bluuebunny/crossref_metadata_2025 huggingface dataset:
On sample size calculation for 2×2 fixed‐effect ANOVA when variances are unknown and possibly unequal
Authors: Guo Jiin‐Huarng , Luh Wei‐Ming
Published: June 2008

The factorial 2 × 2 fixed‐effect ANOVA is a procedure used frequently in scientific research to test mean differences between‐subjects in all of the groups. But if the assumption of homogeneity is violated, the test for the row, column, and the interaction effect might be invalid or less powerful. Therefore, for planning research in the case of unknown and possibly unequal variances, it is worth developing a sample size formula to obtain the desired power. This article suggests a simple formula to determine the sample size for 2 × 2 fixed‐effect ANOVA for heterogeneous variances across groups. We use the approximate Welch t test and consider the variance ratio to derive the formula. The sample size determination requires two‐step iterations but the approximate sample sizes needed for the main effect and the interaction effect can be determined separately with the specified power. The present study also provides an example and a SAS program to facilitate the calculation process.
Retracted: The word concreteness effect occurs for positive, but not negative, emotion words in immediate serial recall
Authors: Tse Chi‐Shing , Altarriba Jeanette
Published: June 2008

The present study examined the roles of word concreteness and word valence in the immediate serial recall task. Emotion words (e.g. happy) were used to investigate these effects. Participants completed study‐test trials with seven‐item study lists consisting of positive or negative words with either high or low concreteness (Experiments 1 and 2) and neutral (i.e. non‐emotion) words with either high or low concreteness (Experiment 2). For neutral words, the typical word concreteness effect (concrete words are better recalled than abstract words) was replicated. For emotion words, the effect occurred for positive words, but not for negative words. While the word concreteness effect was stronger for neutral words than for negative words, it was not different for the neutral words and the positive words. We conclude that both word valence and word concreteness simultaneously contribute to the item and order retention of emotion words and discuss how Hulme et al.'s (1997) item redintegration account can be modified to explain these findings.
Assessing inattention and impulsivity in children during the Go/NoGo task
Authors: Bezdjian Serena , Baker Laura A. , Lozano Dora Isabel , Raine Adrian
Published: June 2008

Behavioural performance in the Go/NoGo task was compared with caregiver and teacher reports of inattention and hyperactivity‐impulsivity in 1,151 children (N=557 boys; N=594 girls) age 9–10 years old. Errors of commission (NoGo errors) were significantly correlated with symptom counts of hyperactivity‐impulsivity, while errors of omission (Go errors) were significantly correlated with symptom counts for inattention in both caregiver and teacher reports. Cross‐correlations were also evident, however, such that errors of commission were related to inattention symptoms, and errors of omission were related to hyperactivity‐impulsivity. Moreover, hyperactivity‐impulsivity and inattention symptoms were highly intercorrelated in both caregiver (r=.52) and teacher reports (r=.70), while errors of commission and omission were virtually uncorrelated in the Go/NoGo task (r=.06). The results highlight the difficulty in disentangling hyperactivity‐impulsivity and inattention in questionnaires, and suggest that these constructs may be more clearly distinguished in laboratory measures such as the Go/NoGo task.
An intact eye‐movement system is not required to generate inhibition of return
Authors: Smith Daniel T. , Jackson Stephen R. , Rorden Chris.
Published: June 2008

AI is unable to make eye‐movements and has a deficit of reflexive attention. Here, we demonstrate that despite these deficits AI exhibits inhibition of return (IOR) for peripherally cued objects and locations. These data suggest that an intact oculomotor system is not required for the generation of either object‐based or location‐based IOR and are consistent with the view that the early, facilitatory effects of peripheral cues and late IOR effects are mediated by different mechanisms.
4 Months, 3 Weeks and 2 Days: The Corruption of Intimacy
Authors: Uricaru Ioana
Published: June 2008

Cristian Mungiu's 4 Months, 3 Weeks and 2 Days shares with other recent Romanian films, notably The Death of Mr. Lazarescu (2005) and 12:08 East of Bucharest (2006), a preoccupation with accessing large-scale phenomena (politics, history, society) through the narrow focus of meticulously observed individual stories.
4 Months, 3 Weeks and 2 Days: An “Abortion Movie”?
Authors: Wilson Emma
Published: June 2008

This essay situates Cristian Mungiu's film, 4 Months, 3 Weeks and 2 Days in relation to a number of films which deal with abortion. However, the argument is made that this film's chief concern is for problems of intimacy and distress pertaining to the central friendship between two women.
Late Ozu, Late Naruse
Authors: Mellen Joan
Published: June 2008

This essay reflects on the shared qualities of the late works of Yasujiro Ozu and Mikio Naruse. Both worked in the shomin-geki genre of middle-class life, depicting the often unhappy social conditions, notably among women, in post-war Japan. But while Ozu is tender and pitying, Naruse is agonized and outraged at injustice.
Tender is the Regard: I Don't Want to Sleep Alone and Still Life
Authors: Bíró Yvette
Published: June 2008

This essay compares Jia Zhang-ke's Still Life (set at the site of the construction of the Three Gorges Dam) and Tsai Ming-liang's I Don't Want to Sleep Alone (set among penniless worker in Kuala Lumpur), finding aesthetic similarities that are offset by contrasting sensibilities, Tsai practicing a certain Zen resignation, Jia more socially engaged.
Places and Other Fictions: Film Culture in Tokyo
Authors: Fujiwara Chris
Published: June 2008

This essay explores places of cinematic interest in Tokyo, including areas of the city filmed by notable directors, and screening/discussion venues such as the National Film Center, Eurospace, and the Institut Franco-Japonais.
Films of the Year, 2007
Authors: Naremore James
Published: June 2008

Prefaced by remarks about methodology, this article presents a survey of films (and one television show) released in the U.S. in 2007 which James Naremore evaluates to be the best of the year. The top three are: Pedro Costa's Colossal Youth, Pere Portabella's Cuadecuc-Vampir, and Abderrahmane Sissako's Bamako.
The Ontology of a Fetish
Authors: Andrew Dudley
Published: June 2008

This article includes a translation, facsimile, and analysis of a typescript fragment by Bazin, which is evidence of his engagement with Sartre's The Imaginary.
"You've Been Wonderful Neighbors": Key Factors in the Successful Integration of a Wiccan Coven into a Suburban Community in the Southeastern United States
Authors: Smith Kenny
Published: June 2008

In May 2000 the House of Oak Spring (HOS), a Wiccan group, purchased eighteen acres of forested land and a home in a typical suburban Atlanta neighborhood, with the goal of establishing a covenstead. While residents of the suburb initially reacted with considerable fear and hostility, they soon came to accept and even appreciate their Wiccan neighbors. This essay seeks to explain the successful integration of HOS into the larger community in terms of the benefits the community enjoys as a result of the presence of HOS. The case of HOS suggests that similar dynamics may have informed the successful integration of other religious minorities in different communities.
Ananda Marga and the Use of Force
Authors: Crovetto Helen
Published: June 2008

Ananda Marga is now an international movement that claims over a million adherents in more than one hundred countries. Ananda Margiis are perceived by some as terrorists, while much of their social service work, positive environmental philosophy, and effective system of tantric spiritual practices are overlooked. It would be more accurate to call Ananda Margiis revolutionary socio-spiritual utopians rather than terrorists. There are several allegations against them concerning the murder of apostates. This article will concentrate on the well-founded doctrinal basis for Ananda Marga's association with the use of force and examine its moral arguments justifying it.
Denied Violence, Glorified Fighting: Spiritual Discipline and Controversy in Ananda Marga
Authors: Voix Raphaël
Published: June 2008

This article tackles the issue of violence inside Ananda Marga, a contemporary Indian religious movement based in West Bengal. It analyzes a controversy Ananda Marga has been through and questions its role within the movement by examining its link with an internal characteristic of the group: an initiatory process into asceticism. Based on long-term anthropological fieldwork in India, I describe the structure of Ananda Marga and then distinguish between the "history" of the movement, which is written and given collectively, and the "stories" of the movement, which are told orally and individually. By confronting these different versions of the same event, I argue that the controversy can be seen as a part of a larger initiatory process in which committed disciples gradually acknowledge the legitimacy of violence.
Millennialism and Violence: The Attempted Assassination of Nasir al-Din Shah of Iran by the Babis in 1852
Authors: Momen Moojan
Published: June 2008

The association of millennialist movements with violence has been a subject of much study following recent high-profile events. This article examines a case of millennialism and violence that occurred just over 150 years ago. It tracks the events leading to the attempted assassination of Nasir al-Din Shah of Iran in 1852 by a small group of followers of the religion of the Bab, a religious leader who claimed to fulfill the prophecies of Shi'i Islam about the coming of the Imam Mahdi. The factors leading to the violence are analyzed and compared with other cases of millennialism and violence. The main factors that stand out in this case include: a pre-existing religious milieu that expected a violent, millennial event and engendered a radically dualist worldview, with the shah's government as the embodiment of an evil destined to be defeated and removed; a severe persecution of the group resulting in some followers' desire for revenge and a dramatic violent act that would bring divine intervention and ultimate victory; government removal of moderate leadership, leaving only radical extremist leaders; and the presence among the Tehran group of Babis, which carried out the attempted assassination, of a charismatic leader whom these Babis believed had access to a source of divine power that could make the plan achievable, when a more rational analysis would have demonstrated the opposite.
Pilgrims and Progress: The Production of Religious Experience in a Korean Religion
Authors: Bell Kirsten
Published: June 2008

Since its inception, Chondogyo has self-consciously maintained an identity as a "new" and "modern" Korean religion. These claims have seen ongoing efforts to rationalize religious practice and theology and purge the movement of "anti-modern," "superstitious" elements. This article explores the differing receptions of pilgrimage and ecstatic trance within the organization: the two major forms of embodied religious experience in Chondogyo. While the former has been actively promoted as a "legitimate" (and modern) form of religious experience, the latter is treated with ambivalence and is often connected with backward superstition. Through a comparison of these practices, I explore the ways in which they intersect with, bolster and challenge conceptions of Korean modernity.
Paternal effect on embryo quality in diabetic mice is related to poor sperm quality and associated with decreased glucose transporter expression
Authors: Kim Sung Tae , Moley Kelle H
Published: June 2008

The objective of this study was to determine whether sperm quality, fertilization capacity, and subsequent embryo development are altered in diabetic male mice and whether differences in facilitative glucose transporter (GLUT; now known as solute carrier family 2, SLC2A) expression in the testis and sperm exist. Using two type 1 diabetic mouse models, SLC2A expression in the testis and sperm was determined by western immunoblotting and immunofluorescence staining. To address sperm quality and fertilization capacity, computer-assisted sperm analysis and in vitro fertilization were performed. SLC2A1, SLC2A3, and SLC2A5 did not change in expression in the testes or sperm between diabetic and non-diabetic mice. SLC2A8 and SLC2A9b were less expressed in the testes of both diabetic models versus controls. SLC2A9a was not expressed in the Akita testis or sperm when compared with strain-matched controls. 3β-hydroxysteroid dehydrogenase (HSD3B) expression was significantly decreased in the Leydig cells from the diabetic mice. Sperm concentration and motility were significantly lower in both the diabetics when compared with the control. These parameters normalized in Akita diabetic males treated with insulin. In addition, fertilization rates were significantly lower in the Akita group (17.9%) and the streptozotocin (STZ)-injected male group (43.6%) when compared with the normal group (88.8%). Interestingly, of the fertilized zygotes, embryo developmental rates to the blastocyst stage were lower in both diabetic models (7.1% Akita and 50.0% STZ) when compared with controls (71.7%). Male diabetes may cause male subfertility by altering steroidogenesis, sperm motility, and SLC2A expression. This is the first study to link a paternal metabolic abnormality to a sperm effect on cell division and subsequent embryonic development.
Coexpression of Gene Polymorphisms Involved in Bilirubin Production and Metabolism
Authors: Lin Zhili , Fontaine Jamie , Watchko Jon F.
Published: June 2008

OBJECTIVE. The potential for genetically determined conditions to modulate the risk for developing neonatal hyperbilirubinemia is increasingly being recognized. The aims of this investigation were to (1) develop genotyping assays for an expanded panel of mutations and polymorphisms across 3 genes that are involved in bilirubin production and metabolism (glucose-6-phosphate dehydrogenase [G6PD], uridine diphosphate glucuronosyl transferase 1A1 [UGT1A1], and organic anion transporter polypeptide 1B1 [OATP1B1]) and (2) determine their allele frequencies in 450 anonymous DNA samples of US residents with ancestry from all of the major regions of the world.

METHODS. Genotyping assays were developed on the basis of allele-specific hybridization and melting peak analysis of the probe set and the match or mismatch template. Allele frequencies and the complexity of coinheritance of multiple genetic variants across G6PD, UGT1A1, and OATP1B1 genes in DNA samples from the DNA Polymorphism Discovery Resource of the National Human Genome Research Institute were determined by using this expanded panel.

RESULTS. Genetic polymorphisms of the UGT1A1 promoter, specifically the T-3279G phenobarbital responsive enhancer module and the (thymidine-adenine)7 dinucleotide repeat TATAA box variants, were common. Similarly, OATP1B1 coding sequence gene variants were frequently observed. Moreover, in more than three quarters of the samples, ≥2 variants were detected, reflecting a high degree of polymorphism coexpression across these genes, including those who carried the African A− G6PD mutation.

CONCLUSIONS. We conclude that this expanded panel of mutations and polymorphisms can serve as an effective instrument to study the genetic architecture of hyperbilirubinemia and speculate an important role for genetic polymorphism coinheritance in determining hyperbilirubinemia risk in newborns.
Effects of In Utero and Childhood Tobacco Smoke Exposure and β2-Adrenergic Receptor Genotype on Childhood Asthma and Wheezing
Authors: Wang Chengwei , Salam Muhammad T. , Islam Talat , Wenten Madé , Gauderman W. James , Gilliland Frank D.
Published: June 2008

OBJECTIVE. Associations between single-nucleotide polymorphisms in the β2-adrenergic receptor gene and asthma and wheeze have been inconsistent. Recent studies indicated that tobacco smoke affects β2-adrenergic receptor gene expression and associations of β2-adrenergic receptor gene variants with asthma in adults. We aimed to investigate the joint effects of in utero and childhood secondhand tobacco smoke exposure and 2 well-characterized functional single-nucleotide polymorphisms (Arg16Gly and Glu27Gln) of β2-adrenergic receptor gene on asthma and wheezing in 3128 non-Hispanic and Hispanic white children of the Children's Health Study.

METHODS. We fitted logistic regression models to estimate odds ratios and 95% confidence intervals for the independent and joint effects of these single-nucleotide polymorphisms and in utero and secondhand tobacco smoke exposure on asthma and wheeze outcomes.

RESULTS. Exposures to in utero maternal smoking and secondhand tobacco smoke were associated with wheezing. Children who were homozygous for the Arg16 allele and were exposed to maternal smoking in utero were at a threefold increased risk for lifetime wheeze compared with children who were unexposed and had at least 1 Gly16 allele. We found similar joint effects of secondhand tobacco smoke and Arg16Gly with wheezing. The risk for lifetime, current, and nocturnal wheeze increased with the number of smokers at home among Arg16 homozygous children. The results were consistent in 2 cohorts of children recruited in 1993 and 1996. Diplotype-based analyses were consistent with the single-nucleotide polymorphism–specific results. No associations were found for Glu27Gln.

CONCLUSIONS. Both in utero and childhood exposure to tobacco smoke were associated with an increased risk for wheeze in children, and the risks were greater for children with the Arg16Arg genotype or 2 copies of the Arg16–Gln27 diplotype. Exposures to smoking need to be taken into account when evaluating the effects of β2-adrenergic receptor gene variants on respiratory health outcomes.
A ranking of European veterinary medicines based on environmental risks
Authors: Kools Stefan AE , Boxall Alistair BA , Moltmann Johann F , Bryning Gareth , Koschorreck Jan , Knacker Thomas
Published: June 2008

The most likely entry pathways of veterinary pharmaceuticals to the environment are via slurry or manure from intensively reared animals to soil and via dung or urine from animals grazing on pasture. These pathways may result in contamination of surface water via runoff or leaching and drainage. Direct entry into water may occur by defecation by pasture animals or by companion animals. In addition, application of medicines for aquaculture is important for a limited number of veterinary medicinal products. For a large number of veterinary medicinal products, consistent data on the environmental risk have never been generated. In this project, a simple risk-based ranking procedure was developed that should allow assessing the potential for environmental risks of active substances of veterinary medicinal products. In the European Union approximately 2000 products containing 741 active substances were identified. In the prescreening step and in agreement with the technical guidelines released by the European Medicines Agency, 294 natural substances, complex mixtures, and substances with low expected exposure were exempted from the ranking procedure. For 233 active substances, sufficient information was collated on 4 exposure scenarios: Intensively reared animals, pasture animals, companion animals, and aquaculture. The ranking approach was performed in 4 phases: 1) usage estimation; 2) characterization of exposure to soil, dung, surface water, and aquatic organisms depending on exposure scenarios; 3) characterization of effects based on therapeutical doses; and 4) risk characterization, which is the ratio of exposure to effects (risk index), and ranking. Generally, the top-ranked substances were from the antibiotic and parasiticide groups of veterinary medicines. Differences occurred in the ranking of substances in soil via application to either intensively reared or pasture animals. In intensive rearing, anticoccidia, for example, are used as feed-administered medicines (feed additives) in comparatively large doses over a long time. For pasture animals, these substances are used less, if at all, and therefore receive lower ranks. Besides that, the risk indices for the aquatic compartment are large for substances used in aquaculture or applied to companion animals. In conclusion, the ranking scheme developed for this project provided a scientifically based and pragmatic means of assessing the relative priority of veterinary medicines for further detailed risk assessment. The outcome of this project will support pharmaceutical industries and competent authorities when seeking authorization for market applications of veterinary pharmaceutical products.
Yield Estimation and Clustering of Chickpea Genotypes Using Soft Computing Techniques
Authors: Khazaei J. , Naghavi M.R. , Jahansouz M.R. , Salimi‐Khorshidi G.
Published: June 2008

Crop growth is a multifactorial nonlinear process and different kinds of models have been developed to predict crop yield. In recent years, crop growth models have become increasingly important as major components of agriculture‐related decision‐support systems. Moreover, clustering is a multivariate analysis technique widely adopted in agricultural studies. Using this method, different genotypes (accessions) of crops can be classified and characterized. This paper discusses the use of soft computing techniques such as artificial neural networks (ANN) and fuzzy logic based approaches in regression and clustering problems. The ANN technology was used for modeling the correlation between crop yield and 10 yield components of chickpea (Cicer arietinum L.). Also, the fuzzy c‐means (FCM) clustering technique was used for the classification of 362 chickpea genotypes based on their agronomic and morphological traits. The ANN performed very well. Among the various ANN structures, a model of good performance was produced by 10–14–3–1 structure with a training algorithm of back‐propagation and hyperbolic tangent transfer function in the hidden and output layers. The model was able to predict the chickpea yield data of 0.32 to 14.38 g plant−1 with a RMSE and T value of 0.0195 g plant−1 and 0.988, respectively. T statistics measures the scattering around line (1:1). When T is close to 1.0, the fitting is desirable. The mean absolute error, relative error, and coefficient of determination between actual and predicted data were 0.0109 g plant−1, −1.07%, and 0.991, respectively. The ANN model predicted 90.3% of the yield data with relative errors ranging between ±5%. The consequent reduction in the number of training data from 250 to 50, decreased the training RMSE, but increased the prediction error. It was found that even with a few number of patterns in the training dataset (50 patterns), the prediction error of the ANN model was in the range of acceptance for yield modeling. Obviously, with 25 × 103 iterations, the ANN models with 5 and 10 input variables gave almost the same estimation of the chickpea yield. The results of clustering showed that the FCM clustering technique can be successfully applied to classify chickpea genotypes in terms of agronomic and morphological traits.
Contribution of Anaerobically Mineralized Nitrogen to the Reliability of Planting or Presidedress Soil Nitrogen Test in Maize
Authors: Sainz Rozas Hernán , Calviño Pablo A. , Echeverría Hernán E. , Barbieri Pablo A. , Redolatti Miguel
Published: June 2008

The objective of this work was to evaluate if soil mineralizable N under anaerobic conditions (Nan) improves the reliability of preplant soil nitrate test (PPNT) and presidedress soil nitrate test (PSNT). The study was conducted under no‐tillage (NT) in the southeastern Buenos Aires province, Argentina, in 26 site‐years. In some site‐years treatments were fixed N rates (0, 70, 140, and 210 kg ha−1 or 0, 60, 120, 180, and 240 kg ha−1) applied at planting, whereas in others site‐years N rates were determined by adding N to lead targets of N supply up to 120, 160, and 200 kg N ha−1. When sites were not separated by Nan, relative yield (RY) correlated with PPNT (r2 = 0.37) and reliability of PPNT did not increase when sites were separated by low (<48 mg kg−1) and high Nan (>48 mg kg−1). A high relationship between RY and PSNT (r2 = 0.56) was determined. However, when sites were separated by Nan, reliability of PSNT increased, mainly for sites with low Nan (r2 = 0.68 and 0.44 for sites with low and high Nan, respectively). Critical PSNT values for 94% of RY were 75 and 90 kg N ha−1 for sites with high and low Nan, respectively. The results show that PSNT was a better diagnostic method for maize (Zea mays L.) than PPNT. However, the separation of sites by its N mineralization capacity increased reliability of PSNT by indicating a lower N requirement to reach 94% of RY, decreasing the risk of overfertilization, an important feature from economical and environmental standpoints.
Corn and Cover Crop Response to Corn Density in an Interseeding System
Authors: Baributsa Dieudonné N. , Foster Eunice F. , Thelen Kurt D. , Kravchenko Alexandra N. , Mutch Dale R. , Ngouajio Mathieu
Published: June 2008

The increasing cost of nitrogen fertilizer and the need for a N source for low‐input and organic farmers have led to the increased exploration of legume cover crops as an alternative to N fertilization. Reliable cropping strategies are needed to enhance legume cover crop use as a N source. Interseeding legume cover crops into corn (Zea mays L.) can affect corn yield and cover crop dry matter. This study, conducted at the Kellogg Biological Station in Hickory Corners, MI, from 2002 to 2005, evaluated (i) the impact of interseeded cover crops on corn yield at various corn densities (37,500 to 75,000 plants ha−1) and (ii) the effect of corn density on cover crop dry matter (DM) when corn was interseeded with red clover (Trifolium pratense L.) or chickling vetch (Lathyrus sativus L., var. AC Greenfix). Interseeded cover crops did not affect corn yield at any corn density. Interseeded cover crop DM decreased as corn density increased. The subsequent spring, red clover DM was similar regardless of previous corn density; AC Greenfix did not regrow. Interseeded cover crops produced less DM than monoculture cover crops. Cover crops can be interseeded into corn densities up to 75,000 plants ha−1 without corn yield reduction and still produce substantial DM the subsequent spring. Interseeding corn with red clover could be used in low‐input farming systems to reduce N fertilizer costs, especially in developing countries and in organic farming systems.
Soybean Cultivar and Planting Date Response to Soil Fumigation
Authors: De Bruin Jason L. , Pedersen Palle
Published: June 2008

Soybean [Glycine max (L.) Merr.] seed yield will be maximized by planting the last week of April or the first week of May in Iowa. Soybean cyst nematode (Heterodera glycines Ichinohe; SCN) is present in the majority of Iowa fields and may influence cultivar responses to planting date. This study was conducted to determine whether specific cultivars need to be selected based on planting date. The effects of soil fumigation, planting date, and cultivar selection were evaluated at three sites in Iowa near De Witt, Nevada, and Whiting during 2005 and 2006. These sites varied in rainfall, soil type, and SCN population densities. Yields of the first two planting dates were increased an average of 10% by fumigation and yields of the SCN‐susceptible cultivar NK‐S32‐G5 and the SCN‐resistant cultivar P91M90 increased 11%. Cultivars with the PI88788 source of SCN resistance produced greater yields than other sources of SCN resistance in the nonfumigated treatment but yields were equal among all sources of SCN resistance in the fumigated treatment. Cultivars responded similarly to planting date, with maximum yields at early dates followed by a consistent decline as planting was delayed. The combination of SCN‐resistant cultivars and early planting resulted in the greatest and most consistent yields across diverse production environments. Cultivar selection should focus on high‐yielding, adapted cultivars with resistance to SCN when SCN is present in a field, and these cultivars should be selected for both early and late planting dates.
Impact of Long‐Term No‐Tillage and Cropping System Management on Soil Organic Carbon in an Oxisol: A Model for Sustainability
Authors: Calegari Ademir , Hargrove W. L. , Rheinheimer Danilo Dos Santos , Ralisch Ricardo , Tessier Daniel , de Tourdonnet Stephane , de Fatima Guimarães Maria
Published: June 2008

Soil organic carbon (SOC) was assessed in a long‐term (19 yr) experiment comparing conventional tillage (CT) and no‐tillage (NT) management systems and various winter cover crop treatments in a Rhodic Hapludox in southern Brazil. After 19 yr, NT resulted in 6.84 Mg C ha−1, in the upper soil layer (0–10 cm), which represented 64.6% more than CT. In the 0 to 20 cm soil layer, the NT system sequestered 1.24 Mg C ha−1yr−1, while CT sequestered 0.96 Mg C ha−1yr−1. Independent of soil management, the fallow treatment resulted in the lowest SOC stocks to the 40‐cm soil depth compared to all other winter treatments. We compared SOC levels of the experimental site with a nearby‐forested area, which has never been cleared. No‐till management combined with winter cover crops resulted in soil properties that most closely resembled the undisturbed forest. Maize grain yields and soybean seed yields were 6 and 5% higher, respectively, under NT than CT. Our results point to NT management combined with winter cover crops as the management system of choice to achieve sustainable crop production on Oxisols in the subtropical and tropical regions of the world.
Harvesting Interval Changes Yield and Nutritive Value of Kenaf in a Dry Tropical Climate
Authors: González‐Valenzuela Eduardo A. , Ávila‐Curiel J. Miguel , Ortega‐S. J. Alfonso , González‐Padrón Miguel A. , Muir James P.
Published: June 2008

Kenaf (Hibiscus cannabinus L.) could be a forage alternative to the cattle production in the dry tropics of Mexico. The objective of this study was to evaluate harvest intervals on yield and nutritive value of kenaf ‘Everglades 41’. Intervals evaluated were 20, 40, and 60 d, and a single harvest in October when growth ceased. Since rainfall varied between 1998 and 1999, there was a year effect (P < 0.05) for yield and plant height. Total dry matter (DM) was lowest from the 20‐d harvest interval and highest from the October‐only harvest (P < 0.05) both years. Multiple harvest treatments resulted in greater leaf:stem ratios. The October‐only harvest had the lowest (P < 0.05) crude protein (CP) with 189 g kg−1 and the multiple harvest ranged from 237 to 286 g kg−1. Leaf neutral detergent fiber (NDF) increased, as harvest interval increased, from 148 g kg−1 DM in the 20‐d treatment up to 175 g kg−1 DM in the October‐only treatment. Stems harvested in October‐only had the greatest NDF. The lowest acid detergent fiber (ADF) concentration (P < 0.05) resulted from regrowth of 20‐d harvests, with 131 g kg−1 DM. October plant density was 27% lower (P < 0.05) at the 20‐d harvest interval than in October‐only harvest. A harvest interval of at least 40 d is required for kenaf persistence and vigorous recovery.
A Bowen Ratio Technique for Partitioning Energy Fluxes between Maize Transpiration and Soil Surface Evaporation
Authors: Zeggaf Adel T. , Takeuchi Shinichi , Dehghanisanij Hossein , Anyoji Hisao , Yano Tomohisa
Published: June 2008

A field experiment was conducted in 2005 at the experimental station of the Arid Land Research Center, Tottori University, Japan, for comparing latent heat fluxes from a maize (Zea mays L.) field, maize transpiration, and soil surface evaporation by two different methods. The Bowen ratio energy balance method (Method 1) was used to measure latent heat fluxes above the maize canopy as well as between the soil surface and the canopy at 0.5‐h time intervals. Then, latent heat flux from maize transpiration was calculated by the difference between that of the maize field and soil surface. In Method 2, a weighing lysimeter and sap flow gauges were used to measure latent heat fluxes from the maize field and maize transpiration, respectively, at 0.5‐h time intervals. Then, latent heat flux from the soil surface was calculated by the difference between that of the maize field and maize transpiration. The coefficient of determination between latent heat fluxes by the two methods was 0.72 from the maize field and 0.77 from the maize transpiration. However, results indicated a low correlation between the latent heat fluxes from the soil surface by the two methods (r2 = 0.36). On the average, the Bowen ratio energy balance method underestimated by 6% the latent heat flux measured by weighing lysimeter data and overestimated by 14% that obtained by sap flow data resulting in a 30% underestimation of the measured latent heat flux at the soil surface. At daily time intervals, results were improved with relative errors around 19 and 21% for the latent heat fluxes from the maize field and maize transpiration, respectively. Finally, this study showed that the use of Method 1 for partitioning evapotranspiration at maize field level is feasible. The use of this technique for irrigation management to improve water use efficiency at crop field level needs to be explored.
Growth and Yield of Winter Wheat as Affected by Preceding Crop and Crop Management
Authors: Anderson Randy L.
Published: June 2008

Producers in eastern South Dakota are interested in adding winter wheat (Triticum aestivumL.) to their crop rotations to improve crop yield and pest management. Our study quantified winter wheat response to preceding crop and crop management. Preceding crops were soybean [Glycine max(L.) Merrill], oat (Avena sativaL.)–pea (Pisum sativumL.) mixture, and spring wheat. Two crop management strategies, high‐input and conventional, were compared. High‐input management differed from conventional management by a 60% higher seeding rate and a split application of N fertilizer. Winter wheat with high‐input management yielded the highest following oat–pea; in contrast, winter wheat with conventional management yielded 28% less following spring wheat. Winter wheat following soybean yielded 88% of the winter wheat with high‐input following oat–pea. Tiller density was 32% higher when winter wheat followed oat–pea compared with soybean. Winter wheat developed faster following oat–pea compared with other preceding crops, as determined by measuring solar radiation at the soil surface in early May and date of heading. Winter wheat production can be improved by increasing seeding rate and banding a starter fertilizer by the seed at planting.
Soybean Response to Plant Population at Early and Late Planting Dates in the Mid‐South
Authors: Lee Chad D. , Egli Dennis B. , TeKrony Dennis M.
Published: June 2008

The widespread adoption of glyphosate [N‐(phosphonylmethyl)‐glycine]‐resistant soybean [Glycine max (L.) Merr.] and the increased cost of soybean seed have generated interest in determining the minimum plant population needed for maximum yield. The objective of this study was to determine yield and economic return responses to plant population for normal and late planting dates. Cultivars with relative maturities of 2.8 to 4.9 were planted at five seeding rates (43,000 to 560,000 seeds ha−1) in May and/or June in 38‐cm rows during 2003 to 2005. The effect of plant population on both yield and economic return was explained with a variation of a Mitscherlich equation. Optimum plant population (OPP) and economically optimum plant population (EOPP) were defined as those resulting in 95% of the estimated yield or estimated economic return, respectively, at the maximum plant population. Optimum plant population ranged from 108,000 to 232,000 plants ha−1 for May planting dates and 238,000 to 282,000 plants ha−1 for June planting dates. Economically optimum plant populations were 7 to 33% less than OPPs. Complete canopy cover at R1 produced maximum yield in 8 of 10 comparisons. These results suggest that seeding rates below those that are currently recommended could lower seed costs without reducing yield.
Crop Nitrogen and Phosphorus Utilization following Application of Slurry from Swine Fed Traditional or Low Phytate Corn Diets
Authors: Paschold J. S. , Wienhold B. J. , McCallister D. L. , Ferguson R. B.
Published: June 2008

Field application of swine (Sus scrofa) slurry provides essential nutrients for crop production. The N to P ratio for slurry is lower than needed by most crops resulting in P accumulation when applied at N rates required for crop growth. Low phytate corn (Zea mays L.) (LPC) contains similar amounts of total P but less phytate P than traditional corn (TC) resulting in improved P bioavailability and reduced P excretion by monogastric animals. While manure from swine‐fed LPC diets has a higher N to P ratio than that from TC diets, field studies comparing crop utilization of nutrients from LPC manure have not been conducted. A field study was conducted to compare N and P utilization by no‐tillage rainfed sorghum [Sorghum bicolor (L.) Moench.] receiving three annual surface applications of nutrients (inorganic fertilizer, LPC slurry, and TC slurry) and by irrigated corn receiving one incorporated application of nutrients. Sorghum grain and total dry matter N utilization exhibited a year by treatment interaction but total dry matter N utilization was similar for both manure types in all years (61.2 ± 2.6% for TC and 53.8 ± 2.6% for LPC). Grain P utilization was similar for inorganic fertilizer and manure but differed among years (44.4 ± 7.0% in 1999, 25.1 ± 1.4% in 2000, and 57.0 ± 2.2% in 2001). Corn grain N and P utilization did not differ among nutrient sources in the year of application (50.7 ± 2.4% for N and 40.4 ± 3.0 for P) and increased little in the year following application (62.2 ± 3.0% for N and 50.2 ± 4.5% for P). Crop N and P utilization from LPC manure and TC manure was similar and nutrient guidelines developed for TC swine slurry should also apply for LPC slurry.
New Oxygen Barrier Stretch Film Enhances Quality of Alfalfa Wrapped Silage
Authors: Borreani Giorgio , Tabacco Ernesto
Published: June 2008

The objectives of this research were to (i) test a new oxygen barrier (OB) stretch film with a 20‐fold lower oxygen permeability than the polyethylene (PE) film commonly used on farms to wrap bales and (ii) determine the effects on microbial status, dry matter (DM) losses, and fermentation of alfalfa (Medicago sativaL.) bale silage. Five field trials were conducted on a farm near Turin, Italy. In Trial 1, the bales were wrapped with two, four, six, or eight layers of either conventional PE or OB film. A further four trials were conducted to compare bales wrapped with four layers of OB with bales wrapped with six layers of PE. In the outer layer of bales, the pH was lower in the OB than the PE silages. There was a significant effect of the film type and number of layers on the percentage of bale surface covered by mold (P< 0.001), with less than 15% in bales wrapped with at least four layers of OB film. Storage DM losses ranged from 50 to 123 g kg−1DM and were affected by the type of film used (P< 0.001) and by the number of layers applied (P= 0.035), with consistently lower values in OB silages. The new stretch film supports the possibility of conserving high quality alfalfa silage for up to 14 mo, with less film than currently used.
Effect of Planting Date on Winter Kabuli Chickpea Growth and Yield under Rainfed Mediterranean Conditions
Authors: López‐Bellido Francisco J. , López‐Bellido Rafael J. , Khalil Shawkat Kasem , López‐Bellido Luis
Published: June 2008

The stability of chickpea (Cicer arietinum L.) yield under rainfed Mediterranean conditions can be improved by winter planting of cultivars resistant or tolerant to Ascochyta blight [Ascochyta rabiei (Pass.) Lab.]. A field study was conducted in southern Spain to evaluate the effect of different planting dates (late autumn, early winter, mid‐winter and the traditional late winter planting date) on growth and yield for two chickpea cultivars: ‘Fardón’ (Ascochyta blight resistant) and the widely grown, local cv. ‘Pedrosillano’ (not Ascochyta resistant and with fungicide treatments applied). Grain yield for late autumn and early and mid‐winter planting dates was between 50 and 80% greater compared to the traditional late winter planting date. The earliest two planting dates had no significant differences for yield. Rainfall during the growing season had a strong effect on biomass production and grain yield for all planting dates. The leaf area duration (LAD) index displayed a strong positive correlation with both dry matter production and grain yield, although variations in spring weather conditions prompted a year × planting date interaction. Plant density was the component most influencing yield; both plant density and pods plant−1 were greater for earlier planting dates. ‘Fardón’ was less productive than ‘Pedrosillano’ (averaging 1.76 vs. 1.94 t ha−1 over all planting dates, respectively). However, there was likely little profitability for Pedrosillano due to the fungicide applications.
Satellite Monitoring of Yield Responses to Irrigation Practices across Thousands of Fields
Authors: Lobell David B. , Ortiz‐Monasterio J. Ivan
Published: June 2008

Geographic information systems (GIS) present new opportunities for empirical agronomic research that can complement experimental and modeling approaches. In this study, GIS databases of irrigation practices for more than 4000 fields were compared with wheat yields derived from remote sensing for five growing seasons in the Yaqui Valley of Northwest Mexico. Significant yield effects were observed for both number and timing of irrigations, but not for reported water volumes, suggesting that proper timing is more important to yields than total water amounts. In most years, yield losses were observed when the second irrigation occurred more than 60 d after preplant irrigation, with an average loss of 11 kg ha−1 for each day above this value. Overall, we estimate that optimal timing and number of irrigations for all fields in Yaqui Valley could increase average yields by roughly 5%. Results varied by year, in part because of variability in growing season rainfall and in part because of variations in water allocations. Interactions with soil types were also evident, with greater yield variability attributed to irrigation on soils with higher clay contents. The results of this study provide new insight into specific causes of yield losses in farmers' fields, which can inform future field experiments, management, and water policy in this region. In general, empirical studies of large GIS databases can help to improve crop management, and meet the dual needs of higher yields and improved water use efficiency.
Evaluation of the Illinois Soil Nitrogen Test in the North Central Region of the United States
Authors: Laboski C. A. M. , Sawyer J. E. , Walters D. T. , Bundy L. G. , Hoeft R. G. , Randall G. W. , Andraski T. W.
Published: June 2008

Recently the Illinois soil nitrogen test (ISNT) was proposed as a means to identify fields where corn (Zea mays L.) will not respond to additional N fertilizer and which may also be used to predict the economic optimum N rate (EONR). Data from 96 corn N rate response trials across Iowa, Illinois, Michigan, Minnesota, Nebraska, and Wisconsin were compiled to evaluate the usefulness of the ISNT in identifying nonresponsive fields, predicting EONR, and estimating mineralizable N. At each trial site, multiple rates of fertilizer N were applied, including zero N and nonyield limiting rates. Corn was grown following several crops. The ISNT could not accurately predict nonresponsive sites, nor could it reliably estimate EONR. Subsetting the data based on soil drainage class and previous crop did not improve the predictive capability of the ISNT even though ISNT values were significantly different among previous crops and soil drainage classes. The ISNT was strongly correlated to soil organic matter (OM) and was apparently measuring a constant fraction of total soil N (TN). The lack of correlation between the ISNT and relative N uptake (check plot N uptake/N uptake at the maximum N rate) suggests that the ISNT is not measuring the readily mineralizable fraction of soil N. Based on results of this project, the ISNT is not suggested for use in adjusting N rate recommendations for corn in the North Central Region (Corn Belt) of the United States.
Ramp Calibration Strip Technology for Determining Midseason Nitrogen Rates in Corn and Wheat
Authors: Raun W. R. , Solie J. B. , Taylor R. K. , Arnall D. B. , Mack C. J. , Edmonds D. E.
Published: June 2008

Midseason fertilizer N recommendations in corn (Zea mays L.) and wheat (Triticum aestivum L.) are not consistent from one region to the next. Preplant soil testing, yield goals, economic optimums, chlorophyll meters, and optical sensor‐based yield prediction models are limited regionally. The objective of this paper is to introduce an applied approach for applying preplant N fertilizer in automated gradients used for determining midseason N rates based on plant response. This approach assumes that midseason biomass estimated using normalized difference vegetation index (NDVI) sensor readings is directly related to corn and wheat grain yield, and that delaying applied N until midseason (eight‐leaf stage in corn and Feekes 5 in winter wheat) can result in near‐maximum yields. The ramped calibration strip (RCS) applicator applies 16 different incremental N rates (3‐to 6‐m intervals), over 45 to 90 m (number of rates, intervals, and distances can be adjusted depending on the crop). Because the RCS is superimposed on the farmer practice, producers can examine plant responsiveness over the range of rates to determine the optimum topdress N rate. The point where midseason growth differences no longer exist is the topdress N rate. Recording distance is required as you walk the RCS since distance is associated with an incremental N rate. Where adequate but not excessive preplant N is available, the ramp interpolated rate provides an applied method to determine how much midseason N should be applied to achieve the maximum yields based on growth response evidenced within the RCS.
Rooting Characteristics and Canopy Responses to Drought of Turfgrasses Including Hybrid Bluegrasses
Authors: Su Kemin , Bremer Dale J. , Keeley Steven J. , Fry Jack D.
Published: June 2008

Drought stress is common among cool‐season turfgrasses during summer in the U.S. transition zone. A 2‐yr field study was conducted near Manhattan, KS, to evaluate rooting characteristics and effects of drought on canopy physiology and appearance of ‘Apollo’ Kentucky bluegrass (Poa pratensis L.) (KBG), ‘Dynasty’ tall fescue (Festuca arundincea Schreb.) (TF), and two hybrid bluegrasses (HBG) ‘Reveille’ and ‘Thermal Blue’; HBG are genetic crosses between native Texas bluegrass (P. arachnifera Torr.) and KBG. Rooting characteristics were measured in the field and greenhouse under well‐watered conditions to evaluate root contributions to drought avoidance. Two irrigation treatments in the field included: (i) 60% (water‐deficit); and (ii) 100% (well‐watered) evapotranspiration (ET) replacement. Ninety to 96% of all root length (0–80 cm) in the field and 74 to 80% of all root length (0–120 cm) in the greenhouse were in the upper 30 cm among Thermal Blue, Reveille, and KBG while in TF, only 86 and 70% of all root length in the field and greenhouse, respectively, were in the top 30 cm. In the field, tall fescue had 3 to 12 times greater root length in the lower profile (60–80 cm) among turfgrasses. Visual quality and gross photosynthesis (Pg) were greatest in TF among turfgrasses in both irrigation treatments. Reveille used more water from the 0 to 50 cm profile and performed better than Thermal Blue during water‐deficit, but both HBG recovered from water‐deficit slightly faster than KBG. Performances in visual quality and Pg generally ranked: TF > Reveille ≥ Thermal Blue = KBG.