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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(3)



  • AGRONOMIC APPLICATION OF GENETIC RESOURCES

    • Fatemeh Etemadi, Masoud Hashemi, Roohollah Abbasi Shureshjani and Wesley R. Autio
      Application of Data Envelopment Analysis to Assess Performance Efficiency of Eight Faba Bean Varieties

      Faba bean (Vicia faba L.) seeds are generally large which limits its adoption as cover crop and/or dual purpose cover crop/cash crop due to the high seed cost. The purpose of this study was to apply data envelopment analysis (DEA) by using seed size as input and fresh pod, fresh seed, and L-Dopa yield as output to evaluate efficiency of eight faba bean varieties. Eight faba bean varieties were evaluated in a 2-yr study. Four common methods of DEA were used for ranking faba bean varieties. (continued)

      Core Ideas:
      • Seed size along with yield should be considered for evaluation of faba bean varieties.
      • Data envelopment analysis can be implemented for ranking the efficiency of faba bean varieties.
      • Varieties ranked high by data envelopment analysis models can promote faba bean production in the Northeast.

      doi:10.2134/agronj2016.10.0617
      Published: May 5, 2017



  • AGRONOMY, SOILS & ENVIRONMENTAL QUALITY

    • Ivan A. Dozier, Gevan D. Behnke, Adam S. Davis, Emerson D. Nafziger and María B. Villamil
      Tillage and Cover Cropping Effects on Soil Properties and Crop Production in Illinois

      Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and subsequent crop yields, yet support for these claims within Illinois remains limited. Cover crops were used in corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotations. We assessed five sets of CCs vs. fallow controls under no-till (NT) and chisel till (Till) on soil attributes and crop yields, encompassing one complete rotation cycle. (continued)

      Core Ideas:
      • Compared corn–soybean rotations with cover crops vs fallows under no-till or till.
      • Corn–soybean rotations with cereal rye after corn decreased soil NO3–N by 42%.
      • Soil attributes and crop yields were generally unaffected by cover crops use.
      • Tillage increased soil organic matter and exchangeable K compared to no-till.
      • Tillage reduced soybean yields by 245 kg/ha compared to no-till.

      doi:10.2134/agronj2016.10.0613
      Published: May 18, 2017



    • Carlos Antonio da Silva, Marcos Rafael Nanni, Paulo Eduardo Teodoro and Guilherme Fernando Capristo Silva
      Vegetation Indices for Discrimination of Soybean Areas: A New Approach

      The aim of this study was to map areas cultivated with soybean [Glycine max (L.) Merr.] in Paraná state, Brazil, using mono- and multitemporal MODerate-resolution imaging spectroradiometer (MODIS) images. We applied the vegetation index perpendicular crop enhancement index (PCEI) and threshold determination for the automation of soybean area discrimination by geo-object (GEOBIA). For this mapping, vegetation indices (normalized difference vegetation index [NDVI], enhanced vegetation index [EVI], and crop enhancement index [CEI]) and the development of the PCEI were used with the aid of time-series images from the TERRA/MODIS system-sensor. A support analysis, based on geo-objects and a decision tree based on data mining, was used to determine the new vegetation index. (continued)

      Core Ideas:
      • Automation of mapping of soybean areas.
      • Use of remote sensors in the recognition of summer crop.
      • Development of exclusive vegetation index for soybean.

      doi:10.2134/agronj2017.01.0003
      Published: May 11, 2017



    • L. C. P. S. Pacheco, V. Damin, A. P. Pelosi, K. R. S. Ferreira and P. C. O. Trivelin
      Herbicides Increase Emission of Ammonia by Pearl Millet and Congo Grass

      In previous works, we demonstrated that some herbicides could increase N losses from the soil–plant system under greenhouse conditions, but the N-output pathways were not investigated. In this context, the aim of this work was to evaluate ammonia (NH3) emission by soil and plants and the total-N accumulation in the straw following herbicide application to pearl millet (Pennisetum glaucum) and congo grass (Urochloa ruziziensis). Two field experiments were conducted in a randomized block, with a factorial design and eight replicates per treatment. The treatments were: 1-control: without herbicide application, 2- glyphosate, 3-glufosinate-ammonium, and 4-paraquat. (continued)

      Core Ideas:
      • • Post-emergent herbicides application increase the emission of ammonia by cover crops.
      • • Post-emergent herbicides application on congo grass decrease the total N in the residues.
      • • Glyphosate application on congo grass or pearl millet strongly reduces the total-N content in the straw.

      doi:10.2134/agronj2016.04.0242
      Published: May 11, 2017



    • Ming Xie, Yan-Jun Zhang, De-Liang Peng, Qian Li, Xin-Ping Hu and Zhao-Rong Zhang
      No Significant Impact of Transgenic Cry1Ab/1Ac Cotton on Rhizosphere-Soil Enzyme Activities and Bacterial Communities

      Transgenic Bt-cotton (Gossypium hirsutum L.) GK 12 is commonly used for control of lepidopteran pests in China, but concerns exist regarding possible unintended effects on soil microbial communities. Bacterial population sizes and community structures in the rhizosphere soil under intensive cultivation of GK 12, its near-isogenic parent Simian 3 and a conventional cotton DP 5415 were analyzed during 2009 to 2011 by quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE). Dehydrogenase, urease, and phosphatase activities were also measured. It was found that these microbial-related parameters were significantly influenced by variations due to the year and plant growth stage. (continued)

      Core Ideas:
      • The selected enzymatic activities were not significantly affected by the GK 12.
      • The bacterial population size was not significantly affected by the GK 12.
      • The bacterial community structure was not significantly affected by the GK 12.

      doi:10.2134/agronj2016.10.0618
      Published: May 5, 2017



    • Daniel Plaza-Bonilla, Jorge Álvaro-Fuentes, Javier Bareche, Albert Masgoret and Carlos Cantero-Martínez
      Delayed Sowing Improved Barley Yield in a No-Till Rainfed Mediterranean Agroecosystem

      The effect of delaying sowing date and maturity class on no-till (NT) winter cereal performance was studied over two periods of 3 yr each. A 3 (sowing date) × 2 (maturity class) randomized complete block design was run for 3 yr with barley (Hordeum vulgare L.) (B-) (2006–2007 to 2008–2009) and soft wheat (Triticum sp.) (W-) (2009–2010 to 2011–2012) in northeastern Spain. Sowing dates corresponded to October (D1- the standard farming practice), November (D2), and December (D3). Maturity classes corresponded to early (-EC) and medium (-MC). (continued)

      Core Ideas:
      • Sowing delay and cultivar effects on cereal production and water and N use efficiencies were studied.
      • Sowing delay increased grain yield due to greater number of grains per m2.
      • Sowing delay maximized the efficiency in the use of resources.

      doi:10.2134/agronj2016.09.0537
      Published: May 5, 2017



    • Brenton Sharratt, Frank Young and Gary Feng
      Wind Erosion and PM10 Emissions from No-Tillage Cropping Systems in the Pacific Northwest

      Wind erosion is a concern in the Inland Pacific Northwest (PNW) of the United States where the emission of particulates ≤10 µm in diameter (PM10) from winter wheat (Triticum aestivum L.)/summer fallow (WW/SF) dryland cropping systems during high winds degrades air quality. There is a potential to reduce the risk of wind erosion using no-tillage or chemical fallow cropping systems, but wind erosion observations are lacking from these systems. We measured sediment and PM10 flux from reduced-tillage WW/SF, no-tillage wheat/chemical fallow (NTW/CF), and no-tillage spring barley (Hordeum vulgare L.)/spring wheat (NTSB/SW) using a portable wind tunnel near Ralston, WA. Horizontal sediment flux, wind speed, and PM10 concentration were measured over two consecutive 10 min sampling periods inside the tunnel after sowing wheat in spring or late summer on four replications of the rotations. (continued)

      Core Ideas:
      • Erosion of agricultural lands affect air quality in the Inland Pacific Northwest.
      • Alternatives to tillage-based cropping systems are needed to reduce wind erosion.
      • No-tillage cereal cropping systems reduce wind erosion and particulates ≤10 µm in diameter emissions.
      • Economically viable strategies are sought for no-tillage cropping systems.

      doi:10.2134/agronj2016.11.0667
      Published: May 5, 2017



    • Aristotelis C. Tagarakis and Quirine M. Ketterings
      In-Season Estimation of Corn Yield Potential Using Proximal Sensing

      Crop sensing is a promising approach for predicting corn (Zea mays L.) yield. Yield prediction is the first step in development of algorithms for sensor-based N management. Here, we evaluated the impact of (i) timing of sensing (growth stage), and (ii) method of reporting sensor data on estimations of corn grain and silage yield in New York. Sensor data were reported as the normalized difference vegetation index (NDVI), in-season estimated yield (INSEY) expressed as NDVI divided by days after planting (DAP; INSEYDAP), growing degree days (GGD; INSEYGGD), and the inverse simple ratio (ISR; [1–NDVI]/[1+NDVI]) divided by DAP (INSEYISR). (continued)

      Core Ideas:
      • Accurate yield prediction is needed for effective sensor-based N management.
      • Field testing is needed to develop reliable algorithms for silage and grain corn.
      • For the most accurate yield prediction, crop sensing should be done at V6 or later.
      • Predictions for corn silage were more accurate than for corn grain.
      • The use of in-season-estimated yield is preferred across variable sites.

      doi:10.2134/agronj2016.12.0732
      Published: May 5, 2017



    • Bent T. Christensen, Johannes L. Jensen and Ingrid K. Thomsen
      Impact of Early Sowing on Winter Wheat Receiving Manure or Mineral Fertilizers

      To reduce over-winter nitrate leaching from temperate soil, nitrate catch crops can be grown between main crops. We hypothesize that earlier sowing can replace catch crops sown before winter wheat (Triticum aestivum L.) and improve wheat yields and N uptake. Early sown (late August) and timely sown (late September) wheat were tested over two cropping seasons (2011–2012 and 2013–2014) using two contemporary cultivars (Hereford and Mariboss) and increasing rates of N (0–300 kg total N ha–1) with animal manure (AM; cattle slurry) or mineral fertilizers (NPK), surface applied in late March. We measured over-winter N uptake in wheat, harvest yields, and N concentrations in grain and straw. (continued)

      Core Ideas:
      • Grain yield benefits of early sown wheat was 0.5 and 1.0 Mg ha–1 for mineral fertilizers and animal manure.
      • Over-winter N uptake was 11 kg N ha–1 higher in early than in timely sown wheat.
      • At harvest, 19 kg N ha–1 more N was removed in early than in timely sown wheat.
      • The beneficial effect of early sowing compares to that of N catch crops.
      • Surface-applied cattle slurry provides a poor N use efficiency and grain protein.

      doi:10.2134/agronj2016.11.0677
      Published: May 5, 2017



    • Lu Wu, Liping Feng, Yi Zhang, Jiachen Gao and Jing Wang
      Comparison of Five Wheat Models Simulating Phenology under Different Sowing Dates and Varieties

      Crop phenology is closely related to yield formation and crop management. Phenology module is one of the essential components that affect the call of model parameters and performance of whole model. We analyzed different algorithms of five widely used wheat models (WOFOST, CERES-Wheat, APSIM-Wheat, SPASS, and WheatSM) and studied the simulation accuracy by field experimental data with three varietal types under varied sowing dates in four sites in the North China plain. Simulation results were in good agreement with the observations in terms of jointing, flowering, and maturity stage. (continued)

      Core Ideas:
      • We compared the mechanism and capacity of five wheat phenology models by varied phases.
      • Models reproduced growing phases well by suitable sowing dates and local varieties.
      • Simulations were unsatisfactory under late sowing dates and colder conditions.

      doi:10.2134/agronj2016.10.0619
      Published: April 20, 2017



  • BIOFUELS

    • Adam J. Heitman, Miguel S. Castillo, T. Jot. Smyth, Carl R. Crozier, Zan Wang, Ron W. Heiniger and Ronald J. Gehl
      Nitrogen Fertilization Effects on Yield and Nutrient Removal of Biomass and Sweet Sorghum

      Sorghum [Sorghum bicolor (L.) Moench] can be used as bioenergy crop for either biomass or sugar yield. Dry matter (DM) yield and nutrient removal information is needed if sorghum is to be planted in high-nutrient receiving areas such as swine (Sus scrofa domesticus) spray fields. The objectives of this 4-yr experiment (2012 through 2015) were to determine the effect of five N fertilization rates (0, 67, 134, 201, and 268 kg N ha–1 yr–1) on DM yield and nutrient (N, P, and K) removal of cultivars Blade ES5200 (biomass) and M81-E (sweet). The DM yield of ES5200 plateaued at 18.5 and 18.9 Mg ha–1 in 2012 and 2014, respectively, when N rate was 67 kg ha–1. (continued)

      Core Ideas:
      • During the 4-yr period of this trial, N fertilization increased dry matter yield in 2 out of 4 yr for biomass sorghum and there was no effect on dry matter yield of sweet sorghum.
      • High DM yield supports sorghum as a bioenergy crop, however, the relatively low nutrient removal rate may limit its utilization in nutrient-rich environments such as spray fields.
      • Greatest dry matter yields achieved were ∼18.5 Mg ha–1 at a N fertilization rate of 67 kg N ha–1 yr–1 for biomass sorghum.

      doi:10.2134/agronj2016.12.0710
      Published: May 18, 2017



    • A. J. Ashworth, A. C. Rocateli, C. P. West, K. R. Brye and M. P. Popp
      Switchgrass Growth and Effects on Biomass Accumulation, Moisture Content, and Nutrient Removal

      Temporal patterns of plant growth, composition, and nutrient removal impact development of models for predicting optimal switchgrass (Panicum virgatum L.) harvest times for bioenergy. Original time-course data are needed to construct useful models. Objectives were to characterize seasonal trends in yield, tissue moisture, ash content, leaf area index (LAI), interception of photosynthetically active radiation (PAR), and macronutrient accumulation and losses. Plots were subjected to 12 single harvests May to February in 2009–2010 and 2010–2011. (continued)

      Core Ideas:
      • Quantifying intra-seasonal fluctuations allows for simulating productivity trade-offs.
      • Biomass yields peaked August–September when N and K and moisture contents were elevated.
      • Delaying harvests to late fall reduces fertilizer replacement needs.

      doi:10.2134/agronj2017.01.0030
      Published: May 18, 2017



  • BIOMETRY, MODELING & STATISTICS

    • K. Raja Reddy, David Brand, Chathurika Wijewardana and Wei Gao
      Temperature Effects on Cotton Seedling Emergence, Growth, and Development

      Establishing vigorous cotton (Gossypium hirsutum L.) seedling stand for an early planted crop will help to develop healthy root and canopy development. Cotton planted early in the season will be subjected to low, but variable temperatures and soil moisture conditions. There has been little exploration of temperature effects on the cotton root system architecture. The objective of this study was to study the effects of a wide range of temperatures during seed germination and early seedling growth stages on above- and belowground growth and developmental parameters of four cotton cultivars. (continued)

      Core Ideas:
      • Little insight of temperature effects on cotton root morphology and seed germination.
      • Cotton cultivars vary in their response to different temperatures.
      • Growth and developmental responses developed will be useful in cotton crop models.

      doi:10.2134/agronj2016.07.0439
      Published: May 5, 2017



  • CLIMATOLOGY & WATER MANAGEMENT

    • Zenghui Sun, Zizhong Li, Baoguo Li, Tao Sun and Huanxi Wang
      Factors Influencing Corn Canopy Throughfall at the Row Scale in Northeast China

      Understanding throughfall (TF) and its influencing factors at crop row scale is a key step to reveal the mechanisms of soil water recharging, soil erosion, and evaporation of intercepted rainfall. The objective of this study was to determine the amount and the variation of TF in relation to plant canopy and rainfall. In this study, TF was measured by a rectangular plexiglass collector at five measurement locations (MLs) with the distances of the (A) 0 to 12 cm, (B) 12 to 24 cm, (C) 24 to 36 cm, (D) 36 to 48 cm, and (E) 48 to 60 cm from corn (Zea mays L.) row during the period of corn plant height growth (HT) approximately from 50 to 250 cm when the leaf area index (LAI) increases from 0.4 to 4.0 in 2013 and 2014. Throughfall increased with total rainfall amount (RA) but decreased with LAI and HT values. (continued)

      Core Ideas:
      • Throughfall was statistically different among five measurement locations.
      • Cumulative throughfall of 24 to 36 cm from row exceeded that of 0 to 12 cm and 48 to 60 cm by 46 to 88%.
      • Coefficient of variation of throughfall decreased with rainfall amount and increased with leaf area index and plant height.

      doi:10.2134/agronj2016.02.0116
      Published: May 5, 2017



  • CROP ECOLOGY & PHYSIOLOGY

    • Ling Gou, Jun Xue, Bingqin Qi, Buyi Ma and Wangfeng Zhang
      Morphological Variation of Maize Cultivars in Response to Elevated Plant Densities

      Increasing plant density is a common method for increasing maize (Zea mays L.) yield. However, the yield increases are limited by light competition and mutual shading that occur within close canopies. The objectives of this 2-yr field experiments were to determine the effect of plant density on maize plant morphology, canopy structure, and canopy light distribution. The leaf length, leaf width, leaf area and leaf area index (LAI) increased from both the top and the bottom of the canopy. (continued)

      Core Ideas:
      • Maize can adjust its morphology to adapt to the low light environment in close planted stands.
      • Maize adapts to close planting by increasing leaf spacing below the ear and leaf orientation value above the ear, and by reducing leaf width and leaf angle.
      • Morphological changes allow more light transmission into the mid- and lower canopy under high plant density.

      doi:10.2134/agronj2016.11.0675
      Published: May 18, 2017



    • Peng Yan, Zhiqiang Tao, Yuanquan Chen, Xuepeng Zhang and Peng Sui
      Spring Maize Kernel Number and Assimilate Supply Responses
      to High-Temperature Stress under Field Conditions

      The productivity of spring maize (Zea mays L.) in North China Plain (NCP) is primarily limited by high-temperature stress (HTS) during the grain-filling stage. To avoid HTS and promote productivity, variable sowing date (SD), treatments were established from 2013 to 2015 (early April, SD1; mid-April, SD2; late April, SD3; early May, SD4; mid-May, SD5; and late May, SD6). During the grain-filling stage, the leaf area index (LAI) and dry matter accumulation (DMA) were greatest at the final SD (SD6) compared with all other treatments. Additionally, the daily mean air temperature (Tmean), daily maximum air temperature (Tmax), and cumulative stressful days (CSD) during this stage across 3 yr decreased at SD6 by 1.4 to 3.2°C, 1.0 to 2.7°C, and 5.7 to 14.7 d, respectively, compared with the values at SD1 to SD5. (continued)

      Core Ideas:
      • Spring maize mono-cropping system is shown to be a water-saving and high-yield maize farming system.
      • Spring maize was traditionally planted in late April or early May but seldom obtained desirable yield.
      • Altering sowing date reduced frequency of high-temperature stress of spring maize around silking and grain-filling stage.
      • Altering sowing date improved assimilate availability of spring maize during the grain-filling stage.
      • Late May turned out to be the better sowing date, rather than traditional sowing dates in late April or early May under current conditions.

      doi:10.2134/agronj2016.11.0662
      Published: May 18, 2017



    • Yang Lu, Xiying Zhang, Suying Chen, Liwei Shao, Hongyong Sun and Junfang Niu
      Increasing the Planting Uniformity Improves the Yield of Summer Maize

      Crop production is often affected by resource limitations, especially water in semiarid areas. This study was conducted to identify whether the changes in inter and intra row spacing could improve soil water availability and radiation interception for maize (Zea mays L) through adjusting spatial distribution of root systems and canopy morphology. A 6-yr field study (2011–2016) was conducted to examine the impacts of five planting patterns on summer maize growth and yields in the North China Plain (NCP), which included two narrow-wide row spacings (20–100 cm, R20-100; 40–80 cm, R40-80), two equal-row spacings (60 cm, R60; 50 cm, R50) and equidistance both in row spacing and in plant distance in a row (38 cm, R38). The results showed that the more uniform planting increased the active soil volume taken by root system, therefore, increased the soil water availability to plants under limited water supply condition. (continued)

      Core Ideas:
      • With the reduction in the inter-row spacing under the same target planting density, the final plant density and kernel numbers per area were increased.
      • The more uniform planting improved the root growth of maize at the earlier growth stages of the crop.
      • The increase in planting uniformity increased the radiation interception of the canopy.
      • The yield of summer maize was improved with the increase in the planting uniformity.

      doi:10.2134/agronj2016.12.0718
      Published: May 11, 2017



    • Baizhao Ren, Lili Li, Shuting Dong, Peng Liu, Bin Zhao and Jiwang Zhang
      Photosynthetic Characteristics of Summer Maize Hybrids with Different Plant Heights

      Three summer maize (Zea mays L.) hybrids with different plant heights, DengHai661 (low-plant height hybrid, DH661), ChaoShi3 (medium-plant height hybrid, CS3), and XianYu335 (high-plant height hybrid, XY335), were used to explore photosynthetic characteristics of maize and its responses to plant density. Results showed that grain yield increased with the increase of plant density. At 90,000 plants ha–1, grain yield of DH661 was the highest. With increasing plant density, yield increment of DH661 was biggest, while leaf area index (LAI), chlorophyll content, and net photosynthetic rate (Pn) of DH661 changed less with increasing plant density. (continued)

      Core Ideas:
      • We investigated the photosynthetic characteristics of high-yield summer maize with different heights.
      • We realized the regulatory effect of plant density on summer maize with different plant heights.
      • We discussed yield potential of summer maize with different plant height.

      doi:10.2134/agronj2016.12.0693
      Published: May 11, 2017



    • Wenling Chen, Menggui Jin, Yang Xian and Ty P.A. Ferré
      Combined Effect of Sodium Chloride and Boron in Irrigation Water on Cotton Growth

      The NaCl and B levels of brackish water are higher than those of fresh water. Cotton (Gossypium hirsutum L.) is probably affected by simultaneous NaCl and B stress when irrigated with brackish water, but little is understood regarding the combined effect of NaCl and B on cotton growth and the absorption of nutrient elements. Cotton growth and nutrient element content were measured at different NaCl and B concentrations in pot experiments. Cotton growth parameters varied with different NaCl and B concentrations in irrigation water. (continued)

      Core Ideas:
      • Cotton growth parameters varied with different NaCl and B concentrations in irrigation water.
      • An antagonistic effect of NaCl and B on cotton growth and yield was observed.
      • The combination of NaCl and B affected nutrient ion absorption of cotton.
      • Brackish water moderately promoted cotton yield, possibly because of the extra quantity of NaCl-resistant nutrient elements such as K and Ca.

      doi:10.2134/agronj2016.07.0416
      Published: May 5, 2017



    • Spyridon Mourtzinis and Shawn P. Conley
      Delineating Soybean Maturity Groups across the United States

      Photoperiod and in-season temperature are the primary factors that dictate the region where a soybean [Glycine max (L.) Merr.] variety is adapted. The first study that defined hypothetical maturity groups (MGs) zones across the US was 45 yr ago, and the most recent used data up to 2003. Although, photoperiod remains constant, climatic conditions, management practices, and soybean genetics have changed during the past decades. Therefore, the objective of this study was to re-delineate soybean MGs across the US using recent genetics. (continued)

      Core Ideas:
      • Seven maturity group zones were identified across the United States.
      • The width of maturity group zones 4 and 5 cover the largest geographic region.
      • Maturity group zones were defined by a downward deflection of the maturity group lines.
      • Maturity group adaptation zones need to be continuously monitored and adjusted.

      doi:10.2134/agronj2016.10.0581
      Published: May 5, 2017



  • CROP ECONOMICS, PRODUCTION & MANAGEMENT

    • Amanda M. Grev, Craig C. Sheaffer, Michelle L. DeBoer, Devan N. Catalano and Krishona L. Martinson
      Preference, Yield, and Forage Nutritive Value of Annual Grasses under Horse Grazing

      Annual grasses such as oat (Avena sativa L.), wheat (Tricum aestivum L.), and barley (Hordeum vulgare L.) can serve as alternative forage but little research exists under horse (Equus caballus) grazing. The objectives were to evaluate annual cool-season grasses for preference, yield, and forage nutritive value under horse grazing during the summer and fall in Minnesota. Spring-planted grasses included spring barley, spring oat, spring wheat, winter wheat, and annual ryegrass (Lolium multiflorum L.). Summer-planted grasses included the same five species plus spring forage oat, winter barley, and winter rye (Secale cereal L.). (continued)

      Core Ideas:
      • Horses preferred winter wheat, annual ryegrass, and spring wheat.
      • Annual ryegrass, spring oat, and winter barley were the highest yielding species.
      • Spring oat, spring barley, and spring wheat had little to no regrowth.
      • Winter wheat and winter rye consistently had higher forage nutritive values.
      • Annual ryegrass can extend the grazing season or provide emergency forage for horses.

      doi:10.2134/agronj2016.11.0684
      Published: May 11, 2017



    • Eric D. Billman, Ben M. Goff, Brian S. Baldwin, Kelly Prince and Tim D. Phillips
      Effects of Vegetative Cool-Season Grasses on Forage Removal by Dairy Heifers

      Identification of forage grasses that are more readily consumed than others during grazing is vital to determining traits that can be used by plant breeders to increase animal intake and digestibility. Producers can benefit from the identification of what species and cultivars are more readily consumed; thus increasing animal production. The objectives were to: (i) determine forage removal by dairy cattle of several species and cultivars of cool-season forage grasses: orchardgrass (Dactylis glomerata L.; eight cultivars), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort; five cultivars], perennial ryegrass (Lolium perenne L.; five cultivars), and festulolium [ × Festulolium braunii (K. Richt.) A. (continued)

      Core Ideas:
      • • Grazing of vegetative swards results in forage removal trends contradictory to established paradigms.
      • • Neutral detergent fiber, and water soluble carbohydrates did not impact forage removal in ways established by studies done on grass with varying maturity.
      • • Conclude that species differences rather than cultivars drive forage removal in dairy cattle.

      doi:10.2134/agronj2016.10.0598
      Published: May 11, 2017



    • Alessandro Menegon, Stefano Macolino, John H. McCalla, Filippo Rimi and Michael D. Richardson
      Turf Quality and Species Dynamics in Bermudagrass and Kentucky Bluegrass Mixtures

      Climatic changes and the need to reduce water consumption for irrigation have led to expanded use of warm-season turf species in transitional zones. Turf managers are often hesitant to use warm-season species because they undergo dormancy for a long period during the winter. Although this issue might be addressed by mixing cool- with warm-season species, there is a lack of information on the performance and dynamics of species succession in such turfgrass mixtures. A 2-yr investigation was conducted in Legnaro, Italy, and Fayetteville, AR, to test the turf quality and species succession in mixtures of various cultivars of bermudagrass (BG) [Cynodon dactylon (L.) Pers.] with Kentucky bluegrass (KBG) (Poa pratensis L.). (continued)

      Core Ideas:
      • In transitional environments, mixtures of bermudagrass and Kentucky bluegrass can provide green cover year-round.
      • In mixtures, cultivars of bermudagrass characterized by slow green-up favor the survival of Kentucky bluegrass.
      • The choice of Kentucky bluegrass cultivars has limited practical impact on the performance of mixtures with bermudagrass.

      doi:10.2134/agronj2016.08.0461
      Published: May 11, 2017



    • Aifen Tao, Reza Keshavarz Afshar, Jinwen Huang, Yesuf Assen Mohammed, Matthew Espe and Chengci Chen
      Variation in Yield, Starch, and Protein of Dry Pea Grown Across Montana

      Pea (Pisum sativum L.) has long been an important component of the human diet, providing an excellent source of protein. In addition to its protein, pea starch, especially resistant starch (RS), has received an extensive attention in food industries in recent years. We evaluated nine pea cultivars varying in cotyledon color, grain weight, maturity group, and phenology planted at five locations with diverse climatic conditions across Montana in 2013 and 2014 to assess genetic and environmental factors affecting their yield, protein, RS, and total starch (TS). Grain yield varied from 982 to 5951 kg ha–1, RS content ranged from 5 to 53 g kg–1, and protein from 159 to 251 g kg–1. (continued)

      Core Ideas:
      • Dry pea yield, protein, and resistant starch varied greatly across Montana.
      • Yield and protein were mainly determined by environments.
      • Resistant starch is controlled by genetics to a great extent.
      • Effects of drought index, growth period, seed size, and seed weight on yield, protein, and starch were analyzed.

      doi:10.2134/agronj2016.07.0401
      Published: May 11, 2017



    • Wade Thomason, Bee Khim Chim, David Holshouser, Harry Behl, Maria Balota, Kang Xia, William Frame and Tyler Black
      Comparison of Full-Season and Double-Crop Soybean and Grain Sorghum Systems in Central and Southeastern Virginia

      Double-cropping soybean [Glycine max (L.) Merr.] after winter small-grains is common in the mid-Atlantic region. Grain sorghum (Sorghum bicolor L. Moench) can also be double-cropped after small grain and sorghum production in the region is increasing due to greater local demand for feed grains. The objective of this experiment was to evaluate and compare the yield and agronomic characteristics of grain sorghum planted full season or double-cropped after wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), or triticale (× Triticosecale) with soybean in the same rotations. (continued)

      Core Ideas:
      • Grain sorghum is a viable alternative crop in the Mid-Atlantic region.
      • Grain sorghum can be successfully doublecropped after small grain in the Mid-Atlantic region.
      • Depending on commodity prices both grain sorghum and soybean can be profitable crop choices.

      doi:10.2134/agronj2016.10.0577
      Published: May 5, 2017



    • Steven B. Mirsky, Victoria J. Ackroyd, Stephane Cordeau, William S. Curran, Masoud Hashemi, S. Chris Reberg-Horton, Matthew R. Ryan and John T. Spargo
      Hairy Vetch Biomass across the Eastern United States: Effects of Latitude, Seeding Rate and Date, and Termination Timing

      Hairy vetch (Vicia villosa Roth) is a legume grown for high biomass and N fixation. Climate, population density, establishment date, and termination timing affect biomass production; the combined effect of these factors has not been documented. We conducted an experiment in Massachusetts, New York, Pennsylvania, Maryland, and North Carolina across a range of hairy vetch seeding rates and dates and termination timings to define biomass production potential and determine minimum seeding rates. Hairy vetch was planted at two dates at rates of 6 to 50 kg ha–1. (continued)

      Core Ideas:
      • Seeding hairy vetch at the optimal time is crucial for biomass production.
      • Optimal hairy vetch seeding rate for maximizing biomass production depends on latitude.
      • The optimal seeding rate is 15 to 20 kg ha–1 in Massachusetts, New York, and Pennsylvania.
      • The optimal seeding rate is 5 to 10 kg ha–1 in Maryland and North Carolina.

      doi:10.2134/agronj2016.09.0556
      Published: April 20, 2017



    • Steven B. Mirsky, John T. Spargo, William S. Curran, S. Chris Reberg-Horton, Matthew R. Ryan, Harry H. Schomberg and Victoria J. Ackroyd
      Characterizing Cereal Rye Biomass and Allometric Relationships across a Range of Fall Available Nitrogen Rates in the Eastern United States

      Cereal rye (Secale cereale L.) is widely grown due to its winter hardiness and adaptability to varied soil and environmental conditions. Fall and spring climate and available soil N drive biomass production. However, there is limited empirical information on the effects of these factors on cover crop performance. Farmers need early spring indicators of cereal rye performance to guide management. (continued)

      Core Ideas:
      • Cereal rye has the capacity for substantial biomass and N accumulation.
      • Cereal rye shoots accumulated roughly 50% of the fertilizer N applied in our study.
      • Cereal rye required 72.4 kg added N ha–1 to reach maximum biomass production.
      • The average maximum biomass was 2853 kg ha–1 at GS25 and 9739 kg ha–1 at GS60.

      doi:10.2134/agronj2016.09.0557
      Published: April 20, 2017



  • INTERNATIONAL TURFGRASS SOCIETY CONFERENCE

    • Chengyan Yue, Jingjing Wang, Eric Watkins, Stacy Bonos, Kristen Nelson, James A. Murphy, William Meyer and Brian Horgan
      Consumer Preferences for Information Sources of Turfgrass Products and Lawn Care

      Consumers need adequate information about turfgrasses attributes and lawn maintenance practices when they choose what types of turfgrasses to grow in their home lawns. We conducted online surveys with 2167 homeowners from the United States to explore what information sources they consider as trustworthy and useful regarding lawn care. We found turfgrass consumers trusted information from families, University extensions, and garden centers/hardware stores the most; these information sources were equally trusted. Whereas, they ranked garden centers/hardware stores, followed by families and then lawn care companies as the most useful information sources. (continued)

      Core Ideas:
      • Turfgrass consumers trusted information from families, university extension, and garden centers the most.
      • Homeowners ranked garden center/hardware stores, followed by families and then lawn care companies as the most useful information sources.
      • Information from university extension and regional water management authorities were considered as trustworthy but less useful.

      doi:10.2134/agronj2016.05.0310
      Published: May 5, 2017



    • Thinh Van Tran, Shu Fukai, Anthony F. van Herwaarden and Christopher J. Lambrides
      Physiological Basis of Sprouting Potential in Bermudagrass

      Despite the popularity of bermudagrass (Cynodon dactylon L.) around the world, there are few studies that report genotypic and seasonal variation for sprouting of stolons used in pasture establishment or revegetation of disturbed land. This study investigated the genotypic/seasonal variation and the physiological basis of sprouting from nodes of aboveground stolons among 12 bermudagrasses. Sprouting percentage, total nodes per m2 (Nds), stolon diameter (SD), total aboveground biomass (TaB), and concentration of water soluble carbohydrate [WSC], concentration of starch [starch], concentration of non-structural carbohydrate [NSC], and concentration of crude protein [CP] were determined in different seasons including winter 2013, winter 2014, spring 2014, summer 2015, and fall 2015. Sprouting percentage for stolons sampled in spring and summer was higher than that for winter and fall. (continued)

      Core Ideas:
      • Large genotypic variation for sprouting of stolons was identified.
      • Sprouting percentage was strongly associated with stolen diameter.
      • Sprouting was related photoassimilate supply on an amount per node basis.
      • The size and/or maturity of the axillary buds were also possible factors.

      doi:10.2134/agronj2016.06.0321
      Published: May 5, 2017



    • Joseph Young, Mike Richardson and Douglas Karcher
      Golf Ball Mark Severity and Recovery as Affected by Mowing Height, Rolling Frequency, Foot Traffic, and Moisture

      Putting greens experience stress from golf balls striking the surface, maintenance equipment, and foot traffic. Improved creeping bentgrass (Agrostis stolonifera L.) cultivars, sand-based root zones, and skilled superintendents maintain plant health while providing firmer conditions. Many researchers have studied effects of compaction and wear on putting greens, but few have determined the effect of these stresses on ball marks. The objective of this research was to evaluate ball mark severity and recovery of creeping bentgrass under different mowing heights (2.5, 3.2, and 4.0 mm), rolling frequencies (0, 3, or 6 d wk–1), and foot traffic using digital image analysis. (continued)

      Core Ideas:
      • Digital image analysis methods to evaluate putting green ball mark severity and recovery.
      • Firmer surfaces from dry conditions or lightweight rolling increased maximum ball mark injury area.
      • Rate of recovery was similar for all treatments, but increased wear increased time to 50% recovery.
      • Demonstrates positive attributes of dispersing foot and equipment traffic throughout the green.

      doi:10.2134/agronj2016.04.0240
      Published: January 5, 2017



    • John R. Brewer, John Willis, Sandeep S. Rana and Shawn D. Askew
      Response of Six Turfgrass Species and Four Weeds to Three HPPD-Inhibiting Herbicides

      Mesotrione (2-[4-(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione), tembotrione (2-[2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy)methyl]benzoyl]-1,3-cyclohexanedione), and topramezone ([3-(4,5-dihydro-3-isoxazolyl)-2-methyl-4-(methylsulfonyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone) are new herbicides that control many troublesome weeds, but little is known about the response of several turfgrass species to these herbicides. A multiyear study was conducted to determine the response of six turfgrass species and four weeds to these three herbicides. Study results generally agreed with previous reports of turfgrass and weed response to mesotrione, and suggest that tembotrione could be safely used, depending on rate, to control weeds such as smooth crabgrass [Digitaria ischemum (Schreb.) Schreb. ex Muhl.], broadleaf plantain (Plantago major L.), and white clover (Trifolium repens L.) selectively in tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. (continued)

      Core Ideas:
      • Tembotrione controlled weeds selectively in bluegrass, fescue, and zoysiagrass turf.
      • Topramezone controlled key weeds better than mesotrione and tembotrione.
      • Topramezone was among the safest herbicides on four of the six turfgrasses tested.
      • Results will aid herbicidal-risk assessment near potentially sensitive turfgrass species.
      • The study supports considerations for herbicide label expansion or registration in turf.

      doi:10.2134/agronj2016.06.0345
      Published: December 1, 2016



    • Quincy D. Law, Jon M. Trappe, Yiwei Jiang, Ronald F. Turco and Aaron J. Patton
      Turfgrass Selection and Grass Clippings Management Influence Soil Carbon and Nitrogen Dynamics

      Little information is available about how grass species and management practices, such as grass clippings management, influence soil C and N accumulation, especially labile soil C. Thus, the objective of this field experiment was to determine the labile soil C, total soil C, soil organic matter (SOM), and total soil N accumulation of Kentucky bluegrass (Poa pratensis L.) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort. syn. Festuca arundinacea Schreb. (continued)

      Core Ideas:
      • Less than 3 yr post-establishment, tall fescue accumulated more soil C (i.e., labile soil C, total soil C, and soil organic matter) than Kentucky bluegrass.
      • Returning grass clippings for 2 yr increased both soil C (i.e., labile soil C and total soil C) and N (i.e., total soil N) compared to collecting clippings over the same period.
      • Labile soil C increased linearly over the 5 yr of the experiment.

      doi:10.2134/agronj2016.05.0307
      Published: December 1, 2016



    • Luqi Li, Matthew D. Sousek, Keenan L. Amundsen and Zachary J. Reicher
      Seeding Date and Bur Treatment Affect Establishment Success of Dormant-Seeded Buffalograss

      Dormant seeding is common for establishing cool-season turfgrasses, but minimal information exists on dormant seeding of the native warm-season buffalograss [Buchloë dactyloides (Nutt.) Engelm.] in the Midwest and northern Great Plains of the United States. The objective of these studies was to determine the effect of commercial KNO3 seed treatment on cultivar Cody buffalograss germination when seeded at various dates in winter and spring. Cody buffalograss burs were either commercially treated or untreated and both were seeded in the field the third week of November, January, March, or May. Buffalograss cover was rated monthly until the following August. (continued)

      Core Ideas:
      • Dormant seeding of buffalograss in November can be as effective as traditional May seeding.
      • Commercially potassium nitrate treated burs resulted in consistently higher cumulative germination regardless of seeding date.
      • Commercial treatment of burs may not be necessary when dormant seeding in November, but maximized buffalograss germination following an exceptionally dry winter.

      doi:10.2134/agronj2016.03.0164
      Published: December 1, 2016



    • Joshua Friell, Eric Watkins, Brian P. Horgan and Matthew Cavanaugh
      Sod Strength Characteristics of 51 Cool-Season Turfgrass Mixtures

      Successful establishment of turfgrass on roadsides often necessitates using species mixtures not typically used for sod production. Evaluating mechanical characteristics of sod produced using such mixtures is necessary to determine if they possess sufficient strength for harvest and handling. The objective of this work was to evaluate tensile strength and work required to tear sod of mixtures of nine cool-season turfgrass species previously determined to perform well on Minnesota roadsides. Three replications of 51 mixtures were established in a randomized complete block design at St. (continued)

      Core Ideas:
      • Turfgrass seed mixtures containing fine fescue species can produce sod that achieves equal or greater strength than those containing large amounts of Kentucky bluegrass when harvested 22 mo after establishment.
      • Change in proportion of fine fescues from each initial seed mixture to the resulting final plant community was negatively correlated with sod strength characteristics.
      • Thatch development was only weakly correlated with either maximum tensile load or work required to tear sod.
      • Mixtures with different seed compositions, but resulting in similar or identical final species compositions, often possessed very different mechanical properties.

      doi:10.2134/agronj2016.05.0295
      Published: October 6, 2016



    • Paul Koch
      Optimal Fungicide Timing for Suppression of Typhula Blight under Winter Covers

      Synthetic covers are often used to protect high-value golf course putting greens throughout much of North America and Scandinavia from injury during harsh winter conditions. However, these covers may trap heat and moisture at the turf surface and provide optimal conditions for snow mold development. This study was conducted to determine the most effective fungicide application strategy under both permeable and impermeable synthetic covers. Three different fungicide timings (early, late, and early + late) were tested under no cover, a permeable Evergreen (Hinspergers Poly Industries, Mississauga, ON) cover, and an impermeable GreenJacket cover (GreenJacket, Genoa City, WI) during the winters of 2011–2012 and 2012–2013 in Antigo, WI. (continued)

      Core Ideas:
      • Winter covers increase snow mold severity on golf course turfgrass.
      • Despite increased pressure, effective fungicides are available to limit disease to acceptable levels.
      • Applying fungicides as a single application shortly before snow cover or splitting out into two applications are both effective at reducing snow mold.

      doi:10.2134/agronj2016.04.0241
      Published: September 29, 2016



    • Matthew D. Jeffries, Travis W. Gannon and Fred H. Yelverton
      Tall Fescue Roadside Right-of-Way Mowing Reduction from Imazapic

      Tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire] is commonly established along roadside rights-of-way in adapted zones due to its tolerance of drought, heat, and wear; however, its upright growth habit coupled with seedhead production can impair motorist vision. Field research was conducted in 2013 and 2014 to quantify tall fescue mowing requirements following imazapic {( ± )-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid}, an herbicide commonly used for plant growth regulation, application (53 g a.i. ha–1) alone, as well as tank-mixed with clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) + triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid} (158 + 473 g a.i. (continued)

      Core Ideas:
      • Imazapic provided 100% tall fescue seedhead suppression through 56 d after treatment.
      • Imazapic reduced tall fescue mowing requirements by two cycles across 23- and 30-cm intervention heights.
      • Imazapic application to tall fescue mown at 30-cm intervention height required one mowing event through 70 d after treatment.

      doi:10.2134/agronj2016.04.0246
      Published: September 22, 2016



  • PEST INTERACTIONS IN AGRONOMIC SYSTEMS

    • Zane J. Grabau, Jeffrey A. Vetsch and Senyu Chen
      Effects of Fertilizer, Nematicide, and Tillage on Plant–Parasitic Nematodes and Yield in Corn and Soybean

      Soybean cyst nematode (SCN, Heterodera glycines) is the most damaging pathogen of soybean [Glycine max (L.) Merr.] in the United States and plant–parasitic nematodes such as Pratylenchus (lesion nematode) and Helicotylenchus (spiral nematode) commonly infect corn (Zea mays L.). There are few management options for these nematodes, so understanding how common agronomic practices affect these nematodes is critical. Therefore, a series of 2-yr experiments were conducted in corn and soybean production. Long-term conventional tillage (CT) and minimum tillage (MT) treatments were in place at the study site. (continued)

      Core Ideas:
      • Tillage decreased plant–parasitic nematode population densities during portions of the study.
      • Fertilizers did not help manage plant–parasitic nematode population densities.
      • Manure application increased both corn and soybean yields.
      • Soybean response to NPK and NPKS was more positive in a lower yielding environment.

      doi:10.2134/agronj2016.09.0548
      Published: May 18, 2017



    • Thierry Besançon, Ronnie Heiniger, Randy Weisz and Wesley Everman
      Weed Response to Agronomic Practices and Herbicide Strategies in Grain Sorghum

      Sicklepod [Senna obtusifolia (L.) H.S. Irwin & Barneby] and large crabgrass (Digitaria sanguinalis L.) are ranked among the top 10 most common or troublesome weeds in grain sorghum [Sorghum bicolor (L.) Moench] in the southeastern United States. Field studies conducted in North Carolina from 2012 to 2014 investigated the effects of three row widths, four sorghum populations, and three herbicide programs on weed control, density, biomass, and grain yield. Results indicated that 19- and 38-cm rows provided greater sicklepod control 7 and 10 wk after planting (WAP) compared to 76 cm but had no effect on crabgrass control. (continued)

      Core Ideas:
      • • High sorghum density and narrow row spacing reduce biomass of troublesome weeds.
      • • High spatial crop uniformity extends large crabgrass and sicklepod control over time.
      • • Optimized crop density and row width may limit the need for postemergence herbicide in sorghum.

      doi:10.2134/agronj2016.06.0363
      Published: May 11, 2017



    • Lia Marchi-Werle, Renata Ramos Pereira, John C. Reese, Tiffany M. Heng-Moss and Thomas E. Hunt
      Yield Response of Tolerant and Susceptible Soybean to the Soybean Aphid

      Soybean aphid, Aphis glycines (Hemiptera: Aphididae), is the most economically important soybean [Glycine max (L.) Merr.] pest of North America. Multiple studies have identified soybean expressing antibiosis and/or antixenosis; however, soybean tolerance remains underexplored. Tolerance to soybean aphid injury was previously identified in soybean KS4202. This research examined the yield response of KS4202 infested with soybean aphid at specific plant stages and identified at what plant stage tolerance initiates. (continued)

      Core Ideas:
      • Soybean aphid-tolerance in KS4202 soybean is plant age dependent.
      • Soybean aphid infestation occurring at the V1 stage impacts both susceptible and tolerant soybean.
      • KS4202 during late vegetative and early reproductive stage tolerated high aphid pressure.

      doi:10.2134/agronj2016.11.0631
      Published: May 5, 2017



  • REVIEW & INTERPRETATION

    • H. Arnold Bruns
      Southern Corn Leaf Blight: A Story Worth Retelling

      The southern corn (Zea mays L.) leaf blight (SCLB) epidemic of 1970–1971 was one of the most costly disease outbreaks to affect North American agriculture, destroying 15% of the crop at a cost of US$1.0 billion (≥$6.0 billion by 2015 standards.). It resulted from an over reliance on cytoplasmic Texas male sterile (cms-T) lines in hybrid seed production and a natural mutation of a race of SCLB Bipolar maydis that for years was seldom of economic importance. This mutation discovered in the Philippines in 1961 first appeared in the Corn Belt in 1969, damaging not only leaves, but stalks, ears, and developing kernels of hybrids containing cms-T genetics. A favorable environment, combined with >85% of the hybrids grown being of cms-T genetics set the stage for an epidemic. (continued)

      Core Ideas:
      • A history of corn leaf blight and its host.
      • A synopsis of southern corn leaf blight.
      • Lessons for the future.

      doi:10.2134/agronj2017.01.0006
      Published: May 5, 2017



    • Qingping Zhang, Zhennan Wang, Fuhong Miao and Guoliang Wang
      Dryland Maize Yield and Water-Use Efficiency Responses to Mulching and Tillage Practices

      Mulching and tillage practices is widely used to increase crop productivity and reduce water evaporation in semiarid regions. This study was conducted to determine which management practice was optimal through improving grain yield and water-use efficiency (WUE). Based on an analysis of 44 recent publications, we synthesized maize (Zea mays L) yield, WUE, and evapotranspiration (ET) in response to ridge furrow mulching (RFM), flat mulching (FM), straw mulching (SM), mulching with other materials (MOM), mulching with two materials combined (MTMC), rotational tillage (RT), no-tillage (NT), and subsoiling tillage (ST) on the Loess Plateau at a broad scale. Yield ranged from 1.0 to 14.6 t ha–1, WUE from 0.30 to 5.70 kg m–3, and ET from 158 to 660 mm under mulching practices; yield ranged from 5.19 to 11.92 t ha–1, WUE from 1.45 to 3.43 kg m–3, and ET from 308 to 556 mm under tillage practices. (continued)

      Core Ideas:
      • The highest yield and water-use efficiency were under plastic mulching and the lowest in conventional practice.
      • Maize yields were more sensitive to soil water at sowing under mulching and subsoiling tillage practices in the Loess Plateau.
      • The synthesis demonstrates that ridge furrow mulching was the optimum practice for maximizing maize yield.

      doi:10.2134/agronj2016.10.0593
      Published: May 5, 2017



    • Sam E. Wortman, Ashley A. Holmes, Elizabeth Miernicki, Kaelyn Knoche and Cameron M. Pittelkow
      First-Season Crop Yield Response to Organic Soil Amendments: A Meta-Analysis

      Organic soil amendments are increasingly promoted as a sustainable alternative to synthetic fertilizers and as a tool for building soil quality through improved chemical, physical, and biological properties. However, short-term yield response to organic amendments is highly variable. A meta-analysis of 53 studies was conducted to (i) develop a global estimate of first-season crop yield response to organic amendments, and (ii) determine the effect of crop type, amendment characteristics, soil properties, cultural practices, and climate on the magnitude of this yield response. Yield response ratios were calculated (organic amendment yield compared to a non-fertilized control) and differences among groups were determined using 95% bootstrap confidence intervals (CI). (continued)

      Core Ideas:
      • Organic amendments are promoted as sustainable alternatives to synthetic fertilizer.
      • Crop yield increased by an average of 43% in the first season after organic soil amendment.
      • Yield benefit from organic amendments was greater in leafy crops than root crops.
      • Poultry manure was commonly used and provided the greatest agronomic benefit.
      • Yield benefit of organic amendment was lower in arid regions with poor soil quality.

      doi:10.2134/agronj2016.10.0627
      Published: May 5, 2017



    • Amod K. Thakur and Norman T. Uphoff
      How the System of Rice Intensification Can Contribute to Climate-Smart Agriculture

      Although there has been controversy over some of the high yields reported with the System of Rice (Oryza sativa L.) Intensification (SRI), an agroecological crop management system developed in Madagascar, substantial increases in average rice yields have been reported from more than 50 countries when these methods are used, not even necessarily fully. Most attention thus far has focused on yield and little on whether or how SRI methods can help farmers adapt to and buffer the adverse stresses of climate change as well as reduce their rice paddies’ contribution to global warming. According to FAO criteria, achieving all three impacts would qualify SRI as “climate-smart agriculture” (CSA).This paper reviews how making SRI modifications in agronomic practices can elicit plant phenotypes from given rice genotypes that are more robust and adaptive as well as more productive. This effect appears to result from SRI’s inducing larger, healthier root systems and enhancing beneficial soil biota. (continued)

      Core Ideas:
      • System of rice intensification increases crop productivity with lesser inputs.
      • System of rice intensification yields more productive and robust rice phenotypes from given plant genotypes.
      • System of rice intensification crops are tolerant to biotic/abiotic stresses and it reduces GHGs from rice fields.
      • System of rice intensification enables farmers to adapt to and mitigate climate change.
      • This paper reviews how and why SRI can be considered as climate-smart agriculture.

      doi:10.2134/agronj2016.03.0162
      Published: May 5, 2017



  • SOIL FERTILITY & CROP NUTRITION

    • Yaru Lin, Dexter B. Watts and Thomas R. Way
      Poultry Litter Placement Effects on Cotton Seedling Emergence and Early Growth

      Interest in using poultry litter (PL) as a nutrient source for row crop production has increased in the southeastern United States. Poultry litter is generally broadcasted on the soil surface. This practice exposes N to volatilization and P to loss with surface water runoff, which potentially negatively impacts the environment. Placing PL in narrow bands below the soil surface has been shown to reduce such losses and improve crop yield, but the influence of band placement on seedling emergence and growth is not well understood. (continued)

      Core Ideas:
      • Sowing into poultry litter bands inhibits seed emergence and root establishment.
      • Aboveground plant production during early cotton growth stages may be negatively impacted by sowing into poultry litter bands.
      • Banding poultry litter beside crop rows may be an effective fertilizer management strategy.

      doi:10.2134/agronj2016.09.0541
      Published: May 11, 2017



    • Jagmandeep Dhillon, Guilherme Torres, Ethan Driver, Bruno Figueiredo and William R. Raun
      World Phosphorus Use Efficiency in Cereal Crops

      A current estimate of global phosphorus use efficiency (PUE) for cereal production is not available. The objectives of this paper were to estimate PUE for cereal crops grown in the world and to review methods for improvement. Phosphorus use efficiency was determined using world cereal harvested area, total grain production, and P fertilizer consumption from 1961 to 2013, in addition to assumptions established from previous literature. World PUE of cereal crops was calculated using both balance and difference methods. (continued)

      Core Ideas:
      • A current estimate of global P use efficiency for cereal production is not available.
      • This study shows that world P use efficiency for cereal crops is low.
      • Using the difference method, average world P use efficiency from 1961 to 2013 was 16%.

      doi:10.2134/agronj2016.08.0483
      Published: April 20, 2017



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