• Authors:
    • Ramos-Espinoza, G.
    • Beer, J.
    • Flores-Macias, A.
    • Harmand, J.
    • Payan-Zelaya, F.
    • de Leon Gonzalez, F.
  • Source: Agroforestry Systems
  • Volume: 87
  • Issue: 2
  • Year: 2013
  • Summary: To investigate the effects of microbial inocula and Erythrina poeppigiana pruning residues on soil K, NO3-, and NH4+ concentrations, a greenhouse trial, a field experiment in an organic farm, and three in vitro tests were conducted. Under controlled conditions, weak, temporary effects (10 %) on maize seedling growth were observed on poor soils (taken from the 10-20 cm layer) in the first 2 weeks after application. Positive effects of pruning residue applications on soil K levels (0.09 cmol kg(-1), on average) were detected in both the field and greenhouse study. However, significant effects due to the addition of microbial inocula on soil K concentrations were not detected in the field; thus, microbial applications were ineffective at enhancing nutrient availability under field conditions. In contrast, in the in vitro experiments, CO2 production was 31 % greater than that of untreated soil on the 8th and 15th days of incubation. These results highlight the importance of adding tree pruning residues to support coffee-plant nutrition. Experimental outcome data could be valuable for further studies focused on microbial application dosage and timing.
  • Authors:
    • Zebarth, B.
    • Laganiere, J.
    • Angers, D. A.
    • Rochette, P.
    • Chantigny, M. H.
    • Pelster, D. E.
    • Goyer, C.
  • Source: Canadian Journal of Soil Science
  • Volume: 93
  • Issue: 4
  • Year: 2013
  • Summary: Freeze-thaw (FT) cycles stimulate soil nitrogen (N) and carbon (C) mineralization, which may induce nitrous oxide (N2O) emissions. We examined how soybean (Glycine max L.) and corn (Zea mays L.) residue incorporation affect N2O emissions from high C content (35 g kg(-1)) silty clay and low C content (19 g kg(-1)) sandy loam soils over eight 10-d FT cycles, as a function of three temperature treatments [constant at +1 degrees C (unfrozen control), +1 to -3 degrees C (moderate FT), or +1 to -7 degrees C (extreme FT)]. In unamended soils, N2O emissions were stimulated by FT, and were the highest with extreme FT. This was attributed to the increased NO3 availability measured under FT. Application of mature crop residues (C:N ratios of 75 for soybean and 130 for corn) caused rapid N immobilization, attenuating FT-induced N2O emissions in the silty clay. In the sandy loam, residue addition also induced immobilization of soil mineral N. However, N2O emissions under moderate FT were higher with than without crop residues, likely because N2O production in this low-C sandy loam was stimulated by C addition in the early phase of incubation. We conclude that FT-induced N2O emissions could be reduced through incorporation of mature crop residues and the subsequent immobilization of mineral N, especially in C-rich soils.
  • Authors:
    • Rimal, B.
    • Lal, R.
    • Shrestha, R.
  • Source: Geoderma
  • Volume: 197
  • Year: 2013
  • Summary: The addition of organic amendments is essential for sustainable soil fertility management and crop production, but can also increase greenhouse gas (GHG) emissions. Thus, understanding the impacts of organic soil amendments on gaseous emissions is pertinent to minimizing agricultural impacts on the net emissions of GHGs. A long-term field experiment was conducted to assess the impacts of continuous application of organic amendments (i.e. compost and farmyard manure) and cover crop [mixture of rye (Secale cereal), red fescue (Festuca rubra), and blue grass (Poa pratensis L)] on selected soil properties, apparent carbon (C) budget (calculated from the difference of sum of all sources of C inputs and outputs), gaseous flux (i.e. carbon dioxide, CO2, and methane, CH4), and relationship with weather parameters under no-till (NT) corn (Zea mays L) cultivation in an Alfisol of central Ohio, USA. Soil properties and gaseous fluxes were measured continuously for 2 years. Ten years of continuous application of soil amendments increased soil pH and electrical conductivity, enhanced soil C pool, and decreased bulk density especially in 0-5 cm depth than that with cover crop and control plots. Two years average, cattle manure, compost, fallow, and cover crop emitted 14.1, 10.2, 7.5, and 7.2 Mg CO2-C ha(-1) yr(-1), respectively. Methane emission was 10.7 kg CH4-C ha(-1) yr(-1) from cattle manure and 4.0 kg CH4-C ha(-1) yr(-1) from compost However, fallow consumed 3.3 and cover crop 5.0 kg CH4-C ha(-1) yr(-1). These data suggest that long-term application of compost in NT corn decreased emissions of CO2 by 38% and of CH4 by 167% compared to application of manuring. In general, soil temperature, air temperature, and precipitation were positively correlated with CO2 emissions. Estimation of C budget indicated that amended soil under NT is a C-sink while a non-amended system is a C-source. The application of composted soil amendments in NT corn enhances soil quality and reduces net GHG emissions. Published by Elsevier B.V.
  • Authors:
    • Macias, F.
    • Martin, F.
    • Verde, R.
    • Martinez, F.
    • Sierra, M.
  • Source: Soil & Tillage Research
  • Volume: 130
  • Year: 2013
  • Summary: The potential of soils as a sink of atmospheric carbon and the implications related to mitigate greenhouse-gas emissions are well recognized. The raising of tree crops on agricultural soils can augment soil-carbon sequestration more than do other agricultural uses such as corn crops. Thus, 6 plots with different durations of use as poplar plantation (5, 10, 20, 30, 50, and 100 years) were studied in comparison with 6 adjacent plots with corn crop. The carbon pool in poplar-plantation soils was positively correlated to the time of use at the three soil depths studied (0-20, 20-50, and 50-100 cm), the mean annual increase being 1.16 Mg C ha(-1) year(-1). Poplar-plantation soils also increased the total carbon content in a more effective way because the duration of use was also correlated with the most recalcitrant carbon forms. Therefore, land-use change from corn crops to poplar-plantation soils is economically profitable as well as positive both for the total organic-carbon pool as well as for the efficiency of carbon sequestration by the increase of non-oxidizable forms in the soil. (c) 2013 Elsevier B.V. All rights reserved.
  • Authors:
    • Qian, B.
    • Li, C.
    • Kroebel, R.
    • Desjardins, R. L.
    • Grant, B. B.
    • Smith, W. N.
    • Worth, D. E.
    • McConkey, B. G.
    • Drury, C. F.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 179
  • Year: 2013
  • Summary: Regions in northern latitudes are likely to be strongly affected by climate change with shifts in weather that may be conducive to increased agricultural productivity. In this study the DNDC model was used to assess the effect of climate change on crop production and GHG emissions at long-term experimental sites in Canada. Crop production in the model was parameterized using measured data, and then simulations were performed using historical weather (1961-1990) and future IPCC SRES climate scenarios (2040-2069). The DNDC model predicted that for western Canada under the SRES scenarios and no change in cultivar, yields of spring wheat would increase by 37% and winter wheat by 70%. Corn responded favorably to an increase in heat units at the eastern site with a 60% increase in yields. At all locations, yields were projected to increase further when new cultivars with higher GDD requirements were assumed. These increases were notable considering that the estimated soil water deficit indices indicated that there could be less water available for crop growth in the future. However, when accounting for increased water use efficiency under elevated CO2, DNDC predicted less crop water stress. Nitrous oxide emissions per ton of wheat were projected to increase across most of western Canada by about 60% on average for the A1b and A2 SRES scenarios and by about 30% for the B1 scenario. Nitrous oxide emissions per unit area were predicted to increase under corn production at the eastern location but to remain stable per ton of grain. Model results indicated that climate change in Canada will favor increased crop production but this may be accompanied by an increase in net GHG emissions for small grain production.
  • Authors:
    • Salokhe, V. M.
    • Taewichit, C.
    • Soni, P.
  • Source: Agricultural Systems
  • Volume: 116
  • Year: 2013
  • Summary: Farm mechanization has been progressively increasing in Thailand for the past decades. Consumption and abuse of energy intensive inputs, machinery and agro-chemicals is increasingly propagated into agricultural production systems. Effects of energy intensive input utilization and farm technologies are directly associated especially with farm economic and atmospheric issues. This warrants the need of energy input-output analyses coupled with its environmental dimension. This paper presents the energy input-output analyses of different agricultural activities and fresh pond-culture (polyculture), for which data were collected from 46 rainfed integrated agricultural production systems (IAPSs) of 281 farm plots surveyed. Total energy consumption including non-renewable energy input (NREI), direct and indirect energy input, and system efficiency are calculated and compared for different crops. Resource-wise energy input utilization and energy consumed by farm operations are also discussed for different crops. Further, this study simultaneously relates energy consumption in agricultural production systems associated with their corresponding greenhouse gases (GHGs) emission - presented in terms of total carbon dioxide equivalent (CO(2)e). Results reveal noticeable variations in energy consumption and CO(2)e emissions from various agricultural production activities. The study reveals that the maximum energy consumer is cassava (32.4 GJ ha(-1)). Major energy input consumption for all productions are indicated by fossil fuel (diesel oil) as fresh pond-culture depended on fish feed. Transplanted rice provides the highest CO(2)e emission (1112 kg CO(2)e ha(-1)) among crops, in which more than 50% is contributed by methane (CH4).
  • Authors:
    • Liu, S. G.
    • Tan, Z. X.
  • Source: Applied and Environmental Soil Science
  • Volume: 2013
  • Issue: 2013
  • Year: 2013
  • Summary: Terrestrial carbon (C) sequestration through optimizing land use and management is widely considered a realistic option to mitigate the global greenhouse effect. But how the responses of individual ecosystems to changes in land use and management are related to baseline soil organic C (SOC) levels still needs to be evaluated at various scales. In this study, we modeled SOC dynamics within both natural and managed ecosystems in North Dakota of the United States and found that the average SOC stock in the top 20 cm depth of soil lost at a rate of 450 kg C ha -1 yr -1 in cropland and 110 kg C ha -1 yr -1 in grassland between 1971 and 1998. Since 1998, the study area had become a SOC sink at a rate of 44 kg C ha -1 yr -1. The annual rate of SOC change in all types of lands substantially depends on the magnitude of initial SOC contents, but such dependency varies more with climatic variables within natural ecosystems and with management practices within managed ecosystems. Additionally, soils with high baseline SOC stocks tend to be C sources following any land surface disturbances, whereas soils having low baseline C contents likely become C sinks following conservation management.
  • Authors:
    • Chi, S. Y.
    • Li, Z. J.
    • Li, N.
    • Wang, B. W.
    • Zhao, H. X.
    • Ning, T. Y.
    • Wang, Y.
    • Tian, S. Z.
  • Source: PLOS ONE
  • Volume: 8
  • Issue: 9
  • Year: 2013
  • Summary: Appropriate tillage plays an important role in mitigating the emissions of greenhouse gases (GHG) in regions with higher crop yields, but the emission situations of some reduced tillage systems such as subsoiling, harrow tillage and rotary tillage are not comprehensively studied. The objective of this study was to evaluate the emission characteristics of GHG (CH4 and N2O) under four reduced tillage systems from October 2007 to August 2009 based on a 10-yr tillage experiment in the North China Plain, which included no-tillage (NT) and three reduced tillage systems of subsoil tillage (ST), harrow tillage (HT) and rotary tillage (RT), with the conventional tillage (CT) as the control. The soil under the five tillage systems was an absorption sink for CH4 and an emission source for N2O. The soil temperature positive impacted on the CH4 absorption by the soils of different tillage systems, while a significant negative correlation was observed between the absorption and soil moisture. The main driving factor for increased N2O emission was not the soil temperature but the soil moisture and the content of nitrate. In the two rotation cycle of wheat-maize system (10/2007-10/2008 and 10/2008-10/2009), averaged cumulative uptake fluxes of CH4 under CT, ST, HT, RT and NT systems were approximately 1.67, 1.72, 1.63, 1.77 and 1.17 t ha(-1) year(-1), respectively, and meanwhile, approximately 4.43, 4.38, 4.47, 4.30 and 4.61 t ha(-1) year(-1) of N2O were emitted from soil of these systems, respectively. Moreover, they also gained 33.73, 34.63, 32.62, 34.56 and 27.54 t ha(-1) yields during two crop-rotation periods, respectively. Based on these comparisons, the rotary tillage and subsoiling mitigated the emissions of CH4 and N2O as well as improving crop productivity of a wheat-maize cropping system.
  • Authors:
    • Arena, C.
    • Amato, U.
    • Maglione, G.
    • Polimeno, F.
    • Ottaiano, L.
    • Vitale, L.
    • Di Tommasi, P.
    • Mori, M.
    • Magliulo, V.
  • Source: Plant, Soil and Environment
  • Volume: 59
  • Issue: 11
  • Year: 2013
  • Summary: The effect of the nitrification inhibitor 3,4-dimethylphyrazole phosphate (DMPP) on N-fertilized crop growth and soil N2O emissions were studied at two experimental sites in Southern Italy, characterised by a Mediterranean climate and different soil texture. The experiments were a randomized block design of two treatments: crop fertilized with NH4NO3 (considered the control treatment) or amended with DMPP plus NH4NO3 (considered the DMPP treatment). ANOVA was performed to assess differences between treatments and fertilization periods whereas simple and multiple linear regressions were performed in order to assess the effect of the soil-related independent variables on soil gases emissions. Growth of potato plants fertilized with DMPP-added nitrogen was enhanced compared to control plants, whereas no benefit on maize plants grown during summer was observed. N2O emissions measured from soil to potato after the first fertilization with DMPP-added nitrogen was reduced during winter, but was higher than control after the second fertilizer application in spring, leading to comparable N2O emission factors (EF1) between treatments. In maize N2O emissions and EF1 were lower for DMPP compared to control treatment. The effectiveness of reduction in soil N2O emission was influenced by soil temperature and water-filled pore space (WFPS) in both experimental sites. However, the overall effect of WFPS was contrasting as N2O emissions were decreased in potato and enhanced in maize.
  • Authors:
    • Dong, W. X.
    • Li, X. X.
    • Zhang, Y. M.
    • Ming, H.
    • Hu, C. S.
    • Wang, Y. Y.
    • Oenema, O.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 164
  • Issue: 1
  • Year: 2013
  • Summary: Agricultural soils are main sources and sinks of the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The source-sink function depends on soil characteristics, climate and management. Emission measurements usually quantify the net result of production, consumption and transport of these gases in the soil; they do not provide information about the depth distributions of the concentrations of these gases in the soil. Here we report on concentrations of CO2, CH4 and N2O in air of 300 cm deep soil profiles, at resolutions of 30-50 cm, over a full year. Gas samples were taken weekly in a long-term field experiment with an irrigated winter wheat-summer maize double cropping system, and four fertilizer N application rates (0, 200, 400 and 600 kg N ha(-1) year(-1)). The results showed distinct differences in CH4, CO2 and N2O concentrations profiles with soil depth. The concentrations of CO2 in soil air increased with soil depth and showed a seasonal pattern with relatively high concentrations in the warm and moist maize growing season and relatively low concentrations in the winter-wheat growing season. In contrast, CH4 concentrations decreased with depth, and did not show a distinct seasonal cycle. Urea application did not have a large effect on CH4 or CO2 concentrations, neither in the topsoil nor the subsoil. Concentrations of N2O responded to N fertilizer application and irrigation. Application of fertilizer strongly increased grain and straw yields of both winter wheat and summer maize, relatively to the control, but differences in yield between the treatments N200, N400 and N600 were not statistically significant. However, it significantly increased mean N2O concentrations peaks at basically all soil depths. Interestingly, concentrations of N2O increased almost instantaneously in the whole soil profile, which indicates that the soil had a relatively high diffusivity, despite compacted subsoil layers. In conclusion, the frequent measurements, at high depth resolutions, of concentrations of CH4, CO2 and N2O in soil air under a winter wheat-summer maize double crop rotation provide detailed insight into the production, consumption and transport of these gases in the soil. Concentrations of CH4, CO2 and N2O responded differently to management activities and weather conditions. (C) 2012 Elsevier B.V. All rights reserved.