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Agronomy Journal : Just Published

 

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. 109(4)



  • AGRONOMY, SOILS & ENVIRONMENTAL QUALITY

    • Shelby Rajkovich, Deanna Osmond, Randy Weisz, Carl Crozier, Daniel Israel and Robert Austin
      Evaluation of Nitrogen-Loss Prevention Amendments in Maize and Wheat in North Carolina

      To reduce environmental losses of N and increase crop use, it is critical to optimize N fertilization rates and determine if N-loss prevention amendments increase yields. Research objectives were to: (i) determine N-release patterns of three N-loss amendments (urea ammonium nitrate [UAN] treated with NBPT+DCD, nitrapyrin, or an organo-Ca) and UAN through a laboratory incubation; (ii) determine effectiveness of these four products for maize (Zea mays L.) and winter wheat (Triticum aestivum L.) produced in two to three regions of North Carolina; and (iii) determine agronomic optimum N rate for wheat and corn compared to state-recommended rates. Nitrogen release was measured in three soils (coastal plain, piedmont, and mountains) during the incubation experiment. Field experiments were randomized complete block designs (four replications of six maize N rates and five wheat N rates), with each rate applied as one of four product treatments (UAN and UAN+ one of three N-loss prevention amendments). (continued)

      Core Ideas:
      • Fertilizer additives to decrease N losses did not provide consistent yield advantages.
      • Plots treated with N-loss products did not increase N use efficiency or N uptake.
      • Agronomic optimum N rates observed in the field aligned with North Carolina recommendations.

      doi:10.2134/agronj2016.03.0153
      Published: July 27, 2017



    • Daniele De Rosa, Bruno Basso, David W. Rowlings, Clemens Scheer, Johannes Biala and Peter R. Grace
      Can Organic Amendments Support Sustainable Vegetable Production?

      Application rates of synthetic fertilizer to agricultural fields can be reduced through better understanding of N supplied by organic amendments (OA). Field and simulation experiments were performed to quantify the effect of N released from OA application on crop production and selected soil properties in an intensively managed vegetable crop rotation. The SALUS crop model was used to simulate yield, soil N, and soil organic carbon (SOC) dynamics under different combinations of composted or raw OA and synthetic N fertilizer application rates. SALUS accurately simulated aboveground crop biomass production (r2 = 0.91, RMSE = 1.7 t ha–1) and crop N uptake (r2 = 0.96, RMSE = 15 kg N ha–1) under different N management strategies as well as SOC level (r2 = 0.51, RMSE = 1 t C ha–1) and soil mineral N (r2 = 0.58, RMSE = 56 kg N ha–1). (continued)

      Core Ideas:
      • Accounting for the N release from organic amendments improves N use efficiency and promotes soil C storage in horticultural soils.
      • Regional N fertilizer recommendations are affected by a high degree of uncertainty.
      • Crop simulation model can help to develop efficient site-specific N management.

      doi:10.2134/agronj2016.12.0739
      Published: July 13, 2017



    • Casey T. Sullivan, Rebecca M. Harman, Neal S. Eash, James A. Zahn, John J. Goddard, Forbes R. Walker, Arnold M. Saxton, Dayton M. Lambert, David W. McIntosh, William E. Hart, Robert S. Freeland and John E. Morrison Jr.
      Utilization of Spent Microbial Biomass as an Alternative Crop Nitrogen Source

      Spent microbial biomass (SMB), a nutrient-rich co-product of industrial white biotechnology processes, is produced in substantial quantities alongside high-value products and most often disposed of in landfills or incinerated. Alternatively, SMB could be reused as a land-applied N source in agricultural crop production, reducing the environmental and economic footprint of synthetic fertilizers. This research compares SMB applied at different rates to current farmer practice (FP) fertilizer use in tall fescue (Festuca arundinacea Schreb.) and corn (Zea mays L.) production on a Dewey silty clay in Lenoir City, TN. The effect of SMB on tall fescue was measured over three harvests through plant biomass production, crop N status using the normalized difference vegetation index (NDVI), and forage quality by near-infrared reflectance spectroscopy (NIRS). (continued)

      Core Ideas:
      • Nutrient-rich spent microbial biomass has potential for reuse in agriculture.
      • Tall fescue data from three harvests showed release of spent microbial biomass nutrients over time.
      • Highest spent microbial biomass rate yielded greater tall fescue biomass than fertilizer in July.
      • All five spent microbial biomass rates produced corn yields consistent with the fertilizer control.
      • The renewable disposal of spent microbial biomass in agriculture may be expanded to other industries.

      doi:10.2134/agronj2016.12.0742
      Published: June 30, 2017



    • E. Martínez, A. Maresma, A. Biau, S. Cela, P. Berenguer, F. Santiveri, A. Michelena and J. Lloveras
      Long-Term Effects of Mineral Nitrogen Fertilizer on Irrigated Maize and Soil Properties

      Nitrogen is a key determinant of growth and grain yield (GY) in maize (Zea mays L.) and is therefore economically and environmentally important. We investigated the performance of maize crops in a 12-yr experiment (2002–2007, 2010–2015) under sprinkler irrigation in a petrocalcic calcixerept soil in northeastern Spain, with controlled mineral N application rates (0, 100, 150, 200, 250, 300, and 400 kg N ha–1 yr–1). The application rate affected maize GY, biomass, N uptake, SPAD units, soil N levels, N efficiencies, and soil organic carbon (SOC). Average maximum GY’s (∼15 Mg ha–1) required 203 kg N ha–1 of available N (defined as initial soil NO3 plus N fertilizer) in the 0- to 30-cm horizon, confirming the importance of the soil N content. (continued)

      Core Ideas:
      • Grain yield, biomass, N uptake, SPAD units, soil N levels and N efficiciencies were affected by the N application rate.
      • Maximum grain yields required 203 kg N ha–1 of available N in the 0- to 30-cm layer soil.
      • Sampling to a depth of 0 to 30 cm provided similar correlations than sampling to 0 to 60 and 0 to 90 cm.
      • Mineral N fertilization increased soil organic C stock.

      doi:10.2134/agronj2017.01.0020
      Published: June 30, 2017



    • Robert S. Gallagher, Richard C. Stehouwer, Víctor Hugo Barrera Mosquera, Soraya Patricia Alvarado Ochoa, Luis Orlando Escudero López, Franklin Valverde, Arnufo Portilla, Katie Webber and Juan Manuel Domínguez Andrade
      Yield and Nutrient Removal in Potato-Based Conservation Agriculture Cropping Systems in the High Altitude Andean Region of Ecuador

      The Illangama region of Ecuador’s highlands is typical of much of the Andean region throughout South and Central America. Steep slopes, frequent soil disturbance and the short fallow periods threaten the sustainability of soil quality and crop production in this region. We evaluated several conservation agricultural practices, including deviation ditches, crop residue retention, and reduced tillage in the context of a potato (Solanum tuberosum L.)–oat/vetch (Avena sativa L./Vicia sativa L.)–barley (Hordeum vulgare L.)–faba bean (Vicia faba L.) rotation from 2011 to 2014 on crop productivity, crop and soil nutrient concentration, and nutrient removal from the system. Crop productivity tended to be higher in plots that had deviation ditches, and where crop and cover residues were retained in the field. (continued)

      Core Ideas:
      • Conservation agriculture practices evaluated in this study were agronomically effective, but expensive.
      • Reduced tillage resulted in similar yields in all crops of the potato–oat/vetch–barley–faba rotation to conventional tillage.
      • Retaining crop and cover crops residues in the field rather than for animal fodder will make the greatest contribution to soil nutrient cycling, but likely to be the least accepted conservation agriculture practice evaluated in this study by regional farmers.

      doi:10.2134/agronj2016.11.0635
      Published: June 22, 2017



    • Adele Muscolo, Carmelo Mallamaci, Giovanna Settineri and Giovanni Calamarà
      Increasing Soil and Crop Productivity by Using Agricultural Wastes Pelletized with Elemental Sulfur and Bentonite

      Waste materials have many characteristics that can be useful to improve soil fertility and crop productivity. This study aims to investigate on recycling orange, olive wastes, elemental S residue to produce new and more efficient S-enriched organic fertilizers. The fertilizer power of the different pads was first assessed in vitro on germination of three crop species (red onion [Purple Allium cepa L.], cayenne pepper [Capsicum annuum], and dwarf French bean [Phaseolus vulgaris L. bronco]) to individuate the doses to be used in pot experiements. (continued)

      Core Ideas:
      • The natural fertilizer potential of agricultural and industrial wastes was investigated.
      • Soil properties, seed germination, and plant metabolism proved their fertilizing properties.
      • A specificity between fertilizers produced and plant species was really evident.

      doi:10.2134/agronj2017.03.0143
      Published: June 15, 2017



  • BIOFUELS

    • Priya Saini, Jason P. de Koff, Abimbola Allison and Choo Hamilton
      Changes in Lignocellulosic Polymers, Carbon and Energy in Switchgrass for Bioenergy Production

      Switchgrass (Panicum virgatum L.) is a potential bioenergy crop recommended by the U.S. Department of Energy. To produce biofuel from switchgrass, high cellulose and low lignin concentrations are ideal for biochemical conversion while high lignin and energy content are desirable for thermochemical conversion. These values change during plant growth. (continued)

      Core Ideas:
      • Depending on the energy conversion method, switchgrass may be harvested over 2 months prior to killing frost.
      • Drought may have caused a delay in the fall increase in C concentrations in switchgrass.
      • Switchgrass cellulose, hemicellulose, lignin, and energy contents were unaffected by drought.
      • Few studies have intensively monitored switchgrass chemical components during natural drought conditions.

      doi:10.2134/agronj2017.02.0063
      Published: June 22, 2017



    • Gregg R. Sanford, Lawrence G. Oates, Sarah S. Roley, David S. Duncan, Randall D. Jackson, G. Philip Robertson and Kurt D. Thelen
      Biomass Production a Stronger Driver of Cellulosic Ethanol Yield than Biomass Quality

      Many crops have been proposed as feedstocks for the emerging cellulosic ethanol industry, but information is lacking about the relative importance of feedstock production and quality. We compared yield and sugar content for seven bioenergy cropping systems in south-central Wisconsin (ARL) and southwestern Michigan (KBS) during three growing seasons (2012 through 2014). The cropping systems were (i) continuous corn stover (Zea mays L.), (ii) switchgrass (Panicum virgatum L.), (iii) giant miscanthus (Miscanthus × giganteus Greef & Deuter ex Hodkinson & Renvoize), (iv) hybrid poplar (Populus nigra × P. maximowiczii A. (continued)

      Core Ideas:
      • Fermentable sugars were greatest in corn stover > perennial grasses > polycultures.
      • Corn stover had the highest ethanol content.
      • Miscanthus had the highest ethanol yield potential on a per hectare basis.
      • Ethanol yield potential per hectare of switchgrass ≥ corn stover.
      • Biomass yield was the strongest driver of per hectare ethanol yield.

      doi:10.2134/agronj2016.08.0454
      Published: June 22, 2017



    • Courtney Payne, Edward J. Wolfrum, Nick Nagle, Joe E. Brummer and Neil Hansen
      Evaluation of Fifteen Cultivars of Cool-Season Perennial Grasses as Biofuel Feedstocks Using Near-Infrared

      Cool-season (C3) perennial grasses have a long history of cultivation and use as animal forage. This study evaluated 15 cultivars of C3 grasses, when harvested in late June for increased biomass yield, as biofuel feedstocks using near- infrared spectroscopy (NIR) based partial least square (PLS) analysis. These grasses were grown near Iliff, CO, for three growing seasons (2009–2011). The carbohydrate composition and released carbohydrates (total glucose and xylose released from dilute acid pretreatment and enzymatic hydrolysis [EH]) were predicted for samples from the study using NIR/PLS. (continued)

      Core Ideas:
      • Harvest yield varies more across species than sugar content and accessibility.
      • Harvest yield and sugar accessibility are both critical parameters for conversion.
      • Near-infrared/partial least square models are valuable for quickly evaluating biomass for bioconversion.

      doi:10.2134/agronj2016.09.0510
      Published: June 22, 2017



  • BIOMETRY, MODELING & STATISTICS

    • Laura Mack, Filippo Capezzone, Sebastian Munz, Hans-Peter Piepho, Wilhelm Claupein, Tim Phillips and Simone Graeff-Hönninger
      Nondestructive Leaf Area Estimation for Chia

      Leaf area (LA) is an important agronomic trait but is difficult to measure directly. It is therefore of interest to estimate LA indirectly using easily measured correlated traits. The most commonly used approach to predict LA uses the product of leaf width (LW) and leaf length (LL) as single predictor variable. However, this approach is insufficient to estimate LA of chia (Salvia hispanica L.) because the leaves are differently shaped depending on leaf size. (continued)

      Core Ideas:
      • Leaf area in chia cannot be accurately predicted by the product of leaf width and length.
      • Regressing leaf area log linearly on width and length accounts for change of shape with size.
      • We provide accurate prediction models valid across experiments, populations, and N levels.
      • Mixed-model meta-regression allows integrating leaf area data across experiments.

      doi:10.2134/agronj2017.03.0149
      Published: July 13, 2017



    • J. Melkonian, H. J. Poffenbarger, S. B. Mirsky, M. R. Ryan and B. N. Moebius-Clune
      Estimating Nitrogen Mineralization from Cover Crop Mixtures Using the Precision Nitrogen Management Model

      Cover crops influence soil N dynamics and N availability to a subsequent crop. Dynamic simulation models, if properly calibrated and tested, can simulate C and N dynamics of a terminated cover crop and estimate crop-available N over diverse production environments. We calibrated and tested a dynamic simulation model modified to simulate C and N cover crop residue dynamics in maize (Zea mays L.) production systems. Data from a 2-yr field study of different cover crop residue mixtures, fertilizer rates, and tillage practices were used in model calibration and testing. (continued)

      Core Ideas:
      • The precision N management model performed reasonably well for estimating cover crop N mineralization.
      • Model performance was sufficient to justify incorporation into an N decision support tool.
      • Cover crops as a best management practice can be assessed with the calibrated model.

      doi:10.2134/agronj2016.06.0330
      Published: June 15, 2017



  • CLIMATOLOGY & WATER MANAGEMENT

    • Fabio Orlandi, Tommaso Bonofiglio, Luigia Ruga and Marco Fornaciari
      Meteorological Influences on Pheno–Morpho–Yield Data of Grain Sorghum Varieties in Central Italy

      Sorghum (Sorghum bicolor L. Moench) is widely grown in many arid and semiarid areas of the world due to its ability to yield well under rainfed or water-limited conditions. In the present study some sorghum varieties (medium-long season) have been studied in relationship with the principal meteorological variables considering also the drought effect in a favorable groundwater situation. The phenological adaptation, morphological and productive features during 11 yr of investigations from 2005 to 2015 in central Italy were evaluated. (continued)

      Core Ideas:
      • Solar radiation was the first greatest forcing variable for the sorghum flowering.
      • Water table during summer and past fruit setting represented a limiting factor.
      • Sorghum morphological development was deeply influenced by precipitation.
      • Medium and long season sorghum varieties showed a yield homogeneity.
      • Brenus and Marcus varieties manifested low relationships with water soil and good yield performance.

      doi:10.2134/agronj2016.10.0570
      Published: July 27, 2017



    • Christian Dold, Jerry L. Hatfield, John Prueger, Tom Sauer, Hakan Büyükcangaz and Wesley Rondinelli
      Long-Term Application of the Crop Water Stress Index in Midwest Agro-Ecosystems

      Corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] are predominantly produced in Iowa under rainfed conditions in which the amount and distribution of rainfall, and ambient air temperature, vary substantially among years. Prairie ecosystems also represent a small but significant portion of the landscape in the Midwest, but are subjected to the same variation in rainfall. Quantifying the effect of rainfall variation on ecosystem productivity is required to understand how the absence and the oversupply of water induces plant water stress and affects plant growth. We used the crop water stress index (CWSI) using canopy temperatures obtained from infrared temperature sensors coupled with eddy flux measurements to quantify the impact of water stress on corn, soybean, and prairie net ecosystem production (NEP) in central Iowa from June to August, 2006 through 2015. (continued)

      Core Ideas:
      • The crop water stress index was calculated for corn, soybean, and prairie using eddy covariance and canopy temperature.
      • Crop water stress index increased with decreasing volumetric soil water content in tallgrass prairie with net ecosystem production sensitive to water deficits.
      • Crop water stress index in corn and soybean increased at low and high volumetric soil water content demonstrating that carbon assimilation is affected by deficit and excess soil water contents.

      doi:10.2134/agronj2016.09.0494
      Published: June 22, 2017



    • K. W. Peterson, D. J. Bremer, K. B. Shonkwiler and J. M. Ham
      Measurement of Evapotranspiration in Turfgrass: A Comparison of Techniques

      Evapotranspiration (ET) from turfgrass can be measured directly using lysimeters (LYS), estimated from weather data using models, or approximated using atmometers. Evapotranspiration measurements from LYS were compared with ET estimates from the American Society of Civel Engineers standardized ET equation using hourly steps from measured net radiation (Rn) (ASCEHM) and Rn calculated from global irradiance (ASCEHC), and daily steps from measured net radiation (ASCEDM) and Rn calculated from global irradiance (ASCEDC), the Priestley–Taylor (PT) model, and atmometers, all collocated in a sward of tall fescue (Festuca arundinacea Schreb.) turfgrass near Manhattan, KS. Data were collected on precipitation free days during the growing seasons 2010 through 2012 and analyzed by periods with high ET, low ET, and pooled across all days. Overall mean ET (May–October) ranged from 5.58 (LYS) to 4.47 mm d–1 (ASCEHC). (continued)

      Core Ideas:
      • Evapotranspiration from ASCEDM, ASCEDC was equivalent to lysimeters.
      • Net radiation from global irradiance is sufficient in daily-step model in absence of measured net radiation.
      • ASCEDC improves irrigation scheduling in turfgrass when measured net radiation is not available.

      doi:10.2134/agronj2017.02.0088
      Published: June 22, 2017



  • CROP ECOLOGY & PHYSIOLOGY

    • Leilei Liu, Jifeng Ma, Liying Tian, Shenghao Wang, Liang Tang, Weixing Cao and Yan Zhu
      Effect of Postanthesis High Temperature on Grain Quality Formation for Wheat

      The protein and starch properties of wheat (Triticum aestivum L.) are important factors for grain quality and these properties are documented to be influenced by temperatures. The present study was undertaken to investigate the effects of high temperature regimes, starting dates, durations and their combinations on grain protein and starch concentrations in two wheat cultivars Yangmai16 and Xumai30 with different heat tolerances. Four temperature regimes of 27/17°C, 31/21°C, 35/25°C, and 39/29°C were implemented for 3 and 6 d after anthesis and 10 d after anthesis. The concentrations of protein and starch components in grains were measured during the periods of postanthesis. (continued)

      Core Ideas:
      • High stress enhanced protein concentration, but reduced total starch concentration.
      • High stress had more advantage effects on protein fractions at anthesis than 10 d after anthesis.
      • High stress had significant negative effects on starch during grain filling.
      • The combination stress did not have significant effects on protein fractions.
      • The combination stress had significant effects on starch concentration.

      doi:10.2134/agronj2016.07.0427
      Published: July 27, 2017



    • Sideris Fotiadis, Spyridon D. Koutroubas and Christos A. Damalas
      Sowing Date and Cultivar Effects on Assimilate Translocation in Spring Mediterranean Chickpea

      In cooler Mediterranean areas autumn sowing of chickpea (Cicer arietinum L.) is avoided because of the increased frost risk. A 2-yr field study was conducted to investigate the potential effects of spring sowing date and cultivar on assimilate dynamics (i.e., dry matter and N accumulation, partitioning and translocation) and productivity of Mediterranean chickpea, and to assess possible N losses from plant foliage. Three local cultivars (i.e., Andros, Kassos, and Serifos) and one foreign cultivar (i.e., Zehavit-27) were evaluated under two sowing dates (i.e., March sowing and April sowing). March sowing resulted in higher dry matter, total N accumulation, and seed N content than April sowing. (continued)

      Core Ideas:
      • March sowing resulted in higher dry matter, total N accumulation, and seed N content than April sowing.
      • Seed yield up to 3320 kg ha–1 were obtained with March sowing.
      • Seed yield was correlated negatively with dry matter translocation to the seeds.

      doi:10.2134/agronj2017.01.0048
      Published: June 22, 2017



    • Julio Isidro-Sánchez, Ben Perry, Asheesh K. Singh, Hong Wang, Ronald M. DePauw, Curtis J. Pozniak, Brian L. Beres, Eric N. Johnson and Richard D. Cuthbert
      Effects of Seeding Rate on Durum Crop Production and Physiological Responses

      Seeding rate can be manipulated to optimize the ability of the crop to capture available resources and therefore increase yield. Seeding rate may vary between regions according to the climate conditions, soil type, sowing time, and other agronomic practices. Insufficient information is available for optimum seeding rate on durum wheat (Triticum turgidum L. var durum) for some production zones, and response to seeding rate is unknown for recently registered durum cultivars in Canada. (continued)

      Core Ideas:
      • Optimum seeding rate on elite durum wheat depends on environment.
      • Seeding rate had a significant positive relationship with grain yield, leaf area index, and carbon isotope discrimination.
      • Seeding rate should be adjusted for environment and genotype for maximum yield.

      doi:10.2134/agronj2016.09.0527
      Published: June 22, 2017



    • Jordan Orwat, Dipayan Sarkar, Juan Osorno and Kalidas Shetty
      Improved Salinity Resilience in Black Bean by Seed Elicitation Using Organic Compounds

      The adaptive responses of plants to abiotic stress include stimulation of secondary metabolites and endogenous antioxidant enzymes through up-regulation of the pentose phosphate pathway (PPP). Therefore improving abiotic stress resilience in food crops through upregulation of critical redox-linked anabolic PPP and enhancement of phenolic-linked antioxidant enzyme responses has merit. This study evaluated the effects of seed elicitor treatments (chitosan oligosaccharide [COS] Kong Poong Bio, Jeju, Korea, and marine hydrolysate [GroPro], Icelandic Bioenhancer, Harrison, NY) to improve salinity stress resilience through up-regulation of PPP in black bean (Phaseolus vulgaris L.) cultivars. Eclipse and Zenith cultivars were subjected to elicitor treatments (1%) and then 1 wk after germination were transplanted into three soil salinity treatments (no salt, 2–3, and 5–6 dS m–1) in greenhouse. (continued)

      Core Ideas:
      • Black bean cultivars were extremely susceptible to high salinity stress.
      • Seed elicitation improved salinity stress resilience.
      • Chitosan oligosaccharide and marine peptide were used for seed elicitation.
      • Adaptive response to salinity stress varied among black bean cultivars.
      • Seed elicitation induced phenolic-linked antioxidant enzyme responses.

      doi:10.2134/agronj2016.12.0699
      Published: June 15, 2017



    • William F. Schillinger, Steven E. Schofstoll, Timothy A. Smith and John A. Jacobsen
      Laboratory Method to Evaluate Wheat Seedling Emergence from Deep Planting Depths

      Planting depth effect on seedling emergence is an important concern for many crops grown around the world. Farmers in the low-precipitation (<300 mm annual) winter wheat (Triticum aestivum L.) (WW) production region of the Inland Pacific Northwest of the United States (PNW) plant seed as deep as 20 cm below the surface of summer-fallowed soils with deep-furrow drills to reach adequate seed-zone moisture. Seedlings need to emerge through 12 to 15 cm of soil cover, most often under marginal seed-zone water potentials. Successful stand establishment is the most critical factor affecting WW grain yield potential in the region. (continued)

      Core Ideas:
      • Stand establishment is the biggest factor afffecting winter wheat yield in the low-precipitation region.
      • Winter wheat seed is planted as deep as 20 cm below the soil surface to reach adequate soil moisture.
      • Determination of a cultivar’s emergence ability in the field is limited to a short time window once a year.
      • We developed a laboratory method to to accurately measure emergence in pots from deep planting depths.
      • Laboratory and field results were strongly correlated under a wide range of soil water potentials.

      doi:10.2134/agronj2016.12.0715
      Published: June 15, 2017



  • CROP ECONOMICS, PRODUCTION & MANAGEMENT

    • Gregg A. Johnson, M. Scott Wells, Kevin Anderson, Russ W. Gesch, Frank Forcella and Donald L. Wyse
      Yield Tradeoffs and Nitrogen between Pennycress, Camelina, and Soybean in Relay- and Double-Crop Systems

      To gain additional value from land during winter fallow periods in corn (Zea mays L.)–soybean [(Glycine max (L.) Merr.] rotations, growers in the Upper Midwest are considering winter annual oilseed crops such as field pennycress (Thlaspi arvense L.) and winter camelina [Camelina sativa (L.) Crantz]. The objective of this study was to (i) explore trade-offs between soybean and winter oilseed crop yield as influenced by timing of winter oilseed crop harvest and of soybean planting, and (ii) evaluate how inorganic soil N was affected by the presence or absence of pennycress or camelina. Field experiments were conducted at three sites in Minnesota to evaluate yield of field pennycress and camelina winter oilseed crops planted in a double-crop system or planted early or late in a relay-cropping system. Soybean grain yield was reduced in one of the three sites in 2014 and at all sites in 2015. (continued)

      Core Ideas:
      • Winter annual oilseed crops are being used in annual cropping systems to add value.
      • We explored trade-offs in oilseed yield and provision of ecosystem services.
      • Oilseed cover crop yield was greatest when harvested late rather than early.
      • Pennycress and camelina reduced N in the soil profile compared to soybean alone.

      doi:10.2134/agronj2017.02.0065
      Published: July 27, 2017



    • Francis Tsiboe, Jennie S. Popp and Kristofor R. Brye
      Profitability of Alternative Management Practices in a Wheat–Soybean, Double-Crop Production System in Arkansas

      Growing concerns about the sustainability of soil and water resources in the highly agriculturally productive lower Mississippi River Valley, particularly in the Delta region of eastern Arkansas, require the investigation of traditional and alternative agricultural management practices and their comparative long-term profitability. Therefore, this study used a simple, but robust, two-step novel procedure, econometrics and simulation, to evaluate the long-term effects of a combination of management practices. It consisted of tillage (conventional tillage [CT] or no-tillage [NT]), wheat residue burning (burn [B] or no burn [NB]), wheat-residue level (low [L] and high [H] achieved with differential N fertilization), and irrigation (irrigated [I] or non- irrigated [NI]), on net farm revenue in a wheat (Triticum aestivum L.) –soybean (Glycine max L. [Merr.]), double-crop production system in the region. (continued)

      Core Ideas:
      • Wheat and soybean yields were estimated using combinations of management practices.
      • The estimated yields were used to simulate profitability differences by combination.
      • Six combinations were 7 to 118% more profitable than the traditional combination.

      doi:10.2134/agronj2017.03.0140
      Published: July 27, 2017



    • Junxiao Pan, Qingfeng Meng, Riyuan Chen, Zhenling Cui and Xinping Chen
      In-Season Nitrogen Management to Increase Grain Yields in Maize Production

      Post-silking N accumulation positively correlates with maize (Zea mays L.) grain yield in production, but the effect of N management post-silking is unclear. This study was to evaluate maize yield and physiological changes in response to in-season nitrogen management (INM) with respect to post-silking N fertilization of maize. Optimal nitrogen rates (ONR) were determined for INM by subtracting soil nitrate-N content measured at the maize root layers from the target N value. Other treatments included a zero N (0N) post-silking control with the same N application pre-silking as ONR and excessive N treatment (Exc. (continued)

      Core Ideas:
      • Optimal N rate treatment increased the maize yield and improved dry matter production and N accumulation post-silking.
      • In-season N management-based post-silking N management can synchronize soil N supply and plant N uptake.
      • Assessing the performance of leaf and root characteristics in response to post-silking N management.

      doi:10.2134/agronj2016.11.0669
      Published: July 27, 2017



    • David D. Tarkalson and Bradley A. King
      Effect of Deficit Irrigation Timing on Sugarbeet

      Increased water demands and drought have resulted in a need to determine the impact of deficit water management in irrigated sugarbeet (Beta vulgaris L.) production. This study was conducted over 3 yr at USDA-ARS in Kimberly, ID, on a Portneuf silt loam soil. Eight irrigation treatments consisted of crop evapotranspiration (ETc) rates combined with application timing. Treatments were: W1 Even: approximately (≈) 100% ETc evenly throughout the growing season; W2 Even: ≈65% crop evapotranspiration; W2 Early: ≈100% ETc early in season, ≈55% ETc the remainder of the season; W2 Late: rain-fed from emergence to end of July, ≈100% ETc the remainder of the season; W3 Even: ≈40% ETc; W3 Early: ≈100% ETc early in season, ≈25% the remainder of the season; W3 Late: rain-fed through mid-August, ≈100% ETc the remainder of the season, and rain-fed: no post emergence irrigation. (continued)

      Core Ideas:
      • Water allocation timing under drip irrigation effected sugarbeet yield.
      • Excessive water stress early in the season reduced yields.
      • Areas with water shortages have options to grow sugarbeet.

      doi:10.2134/agronj2017.01.0061
      Published: July 13, 2017



    • Xia Vivian Zhou, James A. Larson, Christopher N. Boyer, Roland K. Roberts and Donald D. Tyler
      Tillage and Cover Crop Impacts on Economics of Cotton Production in Tennessee

      The objective of this study was to evaluate the long-term effects of winter cover crops with and without tillage on profit-maximizing N fertilization rate and net return for upland cotton (Gossypium hirsutum L.) production. Data came from a 29-yr (1984–2012) cotton experiment located in Jackson, TN. The experiment included four cover crop treatments (no cover, winter wheat [Triticum aestivum L.], hairy vetch [Vicia villosa L.], and crimson clover [Trifolium incarnatum L.]); two tillage systems (no-tillage [NT] and conventional tillage [CT]), and four N fertilizer rates (0, 34, 67, or 101 kg N ha–1). Lint yield was de-trended for temporal yield variation and quadratic yield response functions to N fertilizer were estimated for each cover crop and tillage system. (continued)

      Core Ideas:
      • Net returns were higher for conventional tillage than no-tillage without cover crops.
      • Net returns were higher for no-tillage than conventional tillage with cover crops.
      • A cotton producer would maximize profits by not planting cover crops.

      doi:10.2134/agronj2016.12.0733
      Published: July 13, 2017



    • Xiaojie Li, Shaozhong Kang, Fusheng Li, Xiaotao Zhang, Zailin Huo, Risheng Ding, Ling Tong, Taisheng Du and Sien Li
      Light Supplement and Carbon Dioxide Enrichment Affect Yield and Quality of Off-Season Pepper

      Off-season vegetable crops in a greenhouse need supplementary light intensity and CO2 concentration to obtain good growth and fruit quality. The objective of this study was to investigate the effects of supplementary light intensity and CO2 concentration on the photosynthesis, yield, and fruit quality of fresh hot pepper (cultivar Meite). Two light intensities—supplementary (SLI) and natural (NLI) light intensity with the averaged photosynthetic active radiation of the whole growth period of 463 and 233 μmol m–2 s–1, respectively—and 4 CO2 concentrations (400, 550, 700, and 900 μmol mol–1) were conducted on pepper planted in pots in phytotrons over the autumn and winter seasons in the arid Northwest region of China. Results showed that: (i) CO2 enrichment significantly increased the net photosynthetic rate (Pn), water use efficiency (WUE), yield parameters, and fruit storage qualities, but decreased the fruit nutrition qualities to different extents. (continued)

      Core Ideas:
      • Carbon dioxide enrichment and light supplement significantly increased the photosynthetic rate, yield, and water use efficiency.
      • Carbon dioxide enrichment reduced fruit nutrition quality, whereas light supplement improved it.
      • Applying light supplement and a CO2 concentration of 550 μmol mol–1 can optimize yield and quality.

      doi:10.2134/agronj2017.01.0044
      Published: June 22, 2017



    • Lisa L. Baxter, Charles P. West, C. Philip Brown and Paul E. Green
      Comparing Nondestructive Sampling Techniques for Predicting Forage Mass in Alfalfa–Tall Wheatgrass Pasture

      Producers rely on subjective visual assessments to estimate forage mass in their pastures, which often are inaccurate and lead to poor stocking decisions. The objective of this trial was to compare five nondestructive sampling techniques for predicting forage mass in three alfalfa–tall wheatgrass [Medicago sativa L.; Thinopyrum ponticum (Host) Beauv.] pastures in the southern High Plains. Procedures included canopy height measured with a pasture ruler and rising plate meter (RPM), percentage of green pixels from ImageJ analyses, percentage of green points from photo point count in PowerPoint, and normalized difference vegetation index (NDVI). Height and RPM were linearly regressed on measured forage mass while the remaining were linearly regressed on the natural log of measured forage mass. (continued)

      Core Ideas:
      • To compare five nondestructive sampling techniques for predicting forage mass.
      • Procedures: pasture ruler, rising plate meter, ImageJ, PowerPoint photo point count, and normalized difference vegetation index.
      • PowerPoint model was the best option if restricted to one sampling procedure.
      • Combined (Height + ImageJ) model was the best option for predicting forage mass.
      • These measurements require simple equipment, are adaptable, and can be automated.

      doi:10.2134/agronj2016.12.0738
      Published: June 15, 2017



  • ERRATUM

    • 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

      doi:10.2134/agronj2015.0610er
      Published: July 27, 2017



    • Mostafa Ibrahim, Chang Oh. Hong, Shikha Singh, Sandeep Kumar, Shannon Osborne and Vance Owens
      Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

      doi:10.2134/agronj2016.07.0380er
      Published: July 27, 2017
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  • INTERNATIONAL TURFGRASS SOCIETY CONFERENCE

    • Jerry Hatfield
      Turfgrass and Climate Change

      Climate change is occurring and is impacting biological systems through increased temperatures, more variable precipitation, and increased CO2 in the atmosphere. These effects have been documented for agricultural species, primarily grain crops, pasture and rangeland species. The extension of these relationships to turfgrass has been limited; however, these plants are an important part of our ecosystems and preservation of these plantings adds to social value and ecosystem services. Turfgrasses can be divided into cool-season and warm-season species and the projected changes in maximum air temperatures, along with increased root zone temperatures may promote a Northward migration of warm-season turfgrasses. (continued)

      Core Ideas:
      • Climate change will affect temperature and precipitation patterns.
      • Increasing temperatures will cause a shift in turfgrass species to more northen climates.
      • Variation among varieties of turfgrass provide opportunity to increase climate resilience.
      • Climate change will increase abiotic and biotic stresses on turfgrass.

      doi:10.2134/agronj2016.10.0626
      Published: June 1, 2017



  • ORGANIC AGRICULTURE & AGROECOLOGY

    • James A. Heilig, Evan M. Wright and James D. Kelly
      Symbiotic Nitrogen Fixation of Black and Navy Bean under Organic Production Systems

      Michigan is a leader in organic dry bean (Phaseolus vulgaris L.) production but previous research has shown that dry bean yields in Michigan were substantially lower under organic conditions compared to conventional production. Since pests are generally well controlled in both systems, fertility appears to be an issue where the two systems may differ. For organic dry bean production, fertility is managed through crop rotation, cover crops, and addition of composts and manures instead of the application of synthetically produced fertilizers. Symbiotic nitrogen fixation (SNF) may also be important for ensuring adequate dry bean yields when external N sources are limiting. (continued)

      Core Ideas:
      • Symbiotic nitrogen fixation of dry bean was evaluated under organic production systems.
      • Lower performance in organic production systems resulted from inadequate levels of N fertility.
      • Improving symbiotic nitrogen fixation of dry bean should contribute to improved performance in these systems.
      • Greenhouse screening for biomass provided an indirect, cost effective method to select for improved symbiotic nitrogen fixation.

      doi:10.2134/agronj2017.01.0051
      Published: June 22, 2017



    • Eric B. Brennan and Richard F. Smith
      Cover Crop Frequency and Compost Effects on a Legume–Rye Cover Crop During Eight Years of Organic Vegetables

      The long-term impacts of adding organic matter to the soil using cover crops (CC) and compost are poorly understood in high-value, tillage-intensive vegetable systems. Therefore, we evaluated the effects of CC frequency (annually vs. every fourth winter) and yard-waste compost (0 vs. 15.2 Mg dry matter ha1 annually) on the performance of a legumerye (Secale cereale L.) CC in three systems during Years 4 and 8 of the Salinas Organic Cropping Systems experiment in Salinas, CA. (continued)

      Core Ideas:
      • Cover crops and compost are common inputs in high-value, organic vegetables.
      • Cover crop frequency and compost effects on a legume–rye mixture were evaluated over 8 yr.
      • Yard-waste compost additions increased soil organic C in vegetable systems.
      • Frequent cover cropping increased soil nitrate levels.
      • Cover crop frequency and compost had subtle effect on legume–rye growth.

      doi:10.2134/agronj2016.06.0354
      Published: June 22, 2017



  • ORGANIC AGRICULTURE &AGROECOLOGY

    • R. A. Vann, S. C. Reberg-Horton, H. J. Poffenbarger, G. M. Zinati, J. B. Moyer and S. B. Mirsky
      Starter Fertilizer for Managing Cover Crop-Based Organic Corn

      Grass and legume cover crops are combined in mixtures to provide both weed and N fertility management in organic production; however, additional N fertility may be required to maximize corn yield. The research was conducted in Beltsville, MD; Kinston, NC; and Salisbury, NC; from 2012 to 2014 to evaluate the effect of starter fertilizer source and application method on weed competition and grain yield in cover crop-based, organic corn production. Fertility treatments included high rate broadcast poultry litter (Plant available nitrogen [PAN] = 160 kg ha–1), low rate broadcast poultry litter (PAN = 72 kg ha–1), subsurface banded feather meal (PAN = 80 kg ha–1), subsurface banded poultry litter (PAN = 12 kg ha–1), and no starter fertility. A cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) mixture was established in the fall and was terminated using a roller-crimper before corn planting. (continued)

      Core Ideas:
      • Grass and legume cover crops are combined for weed and fertility management.
      • A cereal rye and hairy vetch mixture provided more than 7500 kg ha–1 biomass.
      • Additional fertility is necessary to maximize cover-crop based organic corn yield.
      • Subsurface banding feather meal is an option to increase organic corn yield.
      • If cover crop biomass is low, providing adequate N fertility is critical for yield.

      doi:10.2134/agronj2016.09.0506
      Published: June 15, 2017



  • SOIL FERTILITY & CROP NUTRITION

    • Jeffrey A. Vetsch, Eric F. Scherder and David C. Ruen
      Does Liquid Swine Manure Application Timing and Nitrapyrin Affect Corn Yield and Inorganic Soil Nitrogen?

      Fall application of liquid swine (Sus scrofa) manure (LSM) is preferred but it can increase N loss potential. Delaying application of LSM or adding a nitrification inhibitor could reduce N losses. This study measured the effects of LSM application timing and nitrapyrin [2-chloro-6-(trichloromethyl) pyridine] as Instinct on soil inorganic N and corn (Zea mays L.) production. Field experiments were conducted from 2010 through 2014 on clay loam soils (Aquic Hapludolls). (continued)

      Core Ideas:
      • Nitrapyrin (Instinct) effectively slowed nitrification of swine manure.
      • Delaying fall application of swine manure increased corn yields and N availability.
      • Instinct enhanced corn production in years with greater than normal precipitation.

      doi:10.2134/agronj2017.03.0163
      Published: July 27, 2017



    • K. Yu, Q. G. Dong, H. X. Chen, H. Feng, Y. Zhao, B. C. Si, Y. Li and D. W. Hopkins
      Incorporation of Pre-Treated Straw Improves Soil Aggregate Stability and Increases Crop Productivity

      Crop straws usually have high lignin and cellulose contents and decompose slowly when returned to the soil, which is not always conducive to crop growth. In this study, we investigated the effects of short and ammoniated straw application on soil properties, crop yield, and water use efficiency (WUE) in a summer maize (Zea mays L.)–winter wheat (Triticum aestivum L.) rotation system on the Loess Plateau, China. There were four treatments: long straw (ca. 50 mm) mulching (S+M), long straw (ca. (continued)

      Core Ideas:
      • The ammoniated straw application improved soil structural stability.
      • The ammoniated straw application increased the yield and water use efficiency, regardless of maize or wheat.
      • The ammoniated straw incorporation is better for the short straw than for the long one, and net income with the ammoniated and short straw incorporation was the highest.

      doi:10.2134/agronj2016.11.0645
      Published: July 27, 2017



    • B. D. Tarfa, N. Maman, K. Ouattara, I. Serme, T. A. Adeogun, U. L. Arunah and C. S. Wortmann
      Groundnut and Soybean Response to Nutrient Application in West Africa

      Groundnut (Arachis hypogaea L.) and soybean (Glycine max L.) are important crops in West Africa for food security and marketing. Yields are low, partly due to soil fertility constraints. High net returns to fertilizer use are needed by poor smallholder farmers. Well-determined nutrient response functions are needed to make profit-oriented decisions. (continued)

      Core Ideas:
      • Leguminous oil seed production is important in West Africa.
      • Well-determined response functions are important for optimization of profit from nutrient application.
      • Crop response varied across Burkina Faso, Niger, and Nigeria.
      • Nutrient response functions were determined for different production areas.

      doi:10.2134/agronj2017.03.0132
      Published: July 27, 2017



    • Nouri Maman, Mohamed Dicko, Gonda Abdou, Zoumana Kouyate and Charles Wortmann
      Pearl Millet and Cowpea Intercrop Response to Applied Nutrients in West Africa

      In the Sahel, crop production is dominated by pearl millet [Pennisetum glaucum (L.) R. Br.] cropping systems including intercropping with cowpea [Vigna unguiculata (L.) Walp]. The research objectives were to determine pearl millet sole crop (PMSC) and intercrop nutrient response functions, profit opportunities from fertilizer use, and a means of relating intercrop to PMSC response. Pearl millet–cowpea trials were conducted in Niger and Mali. (continued)

      Core Ideas:
      • Pearl millet and cowpea intercrop production is important in the Sahel.
      • Inadequate nutrient supply constrains crop growth.
      • Pearl millet sole crop nutrient response information is applicable for intercropping.
      • Application of N and P to intercrop compared to sole crop has more profit potential.

      doi:10.2134/agronj2017.03.0139
      Published: July 27, 2017



    • Ganghua Zou, Yong Li, Tieping Huang, De Li Liu, David Herridge and Jinshui Wu
      A Mixed-Effects Regression Modeling Approach for Evaluating Paddy Soil Productivity

      Soil productivity (SP) is a description of the soil’s inherent capacity for crop production and approximates the long-term average crop yield. Knowledge of the key driving factors of SP is essential for short-term soil management and long-term agricultural sustainability. Representative 50-cm intact soil profiles from high-, moderate-, and low-yielding paddy fields with long rice (Oryza sativa L.)-production histories were collected in southern China. Each profile was stratified into 10 layers at 5-cm intervals. (continued)

      Core Ideas:
      • Cation exchange capacity, Ca2+, K+, available soil potassium, pH, and clay significantly affect paddy soil productivity.
      • A mixed-effects linear regression model evaluates soil productivity well.
      • The two-layer soil stratification scheme is the best for assessing soil productivity.

      doi:10.2134/agronj2017.02.0089
      Published: July 13, 2017



    • Amritbir Riar, Gurjeet Gill and Glenn McDonald
      Effect of Post-Sowing Nitrogen Management on Canola and Mustard: I. Yield Responses

      Altering the amount and the timing of N according to phenological development can be an effective way of managing variation in seasonal rainfall, which could improve seed yield. The aim of this study was to investigate the effect of post-sowing N applications at different phenological growth stages on the seed yield of different canola (Brassica napus L.) and mustard [Brassica juncea (L.) Czern. & Coss.] cultivars. Field experiments were conducted in South Australia with four canola and two mustard cultivars. (continued)

      Core Ideas:
      • Yield of canola and mustard was associated with total dry matter production and seeds m–2.
      • The yield penalty for triazine-tolerant cultivars was lower in the season with dry spring.
      • Seed yield of canola and mustard was highly responsive to the application of N at the rosette stage.
      • Yield with 100 kg ha–1 N at rosette was equivalent to 85 and 94% of the maximum in canola and mustard.
      • Increasing the sink capacity by improving the pre-flowering crop biomass has an important influence on seed yield of canola and mustard.

      doi:10.2134/agronj2016.12.0728
      Published: July 13, 2017



    • Lucie A. Kablan, Valérie Chabot, Alexandre Mailloux, Marie-Ève Bouchard, Daniel Fontaine and Tom Bruulsema
      Variability in Corn Yield Response to Nitrogen Fertilizer in Eastern Canada

      Corn (Zea mays L.) yield response to N has been found to vary spatially within a field. The objective of this study was to examine how grain corn yield response to N varies with planting date, soil texture, and spring weather across sites and years in the Montérégie region. Trials were conducted from 2002 to 2004 and 2006 to 2010, at 11 sites with 23 hybrids and four N application rates, for a total of 45 site-years. Each site-year involved five or six N rates ranging from 80–90 to 240 kg N ha–1. (continued)

      Core Ideas:
      • A 8-yr study of corn N fertilization on high-yielding fields in Québec, eastern Canada.
      • Grain yield response to N rates varied among site-years.
      • The economically optimal N rate was affected by soil textural classes, planting date, and rainfall.
      • Averaged across textures, planting date, and weather, economically optimal N rate was 195 kg N ha–1.
      • Nitrogen applications at rates above the current N recommendation increased grain yield.

      doi:10.2134/agronj2016.09.0511
      Published: July 13, 2017



    • Lance S. Conway, Matt A. Yost, Newell R. Kitchen and Kenneth A. Sudduth
      Using Topsoil Thickness to Improve Site-Specific Phosphorus and Potassium Management on Claypan Soil

      Precise P and K fertilizer management on claypan soils can be difficult due to variable topsoil thickness, or depth to claypan (DTC), across landscapes, nutrient supply from subsoils, and crop removal. Therefore, a study was performed to determine if DTC could be used to improve P and K management for corn (Zea mays L.), soybean [Glycine max (L.)], and switchgrass (Panicum virgatum L.). Research was conducted on a claypan soil at the University of Missouri’s (MU) South Farm Research Center in Columbia, MO, from 2009 to 2016. Corn, soybean, and switchgrass were grown each year on 16 plots with constructed DTC ranging from 0 to 94 cm. (continued)

      Core Ideas:
      • Topsoil depth influences P and K dynamics on claypan soils.
      • Most P and K dynamics were inversely affected by depth to claypan.
      • Accounting for depth to claypan could improve P and K fertilizer management.

      doi:10.2134/agronj2017.01.0038
      Published: June 22, 2017



    • Roberto Alvarez and Haydee S. steinbach
      Modeling Soil Test Phosphorus Changes under Fertilized and Unfertilized Managements Using Artificial Neural Networks

      The build-up and maintenance criteria have been introduced for P fertilizer management in the Pampas of Argentina. However, methods for predicting soil test P changes under contrasting fertilizer rates are not available. We performed a meta-analysis using results from 18 local field experiments performed under the most common crop rotations, in which soil test P changes with and without P fertilization and soil P balance were assessed. We assembled 329 soil test P variation data sets corresponding to a period 12 yr and 129 P balance records. (continued)

      Core Ideas:
      • An artificial neural network was developed to describe soil P dynamics.
      • The model accurately predicts soil test P increases and decreases.
      • A meta-model was derived to apply the build-up and maintenance philosophy.

      doi:10.2134/agronj2017.01.0014
      Published: June 22, 2017



    • J. Mabry McCray, Shangning Ji and Gerald Powell
      Sugarcane Yield Response to Potassium Fertilization as Related to Extractable Soil Potassium on Florida Histosols

      Sugarcane (Saccharum spp.) has a large K requirement and so K fertilizer can be a major cost for growers. Histosols in the Everglades Agricultural Area (EAA) of Florida are shallower with higher pH than when current sugarcane K fertilizer recommendations were established in the 1970s. This study was conducted to determine sugarcane yield response to K fertilizer as related to extractable soil K on Florida Histosols. Six small-plot (83, 120, or 138 m2) field experiments were established as randomized complete block (RCB) designs (four or six replications) with annual K rates ranging from 0 to 279 kg K ha–1. (continued)

      Core Ideas:
      • Sugarcane yield responses to K fertilizer were attributable to increases in sugarcane biomass.
      • There was reduced sucrose concentration at higher K rates in 4 of 14 crop years.
      • Maximum K fertilizer requirement determined was 27% less than current recommendation.
      • Soil test K limit for K fertilizer application was within 12% of the current limit.

      doi:10.2134/agronj2016.11.0630
      Published: June 15, 2017



  • SOIL TILLAGE, CONSERVATION & MANAGEMENT

    • Mahdi M. Al-Kaisi, David Kwaw-Mensah and En Ci
      Effect of Nitrogen Fertilizer Application on Corn Residue Decomposition in Iowa

      Corn (Zea mays L.) residue is one of the sources of soil organic carbon (SOC) in row cropping systems in the Midwest. Farmers in Iowa apply liquid N to corn residue after harvest, assuming it will increase corn residue decomposition. The objective of this study was to investigate the effectiveness of N application for increasing corn residue decomposition. The study included two fields with three N rates (0, 34, or 67 kg N ha–1) of liquid 32% urea ammonium nitrate (UAN) applied after harvest, and two laboratory incubation experiments with three temperatures (0, 25, and 35°C) in 2012 and 2013. (continued)

      Core Ideas:
      • Application of 32% urea ammonium nitrate after harvest has no effect on residue decomposition.
      • Three months after N addition, 54 to 69% of residue remained with no N rate differences.
      • The remaining amount of residue after 12 mo was 35 to 49% across all N treatments.
      • Incubation study shows soil temperature as a major factor in residue decomposition.
      • Nitrogen addition suppressed CO2–C evolution during residue incubation.

      doi:10.2134/agronj2016.11.0633
      Published: July 27, 2017



    • Chengren Ouyang, Kaixian Wu, Tongxin An, Jia He, Shuhui Zi, Youqiong Yang and Bozhi Wu
      Productivity, Economic, and Environmental Benefits in Intercropping of Maize with Chili and Grass

      Intercropping is a widespread cropping system to increase land productivity and decreases soil erosion. However, considering economic benefits of intercropping mountain agriculture is deficient. A field experiment was conducted to determine productivity, economic efficiency, and soil conservation benefits of intercropping of maize (Zea mays L.) with chili (Capsicum annuum L.) and setaria grass (Setaria anceps Stapf ex Massesy) in Yunnan. Runoff, sediment, crop yield, and economic benefits were evaluated under sole maize (SM), sole chili (SC), maize/chili intercropping (MCI), and maize/setaria grass intercropping (MGI). (continued)

      Core Ideas:
      • In upland, how to integrate soil conservation, productivity, and economic benefits is still a challenge.
      • Using a 4-yr experiment, we found the maize/chili intercropping could be a valuable choice, which decreased erosion and increased economic benefits.
      • The multiple cropping system combined with staple and cash crops should be given greater attention in hilly areas.

      doi:10.2134/agronj2016.10.0579
      Published: June 30, 2017



    • Xiang Zhao, Huisen Zhu, Kuanhu Dong and Deying Li
      Plant Community and Succession in Lowland Grasslands under Saline–Alkali Conditions with Grazing Exclusion

      Rangeland degradation poses a serious environmental and economic problem in northern China. This study investigated soil conditions and plant community patches prior to and after grazing exclusion in Youyu County, Shanxi Province. The soil at this site has a pH of 8.2 to 10.1 and electrical conductivity of 0.4 to 5.9 dS m–1. With the exception of bare patches, the patches were named after the dominant species, that is, Artemisia anethifolia Weber ex Stechm. (continued)

      Core Ideas:
      • Soil properties are important factors for pasture degradation in addition to grazing management.
      • Community patch formation could be predicted from soil variables.
      • Community patch types may be used as an indicator of the degree of grassland degradation.
      • Grazing exclusion affects biomass production and species diversity differently.

      doi:10.2134/agronj2016.12.0734
      Published: June 22, 2017



  • SOIL TILLAGE, CONSERVATION &MANAGEMENT

    • David D. Tarkalson and Bradley A. King
      Effects of Tillage and Irrigation Management on Sugarbeet Production

      Increased water demands and drought have resulted in a need to determine the impact of tillage and deficit water management practices in irrigated sugarbeet (Beta vulgaris L.) production. This study was conducted over three growing season (2011–2015) at the USDA-Agricultural Research Service facility in Kimberly, ID, on a Portneuf silt loam soil. Treatments consisted of two tillage treatments (strip tillage [ST] and conventional tillage [CT]) and four water input treatments ranging from 100 to 25% of model calculated crop evapotranspiration [ETc]). Estimated recoverable sucrose (ERS) yield, root yield, and sucrose and brei nitrate concentrations were similar for ST and CT across all water treatments. (continued)

      Core Ideas:
      • Strip tillage and conventional tillage had the same sugar yields under all irrigation levels.
      • Relationships between water input/use and sugarbeet yields were established.
      • Sucrose yields were the same under strip tillage and conventional tillage.
      • Strip tillage reduced runoff and increase water inflitration compared to conventional tillage.

      doi:10.2134/agronj2016.09.0530
      Published: July 13, 2017



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