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Accepted, edited articles are published here after author proofing to provide rapid publication and better access to the newest research. Articles are compiled into issues at dl.sciencesocieties.org/publications/aj, which includes the complete archive.

Citation | Articles posted here are considered published and may be cited by the doi.

Zhu, Q., M.J. Schlossberg, R.B. Bryant, and J.P. Schmidt. 2012. Creeping bentgrass putting green response to foliar nitrogen fertilization. Agron. J. doi:10.2134/agronj2012.0157

Current issue: Agron. J. 108(4)



  • AGRONOMIC APPLICATION OF GENETIC RESOURCES

    • Xiaocong Zhang, HongJun Yong, Lin Zhang, Xianjun Liu, Jinge Hua, Chaoshu Zhang, Zhiqiang Zhou, Jianfeng Weng, Zhuanfang Hao, Degui Zhang, Mingshun Li, Shihuang Zhang, Zhenhua Wang and Xinhai Li
      Genetic Diversity of Seven Representative Germplasm Populations in Chinese Maize Breeding Programs

      Knowledge of the genetic diversity of elite germplasm is of fundamental importance for crop improvement. The objectives of this study were to examine molecular genetic diversity within and among seven representative germplasm populations in China, and identify valuable allelic variation that may be used in maize (Zea mays L.) improvement. Thirty individuals from each of the populations were genotyped using 61 simple sequence repeat (SSR) markers that are uniformly distributed across the entire maize genome. A total of 308 alleles were detected in the 210 genotypes assayed. (continued)

      Core Ideas:
      • Molecular genetic diversity within and among seven representative germplasm populations in Chinese maize breeding programs.
      • Alleles unique within each population or those at highly different frequencies among populations can be used to distinguish the seven maize populations and allow their efficient utilization in germplasm improvement.
      • Molecular characterization of the seven diverse maize populations will contribute to their efficient management and effective utilization in maize improvement.

      doi:10.2134/agronj2016.02.0073
      Published: July 21, 2016



  • AGRONOMY, SOILS & ENVIRONMENTAL QUALITY

    • A. M. P. Netthisinghe, P. B. Woosley, R. A. Gilfillen, T. W. Willian, K. R. Sistani and N. S. Rowland
      Corn Grain Yield and Soil Properties after 10 Years of Broiler Litter Amendment

      Use of broiler litter (BL) nutrients for crop production benefits crops, soils, and aids in disposing manure. Understanding corn (Zea mays L.) grain production and soil properties resulting from long-term BL amendment helps establish a sustainable manure-based corn production with low environmental risk potential. This study conducted at Bowling Green, KY, during 2005 to 2015 examined effects of supplying N requirement of corn grain crop monoculture by broiler litter (full broiler litter, FBL), 1:1 mixture of BL and inorganic N (half broiler litter rate, HBL), and chemical fertilizer (CF) on corn grain yield and post-harvest soil properties under no-till (NT) and conventional tillage (CT). The FBL produced significantly higher grain yield (10.1 Mg ha–1) than the HBL (9.6 Mg ha–1), but similar to CF (9.8 Mg ha–1). (continued)

      Core Ideas:
      • This study examined effects of long-term broiler litter amendment on corn grain yield and post-harvest soil properties.
      • Broiler litter at full and half rates has similar corn grain production potential as chemical fertilizer.
      • Broiler litter induced high soil nutrient levels, but levels elevated by half litter rate was not environmentally significant.
      • No-till and conventional tillage treatments have similar agronomic benefits and environmental risks.

      doi:10.2134/agronj2016.02.0113
      Published: July 28, 2016



    • Alexandra Keith, Balwant Singh, Feike A. Dijkstra and Floris van Ogtrop
      Biochar Field Study: Greenhouse Gas Emissions, Productivity, and Nutrients in Two Soils

      Application of biochar to soil has potential to reduce greenhouse gas (GHG) emissions, store C for long-term and provide agronomic benefits. However, the extent of these benefits are dependent on the type of biochar used and the environmental system in which it has been placed. While there are a large number of laboratory and glasshouse experiments, the number of biochar field studies is still limited. We conducted a 2-yr field study to evaluate the effect of a wood-based (blue mallee; Eucalyptus polybractea) biochar on GHG fluxes, pasture biomass, soil nutrient leaching, and nutrient uptake under different fertilizer rates in two soils (Arenosol and Cambisol) under a perennial pasture. (continued)

      Core Ideas:
      • A wood-based biochar was added to two soil types in a 2-yr field study.
      • Biochar had minimal effect on soil greenhouse gas emissions.
      • Biochar had no effect on plant biomass or soil leachate nutrient concentration.

      doi:10.2134/agronj2016.02.0074
      Published: July 21, 2016



    • Kun Han, Xue Han, Dell J. Curtis, Peter J.A. Kleinman, Dong Wang and Linquan Wang
      Impact of Irrigation, Nitrogen Fertilization, and Spatial Management on Maize

      Improving water and N use efficiency is essential to the sustainable intensification of irrigated agriculture, providing both crop production and environmental benefits. Partial root-zone irrigation has emerged as one of the most promising forms of deficit irrigation, irrigating only one side of the root zone during an irrigation event while keeping the other side dry. By alternating partial root-zone irrigation with N fertilization it is a possible trigger to physiologic responses in growing crops that reduce evapotranspiration as well as to curtail nitrate leaching associated with conventional irrigation. A growing body of research reveals that careful manipulation of irrigation and N fertilizer application increases maize yield, water use efficiency, and N use efficiency while decreasing soil N leaching, N2O emission, and NH3 loss. (continued)

      Core Ideas:
      • Part of the root system in drying soil could respond to drying by sending root-sourced signals, such as abscisic acid, to the shoots where some of stomata may be closed to reduce water loss by evapotranspiration, but with little effect on photosynthesis.
      • Partial root-zone irrigation could increase water use efficiency and nitrogne use efficiency, and improve fruits quality.
      • The separation of nitrogen and water with alternating furrow irrigation could not only keep the benefit of water saving due to soil re-watering and re-drying, but also have an effective strength on N use and reducing N leaching.
      • The soil moisture with fertilized furrows is co-related to the availability and losses of nutrients, which has a major role on the benefits of separation of nitrogen and water with alternating furrow irrigation.

      doi:10.2134/agronj2015.0551
      Published: June 29, 2016



  • BIOMETRY, MODELING & STATISTICS

    • Thiago W. A. Balsalobre, Melina C. Mancini, Guilherme da S. Pereira, Carina O. Anoni, Fernanda Z. Barreto, Hermann P. Hoffmann, Anete P. de Souza, Antonio A. F. Garcia and Monalisa S. Carneiro
      Mixed Modeling of Yield Components and Brown Rust Resistance in Sugarcane Families

      Sugarcane (Saccharum spp.) is a complex autopolyploid with high potential for biomass production that can be converted into sugar and ethanol. Genetic improvement is extremely important to generate more productive and resistant cultivars. Populations of improved sugarcane are generally evaluated for several traits simultaneously and in multi-environment trials. In this study, we evaluated two full-sib families of sugarcane (SR1 and SR2) at two locations and 3 yr for stalk diameter, stalk height, stalk number, stalk weight, soluble solid content (Brix), sucrose content of cane, sucrose content of juice, fiber, cane yield, sucrose yield, and resistance to brown rust (Puccinia melanocephala). (continued)

      Core Ideas:
      • A linear mixed model is efficient in production data analysis of sugarcane.
      • In general, the broad-sense heritability of the traits were high, ranging from 0.78 to 0.94.
      • A generalized linear mixed model can be applied in brown rust analysis of sugarcane.
      • Multi-environment trials were applied to the genetic improvement of sugarcane.

      doi:10.2134/agronj2015.0430
      Published: July 28, 2016



    • René Morissette, Guillaume Jégo, Gilles Bélanger, Athyna N. Cambouris, Judith Nyiraneza and Bernie J. Zebarth
      Simulating Potato Growth and Nitrogen Uptake in Eastern Canada with the STICS Model

      The ability of process-based soil–crop models to simulate potato (Solanum tuberosum L.) yield and N uptake for a range of N fertilization under the conditions of eastern Canada has never been tested. Our objectives were (i) to calibrate and evaluate the performance of the STICS model for the Shepody and Russet Burbank cultivars with cultivar-specific critical N concentration dilution curves, and (ii) to quantify the gain in model performance with cultivar-specific N concentration curves rather than a generic curve. Data sets including measurements of leaf area index (LAI), total and tuber biomass, and total and tuber N uptake for several N rates (0–280 kg N ha–1) collected at Charlottetown, PE; Fredericton, NB; and Québec, QC, Canada were used. Calibration was done with one data set from Charlottetown for Shepody and one data set from Québec for Russet Burbank, while all the other data sets were used to evaluate model performance. (continued)

      Core Ideas:
      • The STICS soil–crop model was calibrated and evaluated for two potato cultivars.
      • Calibrated and evaluated variables were LAI, total and tuber biomass, and total and tuber N uptake.
      • Cultivar-specific critical N concentration curves are recommended for N budget assessment.

      doi:10.2134/agronj2016.02.0112
      Published: July 28, 2016



    • Mahendra Dia, Todd C. Wehner and Consuelo Arellano
      Analysis of Genotype × Environment Interaction (G×E) Using SAS Programming

      Genotype × environment interaction (G×E) can lead to differences in the performance of genotypes across environments. A G×E analysis can be used to analyze the stability of genotypes and the value of test locations. We developed a SAS program (SASG×E) that calculates univariate stability statistics, descriptive statistics, pooled and yearly ANOVA, genotypic and location variation, cluster analysis for location, and correlations among stability parameters. Univariate stability statistics calculated are Wricke’s ecovalence (Wi2), Shukla’s variance (σi2), Lin and Binns cultivar superiority measure (Pi), Francis and Kannenberg coefficient of variation (CVi), Kang’s yield stability statistic (YSi), Perkins and Jinks β (βi), regression slope (bi), and deviation from regression (Sd2). (continued)

      Core Ideas:
      • Genotype × environment interaction can lead to differences in genotype performance.
      • G×E analysis can analyze genotype stability and the value of test locations.
      • SASG×E uses SAS and R programming to compute uni- and multi-variate stability statistics.
      • SASG×E output includes univariate stability statistics, ready to go input files, and R code for AMMI and GGE biplot analysis, ANOVA, descriptive statistics, cluster analysis of location, rank correlation among stability parameters, and Pearson correlation of location with average location performance.

      doi:10.2134/agronj2016.02.0085
      Published: June 29, 2016



  • CLIMATOLOGY & WATER MANAGEMENT

    • Emily H. Christ, Peter J. Webster, John L. Snider, Violeta E. Toma, Derrick M. Oosterhuis and Daryl R. Chastain
      Predicting Heat Stress in Cotton Using Probabilistic
      Canopy Temperature Forecasts

      Heat stress can reduce crop yield or even cause total crop failure. The ability to predict heat stress in advance would allow growers time to implement protective measures, helping to avoid such losses. This study presents a strategy for producing probabilistic heat stress forecasts for well-watered cotton (Gossypium hirsutum L.) in the Camilla, GA, region. Multiple linear regression was used to develop a cotton canopy temperature model based on predicted air temperature, humidity, solar radiation, and wind speed. (continued)

      Core Ideas:
      • Creating heat stress advisories for crops provide growers time to protect assets.
      • Coupling crop and atmospheric models translates weather data into usable information for growers.
      • Probabilistic canopy temperature forecasts can be used to evaluate on-farm weather-related risks.

      doi:10.2134/agronj2015.0576
      Published: July 28, 2016



  • CROP ECOLOGY & PHYSIOLOGY

    • Baohua Liu, Liang Wu, Xinping Chen and Qingfeng Meng
      Quantifying the Potential Yield and Yield Gap of Chinese Wheat Production

      Quantifying potential yield (PY) and yield gap (YG) is essential for prioritizing research and formulating food security policies. Here we used the highest recorded yield published in the literature based on 213 sites (n = 548) across China to estimate PY, the best farmers’ yield (the mean yield of 94th to 99th decile) according to 4552 farm surveys to estimate attainable yield (AY) in five wheat (Triticum aestivum L.) agro-ecological regions in China. These data were compared with the average farmers’ yield (FY) to assess YG. The PY averaged 9.0 Mg ha–1 while AY was 8.0 Mg ha–1. (continued)

      Core Ideas:
      • We evaluated potential yield and yield gap of wheat production for all of China.
      • Yield gap was calculated based on field measurements and farmer surveys.
      • Farmers achieved 62% of potential yield and 71% of attainable yield.
      • Wheat yield gaps varied a great deal across China.

      doi:10.2134/agronj2016.03.0147
      Published: August 11, 2016



    • B. L. Ma, H. Zhao, Z. Zheng, C. Caldwell, A. Mills, A. Vanasse, H. Earl, P. Scott and D. L. Smith
      Optimizing Seeding Dates and Rates for Canola Production in the Humid Eastern Canadian Agroecosystems

      Optimum seeding date (OSD) and seeding rate is an important management practice to improve the performance of canola (Brassica napus L.) production. A field study was conducted to investigate the influence of seeding date and rate on plant stand count, yield components, yield, and seed oil and protein concentrations, and to develop a location-sensitive model for estimating OSD for maximizing canola yield. The factorial experiment of three seeding dates (early, intermediate, and late) and three seeding rates (2.5, 5.0, and 7.5 kg ha–1) was performed in 2011 and 2012 at seven locations across eastern Canada. An independent dataset from an additional 2-yr field experiment at the Ottawa site was used for model verification. (continued)

      Core Ideas:
      • Quantitative relationship between optimum seeding date and mean minimum temperature in April and May.
      • A regression model to predict optimum seeding date for spring canola.
      • A suitable seeding rate for canola production in eastern Canada.
      • The impact of seeding date on canola seed oil and protein concentration.
      • Canola yield and yield components as affected by seeding date and rate.

      doi:10.2134/agronj2015.0209
      Published: July 28, 2016



    • A. Varmaghani and W. E. Eichinger
      Early-Season Classification of Corn and Soybean Using Bayesian Discriminant Analysis on Satellite Images

      There are numerous applications that require crop classification as early as possible in the growing season. However, information about land cover from official land cover maps of the United States (cropland data layer [CDL] maps by the National Agricultural Statistics Service) are generally not available until after harvest. In the Upper Midwest, the primary rotating crops are corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] (covering ~63% of Iowa) with an irregular annual rotation. This study investigated the feasibility of early-season classification of corn and soybean fields in Iowa by comparing the current and previous years’ 30-m 16-d Landsat 8 images during the growing season to produce normalized difference vegetation index (NDVI) maps, along with the last-updated CDL land cover, to construct “agricultural units.” We assigned a geometric weight to each unit by performing Bayesian discriminant analysis using the concept of a sliding threshold to categorize pixels. (continued)

      Core Ideas:
      • Classification of corn and soybeans in Iowa is important early in the season.
      • Bayesian discriminant analysis and field geometry were combined with a sliding threshold.
      • This geometrical approach is a promising method for early-season crop classification.

      doi:10.2134/agronj2015.0454
      Published: July 21, 2016



  • CROP ECONOMICS, PRODUCTION & MANAGEMENT

    • Dâmiany Pádua Oliveira, Marislaine Alves de Figueiredo, Bruno Lima Soares, Otávio Henrique Stivanin Teixeira, Fábio Aurélio Dias Martins, Márcia Rufini, Augusto Ramalho de Morais, Fatima Maria de Souza Moreira and Messias José Bastos de Andrade
      Seed Treatment with Fungicides Does Not Affect Symbiosis between Common Bean and Rhizobia

      Results of the few studies on the symbiosis of rhizobia and common bean (Phaseolus vulgaris L.) that have evaluated the effects of new fungicides applied to seeds have been inconclusive, that is, some showed no effects and others showed harmful effects. This study tested the compatibility between commercial fungicides, currently recommended for treatment of seeds, and symbiosis of common bean with rhizobia. Two field experiments were performed in the 2012/2013 spring–summer crop season in two Brazilian municipalities. A randomized block experimental design with four replicates and a 5 × 2 factorial arrangement was used, consisting of five seed treatments {the fungicides: carboxin(carboxamide) + thiram (dimethyldithiocarbamate) = Vitavax-Thiram (Macdermid Agricultural Solutions Ltda, Sumaré, Brazil); fludioxonil(phenylpyrrol) + metalaxyl-M(acilalaninato) = MaximXL (Syngenta Ltda, São Paulo, Brazil); fluazinam (phenylpyridin-amine) + thiophanate-methyl[benzimidazole(precursor of)] = Certeza (Iharabras S.A., Sorocaba, Brazil), and carbendazim (benzimidazole) = Carbomax (Nufarm S.A., Maracanaú, Brazil) and one control without fungicide} with or without rhizobial inoculation. (continued)

      Core Ideas:
      • Environment influences effects of fungicide on rhizobia symbiosis.
      • Native rhizobia resulted in grain yield similar to inoculation with CIAT 899T.
      • The fungicides did not influence rhizobia symbiosis effects on plant.

      doi:10.2134/agronj2016.02.0105
      Published: August 4, 2016



    • Tiago A. N. Hörbe, Telmo J. C. Amado, Geovane B. Reimche, Raí A. Schwalbert, Antônio L. Santi and Cristian Nienow
      Optimization of Within-Row Plant Spacing Increases Nutritional Status and Corn Yield: A Comparative Study

      Uniform within-row plant spacing is a key crop management strategy to achieve high corn (Zea mays L.) yield. A new precision planting concept is emerging based on the use of modern devices in planters. The objective of this study was to investigate the impact of optimizing within-row plant spacing to enhance plant nutritional status and corn yield. The treatments investigated were (a) traditional planter with mechanical horizontal plate metering system (TP), (b) precision planter with vSet (Precision Planting, Tremont, IL) vacuum meter system (PP) and (c) PP pulled by a tractor equipped with an real time kinematic (RTK)-based auto-steering system (APP). (continued)

      Core Ideas:
      • For every 10 percentage points increase in CV, yield decreased 1.22 Mg ha–1.
      • A higher plant spacing uniformity is necessary to achieve high yields.
      • Different planter types produced distinct within-row plant spacing uniformity.

      doi:10.2134/agronj2016.03.0156
      Published: July 28, 2016



    • Marie-Pier Aubin, Philippe Seguin, Anne Vanasse, Olivier Lalonde, Gaëtan F. Tremblay, Arif F. Mustafa and Jean-Benoit Charron
      Evaluation of Eleven Industrial Hemp Cultivars Grown in Eastern Canada

      Industrial hemp (Cannabis sativa L.) is a multipurpose crop for which there is growing interest in Canada. There is, however, currently limited information on the adaptation and production potential of government approved cultivars in eastern Canada. Eleven cultivars were evaluated in terms of biomass and seed yields and composition, when grown in seven contrasted environments in the province of Québec. Dry matter yields varied considerably across cultivars and environments, ranging between 172 and 8837 kg ha–1 (average of 3226 kg ha–1) for biomass, and between 47 and 3781 kg ha–1 (average of 1315 kg ha–1) for seeds. (continued)

      Core Ideas:
      • Biomass and seed dry matter yields of the 11 industrial hemp cultivars evaluated varied considerably across cultivars and environments.
      • Despite the presence of cultivar × environment interactions for biomass and seed yields, some cultivars consistently produced high yields of both biomass and seeds.
      • Limited variation was observed among cultivars in terms of biomass and seed chemical composition.

      doi:10.2134/agronj2016.04.0217
      Published: July 28, 2016



    • Wei Zhou, Tengfei Lv, Peipei Zhang, Yun Huang, Yong Chen and Wanjun Ren
      Regular Nitrogen Application Increases Nitrogen Utilization Efficiency and Grain Yield in Indica Hybrid Rice

      On the basis of research and practical production experience of many years, regular nitrogen fertilizer application (RFA) was used to improve rice (Oryza sativa L.) yield and increase nitrogen utilization efficiency (NUE). Two field experiments (manually transplanted rice with three indica hybrid rice cultivars and four N treatments, mechanically transplanted rice with eight N applications) were conducted in 2011 and 2012, to investigate the effects of RFA on rice yield and NUE. The results showed that RFA increased the total amount of N uptake in the plants and improved NUE when compared with the farmers’ nitrogen fertilizer practices (FFP). The average increment in agronomy efficiency (AE), recovery efficiency (RE), and partial factor productivity for applied nitrogen (PFP) were 12.16, 10.91, and 6.01% for the mechanically transplanted rice and 30.81, 65.57, 6.18% for the manually transplanted rice. (continued)

      Core Ideas:
      • Regular nitrogen fertilizer application significantly increased grains per panicle and then improve rice yield.
      • Regular nitrogen fertilizer application improved plant N concentration and then increased N use efficiency.
      • Jointing stage and 15 to 20 d after jointing stage are the two key stages to apply N fertilizers.
      • Regular N fertilizer application is suitable for both manually and mechanically transplanted rice.

      doi:10.2134/agronj2016.03.0137
      Published: July 28, 2016



    • Jennifer L. Corbin, John M. Orlowski, Dustin L. Harrell, Bobby R. Golden, Larry Falconer, L. Jason Krutz, Jeffrey Gore, Michael S. Cox and Timothy W. Walker
      Nitrogen Strategy and Seeding Rate Affect Rice Lodging, Yield, and Economic Returns in the Midsouthern United States

      Seeding rate and N application strategies have been extensively researched for drill-seeded, delayed flood rice (Oryza sativa L.) production in the midsouthern United States. However, little economic analysis has been performed to determine the effects of seeding rate and N fertilization strategies on high-yielding, lodging susceptible rice cultivars. The purpose of this research was to determine the effect of multiple N fertilization strategies and seeding rates on rice lodging and grain yield and use the data to determine optimal rice management practices based on evaluation of economic returns. Studies were established in Louisiana and Mississippi during the 2010 and 2012 growing seasons. (continued)

      Core Ideas:
      • Split N application in rice limits lodging but also reduce grain yield.
      • High N rates and seeding rates increase lodging and harvest costs.
      • Appropriate early-season (preflood) N is necessary to maximize rice grain yield.

      doi:10.2134/agronj2016.03.0128
      Published: July 21, 2016



    • Wes Weeks, Michael P. Popp, Montserrat Salmeron, Larry C. Purcell, Edward E. Gbur, Fred M. Bourland, Normie W. Buehring, Larry Earnest, Felix B. Fritschi, Bobby R. Golden, Daniel Hathcoat, Josh Lofton, Angela Thompson McClure, Travis D. Miller, Clark Neely, Grover Shannon, Theophilus K. Udeigwe, David A. Verbree, Earl D. Vories, William J. Wiebold and Bruce L. Dixon
      Diversifying Soybean Production Risk Using Maturity Group and Planting Date Choices

      While soybean [Glycine max (L.) Merr.] production risk is typically managed by planting a range of maturity groups (MGs) across a few different planting dates (PDs), there have been no reports that have quantified changes in risk and profitability using this diversification strategy. Three years of field-trial data from eight locations in six states were analyzed to determine risk–return tradeoffs across MG and PD. Producer revenue expectations were adjusted by soybean harvest date, assessing oil and meal premiums or discounts, and differential irrigation requirements by MG and PD, whereas costs for seed, fuel, fertilizer, equipment, and chemicals were held constant. Using portfolio theory, an efficient frontier—maximizing net returns for a given level of risk or minimizing risk for a given level of net return—was estimated by location. (continued)

      Core Ideas:
      • Producers often like to diversify by planting across a range of dates and maturity groups.
      • Diversification is common but risk–return tradeoffs have not been meaningfully quantified.
      • Early-season planting combinations were riskier but led to sale price premiums.
      • Using two to six combinations lowered risk by 29–40% but decreased returns by 2–22%.

      doi:10.2134/agronj2016.01.0056
      Published: July 21, 2016



    • C. L. Keene and W. S. Curran
      Optimizing High-Residue Cultivation Timing and Frequency in Reduced-Tillage Soybean and Corn

      Integrated weed management (IWM) practices are needed to prevent the development of herbicide-resistant weeds and create more robust weed management programs. This experiment was conducted to determine the optimal timing and frequency of high-residue cultivation in reduced-tillage soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) in Pennsylvania. Banded herbicides were applied at planting and high-residue cultivation frequency ranged from one to three passes. A split-plot assessed the effects of cover crop residue, either cereal rye (Secale cereale L.) in soybean or a hairy vetch (Vicia villosa Roth)-triticale (X Triticosecale Wittm.) mixture in corn, on weed control and yields. (continued)

      Core Ideas:
      • New integrated weed management approaches are greatly needed in reduced-tillage systems to help preempt the continued evolution of herbicide-resistant weeds.
      • High-residue interrow cultivation following banded herbicide application at planting is an in-season weed management program that combines mechanical and chemical weed control tactics. Under conditions of the experiment, two passes with a high-residue cultivator achieved similar cash crop yield as a post-glyphosate application in soybean and corn. Single-pass treatments usually resulted in higher weed biomass and lower yields than two-pass treatments, and no weed control or crop yield benefit was observed with three passes.
      • Rolled cereal rye and hairy vetch–triticale cover crop residues increased soybean and corn yields, respectively, in dry years despite increasing weed biomass.
      • Economic analyses indicated that the benefit to cash crop yield from cover crop residues will not likely exceed establishment costs in every year; however in dry years, residues can increase cash crop yield beyond breakeven levels. The higher seed cost of the hairy vetch–triticale used before corn was able to pay for itself if N provided by the hairy vetch was assumed to offset the cost of urea fertilizer.

      doi:10.2134/agronj2015.0604
      Published: July 14, 2016



    • Pengfei Zhao, Guoxin Cao, Yi Zhao, Hongyan Zhang, Xinping Chen, Xiaolin Li and Zhengling Cui
      Training and Organization Programs Increases Maize Yield and Nitrogen-Use Efficiency in Smallholder Agriculture in China

      The knowledge and technologies to achieve both high yield and high N-use efficiency in northern China already existed; however, there has been little progress in their implementation. We hypothesized that their adoption could be improved by offering farmers training programs (TPs, two trainings a year) and organizational and training programs (OTPs, besides training, which also provide in- field guidance and the cooperative purchase of seeds and fertilizers by groups of smallholder farmers.). In this study we evaluated maize (Zea mays L.) yield, N application rates, N-use efficiency (partial factor productivity), net economic gains (defined as the difference between economic return of maize and N fertilizer cost), and technology adoption rate by farmers in a county who were assigned to TP and OTP groups vs. those following conventional farming practices (FPs) during the years 2009 to 2013. (continued)

      Core Ideas:
      • Maize yield and N-use efficiency was significantly increased by offering farmer training program and organizational and training program.
      • Adoption rate of the technology package was improved by farmers who attended the training program and the organizational and training program.
      • These results demonstrated that innovation and participatory approaches in agronomic and management practices are essential to improve both grain yield and N-use efficiency in the smallholder agriculture.

      doi:10.2134/agronj2016.03.0130
      Published: August 4, 2016



    • Wenhai Mi, Xin Yang, Lianghuan Wu, Qingxu Ma, Yanling Liu and Xuan Zhang
      Evaluation of Nitrogen Fertilizer and Cultivation Methods for Agronomic Performance of Rice

      Nitrogen fertilization and cultivation methods are the two principal management approaches used in agronomy to determine the growth and grain yield of rice. In this study, a field experiment was conducted to evaluate the performance of three cultivation methods (conventional manual transplanting of field-grown seedlings [TFS], direct seeding [DS], and transplantation of glasshouse-grown seedlings followed by manual transplanting [TGS]) under two N management treatments (split applications of urea [PU] vs. a single basal application of a controlled-release fertilizer [CRF]) for growing rice under a subtropical monsoon climate in China (2011–2014). Annual grain yield, yield components, and total biomass were determined at maturity over the 4-yr experiment. (continued)

      Core Ideas:
      • Controlled-release fertilizer increased the grain yield compared with urea for transplanting rice.
      • Split applications of urea produced more grain yield than controlled-release fertilizer for direct seeding rice.
      • Conventional manual transplanting of field-grown seedlings and glasshouse-grown seedlings followed by manual transplanting produced higher grain yield than direct seeding, irrespective of how N was managed.

      doi:10.2134/agronj2016.01.0038
      Published: June 29, 2016



  • ERRATUM

    • William L. Pan, Tai McClellan Maaz, W. Ashley Hammac, Vicki A. McCracken and Richard T. Koenig
      Mitscherlich-Modeled, Semi-Arid Canola Nitrogen Requirements Influenced by Soil Nitrogen and Water

      doi:10.2134/agronj2015.0378er
      Published: July 28, 2016



  • FORUM

    • Dennis Timlin, Olaf David, Timothy R. Green, David H. Fleisher, Soo-Hyung Kim and Laj R. Ahuja
      Proposed Standards for Peer-Reviewed Publication of Computer Code

      The use of computers in agricultural research has expanded rapidly in recent years. Such code can be considered a scientific product that has applications in both research and education. Usage of this code can be expanded to a wide range of potential end users. We propose that the Agronomy Journal peer review and publish software code in the form of small, self-contained modules. (continued)

      Core Ideas:
      • Computer models are scientific products important for both reseach and education.
      • The computer code is subject to change and may be used by a wide variety of people.
      • Code for these models should be written in a clear, understandable format and be well documented.
      • Well documented and well written code will increase the scientific value of the code.

      doi:10.2134/agronj2015.0481
      Published: July 28, 2016



  • NOTES & UNIQUE PHENOMENA

    • David W. Franzen, Lakesh K. Sharma, Honggang Bu and Anne Denton
      Evidence for the Ability of Active-Optical Sensors to Detect Sulfur Deficiency in Corn

      Prediction of S deficiency is difficult due to poor soil test relationship to crop response. The purpose of this article is to provide evidence that the use of an N-sufficient area established for use as a standard for active-optical (AO) sensor directed in-season N application could also serve to detect S deficiency in corn (Zea mays L.). Nitrogen rate experiments at Oakes and Arthur, ND, exhibited corn upper-leaf yellowing in high N treatments while control treatments (0 N) were greenest. Two AO sensors were utilized to record red normalized differential vegetation index (NDVI) and red edge NDVI values. (continued)

      Core Ideas:
      • Sulfur deficiency in corn is difficult to anticipate using soil analysis.
      • When N availability is low, the affect of S deficiency in corn is minimized.
      • When N availability is high, the affect of S deficiency is intensified.
      • Active-optical sensors can be used along with an N-sufficient area to reveal S deficiency.

      doi:10.2134/agronj2016.05.0287
      Published: August 4, 2016



  • ORGANIC AGRICULTURE & AGROECOLOGY

    • Elina M. Snyder, Heather D. Karsten, William S. Curran, Glenna M. Malcolm and Jeffrey A. Hyde
      Green Manure Comparison between Winter Wheat and Corn: Weeds, Yields, and Economics

      Red clover (Trifolium pratense L.) and hairy vetch (Vicia villosa Roth) are leguminous crops (“green manure” hereafter), widely studied for their N2-fixing contributions to cropping systems. Under certain circumstances they can provide weed control in cash crops. This study compared weed control, crop yields, herbicide use, and economic performance of these green manures in a no-till winter cereal–green manure–corn (Zea mays L.) silage cropping sequence in central Pennsylvania. Red clover was interseeded into winter wheat (Triticum aestivum L.) or rye (Secale cereale L.), while hairy vetch and triticale (X Triticosecale) were planted after winter cereal harvest. (continued)

      Core Ideas:
      • As a green manure, red clover provided multiple benefits over hairy vetch and triticale.
      • Red clover underseeded in winter grain, produced continuous cover, forage, and higher corn yield.
      • Compared to hairy vetch and triticale, red clover controlled weeds with less herbicide.
      • Red clover was more profitable than hairy vetch.

      doi:10.2134/agronj2016.02.0084
      Published: July 21, 2016



    • J. T. Spargo, M. A. Cavigelli, S. B. Mirsky, J. J. Meisinger and V. J. Ackroyd
      Organic Supplemental Nitrogen Sources for Field Corn Production after a Hairy Vetch Cover Crop

      Legume cover crops and organic amendments in combination could meet corn (Zea mays L.) nitrogen (N) needs while optimizing phosphorus (P) inputs. In a 2-yr field study, we characterized the N-mineralization dynamics and impacts on corn grain yield of feather meal (FM), poultry litter (PL), pelletized PL (PPL), and a PPL-FM blend (PFMB) with or without a hairy vetch (Vicia villosa Roth) cover crop. The four amendments, which differed substantially in chemical and laboratory N-release characteristics, provided corn yield benefits only when vetch biomass was low. In 2010, vetch produced 4630 kg biomass ha−1 and increased corn grain yield from 8.7 to 13.3 Mg ha−1 compared with a no-vetch treatment. (continued)

      Core Ideas:
      • Impact of organic amendments on corn grain yield depends on vetch biomass production.
      • Organic amendments did not increase corn yield when vetch biomass was >4500 kg ha–1.
      • Vetch provided no benefit to corn yield when biomass was <1600 kg ha–1.
      • Organic amendments increased corn yield when vetch biomass was <1600 kg ha–1.
      • Amendments applied at 45 kg N ha–1 did not raise concerns about residual P.

      doi:10.2134/agronj2015.0485
      Published: July 14, 2016



    • Kristen Podolsky, Robert E. Blackshaw and Martin H. Entz
      A Comparison of Reduced Tillage Implements for Organic Wheat Production in Western Canada

      Low-tillage systems are needed to improve soil conservation in organic farming. This study evaluated three no-till/low-till cover crop termination strategies on the basis of weeds, N dynamics and growth and yield of a wheat (Triticum aestivum L.) test crop. Field experiments were conducted in two different Canadian provinces. The blade roller, flail mower, and undercutter cultivator were comparable with standard tillage for controlling a full-season barley (Hordeum vulgare L.)–pea (Pisum sativum L.) cover crop. (continued)

      Core Ideas:
      • Alternative tillage tools were tested for control of cover crops preseeding spring wheat.
      • Perennial weeds meant low tillage options were not feasible when wheat seeding was delayed.
      • Undercutting liberated more cover crop N than blade roll but weeds sometimes captured this N.

      doi:10.2134/agronj2016.01.0032
      Published: June 29, 2016



    • Suellen B. de M. Costa, Alexandre C. L. de Mello, José C. B. Dubeux, Mércia V. F. dos Santos, Mario de A. Lira, João T. C. Oliveira and Valéria X. O. Apolinário
      Livestock Performance in Warm-Climate Silvopastures Using Tree Legumes

      Tree legumes are a viable option to increase ecosystem services provided by warm-climate grasslands. Benefits of using tree legumes in silvopasture systems (SPS) include the provision of shade for livestock, biological N2 fixation, and C sequestration. This study assessed cattle performance and pasture characteristics in signalgrass (Brachiaria decumbens Stapf.) pastures in monoculture or in SPS. The following treatments were assessed: (i) signalgrass/sabiá (Mimosa caesalpiniifolia Benth.), (ii) signalgrass/gliricidia [Gliricidia sepium (Jacq.) Kunth ex Walp.], and (iii) signalgrass monoculture. (continued)

      Core Ideas:
      • Livestock production was similar in silvopasture systems and signalgrass monoculture.
      • Silvopasture systems provided additional ecosystem services compared with grass monoculture.
      • The use of tree legumes adds biologically fixed N2 and provide other ecosystem services.
      • Trees compete with herbaceous vegetation and might reduce livestock production in the long term.

      doi:10.2134/agronj2016.03.0180
      Published: June 24, 2016



  • REVIEW & INTERPRETATION

    • Dave Franzen, Newell Kitchen, Kyle Holland, James Schepers and William Raun
      Algorithms for In-Season Nutrient Management in Cereals

      The demand for improved decision-making products for cereal production systems has placed added emphasis on using plant sensors in-season, and that incorporate real-time, site specific, growing environments. The objectives of this work were to describe validated in-season sensor-based algorithms presently being used in cereal grain production systems for improving nitrogen use efficiency (NUE) and cereal grain yields. A review of research programs in the central Great Plains that have developed sensor-based N recommendations for cereal crops was performed. Algorithms included multiple land-grant university, government, and industry programs. (continued)

      Core Ideas:
      • Normalized difference vegetation index algorithms can improve fertilizer N efficiency.
      • Normalized difference vegetation index sensors currently sold employ these algorithms.
      • Algorithms rely on knowledge that increased yields increase fertilizer N demand.
      • Yield potential and N response are independent.
      • Nitrogen-rich strips help to predict in-season grain yields.

      doi:10.2134/agronj2016.01.0041
      Published: July 14, 2016



    • J. L. Guil-Guerrero, L. Ramos, C. Moreno, J. C. Zúñiga-Paredes, M. Carlosama-Yepez and P. Ruales
      Plant Foods By-Products as Sources of Health-Promoting Agents for Animal Production: A Review Focusing on the Tropics

      In recent years there has been an increasing trend toward antibiotic use for animal production in tropical countries. As a suitable alternative to such drugs, several highly available plant-food by-products are reviewed here as supplements to feed farm animals. Such materials contain bioactive compounds, such as phenolics, carotenoids, saponins, essential oils, active peptides, and sterols. Phenolics are abundant in mango, avocado, and potato peels and are also found in pineapple and papaya by-products. (continued)

      Core Ideas:
      • Crop by-products from tropical countries contain high levels of bioactive compounds.
      • Mango, avocado, and potato peels contain high concentrations of phenolics.
      • By-products of tropical origin could help against microbial resistance to antibiotics.
      • Carotenoids stand out in papaya by-products and essential oils in mango peels.

      doi:10.2134/agronj2015.0555
      Published: July 14, 2016



  • SOIL FERTILITY & CROP NUTRITION

    • Trenton L. Roberts, Nathan A. Slaton, Jason P. Kelley, Chester E. Greub and Anthony M. Fulford
      Fertilizer Nitrogen Recovery Efficiency of Furrow-Irrigated Corn

      Corn (Zea mays L.) yield under irrigated production systems is influenced by N rate and timing of application. This study was conducted to determine how current N application strategies (two-way vs. three-way split application) and N rate (optimal vs. suboptimal) influence fertilizer-nitrogen recovery efficiency (FNRE) for furrow-irrigated corn production in the mid-South. (continued)

      Core Ideas:
      • Fertilizer N recovery efficiency ranged from 61 to 91%.
      • Fertilizer N recovery efficiency influenced by rate and application timing.
      • High fertilizer N recovery efficiency can be achieved in irrgated corn production systems.

      doi:10.2134/agronj2016.02.0092
      Published: August 11, 2016



    • Harold P. Collins, Emi Kimura, Craig S. Frear and Chad E. Kruger
      Phosphorus Uptake by Potato from Fertilizers Recovered from Anaerobic Digestion

      The rising costs of fertilizers have encouraged the development of technologies to recover nutrients from dairy, cattle, swine, and poultry operations. Field experiments were conducted in the Columbia Basin of Washington to assess the yield of potato (Solanum tuberosum L.) to application of P-enriched materials recovered from anaerobic digestion of manure. Four rates of P from five sources, three recovered from anaerobic digesters (AD), AD-dairy P-enriched fine solids (ADD), AD centrifuged poultry solids (ADP), and AD dairy struvite-P (ADS) compared to a commercial poultry fertilizer (PBP) were compared to mono-ammonium phosphate (MAP) and non-amended control (No-P). Fertilized treatments had higher yields than the No-P treatment. (continued)

      Core Ideas:
      • Phosphorus recovered from anaerobic digesters can effectively substitute for commercial mined P fertilizers.
      • Potato yields among recovered P fertilizers and rates of P application were not significantly different.
      • Recovered P fertilizer performed similarly when equal rates were applied and method of application was comparable.

      doi:10.2134/agronj2015.0302
      Published: August 11, 2016



    • Bobby R. Golden, John M. Orlowski and Jason A. Bond
      Corn Injury from Foliar Zinc Application Does Not Affect Grain Yield

      Zinc deficiency symptoms have been observed on corn (Zea mays L.) grown on coarse-textured, high-pH soils in the Mississippi Delta. To correct deficiencies, many corn producers apply foliar Zn. Corn injury from foliar Zn application has been observed; however, it is not clear whether foliar Zn injury affects grain yield. Also, little information currently exists about the ability of foliar Zn sources to increase corn tissue Zn concentration. (continued)

      Core Ideas:
      • Citrate-Zn application to corn caused more foliar injury than EDTA-Zn and Zinc sulfate.
      • Citrate-Zn resulted in highest corn tissue Zn concentrations.
      • Corn injury from foliar Zn application did not affect grain yield.

      doi:10.2134/agronj2015.0593
      Published: July 28, 2016



    • Yan Li, Haijun Liu and Guanhua Huang
      The Effect of Nitrogen Rates on Yields and Nitrogen Use Efficiencies during Four Years of Wheat–Maize Rotation Cropping Seasons

      Nitrogen is a major limiting factor to crop production of the intensive wheat (Triticum aestivum L.)–maize (Zea mays L.) rotation cropping system in the North China Plain (NCP). This 4-yr study was to evaluate the effects of N application on soil NO3–N dynamics and N use efficiency under sprinkler irrigation in the Beijing region of the NCP. There were four treatments, named CK, N1, N2, N3 with N application of 0, 110, 220, and 330 kg N ha–1 per crop season, respectively. Results indicate that no water and NO3–N leached out of the 0 to 100 cm soil layer in the winter wheat seasons, whereas they moved into soil layers deeper than 100 cm in the summer maize seasons. (continued)

      Core Ideas:
      • Larger deep percolation and nitrate leaching were found in maize season than those in wheat season.
      • Nitrogen application greatly improved crop growth and yield.
      • Application of 110 to 130 kg N ha–1 per crop season is recommended for the wheat–maize cropping system in the North China Plain.

      doi:10.2134/agronj2015.0610
      Published: July 28, 2016



    • Estêvão Vicari Mellis, José Antonio Quaggio, Gustavo Ricardo Gonçalves Becari, Luiz Antonio Junqueira Teixeira, Heitor Cantarella and Fabio Luiz Ferreira Dias
      Effect of Micronutrients Soil Supplementation on Sugarcane in Different Production Environments: Cane Plant Cycle

      Fertilization of sugarcane (Saccharum spp.) with micronutrients is not common and this can affect crop yield. Research results of micronutrients in sugarcane in Brazil are still scarce and inconclusive. The aim of the present study was to assess the sugarcane crop response to Cu, Zn, Mn, Mo, and B fertilization in different sugarcane production environments in the state of São Paulo, Brazil. An experiment was conducted at 11 locations. (continued)

      Core Ideas:
      • Micronutrients can increase sugarcane yield.
      • Zinc is the principal micronutrient to sugarcane producer.
      • The application of high doses of micronutrients may increase the productivity of sugarcane Brazilians.

      doi:10.2134/agronj2015.0563
      Published: July 28, 2016



    • Susana M. Albarenque, Bruno Basso, Octavio P. Caviglia and Ricardo J.M. Melchiori
      Spatio-Temporal Nitrogen Fertilizer Response in Maize: Field Study and Modeling Approach

      Maize (Zea mays L.) yield and its response to nitrogen (N) are affected by the spatial variability of the interaction between weather, management, and soil properties. The objectives of this study were (i) to evaluate the response of spatial variability of maize yield by homogeneous zones (HZs) to different N fertilizer rates under rainfed conditions, (ii) to test the ability of the SALUS (System Approach to Land Use Sustainability) model to simulate the effects of N rates on maize yield under rainfed and irrigated conditions, and (iii) to estimate spatial and temporal N fertilizer response risk in maize through the use of long-term simulations. In two field experiments in Parana, Argentina (−31.8333°, −60.5167°) in 2011 (Field 1) and 2012 (Field 2), four fertilization treatments (0, 70, 140, and 210 kg ha−1) were evaluated in different HZs. The SALUS model was used to evaluate spatial variability in yield, N response, and net revenue over the long-term period (1971–2012). (continued)

      Core Ideas:
      • Model-based approach accounted for spatio-temporal variability of maize N response.
      • Temporal variability of grain yield, N response, and net revenue increased with N rate.
      • The N rate required to reach the highest net revenue differed between homogenous zones within fields.
      • Selecting N rate by homogenous zones might reduce environmental and economic risk.

      doi:10.2134/agronj2016.02.0081
      Published: August 4, 2016



    • Qiang Ji, Shi-Xiang Zhao, Zhong-Hui Li, Yuan-Yuan Ma and Xu-Dong Wang
      Effects of Biochar-Straw on Soil Aggregation, Organic Carbon Distribution, and Wheat Growth

      Exogenous C application can improve the physicochemical properties and fertility of soil. This study was conducted to determine whether the application of biochar (BC) was better than straw for improving soil structure and crop growth. The short-term effects of exogenous C application on the size distribution of water-stable aggregates, organic C sequestration, and grain yield of winter wheat (Triticum aestivum L.) were investigated on a silty clay loam soil in the Guanzhong Plain, Northwest China. Biochar and straw were applied at equal C rates: 1, 3, and 10% in straw treatments (Str1.0, Str3.0, and Str10.0, respectively) and 0.8, 2.4, and 8% in BC treatments (BC0.8, BC2.4, and BC8.0, respectively). (continued)

      Core Ideas:
      • Biochar addition enhanced macroaggregate formation and microaggregate agglomeration.
      • Biochar particles mostly existed in the macroaggregate (>0.25 mm) fractions.
      • Low and moderate biochar application at 0.8% and 2.4% increased microbial biomass C and wheat yield.
      • Heavy straw application at 3% and 10% inhibited wheat growth and yield increase.

      doi:10.2134/agronj2016.02.0121
      Published: August 4, 2016



    • Tai Maaz, William Pan and W. Hammac
      Influence of Soil Nitrogen and Water Supply on Canola Nitrogen Use Efficiency

      Nitrogen fertilizer requirements for economic optimization of spring canola (Brassica napus L.) production in eastern Washington varies with yield potential. Recent research has revealed that more N is needed per unit of grain (UNR) as yield potential decreases. Because UNR is the inverse of N use efficiency (NUE) at optimal yield, the implication of this research is that canola becomes less efficient at using N as yield potential decreases. Our research goal was to identify the NUE components that contribute to higher potential yields with more available water. (continued)

      Core Ideas:
      • Spring canola exhibited Mitscherlich response to soil N and Liebig response to plant N.
      • Water availability limited yields by restricting N utilization, retention, and uptake.
      • Water availability limited grain N accumulation by lowering N uptake from soil.

      doi:10.2134/agronj2016.01.0008
      Published: June 29, 2016



    • Bijesh Maharjan, Carl J. Rosen, John A. Lamb and Rodney T. Venterea
      Corn Response to Nitrogen Management under Fully-Irrigated vs. Water-Stressed Conditions

      Characterizing corn (Zea mays L.) grain yield (GY) response to N is critical for maximizing profits, increasing N use efficiency and minimizing environmental impacts. Although a large database of GY response to N exists for highly productive soils, few data exist for less productive soils. While changes in precipitation are expected in the future, few studies have compared GY response to varying N management practices under conditions of varying water availability. We measured GY and basal stalk nitrate nitrogen (BSN) at harvest using split-applied urea at eight N rates under fully-irrigated (FI) and water-stressed (WS) conditions in a loamy sand over 2 yr (2009 and 2010). (continued)

      Core Ideas:
      • Better understanding of water stress effects on corn response to N is needed.
      • We measured yield response to N management with full irrigation and under water-stress.
      • Optimum N rate did not vary by water management despite significant yield differences.
      • Optimizing fertilizer timing or source increased yield but only with full irrigation.
      • Basal stalk nitrate was higher with water-stress than with full irrigation.

      doi:10.2134/agronj2016.01.0006
      Published: June 24, 2016



    • R. Sakurada L., M. A. Batista, T. T. Inoue, A. S. Muniz and P. H. Pagliari
      Organomineral Phosphate Fertilizers: Agronomic Efficiency and Residual Effect on Initial Corn Development

      This research investigated the efficiency and residual effects of two solid organomineral fertilizers on corn (Zea mays L.) shoot dry matter (SDM), P uptake, P recovery index, P use efficiency index, accumulated SDM (ASDM), and total P uptake. This was a greenhouse pot study where organomineral-granulated (OG) fertilizer, organomineral-pelletized (OM) fertilizer, and inorganic fertilizer mix (MM) were tested on a Eutropherric Red Latossol clay soil (Oxisol). Phosphorus (P) rates were 0, 25, 50, 100, and 200 mg kg−1. Two plants were grown in each pot for 35 d before harvest; this cropping cycle was repeated consecutively four times on the same pots. (continued)

      Core Ideas:
      • Organomineral fertilizers made with different techniques yield fertilizers with different P availability.
      • We observed a different residual effect among the mineral and organomineral fertilizers.
      • The P release kinetics of the mineral fertilizer are different compared with the organomineral.
      • The P content extracted by water in the fertilizers is the main index of the phosphate fertilizer efficiency.

      doi:10.2134/agronj2015.0543
      Published: July 14, 2016



  • SOIL TILLAGE, CONSERVATION & MANAGEMENT

    • V. K. Choudhary
      Response of Land Configuration and Mulches on Maize–Frenchbean–Toria Cropping System

      Alteration in soil-topography and placement of mulches could play an important role in in situ conservation of resources. The objective of this study was to assess the productivity, water use, and weed smothering in the rainfed maize (Zea mays L.)–frenchbean (Phaseolus vulgaris L.)–toria (Brassica campestris L.) cropping system. Results revealed that the yield improvement under broad bed and furrow (BBF) was noticed up to 33.7% in maize grain, 35.3% in frenchbean green pod, and 28.2% in toria seeds followed by ridges and furrow (R&F) over flat bed (FB). Placement of mulch improved the crop yield by 14.2, 14.4 and 12.4%, respectively than without mulch plots. (continued)

      Core Ideas:
      • Land configuration and mulches improved the crop productivity.
      • Highest weed smothering obtained under broad bed and furrow with mulch.
      • Water-use efficiency improved under broad bed and furrow along with mulch.

      doi:10.2134/agronj2016.02.0088
      Published: July 28, 2016



    • Angela Nansamba, Kayuki C. Kaizzi, Ateenyi B. Twaha, Peter Ebanyat and Charles S. Wortmann
      Grain Sorghum Response to Reduced Tillage, Rotation, and Soil Fertility Management in Uganda

      Grain sorghum [Sorghum bicolor (L.) Moench] is an important staple crop in Uganda, but its productivity is limited by numerous constraints. Practices including reduced tillage (RT), conventional tillage (CT), sorghum rotation with mucuna (Mucuna pruriens L.) and cowpea (Vigna unguiculata L.), and soil fertility management treatments (SFTs) were evaluated to determine their effects on grain yield over a 7-yr period with two cropping seasons per year at Bulegeni and IkiIki representing high and low potential agroecological zones, respectively. At Bulegeni and IkiIki, respectively, mean grain yield was 13.0 and 8.6% greater with RT compared with CT, 10.9 and 14.4% greater following mucuna compared with cowpea, and 134 and 249% greater with farmyard manure (FYM)+N+P compared with no nutrient applied. At Bulegeni, SFT effects on sorghum yields increased with time. (continued)

      Core Ideas:
      • Sorghum grain yield was increased by additive effects of nutrient application, reduced tillage, and rotation.
      • Synergistic effects of combining two or more practices were small and uncommon.
      • Sorghum yield was greatly increased by nutrient application.
      • Farmers can benefit from adopting any of the more beneficial practices alone or in combination.

      doi:10.2134/agronj2015.0608
      Published: July 28, 2016



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