resistances from Canopy Temperature1
Authors: O'Toole J. C. , Real J. G. 
Published: July 2010

AbstractPrevious reports illustrated two methods of interpreting canopy minus air temperature (Tc— Ta). The first was empirically based on linear regression of Tc— Taon air water vapor pressure deficit (VPD) and appeared to illustrate crop specific characteristics. The second approach was an energy balance equivalency for Tc— Tain which the crop parameters aerodynamic (ra) and canopy resistance (rc) were the primary crop specific components. From a crop physiology perspective, the previous reports provided an opportunity to couple crop specific physiological and micrometeorological parameters. Using data obtained from irrigated field plots in Arizona, California, and Philippines, we evaluated both approaches and tested a solution for the merger of the empirical and energy balance concepts. Briefly, the regression statistics from the regression of Tc— Taon VPD were substituted into the energy balance allowing a mean value of ra(r̄ap) and rc(r̄cp) to be estimated given conditions of potential evapotranspiration by the crop canopy. Estimation of the mean resistances are illustrated for nine crop species with r̄apanr̄cpranging from about 5 and 14 s m−1for rice (Oryza sativaL.) to 16 and 69 s m−1for fig tree (Fiscus CaricaL.). Trends in r̄apand r̄cpwere related to ecophysiological adaptation of the different species as well as phenological changes. Four growth stages of a rice crop showed increased r̄cpassociated with postanthesis senescence of panicles and leaves in the canopy. The combination of empirical regression and energy balance approaches assists in our understanding and interpretation of Tc— Ta. It also provides a means of estimating species specific values of rcand ranecessary to more fully exploit the energy balance based assessment of Tc— Ta.
Leaf Area Development in Field‐Grown Maize1
Authors: Dwyer L. M. , Stewart D. W. 
Published: July 2010

AbstractLeaf area is important for crop light interception and therefore has a large influence on crop yield. In this study, a method was devised to characterize and predict the development process of maize (Zea maysL.) leaf area by separating the process into time of appearance of each mature leaf (leaf stage) and leaf area of each mature leaf (leaf expansion). Leaf area was measured for several years on each of two soil types [a sandy loam of the Uplands association (Typic Haplorthod) and a clay of the Dalhousie association (Typic Haplaquoll)] at Ottawa, Canada. Analysis of field data indicated that leaf stage was highly correlated with growing degree days (base temp of 10°C) accumulated from planting (r= 0.98). However, air temperature alone did not account for the annual variability in leaf area of mature leaves. To separate leaf expansion from leaf stage, mature area per leaf was plotted as a function of leaf number. The resultant curve had a slightly skewed bell shape whose amplitude represented the leaf area of the largest leaf. When these curves were normalized with respect to their amplitudes they varied little from year to year. The amplitudes compared well (r=0.87) to plant‐available water averaged from planting to development of the largest leaf and the sum of minimum daily temperature for the same period. Total mature plant leaf area for each year was then calculated by multiplying the integration of the normalized bell shaped curve times the amplitude calculated by the regression equation. These calculated total mature plant leaf areas were used to normalize total plant leaf areas (expanding plus mature leaf area in the absence of senescence). The normalized plant leaf areas were expressed as an S‐shaped logistic function of growing degree days and total plant leaf areas were calculated over each growing season. An additional relationship related water deficit during growth to senescence and the amount of leaf area senesced was subtracted from total plant leaf areas to obtain actual plant leaf area. Estimates of actual plant leaf area for the six growing seasons used to develop the method compared well with measured values (rbetween 0.94 and 0.99). Estimates of actual plant leaf area for two independent years at the same location were also good (r=0.91 and 0.97). This approach reduces prediction of maize leaf area to relatively simple functions of temperature and available water.
A Thermogradient Incubator for Seed Germination Studies1
Authors: Mohapatra S. C. , Johnson W. H. 
Published: July 2010

AbstractMultiple temperature regimes in seed germination and seedling development studies are usually obtained with the use of several isothermal incubators. A thermogradient incubator measuring 15 by 36 by 54.5 cm and weighing less than 20 kg was built from 6.3‐mm thick aluminum sheet. It was heated electrically at the top and cooled by circulating water at the bottom. It contained 12 equidistant (2.5 cm) sample compartments separated by fixed shelves. Each shelf supported a removable tray to accommodate a row of three standard petri dishes. The mean temperature gradient along the sample compartments (but excluding the cooling and heating compartments) was linear at all temperature differentials (ΔT) tested. Settings for maximum heating at the top shelf and cooling at the bottom shelf gave approximately 54° and 0°C, respectively, thus giving a ΔT of 54°C across the 12 sample compartments. With these settings, temperature cycling with time and temperature nonuniformity within a given shelf was higher for warmer (upper) shelves but negligible for cooler (lower) shelves. However, temperature cycling in the upper shelves was minimized by selecting smaller temperature differential(s). In addition to being more portable and less expensive than other reported devices, the incubator occupies less space and permits the use of standard petri dishes or paper towels in triplicates. Construction specifications for the thermogradient incubator are provided.
Sulfur Fertilization Effects on Winter Wheat Yield and Extractable Sulfur in Semiarid Soils1
Authors: Rasmussen P. E. , Allmaras R. R. 
Published: July 2010

AbstractWinter wheat (Triticum aestivumL.) yield response to sulfur (S) in semiarid climates is inconsistent on coarse‐silty, mixed mesic haploxerolls containing < 2.0 mg extractable S kg −1in the upper 0.6 m of soil. To develop more efficient S fertilization practices, we determined the initial and residual grain yield, S uptake, and extractable soil S response to 7,14,28, and 42 kg S ha −1applied as gypsum at three wheat/fallow sites and residual response to 270, 540, 810, and 1570 kg S ha 1at an annual crop site. Applied S increased grain yield at one of the three wheat/fallow sites. Maximum yield at this site was always > 3.5 Mg ha −1, whereas yield at the nonresponding sites was < 2.6 Mg ha 1. Residual S at the annual crop site increased grain yield in 10 of 16 yr, with increases occurring at yields < 2.0 Mg ha 1. Maximum yield increase was obtained with 14 S ha −1. The 14 kg S ha 1application supplied adequate S to a second, and the 28 and 42 kg ha 1applications, to a third wheat crop, even though increased extractable S from 14 kg S ha 1was not detectable in the upper 0.6 m of soil at seeding of the second crop, and residual from 28 and 42 kg S ha 1not detectable at seeding of the third crop. Periodic soil sampling at the S‐responsive site indicated progressive downward movement of S to at least 1.8 m within 4 yr. Substantial leaching of S was suggested for both annual crop and wheat/fallow systems, with partial retention in calcic horizons when present in the soil profile.
Influence of Harvest Frequency and Season on Bermudagrass Cultivar Yield and Forage Quality1
Authors: Holt E. C. , Conrad B. E. 
Published: July 2010

AbstractDigestibility of bermudagrass [Cynodon dactylon(L.) Pers.] decreases with age and varies during the growing season, but cultivar responses are not well documented. Five cultivars of bermudagrass (‘Coastal’, ‘Callie’, ‘Tifton 68’, ‘S‐16’, and ‘S‐83’), representing a wide range in digestibility, were grown in replicated plots at College Station, TX on a fine, loamy, mixed, thermic Typic Udifluvent soil and harvested at 14‐, 28‐, 42‐, and 56‐day intervals for 2 yr to determine responses to harvest frequency and seasonal trends in digestibility. Forage was separated into leaf and stem tissue to determine leafiness the first year and also analyzed for dry matter digestibility both years using the in vitro fermentation technique (IVDDM). Coastal produced significantly more forage than the other cultivars, but was the lowest in IVDDM. Total annual forage yield increased 0.15 Mg ha 1for each day of advancing age at harvest > 14 days of age, total yields being 58% higher when harvested every 56 days than when harvested every 14 days. Both IVDDM and leafiness declined with advancing age, 56‐day‐old forage having 89 g kg 1less digestibility and 180 g kg−1less leaf content than 14‐day‐old forage. Leafiness closely correlated to age of forage at harvest but not to IVDDM within specified ages. One cultivar (S‐83) tended to increase in yield more rapidly and to decrease in IVDDM less rapidly with advancing age than the other cultivars. The rate of decline (average of all cultivars) in forage IVDDM was 2 g kg 1of dry matter for each day of advancing age between 14 and 56 days. Forage IVDDM declined from spring to early summer, independent of age at harvest and somewhat independent of leafiness. Young forage increased in IVDDM after midsummer. Results of this study suggest that cultivars of bermudagrass can be selected for higher forage digestibilities. However, cultivars with higher digestibility tend to follow the same pattern as Coastal, which is a decline in digestibility with increasing age and advancing season.
Yield and Grain Quality Responses of Soft Red Winter Wheat Exposed to Ozone During Anthesis1
Authors: Mulchi C. L. , Sammons D. J. , Baenziger P. S. 
Published: July 2010

AbstractSix soft red winter wheat (Triticum aestivum L.) cultivars were exposed to a simulated air pollution episode during anthesis in field studies conducted during 1979 and 1980. The air pollution treatments equaled 23 ± nL L−1, 47 ± 10 nL L−1 (ambient) and 123 ± 4 nL L−1 ozone for 4 h day−1 for 5 days in May. The primary objectives were to examine the effects of air pollution episodes along the mid‐Atlantic states during wheat pollination in May on yields and grain quality characteristics. Plant characteristics examined included total plant dry weights, grain weights, harvest index, seed set, seed weight, grain protein contents, particle size index, and alkaline water retention capacity. Environmental conditions in 1979 favored greater plant productivity than in 1980 and significant (P≤0.05) year effects were observed for four of eight characteristics examined. Also, ozone treatment responses were greater in 1979 than in 1980. Significant (P≤0.05) ozone treatment effects were observed for seven of eight characteristics and significant year ✕ treatment interactions were found for all eight variables. Although significant cultivar differences were noted for all eight variables, the only significant treatment ✕ cultivar interactions found were for grain weights, harvest index, and seed weights. The results further suggest that multiple environments should be considered and grain quality characteristics should be examined in addition to yields and yield components when evaluating responses among wheat cultivars to ozone stress.
Climatic Change, Weather Variability, and Corn Production1
Authors: Thompson Louis M. 
Published: July 2010

AbstractA crop/weather model was used to determine the impact of changes in climate and weather variability on corn (Zea mays L.) production from 1891 to 1983. Five Corn Belt states, Illinois, Indiana, Iowa, Missouri, and Ohio, were included in the study. These states produce over 50% of the U.S. corn crop. A cooling trend from 1930 to 1972 was accompanied by increasing rainfall in July and August, and by decreasing weather variability. These three factors were favorable for corn yield increase. Simulated corn yields, calculated from weather data, increased 970 kg ha−1 from 1930 to 1972 because of improved weather for corn. After 1972 there was greater weather variability and higher intensity rainfall events. Fertilizer use on corn increased substantially in the 1960s and increased at slower rate after 1972. The annual increase in corn yield with normal weather after 1972 was less than half as much as it was from 1960 to 1972. Highest yields of corn have been associated with normal preseason precipitation, normal June temperature, below normal temperature in July and August, and above normal rainfall in July and August. The period after 1970 was expected to warm but weather variability has masked the identification of a trend.
Response of Spring Wheat, Barley, and Oats to Chloride in Potassium Chloride Fertilizers1
Authors: Fixen P. E. , Gelderman R. H. , Gerwing J. , Cholick F. A. 
Published: July 2010

AbstractCereal grain yield response to KCI fertilization has been reported on high K‐testing soils in the Northern Plains. Other field studies have demonstrated that wheat (Triticum aestivum L.) yield increases to CI fertilization occurred where disease incidence was high. Therefore, field experiments on high K‐testing soils were conducted over a 3‐yr period to determine the responsiveness of spring wheat, barley (Hordeum vulgare L.), and oats (Avena sativa L.) to KCI fertilization and to determine whether responses were due to K or to Cl. Experiments were conducted on soils representing Typic Argiustolls, Pachic Udic and Udic Haploborolls, and Pachic and Udic Haplustolls in eastern South Dakota. Spring wheat, barley, and oats showed grain yield increases (0.10 probability level) at four out of six, three out of six, and zero out of five sites, respectively, on soils that tested very high in ammonium acetate‐extractable K. Wheat grain yield increases varied form 0.2 to 0.5 Mg ha−1. Comparison of KCI, KNO3, and CaC12 treatments, soil analysis, and plant analysis all indicated that the yield increases on very high K‐testing soils were due to the CI in the KCI and not due to the K. Six additional wheat experiments were conducted to determine the influence of starter K and CI (applied with seed) on grain yield; however, no yield increases to CI were detected in these studies. Both KCI and KNO3 at a 20 kg K ha−1 rate significantly decreased yield at one of six sites. Other experiments showed that if sufficient CI was present in the soil or broadcast applied, no additional benefit to seed placed CI occurred. Generally, broadcast and seed placed KCI appeared equally effective. However, rates required for maximum yield at several sites were too high to be placed in direct seed contact with drill application due to potentially adverse salt effects. Grain yield increases were large enough to make KCI fertilization of these soils very economical, provided responsive sites could be predicted.
Dryland Grain Sorghum Water Use, Light Interception, and Growth Responses to Planting Geometry1
Authors: Steiner J. L. 
Published: July 2010

AbstractCrop yields are primarily water‐limited under dryland production systems in semiarid regions. This study was conducted to determine whether the growing season water balance could be manipulated through planting geometry. The effects of row spacing, row direction, and plant population on the water use, light interception, and growth of grain sorghum [Sorghum bicolor (L.) Moench] were investigated at Bushland, TX, on a Pullman clay loam (fine, mixed, tbermic Torrertic Paleustoll). In 1983, which had a dry growing season, narrow row spacing and higher population increased seasonal evapotranspiration(ET) by 7 and 9%, respectively, and shifted the partitioning of ET to the vegetative period. Medium population crops yielded 6.2 and 2.3 Mg/ha of dry matter and grain, respectively. High population resulted in high dry matter (6.1 Mg/ha) and low grain yield (1.6 Mg/ha), whereas low population resulted in low dry matter (5.4 Mg/ha) and high grain yield (2.3 Mg/ha). Row direction did not affect water use or yield. In 1984, dry matter production for a given amount of ET and light interception was higher in the narrow‐row crops. Evapotranspiration was less for a given amount of light interception in the narrow‐row crops and in the north‐south row crops. Narrow‐row planting geometry appears to increase the partitioning of ET to the transpiration component and may improve the efficiency of dryland cropping systems.