bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maize and Sorghum Simulation in Diverse Texas Environments
Authors: Kiniry James R. , Bockholt Anton J. 
Published: July 2010

AbstractCrop models for decision making should accurately simulate grain yields across a wide range of soils and climate regimes. This study was designed to evaluate two models' ability to simulate plot grain yields under diverse weather conditions and soils in Texas. The objective was to compare measured grain yields of maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] with grain yields simulated by the ALMANAC (Agricultural Land Management Alternatives with Numerical Assessment Criteria) model and to compare measured maize yields with grain yields simulated by a new version of the CERES‐Maize (Crop‐Environment Resource Synthesis) model. Using yield performance trials, both models were tested for their ability to simulate the mean yield for five years at each location and their ability to describe year‐to‐year variability in measured yields. Both models were tested at nine locations for maize and ALMANAC was tested at eight locations for sorghum. Model inputs included parameters for the soil type, planting dates, planting rates, and locally measured weather data. Mean simulated grain yield for each site was within 10% of the mean measured grain yield for all cases, except for CERES at Thrall, where mean simulated yield was 13% lower than mean measured yield. When the models did not account for a significant amount of the year‐to‐year variability in measured grain yield at a site, it was usually due to the narrow range of measured grain yields. The soils, weather, and crop parameter data sets developed here can be useful starting points for deriving data at similar sites, giving model users examples of realistic input data.
A Database for Agroecological Research Data: I. Data Model
Authors: van Evert Frits K. , Spaans Egbert J. A. , Krieger Scott D. , Carlis John V. , Baker John M. 
Published: July 2010

AbstractData from agroecological experiments are typically stored in a collection of minimally documented computer files, with additional information entered into field or lab books. As a result of this fragmentation of data and lack of proper documentation, information may be lost and data manipulation is generally cumbersome, error‐prone, and hard to automate. Modern database technology has the potential to resolve these issues. Storing experiment data in a database solves the problem of fragmentation because all data are in the database; the problem of documentation is solved by making the relations between different items of information explicit during the design of the database; and the problem of manipulation is solved by the powerful query languages available with modern database management systems. As a first step in the construction of a generally applicable database for use in agroecological research, we used a formal method to design a data model that explicitly describes the types of information (‘entities’) one may want to remember about experiments and the relationships between these entities. The data model described here consists of 40 entities and 54 relationships. The entities are classified in five categories: (i) experiments, including statistical design; (ii) objects on which measurements are made; (iii) measurement protocol and equipment; (iv) measurements; and (v) field operations. We describe in detail how the information from several common types of measurements is stored using the proposed data model and conclude that the data model adequately describes the information that scientists in agroecological disciplines need to remember about their experiments.
A Database for Agroecological Research Data: II. A Relational Implementation
Authors: van Evert Frist K. , Spaans Egbert J. A. , Krieger Scott D. , Carlis John V. , Baker John M. 
Published: July 2010

AbstractWith the goal of creating a generally applicable database for agroecological research data, we developed and described a data model. The objective of the present work was to determine the practical usefulness of a database implemented from that data model. We used a commercially available relational database management system and mapped the entities of the logical data structure to tables, entity attributes to table columns, and entity relationships to foreign keys. The attributes of the entity representing measurement values were distributed over two tables, both to reduce the size of the database and to reduce the response time of queries involving this entity. We found that loading data into the database was the most significant hurdle to its use, and so developed a set of stored procedures that function as a data input language. The input language and other methods were used to load the data from an intensively monitored, multisite, multiyear experiment into the database. The database was used to manage, explore, and analyze the data from these experiments, as well as to share the data between collaborators and with others in an effective way. We conclude that a database implemented from the previously designed data model is a practical and extremely useful tool for research.
Red Clover and Tillage Influence on Soil Temperature, Water Content, and Corn Emergence
Authors: Drury Craig F. , Tan Chin‐Sheng , Welacky Thomas W. , Oloya Tom O. , Hamill Allan S. , Weaver Susan E. 
Published: July 2010

AbstractNo‐tillage systems on fine‐textured soil are not well suited for corn (Zea mays L.) because of problems with excess water, lower temperatures, and residue management during the early stages of corn growth. This is a problem, as corn is commonly used in rotation with wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.]. Furthermore, when corn follows winter wheat there may be additional problems associated with residue management during the early stages of corn growth. Hence, the objectives of this study were to measure the effect of the red clover (Trifolium pratense L.) cover crop underseeded in wheat and no‐tillage on soil temperature, water content, corn emergence, surface residue, and yields in a wheat‐cornsoybean rotation in southwestern Ontario. Treatments included conventional vs. no‐tillage both with and without underseeded red clover in a wheat‐corn‐soybean rotation in a clay loam soil. A no‐tillage and red clover treatment that had the wheat straw baled was also included. No‐tillage (with and without red clover) increased soil water content by 2 to 5% and reduced soil temperatures by 1 to 2°C during early corn emergence. Soil drying occurred along the planting slot of the no‐tillage treatments, which enabled the soil seed furrow to open and the corn seedlings to become water stressed even though the notillage treatments were wetter in the spring. Corn emergence in the no‐tillage treatment without red clover was delayed by 3 to 4 d and the final plant stand was reduced by 24% compared with the conventional tillage treatment. The no‐tillage treatment without red clover had 13% lower corn grain yield than the conventional tillage treatment averaged over three years. However, when red clover was included with no‐tillage, corn emergence was increased and corn grain yields were not significantly different from conventional tillage in both 1994 and 1996. There was also 15% less dry weight of surface plant residue present in the no‐tillage treatments when red clover was included. Hence, red clover alleviated some of the problems of no‐tillage for corn production.
Evaluation of the Root Zone Water Quality Model Using Field‐Measured Data from a Sandy Soil
Authors: Wu Laosheng , Chen W. , Baker John M. , Lamb John A. 
Published: July 2010

AbstractTesting of simulation models against field‐measured data is an important step that must be taken before a model can be used as a management tool. Field soil water contents, intensively measured by time‐domain reflectometry (TDR) on a Zimmerman fine sand soil (Argic Udipsamments) in the Minnesota Management System Evaluation Area (MSEA), were used to evaluate the Root Zone Water Quality Model (RZWQM) over two rotated crop growing seasons in 1992 (corn, Zea mays L.) and 1993 [soybean, Glycine max (L.) Merr.]. The model was evaluated based on laboratory‐measured soil hydraulic properties. Reasonable agreement exists between the daily TDR‐measured and RZWQM‐predicted water contents for the upper soil depths. However, the model overestimated the lower soil profile, leading to a consistent overestimation of the total water depth (TWO) in the entire root zone (0 to 150 cm) during both the 1992 and 1993 growing seasons. The maximum errors in TWD for the entire root zone were 2.47 and 2.77 cm, respectively, in 1992 and 1993. Predictions of solute transport by RZWQM were examined for three herbicides: atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], alachlor [2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl) acetamide], and metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one]. Comparison between measured and predicted soil herbicide concentrations averaged over the top 15‐cm layer showed that the model matched the temporal changes of the field measurements reasonably well, although the measurements showed that all pesticides were somewhat more persistent over time than the model predicted.
Improving Nitrogen Use Efficiency for Cereal Production
Authors: Raun William R. , Johnson Gordon V. 
Published: July 2010

AbstractWorldwide, nitrogen use efficiency (NUE) for cereal production (wheat, Triticum aestivum L.; corn, Zea mays L.; rice, Oryza sativa L. and O. glaberrima Steud.; barley, Hordeum vulgare L.; sorghum, Sorghum bicolor (L.) Moench; millet, Pennisetum glaucum (L.) R. Br.; oat, Avena sativa L.; and rye, Secale cereale L.) is approximately 33%. The unaccounted 67% represents a $15.9 billion annual loss of N fertilizer (assuming fertilizer‐soil equilibrium). Loss of fertilizer N results from gaseous plant emission, soil denitrification, surface runoff, volatilization, and leaching. Increased cereal NUE is unlikely, unless a systems approach is implemented that uses varieties with high harvest index, incorporated NH4‐N fertilizer, application of prescribed rates consistent with in‐field variability using sensor‐based systems within production fields, low N rates applied at flowering, and forage production systems. Furthermore, increased cereal NUE must accompany increased yields needed to feed a growing world population that has yet to benefit from the promise of N2‐fixing cereal crops. The Consultative Group on International Agricultural Research (CGIAR) linked with advanced research programs at universities and research institutes is uniquely positioned to refine fertilizer N use in the world via the extension of improved NUE hybrids and cultivars and management practices in both the developed and developing world.
Wheat Grain Yield and Soil Profile Water Distribution in a No‐Till Arid Environment
Authors: Bonfil David J. , Mufradi I. , Klitman S. , Asido S. 
Published: July 2010

AbstractYields of dryland crops in semiarid and arid zones are limited by precipitation, and so water content and placement are very important at each stage of development. Spring wheat (Triticum aestivum L.) grown in a wheat‐fallow (WF) rotation system (1 crop in 2 years) generally occupies the greatest area in the Israeli dryland region, more than the continuous wheat (CW) rotation system. To identify the optimal crop management for dryland farming where annual precipitation is <250 mm, we compared the effects of no‐tillage (NT) and conventional tillage (CT) on wheat growth and water use efficiency (WUE) in both the WF and the CW rotation systems, and on water storage in fallow (F) plots. During the 4‐year period from 1994 to 1997, experiments were conducted at Gilat Experimental Station, located in the south of Israel (average annual precipitation, 237 mm; soil type, sandy loam loess‐Calcic Xerosol). In the fallow year, F‐NT increased water infiltration and soil water content in comparison with F‐CT. However, most of the water evaporated during the summer, especially from the upper soil layer (0–120 cm). During growth, uncultivated soil with straw mulch increased water content in the upper soil layer and also encouraged the development of a longer root system capable of utilizing deeper water. During 1995, similar grain yields were obtained with both NT and CT treatments, an average of 3.45 t ha−1 for WF and 2.9 t ha−1 for CW. In the last 2 drought years (1996 and 1997), NT management increased yields by 62 to 67% for WF and by 18 to 75% for CW, relative to CT management. During the 2 years when water deficiency occurred during the grain‐filling stage (1994 and 1997), NT management increased grain weight by 20% and test weight by 5 to 7%, in addition to the 70 to 200% increase in the total grain yield, relative to CT management. Crop yield and WUE can be increased in arid zones with annual precipitation of <200 mm, through use of a wheat‐fallow rotation system that is managed by NT.
Response of Tall Fescue to Saline Water as Influenced by Leaching Fractions and Irrigation Uniformity Distributions
Authors: Leskys Algirdas M. , Devitt Dale A. , Verchick Linda S. , Morris Robert L. 
Published: July 2010

AbstractThe use of poor quality water for irrigation purposes in the urban landscape has the potential to save significant quantities of good quality water for higher priority uses. Research was conducted to determine the impact leaching fractions (LF = drainage volume/irrigation volume) and irrigation‐uniformity distributions have on the spatial distribution of water and salts and plant response when irrigating with saline water. Tall fescue (Festuca arundinacea Schreb. ‘Monarch’) was grown in 18 plots, each with a centrally located lysimeter that enabled estimates of evapotranspiration and irrigation requirements. Imposed treatments included setting LF at 0.05, 0.15, or 0.25 and manipulating plot irrigation systems such that the Christiansen uniformity coefficient (CUC) was set at 0.65, 0.75, or 0.85. Saline irrigation water (2.5 dS m−1) was applied for an 18‐mo period. Significant LF × CUC interactions were observed for depth‐weighted soil salinity, yield, evapotranspiration (ET), tissue moisture content, and canopy temperatures. Although the coefficient of variation increased with each measured parameter as the CUC decreased, only the depth‐weighted electrical conductivity (ECc) showed a coefficient of variation > 20%. A 14% savings in irrigation water was obtained when the high CUC, low LF treatment was compared with the high LF, low CUC treatment. Ninety‐one percent of the variability in the average plot ECc could be accounted for if the actual LF, lysimeter ET, and average plot canopy temperatures at the end of the experiment were taken into consideration. Under the conditions of this experiment, irrigating tall fescue with 2.5 dS m−1 water would be an acceptable practice even at LFs as low as 0.05 if the CUC is optimized.
Soil Oxygen Contents and Ion Uptake by Corn
Authors: Shapiro R. E. , Taylor George S. , Volk G. W. 
Published: July 2010

AbstractA method was developed to maintain the oxygen content of soil air in pots at different levels by means of a controlled diffusion technique.The yield of plant tops and roots was reduced by low soil oxygen contents. Decreasing the soil oxygen contents also reduced the percentages of K, Mg, P, and N found in the plant tops, while the percentage values for these elements in the roots increased. These results indicated that low soil oxygen may affect the translocation of ions from the roots to the tops more than absorption of these elements from the soil.Elements other than potassium, particularly phosphorus, were of importance in explaining reduced yields with low soil oxygen contents.When gaseous diffusion between soil and the atmosphere was eliminated after a period of normal plant growth, the percentages of K and Ca in the tops were reduced while the percentages of these elements increased in the roots. Again, the data indicated a translocation effect resulting from poor aeration.
Possible Relationships of Cation‐Exchange Capacity of Plant Roots to Cation Uptake
Authors: Huffaker R. C. , Wallace A. 
Published: July 2010

AbstractThe K, Ca, and Mg contents of different plant species grown under similar conditions could be related in a majority of cases by CEC1/CEC2 = K2/K1 = (Ca1 + Mg1/Ca2 + Mg2)1/2, where the subscripts 1 and 2 represent different species. It was shown that K1/K2 should be expected for single‐salt solutions while K2/K1 is expected when K is mixed with divalent cations. Data on root CEC and plant contents of K, Ca, and Mg obtained from a large number of citrus, corn, and soybeans grown in soil gave correlation coefficients as follows:
urn:x-wiley:03615995:saj2sssaj195803615995002200050007x:equation:saj2sssaj195803615995002200050007x-math-0001 Even though the correlations were significant, the relations appeared to be far from simple and in some cases did not hold. For example, plants grown in sand corresponded less in the divalent ratios because of high Mg contents in corn. In some cases CEC ratios corresponded well with K1/K2 rather than K2/K1.
Correlations of Soil pH and Percent Base Saturation as Influenced by Soil‐Forming Factors
Authors: Blosser D. L. , Jenny Hans 
Published: July 2010

AbstractEighty soils collected more or less at random over a large area gave very low correlations between soil pH and percent base saturation. In the same area, soils chosen according to soil‐forming factor ordinations gave very high correlations between the two soil properties. Climate was the dominant determining factor.
Shortleaf Pine Site‐Index Relationships in the Ozark Highlands
Authors: Graney David L. , Ferguson Edwin R. 
Published: July 2010

AbstractBy carefully limiting the area of application and the soils included in individual analyses, practical equations were developed for predicting shortleaf pine (Pinus echinata Mill.) growth on major soils in the Ozark Highlands. Large pits were dug to adequately classify the soils, and soil properties were determined by standard techniques. Shortleaf pine site index at age 50 was correlated with aspect, slope shape, loss‐on‐ignition of the A1 and Ap1 horizons, depth to fragipan, and latitude. Regression equations developed for limestone and dolomite soils, sandstone soils, and fragipan soils predicted site indexes within an average of 0.6 m (2 feet) on confirmatory plots.
Inherited and Detrital 2:1 Type Phyllosilicates in Soils Developed from Mazama Ash
Authors: Dudas M. J. , Harward M. E. 
Published: July 2010

AbstractPrevious studies of soils developed from Mazama ash have indicated the occurrence of a complex suite of 2:1 and 2:2 type phyllosilicates. Before interpreting the phyllosilicates as weathering products from the ash, it must be established that they have formed in situ. Origin of 2:1 and 2:2 type phyllosilicates in soils of the coarse Mazama pumice in central Oregon was traced to the pyroclastic lithic fragments in the deposit. Clay minerals separated from lithic fragments included chlorite, chloritic intergrades, mica, smectites, and possibly vermiculite. The inherited origin of these crystalline clays corrects previous suggestions of origin which involved weathering of ash.For volcanic ash soils in forested areas located at distances farther than 100 km from the source at Crater Lake, 2:1 type clay minerals separated from ash horizons were shown to be relics from underlying paleosols. Crystalline clay suites in different ashy profiles exhibited greater similarity to their respective palesol clay fraction than to other profiles in the same ash deposit. Once incorporated into ashy horizons, palesol clay high in montmorillonite exhibited partial chloritization and samples high in mica exhibited some loss of interlayer K. Uprooting of trees is believed to be the major mechanism involved in mixing ash soils with palesols in forested areas where the Mazama deposit is relatively thin (< 100 cm).
Detachment of Soil Aggregates by Simulated Rainfall from Heavily Manured Soils in Eastern Nebraska
Authors: Mazurak A. P. , Chesnin Leon , Tiarks A. E. 
Published: July 2010

AbstractA field experiment was established to measure the effects of annual applications of high rates of manure for the production of crops under irrigation. The effects of incorporating the manure into the soil by disk plowing to depths of 10 cm, 20 cm, and 30 cm on the stability of the soil mass was measured under simulated rainfall conditions. The effect of simulated rainfall on soil surface compaction as influenced by rate of application of manure and depth of incorporation was measured with a penetrometer.The amount of soil material detached from undisturbed soil cores by simulated raindrops was curvilinearly related to the rainfall intensity. When the plots were disk plowed to a depth of 10 cm, soil detachment increased from 55 mg/cm3 of water for the nonmanured plots to 89 mg/cm3 for the 415 metric tons/ha per year. The amount of soil particles detached by the raindrops was reduced about 15 mg/cm3 of water as the depth of disking the manure into the soil was increased from 10 to 30 cm. Aggregate size distribution of the splashed material showed that prior application of manure to the soil increased the amount of soil aggregates in the large diameter classes. The penetrometer resistance of the crust formed by the waterdrops decreased from 36 kg/cm2 for nonmanured plots to 4.4 kg/cm2 for the plots receiving 360 metric tons of manure/ha/year.