• Authors:
    • Mary, B.
    • Jeuffroy, M. H.
    • Amosse, C.
    • David, C.
  • Source: NUTRIENT CYCLING IN AGROECOSYSTEMS
  • Volume: 98
  • Issue: 1
  • Year: 2014
  • Summary: Nitrogen (N) management is a key issue in livestock-free organic grain systems. Relay intercropping with a legume cover crop can be a useful technique for improving N availability when two cash crops are grown successively. We evaluated the benefits of four relay intercropped legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) on N dynamics and their contribution to the associated and subsequent cash crops in six fields of organic farms located in South-East France. None of the relay intercropped legumes affected the N uptake of the associated winter wheat but all significantly increased the N uptake of the succeeding spring crop, either maize or spring wheat. The improvement of the N nutrition of the subsequent maize crop induced a 30 % increase in grain yield. All relay intercropped legumes enriched the soil-plant system in N through symbiotic fixation. From 71 to 96 % of the N contained in the shoots of the legumes in late autumn was derived from the atmosphere (Ndfa) and varied between 38 and 67 kg Ndfa ha(-1). Even if the cover crop is expected to limit N leaching during wintertime, the presence of relay intercropped legumes had no significant effect on N leaching during winter compared to the control.
  • Authors:
    • Bandyopadhyay, K. K.
    • Lal, R.
  • Source: Geoderma
  • Volume: 232/234
  • Year: 2014
  • Summary: Soils can be a source or sink for the atmospheric greenhouse gases (GHGs) depending on the land use management, which needs to be understood properly for devising management strategies to mitigate climate change. It is hypothesized that the aggregate size distribution under different land use management practices and the C and N concentration in these aggregates may influence GHG (CO 2, N 2O and CH 4) emissions from soil. To test this hypothesis, a laboratory incubation study was conducted using soils from a 16-year old tillage experiment on corn ( Zea mays L.) and the adjoining forest on a Crosby silt loam soil (Haplic Luvisols) at the Waterman Agricultural and Natural Resource Laboratory of the Ohio State University (OSU), Columbus, Ohio. It was observed that in forest soil, cumulative CO 2 and N 2O emissions were significantly higher than those from the cultivated soil by 81.2 and 100%, respectively. However, there was no significant difference between conventional tillage (CT) and no till (NT) with respect to the cumulative CO 2 and N 2O emissions. Emissions were significantly higher from the large macro-aggregates than from other aggregate size fractions. There was net CH 4 uptake by the soil during the incubation period. The cumulative CO 2 and N 2O emissions and CH 4 uptake from different aggregate size fractions accounted for 59, 56, and 47% of the emissions/uptake of these gases from the bulk soil, respectively. The contributions of the large macro-aggregates towards the bulk soil CO 2 (39%) and N 2O (37.9%) emissions and CH 4 uptake (49.7%) were significantly higher than those of the micro-aggregates and mineral fraction. Total soil carbon, nitrogen, particulate carbon and nitrogen, and mineral associated carbon and nitrogen accounted for 87, 87 and 66% variation in the cumulative CO 2 and N 2O emissions and CH 4 uptake, respectively.
  • Authors:
    • Grassini, P.
    • Gayler, S.
    • Sanctis, G. de
    • Deryng, D.
    • Corbeels, M.
    • Conijn, S.
    • Boogaard, H.
    • Biernath, C.
    • Basso, B.
    • Baron, C.
    • Adam, M.
    • Ruane, A. C.
    • Rosenzweig, C.
    • Jones, J. W.
    • Lizaso, J.
    • Boote, K.
    • Durand, J. L.
    • Brisson, N.
    • Bassu, S.
    • Hatfield, J.
    • Hoek, S.
    • Izaurralde, C.
    • Jongschaap, R.
    • Kemanian, A. R.
    • Kersebaum, K. C.
    • Kim, S. H. (et al)
  • Source: Global Change Biology
  • Volume: 20
  • Issue: 7
  • Year: 2014
  • Summary: Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, growth, and yield. With the goal of analyzing the sensitivity of simulated yields to changes in temperature and atmospheric carbon dioxide concentrations [CO 2], we present the largest maize crop model intercomparison to date, including 23 different models. These models were evaluated for four locations representing a wide range of maize production conditions in the world: Lusignan (France), Ames (USA), Rio Verde (Brazil) and Morogoro (Tanzania). While individual models differed considerably in absolute yield simulation at the four sites, an ensemble of a minimum number of models was able to simulate absolute yields accurately at the four sites even with low data for calibration, thus suggesting that using an ensemble of models has merit. Temperature increase had strong negative influence on modeled yield response of roughly -0.5 Mg ha -1 per °C. Doubling [CO 2] from 360 to 720 mol mol -1 increased grain yield by 7.5% on average across models and the sites. That would therefore make temperature the main factor altering maize yields at the end of this century. Furthermore, there was a large uncertainty in the yield response to [CO 2] among models. Model responses to temperature and [CO 2] did not differ whether models were simulated with low calibration information or, simulated with high level of calibration information.
  • Authors:
    • Yang, X. M.
    • McLaughlin, N. B.
    • Tan, C. S.
    • Reynolds, W. D.
    • Drury, C. F.
    • Calder, W.
    • Oloya, T. O.
    • Yang, J. Y.
  • Source: Canadian Journal of Soil Science
  • Volume: 94
  • Issue: 3
  • Year: 2014
  • Summary: A field study was established in 1959 to evaluate the effects of fertilization and crop rotation on crop yields, soil and environmental quality on a Brookston clay loam. There were two fertilizer treatments (fertilized and not-fertilized) and six cropping treatments including continuous corn (CC), continuous Kentucky bluegrass sod and a 4-yr rotation of corn-oat-alfalfa-alfalfa with each phase present each year. We measured N 2O emissions, inorganic N and plant N uptake over three growing seasons (2007-2009) in the corn phase. Nitrous oxide emissions varied over the 3 yr as a result of the seasonal variation in precipitation quantity, intensity and timing and differences in crop growth and N uptake. Fertilized CC lost, on average, 7.36 kg N ha -1 by N 2O emissions, whereas the not-fertilized CC lost only 0.51 kg N ha -1. Fertilized rotation corn (RC) lost 6.46 kg N ha -1, which was 12% lower than fertilized CC. The not-fertilized RC, on the other hand, emitted about half as much N 2O (2.95 kg N ha -1) as the fertilized RC. Fertilized RC had corn grain yields that averaged 10.0 t ha -1 over the 3 yr followed by fertilized CC at 5.48 t ha -1. Not-fertilized RC corn had yields that were 61% lower (3.93 t ha -1) than fertilized RC, whereas the not-fertilized CC had yields that were 75% lower (1.39 t ha -1) than fertilized CC. Nitrous oxide emissions were found to be dramatically affected by long-term management practices and crop rotation had lower emissions in the corn phase of the rotation even though the N input from fertilizer addition and legume N fixation was greater. These N 2O emission and yield results were due to both factors that are traditionally used to describe these processes as well as long-term soil quality factors, which were created by the long-term management (i.e., soil organic carbon, soil physical parameters such as bulk density, and porosity, soil fauna and micro-flora) and that influenced crop growth, N uptake and soil water contents.
  • Authors:
    • Fleming, R.
    • McKenney, D. J.
    • Guo, X.
    • Tan, C. S.
    • Yang, X. M.
    • Reynolds, W. D.
    • Drury, C. F.
    • Denholme, K.
  • Source: Canadian Journal of Soil Science
  • Volume: 94
  • Issue: 3
  • Year: 2014
  • Summary: The impacts of compost type on corn grain yields over 10 yr and N 2O and CO 2 emissions in the first 3 yr after compost application were evaluated on a Brookston clay loam soil in Woodslee, ON. The treatments included yard waste compost (YWC), kitchen food waste compost (FWC), and pig manure compost (PMC), which were applied once in the fall of 1998 to field plots at a rate of 75 Mg ha -1 (dry weight basis) and no further applications occurred thereafter as well as a fertilized control treatment. Large application rates were examined to see if the various compost sources could have a lasting effect on soil C storage, N 2O and CO 2 emissions and corn yields. Compost application significantly increased corn grain yields by 12.9 to 19.4% over 3 yr. However, after 10 yr, FWC was the only compost source which significantly increased yields by 11.3% compared with the fertilized control. Emissions of N 2O and CO 2 varied with compost type, soil water content and time. Greater N 2O emissions occurred in 1999 from PMC (5.4 kg N ha -1) than YWC (2.7 kg N ha -1) and FWC (1.3 kg N ha -1); however, the N 2O emissions from the PMC were less than from YWC and FWC in 2001. The 3-yr average N 2O emissions were significantly greater with PMC (2.7 kg N ha -1) and YWC (2.5 kg N ha -1) compared with the control (1.5 kg N ha -1). Hence, the timing of N 2O emissions varied by compost type, but the overall losses were similar as the higher N 2O losses in the first year with PMC were offset by the reduced losses with PMC in the third year. Significantly more CO 2 was produced from the FWC in 2000 and from PMC in 2001 than the control.
  • Authors:
    • Liu, X.
    • Vidon, P.
    • Jacinthe, P. A.
    • Fisher, K.
    • Baker, M. E.
  • Source: Journal of Environmental Quality
  • Volume: 43
  • Issue: 1
  • Year: 2014
  • Summary: Riparian buffers are important nitrate (NO 3-) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (N 2O) emission from these buffers. This study monitored (December 2009-May 2011) N 2O fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( Zea mays L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of N 2O fluxes. Strong relationships between N mineralization and N 2O fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest N 2O peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg N 2O-N m -2 d -1) and N fertilizer application to crop fields. Annual N 2O emission (kg N 2O-N ha -1) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( P<0.02) in annual N 2O emission between the riparian buffers was detected (4.32 vs. 1.03 kg N 2O-N ha -1 at WR and LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of N 2O emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional N 2O budget in riparian ecosystems.
  • Authors:
    • Grosso, S. J. del
    • Blaylock, A. D.
    • Snyder, C. S.
    • Halvorson, A. D.
  • Source: Agronomy Journal
  • Volume: 106
  • Issue: 2
  • Year: 2014
  • Summary: Enhanced-efficiency N fertilizers (EENFs) have potential for mitigating N 2O emissions from N-fertilized cropping systems. Stabilized EENFs contain nitrification and/or urease inhibitors. Slow-release EENFs contain N components that are slowly released with variable release rates. Controlled-release EENFs release N at more predictable rates. The effectiveness of several EENFs in reducing soil N 2O emissions from a clay loam soil under irrigated, corn ( Zea mays L.)-based production systems in Colorado (2002-2012) was investigated. A controlled-release, polymer-coated urea, ESN, reduced N 2O emissions by 42% compared with urea and 14% compared with urea-NH 4NO 3 solution (UAN) in no-till and strip-till environments, but had no effect in a conventional tillage environment. A stabilized urea source, SuperU, reduced N 2O emissions by 46% compared with urea and 21% compared with UAN. A stabilized UAN source, UAN+AgrotainPlus, reduced N 2O emissions by 61% compared with urea and 41% compared with UAN alone. A slow-release UAN source, UAN+Nfusion, reduced N 2O emissions by 57% compared with urea and 28% compared with UAN. Urea-NH 4NO 3 reduced N 2O emissions by 35% compared with urea. A linear increase in N 2O emissions with increasing N rate was observed for untreated urea and UAN. Developers of management protocols to reduce N 2O emissions from irrigated cropping systems in semiarid areas can use this information to estimate reductions in N 2O emissions when EENFs are used. Policymakers can use this information to help determine financial credits needed to encourage producers to use these technologies in their crop production systems.
  • Authors:
    • Messina, C. D.
    • Dong, Z. S.
    • Tardieu, F.
    • Harrison, M. T.
    • Hammer, G. L.
  • Source: Global Change Biology
  • Volume: 20
  • Issue: 3
  • Year: 2014
  • Summary: Global climate change is predicted to increase temperatures, alter geographical patterns of rainfall and increase the frequency of extreme climatic events. Such changes are likely to alter the timing and magnitude of drought stresses experienced by crops. This study used new developments in the classification of crop water stress to first characterize the typology and frequency of drought-stress patterns experienced by European maize crops and their associated distributions of grain yield, and second determine the influence of the breeding traits anthesis-silking synchrony, maturity and kernel number on yield in different drought-stress scenarios, under current and future climates. Under historical conditions, a low-stress scenario occurred most frequently (ca. 40%), and three other stress types exposing crops to late-season stresses each occurred in ca. 20% of cases. A key revelation shown was that the four patterns will also be the most dominant stress patterns under 2050 conditions. Future frequencies of low drought stress were reduced by ca. 15%, and those of severe water deficit during grain filling increased from 18% to 25%. Despite this, effects of elevated CO 2 on crop growth moderated detrimental effects of climate change on yield. Increasing anthesis-silking synchrony had the greatest effect on yield in low drought-stress seasonal patterns, whereas earlier maturity had the greatest effect in crops exposed to severe early-terminal drought stress. Segregating drought-stress patterns into key groups allowed greater insight into the effects of trait perturbation on crop yield under different weather conditions. We demonstrate that for crops exposed to the same drought-stress pattern, trait perturbation under current climates will have a similar impact on yield as that expected in future, even though the frequencies of severe drought stress will increase in future. These results have important ramifications for breeding of maize and have implications for studies examining genetic and physiological crop responses to environmental stresses.
  • Authors:
    • Dick, W. A.
    • Ladwig, K.
    • Tian, Y. Q.
    • Guo, X. L.
    • Chen, L. M.
    • Kost, D.
  • Source: Journal of Environmental Quality
  • Volume: 43
  • Issue: 1
  • Year: 2014
  • Summary: Gypsum (CaSO 4.2H 2O) is a quality source of Ca and S and has various beneficial uses that can improve agricultural production. This study was conducted to compare rates of flue gas desulfurization (FGD) gypsum and commercially available agricultural (i.e., mined) gypsum as soil amendments on soils typical of eastern Ohio or western Pennsylvania. Two field experiments were conducted, one involving a mixed grass hay field and the other corn ( Zea mays L.). Gypsum was applied once at rates of 0.2, 2.0, and 20 Mg ha -1 and a seventh treatment was a zero rate control. Corn grain yields response to gypsum was mixed with significant differences between low and high gypsum rates in 2010 but not between gypsum and no gypsum treatments. In the hay study, the low and intermediate gypsum rates generally did not result in any significant changes compared with the control treatment. At the high rate of 20 Mg ha -1, the following results were observed for the hay study: (i) both gypsums generally increased Ca, S, and soluble salts (electrical conductivity) in the topsoil and subsoil, when compared with the control; (ii) the FGD gypsum decreased Mg in soil when compared with all other treatments, and mined gypsum decreased Mg when compared with the control; and (iii) there were few effects on soil concentrations of trace elements, including Hg. Also at the high application rate, hay yield for the first cutting (May) in 2009 and 2010 was significantly less for mined and FGD gypsum compared with the control, but increased yields in subsequent cutting resulted in no significant treatment differences in total annual hay yield for 2008, 2009, or 2010 or cumulative yield for 2008 to 2010. Overall, for the hay study, the absence of significant soil chemical effects for the intermediate gypsum rate and the decrease in soil Mg concentrations for the high gypsum rate indicate that an application rate of approximately 2.0 Mg ha -1 would be optimal for this soil.
  • Authors:
    • Miao, S. J.
    • Han, X. Z.
    • Doane,T. A.
    • Qiao, Y. F.
  • Source: Journal of Food, Agriculture & Environment
  • Volume: 12
  • Issue: 2
  • Year: 2014
  • Summary: The impact of long-term fertilizer application on greenhouse gas emission and global warming potential (GWP) is not well documented. A long-term fertilizer experiment, located at the Hailun State Key Agro-ecological Experiment Station, Hailun County, Heilongjiang Province, China, was used in this study to completely account for emission of CO 2 and N 2O from maize-soybean rotation systems. Five treatments were implemented, including nitrogen and potassium (NK), nitrogen and phosphorus (NP), balanced inorganic fertilizer (NPK), combined inorganic/organic fertilizer (NPKM), and no fertilizer (Cont.). CO 2 and N 2O fluxes were measured using a closed-chamber method from May 2006 to April 2007, and net GWP was estimated using emission data and considering CO 2 fixed by crops. With the exception of NK in soybean, long-term fertilizer application significantly increased crop biomass in all treatments and both crops compared to Cont. plots. Long-term inorganic fertilizer application tended to decrease total CO 2 emission and increase total N 2O emission. Inorganic/organic combination fertilizer significantly increased CO 2 and N 2O emission by 41% and 388% compared to the Cont., respectively. Compared with the Cont., inorganic fertilizer application significantly decreased total net GWP by 179%; in contrast, net GWP was increased 82% by inorganic/organic combination fertilizer application. The results of this study indicate that reduction of GWP and agricultural economic gain can be simultaneously achieved by appropriate fertilizer application.