bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the EPIC Simulation Model Using a Dryland Wheat‐Sorghum‐Fallow Crop Rotation1
Authors: Steiner J. L. , Williams J. R. , Jones O. R. 
Published: July 2010

AbstractDryland cropping is extremely variable, and stability over time is important. Analysis of soil‐crop‐climate interactions using simulation models can expand dryland cropping research through extrapolation of experimental results across a range of soils, climates, and management practices and over longer time periods. The Erosion‐Productivity Impact Calculator (EPIC) simulates evapotranspiration (ET), runoff, plant growth, and related processes; but validation was needed for semiarid regions. Predicted ET, runoff, soil water, and crop yield were compared to data collected from 1958 to 1984 at Bushland, TX. Wheat (Triticum aestivum L.) and sorghum [Sorghum bicolor (L.) Moench] were grown on a Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll), with each crop grown each year. Predicted mean growing season ET, soil water depletion, and annual runoff were not significantly different from observed values. EPIC tended to underpredict high values of water balance components and overpredict low values, but predicted realistic distributions of values. Local calibration of the conversion factor of dry matter production from intercepted radiation was required for yield prediction of 1.3 and 2.7 Mg/ha for wheat and sorghum, respectively, which then did not significantly differ from observed values of 1.3 and 2.3 Mg/ha. EPIC was generally satisfactory in predicting the water balance over long periods of time, with means, standard errors, ranges, and probability distributions being similar for observed and predicted values. Satisfactory yield prediction required calibration to the location. Prediction of yield or water balance components for specific fields in specific years is not recommended.
Differences in Drought Resistance between Two Corn Hybrids. II. Component Analysis and Growth Rates1
Authors: Lorens G. F. , Bennett J. M. , Loggale L. B. 
Published: July 2010

AbstractRelatively little research has been conducted to evaluate differing responses to water stress among genotypes of the same species. The objective of this study was to identify differences in growth and development of plant parts resulting from water stress imposed on two corn (Zea mays L.) hybrids that had been observed to differ in their sensitivity to water stress. During 1983 and 1984, two corn hybrids (Pioneer Brands 3192 and 3165) were subjected to three water management treatments: optimal irrigation, rainfed, and stress during vegetative (1983) or early reproductive (1984) growth. Growth analysis revealed few differences between hybrids for leaf area index, and crop and seed growth rates when well‐watered or stressed during vegetative growth, except that hybrid 3192 showed more rapid early growth. When well‐watered, grain yield of hybrid 3192 was the same (1983) or higher (1984) than grain yield of hybrid 3165. However, the two hybrids differed in their ability to resist severe water stress. The greater grain yield of hybrid 3165 in the rainfed treatment was associated with relatively smaller reductions in crop growth rate, total biomass accumulation, seed number, effective filling period, and harvest index with stress when compared to hybrid 3192. The greater crop growth rate and final biomass and grain yield of hybrid 3165 during severe stress most likely resulted from the maintenance of higher leaf water and turgor potentials and lower leaf diffusive resistances that were apparently mediated by higher root length densities in deeper zones of the soil profile as described in a companion paper.
Effects of Alfalfa Proportions and Clipping Frequencies on Timothy‐Alfalfa Mixtures. II. Nitrogen Fixation and Transfer1
Authors: Ta T. C. , Faris M. A. 
Published: July 2010

AbstractThe inclusion of legumes in grass pastures often increases grass yields due to the contribution of the N fixed by the legume to the associated grass. This benefit was evaluated in field experiments under different management conditions at Ottawa, Ontario, Canada, on a Manotick mixed sandy loam soil (Typic Dystrochrett) labeled with 15N. Timothy (Phleum pratense L.) and alfalfa (Medicago sativa L.) were grown in pure stands and in mixtures at two proportions (1:1 and 1:2) and harvested at three alfalfa maturity stages (early, mid‐, and late bloom). Nitrogen fixed by alfalfa and N transfer from alfalfa to timothy were calculated from the differences between the isotopic compositions of the two species in mixture and timothy in pure stand. The highest amounts of N in alfalfa shoots originating from N fixed were 192 and 215 kg N ha−1 yr−1 in the first and second year, respectively, when harvested at mid‐bloom (four cuts). The inclusion of timothy in alfalfa stands increased the proportion of N fixed by alfalfa. Nitrogen transfer from alfalfa to associated timothy contributed up to 22% (first year) and 30% (second year) of the total N yield of timothy and amounted to up to 13 kg N ha−1 yr −1. This transfer increased with progressive cuts and with an increased proportion of alfalfa in the mixture. Growing alfalfa in mixture with timothy at a high proportion to timothy is an ideal system for maximum N transfer and for reducing N fertilizer usage.
Cabbage Plant Responses to Residual Phosphorus and Potassium in the Soil and to Band‐Applied Concentrated Superphosphate and Potassium Chloride Fertilizers1
Authors: Peck N. H. , MacDonald G. E. , Hemmat M. 
Published: July 2010

AbstractFertilization with P and K should be adjusted to supplement the available residual P and K in the soil to supply sufficient nutrients for crops. The objective of this study was to determine the responses of cabbage (Brassica oleracea (L.) Capitata group, cv. King Cole) plants to levels of residual P and K in the soil from previous applications of concentrated superphosphate (CSP) and potassium chloride (KCl) and to banded CSP and KCl fertilizers at planting. Cabbage plants were grown in a Honeoye fine sandy loam soil (fine loamy, mixed, mesic Glossoboric Hapludalf). Main plots were arranged in a factorial combination of four levels of residual P in the soil from CSP times four levels of residual K in the soil from KCl applied during 1963 through 1972. Banded fertilizer treatments of (i) no CSP or KCl, (ii) CSP, (iii) KCl, and (iv) CSP plus KCI were applied at planting time in each main plot in 1973 and 1985. At harvest, the yields of whole heads and of burst heads were measured and the concentrations of P, K, Cl, Na, Mg, S, N, Zn, Mn, Fe, and Cu in the heads were determined. Increasing the level of residual P in the soil increased the concentration of P from 3.0 to 3.8 mg g−1 dry weight in the heads in 1973, and from 2.6 to 3.4 mg g−1 dry weight in the heads in 1985. Increasing the level of residual K in the soil increased the concentration of K from 24 to 32 mg g−1 dry weight in the heads in 1973, and from 22 to 26 mg g−1 dry weight in the heads in 1985. Applications of KCl during 1963 through 1972 increased the concentration of Cl from 2.0 to 3.4 mg g−1 dry weight in the heads in 1973, but did not affect Cl in the heads in 1985. Increasing the level of residual P in the soil up to 30 kg ha−1 in 1973 and to 21 kg ha−1 in 1985 increased the yield of heads. Banded CSP increased the yield of heads at the lower levels of soil P but not at the highest level. Increasing the level of residual K in the soil or banded KCl fertilizer, or both, increased the yield of heads but also increased the percentage of burst heads. Heads of cabbage plants with the highest yield had concentrations of P and K of 3.2 and 30 mg g−1 dry weight, respectively, in the heads; however, a concentration of K of over 26 mg g−1 dry weight caused excessive burst heads.
Infuence of Calcium, Nitrogen, and pH on Alfalfa Root Growth and Nitrogen Fixation Using the Implanted Soil Mass Technique1
Authors: Rechcigl J. E. , Edmisten K. L. , Wolf D. D. , Reneau R. B. 
Published: July 2010

AbstractSoil acidity is a major growth‐limiting factor responsible for stunting roots, reducing forage yield, and limiting N2 fixation in alfalfa (Medicago saliva L.). The implanted soil mass technique was utilized to investigate the influence of subsurface amendments on root systems. It consisted of mixing a study soil with chemical treatments of interest, burying the mixture in mesh bags 15 cm below an existing alfalfa stand, removing the bags after 1 yr, and determining root mass and N2 fixation via acetylene reduction. A Tatum clay loam (clayey, mixed, thermic Typic Hapludult) soil with an initial pH of 4.4 and amended with either CaSO4, NH4NO3, CaSO4, + NH4NO3, KOH, or Ca(OH)2 was buried in the mesh bags, in an Ernest silt loam (fine‐loamy, mixed, mesic Aquic Fragidult) that had received either 0 or 6.7 Mg ha−1 of surface‐applied dolomitic limestone. After liming, the pH of the soil surface (0–5 cm) increased from 5.3 to 6.3. Surface liming increased the root mass in only the implanted soil mass receiving a Ca(OH)2 or KOH amendment and did so by 7.5‐ and fivefold, respectively. With the unlimed soil, only Ca(OH)2 increased root mass in the implanted soil mass. With the exception of Ca(OH)2, treatments had no influence on N2 fixation in the implanted soil mass. For the Ca(OH)2 amendment there was a fourfold increase in N2 fixation in the surface‐limed soil and a 20‐fold increase in the unlimed soil.
A Method for Evaluation of Salt Tolerance during Germination, Emergence, and Seedling Establishment1
Authors: McKimmie T. , Dobrenz A. K. 
Published: July 2010

AbstractSalinity is an increasing problem for irrigated agriculture, but few well‐defined methods exist for providing uniform, repeatable conditions to select plants for salt tolerance. A floodable planter box (salt box) was designed and used as a screening method for salt tolerance in alfalfa (Medicago sariva L.). The Salt box was used to screen over 100 000 seedlings. Vigorous plants were selected after 6 weeks growth in −0.8 MPa salinity (NaCl). This system provides a method to identify salt tolerant plant, and to test selections against other populations.
Application of Phosphorus and Sulfur on Irrigated Alfalfa1
Authors: Rehm G. W. 
Published: July 2010

AbstractLow nutrient supplies often limit crop production on irrigated sandy soils. Soils in the Sandhills region of Nebraska have a limited capacity to supply P and S to crops. This study was conducted to determine optimum application rates of P and S for intensive alfalfa (Medicago sativa L.) production and to determine the relationship between nutrient application rate and concentration of these nutrients in plant tissue. Seven rates of P were combined with seven rates of S in a central composite factorial design with three replications. Treatments were broadcast and incorporated into a Typic Ustipsamment prior to seeding in August 1978. Applications were repeated on the established stand in the early spring of 1980, 1981, and 1982. Dry matter yields were recorded in four cuttings each year. Whole plant samples were taken from each harvest and analyzed for P and S. Except for 1982, alfalfa yield increased curvilinearly with the application of both P and S, but there was no significant interaction between these nutrients. In 1982, there was no response to applied S, but the response to P was curvilinear. Rates of 44 kg P ha−1 and 56 kg S ha−1 were needed for maximum production. The P concentration in the tissue increased with the rate of applied P, while fertilizer S had no consistent effect. The S concentration in the tissue increased with the rate of applied S. Sulfur concentration decreased as the P rate increased. This reduction was attributed to plant dilution effects. Concentrations of both P and S were near reported critical values when rates of P and S needed for highest yield were applied.
Optimizing Row Spacing and Seeding Rate for Soft Red Winter Wheat
Authors: Johnson J. W. , Hargrove W. L. , Moss R. B. 
Published: July 2010

AbstractIntensive management practices, such as high fertility, fungicides, and plant growth regulators, have substantially increased grain yield of soft red winter wheat (Triticum aestivum L.) in the northeastern and mid‐Atlantic USA. Our objective was to determine the effects of row spacing and seeding rate on grain yield and yield components of several cultivars in a high‐yield environment in the southeastern USA. Five cultivars, Coker 916, Coker 983, Hunter, Florida 301, and Florida 302, were grown during 1985 and 1986 on a Greenville sandy clay loam (clayey, kaolinitic, thermic Rhodic Paleudult) in row spacings of 0.10 and 0.20 m at seeding rates of 288 and 576 seeds m−2. Management practices included a high rate of fertilizer‐N (176 kg ha−1) in multiple applications, fungicide and plant growth regulator applications, irrigation, and adequate levels of P, K, S, and Mg. Grain yields ranged from 3.9 to 6.3 Mg ha−1 and averaged 5.0 Mg ha−1. Narrow row spacing (0.10 m) yielded 0.4 Mg ha−1 or about 8% greater than the 0.20‐m spacing. Grain yield was not influenced by seeding rates when averaged over years. Number of spikes per square meter was the yield component most affected by row spacing and seeding rate. Neither the cultivar × row spacing nor cultivar × seeding rate interaction for grain yield was significant. Therefore, new cultivars should react similarly to those studied here.
Corn Hybrid Responses to Reconstructed Mine Soils in Western Illinois
Authors: Dunker R. E. , Jansen I. J. , Pedersen W. L. 
Published: July 2010

AbstractFederal law requires that surface‐mined prime farmland be reclaimed and restored to productivity for row crops equivalent to that present before mining (Surface Mining Control and Reclamation Act, 1977. Public Law 95‐87. U.S. Code Vol. 30, Sect. 1265). Success of reclamation of such cropland shall be determined on the basis of crop production from the mined area compared to an approved reference area or other technical guidance procedure (Surface Coal Mining Land Conservation Act, 1981. Illinois Public Act 81‐1015). The objective of this study was to evaluate a wide range of corn (Zea mays L.) genotypes grown on mined land compared to corn grown on an adjacent natural soil. Forty corn hybrids in 1984 and 38 hybrids in 1985, with 29 hybrids being common to both years, were planted on two reclaimed soils and an undisturbed tract. The two mine soils consisted of: (i) 45 cm of topsoil replaced over graded wheel spoil, and (ii) graded wheel spoil only. Both soils are Typic Udorthents. A nearby tract of Sable soil (fine‐silty, mixed, mesic Typic Haplaquoll) was used as the unmined comparison. Results indicate that hybrid yield variation is associated more with weather variation on mine soils than on the undisturbed Sable soil. Pollination dates were delayed, and yield potential varied among hybrids grown on these disturbed soils. Those hybrids with the highest yield potential on the Sable soil did not necessarily produce the highest yields on the disturbed soils. No significant yield response to topsoil replacement was observed for any hybrid in 1984, and only one hybrid had a significant positive response and two hybrids responded negatively to topsoil replacement in 1985.
Growth and Composition of Grain Sorghum with Limited Nitrogen
Authors: Lafitte H. R. , Loomis R. S. 
Published: July 2010

AbstractA study of N fertilization of grain sorghum [Sorghum bicolor (L.) Moench] was conducted in two fields on a Typic Xerorthent with contrasting patterns of N availability, to extend our understanding of how the partitioning of N to vegetative parts and to structural biomass influences grain yield and N‐use efficiency. The study was supported by detailed analyses of N and dry matter distribution, and proximal analyses of biochemical composition. Nitrogen accumulation differed greatly, but the patterns of N partitioning and the structural carbohydrate content of vegetative parts at equivalent developmental stages were little affected. Changes in dry weight partitioning among vegetative parts were primarily a result of the parts' differential abilities to store nonstructural compounds. In contrast, the structural carbohydrate content of panicles was affected by N availability. Low N supply resulted in leaves with a smaller N content, and lower light conversion efficiency was observed. In addition, those canopies were not able to supply as much N to panicle growth. Roughly two‐thirds of the observed effects of N deficiency on grain yield were due to structural limitations to growth; the remaining effects were associated with reduced conversion efficiency per unit leaf area.
Switchgrass and Big Bluestem Responses to Amendments on Strongly Acid Soil
Authors: Jung G. A. , Shaffer J. A. , Stout W. L. 
Published: July 2010

AbstractNative perennial warm‐season grasses are established and used in the northeastern United States for beef cattle (Bos taurus) production, wildlife habitat, and soil conservation. This research was conducted in Pennsylvania to study select plant growth responses and forage quality of switchgrass (SWG), Panicum virgatum L., and big bluestem (BBS), Andropogon gerardii Vitman, to dolomitic lime, and P and N fertilizers on strongly acid, fine‐loamy, mixed, mesic, Typic Fragiaqualfs. The soil amendments were applied after the first growing season. Growth of SWG and BBS was markedly improved by topdressings of lime and N fertilizer. In 1981 and 1982, untreated warm‐season grass yielded approximately 50%, and grass receiving the low rate of applied nutrients yielded 90%, of that with the high lime and fertilizer rate (8.76 Mg ha−1). Nitrogen fertilizer increased production of stems and leaf sheaths more than leaf laminae. Crude protein concentration (CPC) of both species generally was low, but N fertilizer increased CPC from 52 to 77 g kg−1. In vitro dry matter disappearance values were low, but significant species X N, lime X N, species X lime X N, and N X year interactions occurred. Lime effects were significant for concentrations of Ca, Mg, and Mn; P fertilizer for Ca, Mg, and P; and N fertilizer for Ca, Mg, P, and Mn. Aluminum concentrations in forage were low even with an exchangeable soil Al of 100 kg ha−1. Approximately 80% of the root mass of each species was within the top 10 cm of soil, but roots were observed growing along prism faces of the fragipan at 60 cm. The warm‐season grasses were productive on strongly acid (31 Mg lime ha−1 needed for neutralization), infertile soil, with low inputs of lime (4.5 Mg ha−1) and fertilizer.
Functional Boron Requirement for Leaf Expansion and Its Use as a Critical Value for Diagnosis of Boron Deficiency in Soybean
Authors: Kirk G. J. , Loneragan J. F. 
Published: July 2010

AbstractThe slow response of shoot dry matter to nutrient stress under many experimental conditions sometimes makes it an unsatisfactory criterion for defining critical concentrations of nutrients for deficiency diagnosis by plant analysis. This study was done to see if the relationship between the B concentration in young leaves and their rate of elongation could be used to define critical values for diagnosis of B deficiency in soybean [Glycine max (L.) Merr.] Soybean was grown in nonrenewed solution culture at two initial B concentrations chosen so that plants at the lower concentration became deficient during the growing period, while those at the higher B concentration remained healthy. Boron deficiency depressed dry matter (DM) of roots and young leaves but increased DM of older, expanded leaves, thus delaying the response of total shoot DM to B deficiency. As B supply became depleted, B concentrations in young leaves declined rapidly from 20 to 3 mg kg−1 DM, giving falsely low values for diagnosis of B deficiency when correlated with shoot DM. The rate of elongation of young expanding leaflet blades was depressed by B deficiency earlier than shoot DM. Correlation of B concentration in young leaves with their elongation rate suggests that they require 12 mg B kg−1 DM to achieve 90% of their maximal rate. It is suggested that this value represents the functional B requirement for leaf expansion and that it provides a more consistent and accurate critical value for diagnosis of B deficiency in soybean than that determined by correlation with shoot DM in the usual way.
Evaluation of Soil Fertility in Some Prehistoric Agricultural Terraces in New Mexico
Authors: Sandor J. A. , Gersper P. L. 
Published: July 2010

AbstractA greenhouse study was conducted to evaluate the fertility of some prehistorically terraced soils in New Mexico that were cultivated sometime between 1000 and 1150 A.D. and then abandoned. The impetus for this study was a finding that these soils still show the effects of cultivation nearly 900 yr after farming ceased. Soil changes, inferred by comparison with nearby uncultivated but otherwise similar soils, were mainly degradative, including accelerated erosion, compaction, and losses of organic matter and nutrients such as N and P. A traditional crop (Chapalote corn, Zea mays L.) and a standard test plant (barley, Hordeum vulgare L.) were grown for 28 d in samples of prehistorically cultivated and uncultivated soil, using a check and up to five fertilizer treatments: NPKS, PKS, NKS, NPS, and NPK. Fertility was assessed with measurements of plant growth and by chemical analyses of soils and whole plants. Results indicated that differences in plant growth and composition were associated with soil differences. For example, corn dry weights were about 45% lower in cultivated soils for the check and PKS treatments, and cultivated soils averaged 39% lower in total N relative to uncultivated soils. However, the opposite trend occurred in the NKS treatment because of lower available P in the uncultivated soil. Manganese uptake was greater in corn grown in cultivated soil. Corn dry weights were not significantly different between soils with the NPKS treatment. The five to ten times increase in plant dry weights in the NPKS versus PKS treatment indicates that N is the main limiting nutrient in the cultivated soil. The strong response of barley to N fertilization and comparison of dry weights to those obtained from similarly tested modern cultivated soils suggest that the soils used for prehistoric agriculture are potentially productive by modern agricultural standards.
Frequency of Fertilizer Applications and Centipedegrass Performance
Authors: Johnson B. J. , Carrow R. N. 
Published: July 2010

AbstractCentipedegrass [Eremochloa ophiuroides (Munro) Hack.] is a low maintenance grass widely used throughout the southeastern United States. Improper fertilization continues to be a major concern and results in Centipedegrass decline. With low fertilization, the grass has a pale green color that is often unacceptable to many turfgrass managers. This research was initiated to determine the influence of frequency of annual fertilizer treatments on turfgrass quality. Treatments were arranged in a split plot design with frequency of annual fertilization treatments as main plots and N rates as subplots. Soil type was a Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludult). The quality of Centipedegrass treated with 50 kg N ha−1 in April and repeated at the same rate in July for a total rate of 100 kg ha−1 was equal to or better than that from a single application of 100 kg N ha−1 in April. Centipedegrass quality from split applications (April + July) was also equal to or better than that when a total of 100 kg N ha−1 was split into three or four equal applications over the growing season. The exception occurred in September in 2 of 4 yr when the quality of Centipedegrass was better when N was applied in three and four annual applications. Centipedegrass decline measured by quality and stand density occurred in plots treated with 100 kg N ha−1 in April after 3 and 4 yr of consecutive applications. Decline was not evident when N was applied annually at 100 kg ha−1 in split applications. At 0 kg N ha−1 yr−1 Centipedegrass failed to provide sufficient growth to maintain an acceptable stand. Also, after two consecutive years without N applications, centipedegrass quality declined, which indicates that some N is necessary every year.