• Authors:
    • Caesar, A.
    • Caesar-TonThat, T.
    • Sainju, U. M.
  • Source: Soil and Tillage Research
  • Volume: 118
  • Issue: January
  • Year: 2012
  • Summary: Portable chamber provides simple, rapid, and inexpensive measurement of soil CO2 flux but its effectiveness and precision compared with the static chamber in various soil and management practices is little known. Soil CO2 flux measured by a portable chamber using infrared analyzer was compared with a static chamber using gas chromatograph in various management practices from May to October 2008 in loam soil (Luvisols) in eastern Montana and in sandy loam soil (Kastanozems) in western North Dakota, USA. Management practices include combinations of tillage, cropping sequence, and N fertilization in loam and irrigation, tillage, crop rotation, and N fertilization in sandy loam. It was hypothesized that the portable chamber would measure CO2 flux similar to that measured by the static chamber, regardless of soil types and management practices. In both soils, CO2 flux peaked during the summer following substantial precipitation and/or irrigation (>15 mm), regardless of treatments and measurement methods. The flux varied with measurement dates more in the portable than in the static chamber. In loam, CO2 flux was 14-87% greater in the portable than in the static chamber from July to mid-August but 15-68% greater in the static than in the portable chamber from late August to October in all management practices. In sandy loam, CO2 flux was 10-229% greater in the portable than in the static chamber at all measurement dates in all treatments. Average CO2 flux across treatments and measurement dates was 9% lower in loam but 84% greater in sandy loam in the portable than in the static chamber. The CO2 fluxes in the portable and static chambers were linearly to exponentially related (R-2 = 0.68-0.70, P < 0.01, n = 40-56). Although the trends of CO2 fluxes with treatments and measurement dates were similar in both methods, the flux varied with the methods in various soil types. Measurement of soil CO2 flux by the portable chamber agreed more closely with the static chamber within 0-10 kg C ha(-1) d(-1) in loam soil under dryland than in sandy loam soil under irrigated and non-irrigated cropping systems. Published by Elsevier B.V.
  • Authors:
    • Barsotti, J. L.
    • Lenssen, A. W.
    • Caesar-TonThat, T.
    • Sainju, U. M.
  • Source: Soil Science Society of America Journal
  • Volume: 76
  • Issue: 5
  • Year: 2012
  • Summary: Information is needed to mitigate dryland soil greenhouse gas (GHG) emissions by using novel management practices. We evaluated the effects of cropping sequence and N fertilization on dryland soil temperature and water content at the 0- to 15-cm depth and surface CO2, N2O, and CH4 fluxes in a Williams loam (fine-loamy, mixed, superactive, frigid, Typic Argiustolls) in eastern Montana. Treatments were no-tilled continuous malt barley (Hordeum vulgaris L.) (NTCB), no-tilled malt barley-pea (Pisum sativum L.) (NTB-P), and conventional-tilled malt barley-fallow (CTB-F) (control), each with 0 and 80 kg N ha(-1). Gas fluxes were measured at 3 to 14 d intervals using static, vented chambers from March to November 2008 to 2011. Soil temperature varied but water content was greater in CTB-F than in other treatments. The GHG fluxes varied with date of sampling, peaking immediately after substantial precipitation (>15 mm) and N fertilization during increased soil temperature. Total CO2 flux from March to November was greater in NTCB and NTB-P with 80 kg N ha(-1) than in other treatments from 2008 to 2010. Total N2O flux was greater in NTCB with 0 kg N ha(-1) and in NTB-P with 80 kg N ha(-1) than in other treatments in 2008 and 2011. Total CH4 uptake was greater with 80 than with 0 kg N ha(-1) in NTCB in 2009 and 2011. Because of intermediate level of CO2 equivalent of GHG emissions and known favorable effect on malt barley yield, NTB-P with 0 kg N ha(-1) might mitigate GHG emissions and sustain crop yields compared to other treatments in eastern Montana. For accounting global warming potential of management practices, however, additional information on soil C dynamics and CO2 associated with production inputs and machinery use are needed.
  • Authors:
    • Liebig, M. A.
    • Caesar-TonThat, T.
    • Stevens, W. B.
    • Sainju, U. M.
  • Source: Journal of Environmental Quality
  • Volume: 41
  • Issue: 6
  • Year: 2012
  • Summary: Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO2, N2O, and CH4 emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and nonirrigated) and five cropping systems (conventional-tilled malt barley [Hordeum vulgaris L.] with N fertilizer [CT-N], conventional-tilled malt barley with no N fertilizer [CT-C], no-tilled malt barley pea [Pisum sativum L.] with N fertilizer [NT-PN], no-tilled malt barley with N fertilizer [NT-N], and no-tilled malt barley with no N fertilizer [NT-C]). The GHG fluxes varied with date of sampling and peaked immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO2 and N2O fluxes were greater in CT-N under the irrigated condition, but CH4 uptake was greater in NT-PN under the nonirrigated condition than in other treatments. Although tillage and N fertilization increased CO2 and N2O fluxes by 8 to 30%, N fertilization and monocropping reduced CH, uptake by 39 to 40%. The NT-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO2 and N2O emissions and increasing CH4 uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO2 emissions along with N2O and CH4 fluxes is needed.
  • Authors:
    • Prior, S.
    • Torbert, H.
    • Way, T.
    • Watts, D.
    • Smith, K.
  • Source: Pedosphere
  • Volume: 22
  • Issue: 5
  • Year: 2012
  • Summary: Tillage and fertilization practices used in row crop production are thought to alter greenhouse gas emissions from soil. This study was conducted to determine the impact of fertilizer sources, land management practices, and fertilizer placement methods on greenhouse gas (CO2, CH4, and N2O) emissions. A new prototype implement developed for applying poultry litter in subsurface bands in the soil was used in this study. The field site was located at the Sand Mountain Research and Extension Center in the Appalachian Plateau region of northeast Alabama, USA, on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults). Measurements of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions followed GRACEnet (greenhouse gas reduction through agricultural carbon enhancement network) protocols to assess the effects of different tillage (conventional vs. no-tillage) and fertilizer placement (subsurface banding vs. surface application) practices in a corn (Zea mays L.) cropping system. Fertilizer sources were urea-ammonium nitrate (UAN), ammonium nitrate (AN) and poultry litter (M) applied at a rate of 170 kg ha(-1) of available N. Banding of fertilizer resulted in the greatest concentration of gaseous loss (CO2 and N2O) compared to surface applications of fertilizer. Fertilizer banding increased CO2 and N2O loss on various sampling days throughout the season with poultry litter banding emitting more gas than UAN banding. Conventional tillage practices also resulted in a higher concentration of CO2 and N2O loss when evaluating tillage by sampling day. Throughout the course of this study, CH4 flux was not affected by tillage, fertilizer source, or fertilizer placement method. These results suggest that poultry litter use and banding practices have the potential to increase greenhouse gas emissions.
  • Authors:
    • Huggins, D.
    • Nelson, R.
    • Kemanian, A.
    • Higgins, S.
    • Stoeckle, C.
    • Marcos, J.
    • Collins, H.
  • Source: Journal of Soil and Water Conservation
  • Volume: 67
  • Issue: 5
  • Year: 2012
  • Summary: Conservation tillage is an agricultural strategy to mitigate atmospheric greenhouse gas (GHG) emissions. In eastern Washington, we evaluated the long-term effects of conventional tillage (CT), reduced tillage (RT) and no-tillage (NT) on soil organic carbon (SOC) storage and nitrous oxide (N2O) emissions at three dryland and one irrigated location using the cropping systems simulation model CropSyst. Conversion of CT to NT produced the largest relative increase in SOC storage (Delta SOC, average yearly change relative to CT) in the top 30 cm (11.8 in) of soil where Delta SOC ranged from 0.29 to 0.53 Mg CO(2)e ha(-1) y(-1) (CO(2)e is carbon dioxide [CO2] equivalent of SOC; 0.13 to 0.24 tn CO(2)e ac(-1) yr(-1)).The Delta SOC were less with lower annual precipitation, greater fallow frequency, and when changing from CT to RT. Overall, Delta SOC decreased from the first to the third decade after conversion from CT to NT or RT. Simulations of Delta SOC for the conversion of CT to NT based on a 0 to 15 cm (0 to 5.9 in) soil depth were greater than the Delta SOC based on a 0 to 30 cm depth, primarily due to differences among tillage regimes in the depth-distribution of carbon (C) inputs and the resultant SOC distribution with depth. Soil erosion rates under CT in the study region are high, posing deleterious effects on soil quality, productivity, and aquatic systems. However, an analysis that includes deposition, burial, and sedimentation on terrestrial and aquatic systems of eroded SOC indicates that the substantial erosion reduction obtained with RT and NT may result only in minor additional SOC oxidation as compared to CT Simulated N2O emissions, expressed as CO2 equivalent, were not very different under CT, RT, and NT However, N2O emissions were sufficiently high to offset gains in SOC from the conversion of CT to RT or NT.Thus, reducing tillage intensity can result in net C storage, but mitigation of GHG is limited unless it is coupled with nitrogen (N) fertilizer management to also reduce N2O emission.
  • Authors:
    • Kuzyakov, Y.
    • Li, X.
    • Marschner, P.
    • Guo, J.
    • Fan, M.
    • Tian, J.
  • Source: European Journal of Soil Biology
  • Volume: 52
  • Issue: September–Octobe
  • Year: 2012
  • Summary: In the last three decades there has been a major shift in China's agriculture with the conversion from cereal fields to vegetable production, however little is known about the impact of this land use change on labile soil carbon and microbial community structure. We conducted a study to characterize dissolved organic carbon (DOC) and soil microbial community by comparing greenhouse vegetable fields with contrasting management intensity and adjacent cereal fields (wheat maize rotation) in Shouguang and Quzhou in North China. Compared with cereal fields, greenhouse vegetable cultivation increased soil organic carbon (SOC) and total nitrogen (TN), while it decreased the soil pH, particularly at the high-intensity site. The DOC concentration was significantly higher in greenhouse vegetable fields than in cereal fields, whereas DOC composition differed between greenhouse vegetable fields and cereal fields only at high management intensity. Chemical fractionation indicated that DOC from greenhouse vegetable fields with high management intensity was less decomposed than DOC from cereal fields, because the percentage of hydrophobic acid (HOA) as DOC was higher in vegetable fields. Vegetable production significantly changed the microbial community structure in comparison to cereal fields: high-intensity management increased total bacteria, G (+) bacteria and fungi, while low-intensity decreased fungi and increased bacteria-to-fungi ratio. The main factor affecting microbial community structure was soil pH in this study, accounting for 24% of the differences. (C) 2012 Elsevier Masson SAS. All rights reserved.
  • Authors:
    • Chi, S.
    • Li, Z.
    • Han, H.
    • Li, N.
    • Wang, B.
    • Zhao, H.
    • Ning, T.
    • Tian, S.
  • Source: Web Of Knowledge
  • Volume: 7
  • Issue: 12
  • Year: 2012
  • Summary: The objective of this study was to quantify soil methane (CH4) and nitrous oxide (N2O) emissions when converting from minimum and no-tillage systems to subsoiling (tilled soil to a depth of 40 cm to 45 cm) in the North China Plain. The relationships between CH4 and N2O flux and soil temperature, moisture, NH4+-N, organic carbon (SOC) and pH were investigated over 18 months using a split-plot design. The soil absorption of CH4 appeared to increase after conversion from no-tillage (NT) to subsoiling (NTS), from harrow tillage (HT) to subsoiling (HTS) and from rotary tillage (RT) to subsoiling (RTS). N2O emissions also increased after conversion. Furthermore, after conversion to subsoiling, the combined global warming potential (GWP) of CH4 and N2O increased by approximately 0.05 kg CO2 ha(-1) for HTS, 0.02 kg CO2 ha(-1) for RTS and 0.23 kg CO2 ha(-1) for NTS. Soil temperature, moisture, SOC, NH4+-N and pH also changed after conversion to subsoiling. These changes were correlated with CH4 uptake and N2O emissions. However, there was no significant correlation between N2O emissions and soil temperature in this study. The grain yields of wheat improved after conversion to subsoiling. Under HTS, RTS and NTS, the average grain yield was elevated by approximately 42.5%, 27.8% and 60.3% respectively. Our findings indicate that RTS and HTS would be ideal rotation tillage systems to balance GWP decreases and grain yield improvements in the North China Plain region. Citation: Tian S, Ning T, Zhao H, Wang B, Li N, et al. (2012) Response of CH4 and N2O Emissions and Wheat Yields to Tillage Method Changes in the North China Plain. PLoS ONE 7(12): e51206. doi:10.1371/journal.pone.0051206
  • Authors:
    • Astrup, T.
    • Wenzel, H.
    • Hamelin, L.
    • Tonini, D.
  • Source: Environmental Science & Technology
  • Volume: 46
  • Issue: 24
  • Year: 2012
  • Summary: In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: (I) anaerobic co-digestion with manure, (II) gasification, (III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow and Miscanthus co-firing, allowed for an improvement as compared with the reference (-82 and -45 t CO2-eq. ha(-1), respectively). The indirect land use changes impact was quantified as 310 + 170 t CO2-eq. ha(-1), representing a paramount average of 41% of the induced greenhouse gas emissions. The uncertainty analysis confirmed the results robustness and highlighted the indirect land use changes uncertainty as the only uncertainty that can significantly change the outcome of the LCA results.
  • Authors:
    • Fernando, L. K.
    • Banuwa, I. S.
    • Buchari, H.
    • Utomo, M.
    • Saleh, R.
  • Source: Journal of Tropical Soils
  • Volume: 17
  • Issue: 1
  • Year: 2012
  • Summary: Although agriculture is a victim of environmental risk due to global warming, but ironically it also contributes to global greenhouse gas (GHG) emission. The objective of this experiment was to determine the influence of long-term conservation tillage and N fertilization on soil carbon storage and CO2 emission in corn-soybean rotation system. A factorial experiment was arranged in a randomized completely block design with four replications. The first factor was tillage systems namely intensive tillage (IT), minimum tillage (MT) and no-tillage (NT). While the second factor was N fertilization with rate of 0, 100 and 200 kg N ha -1 applied for corn, and 0, 25, and 50 kg N ha -1 for soybean production. Samples of soil organic carbon (SOC) after 23 year of cropping were taken at depths of 0-5 cm, 5-10 cm and 10-20 cm, while CO2 emission measurements were taken in corn season (2009) and soybean season (2010). Analysis of variance and means test (HSD 0.05) were analyzed using the Statistical Analysis System package. At 0-5 cm depth, SOC under NT combined with 200 kg N ha -1 fertilization was 46.1% higher than that of NT with no N fertilization, while at depth of 5-10 cm SOC under MT was 26.2% higher than NT and 13.9% higher than IT. Throughout the corn and soybean seasons, CO2-C emissions from IT were higher than those of MT and NT, while CO2-C emissions from 200 kg N ha -1 rate were higher than those of 0 kg N ha -1 and 100 kg N ha -1 rates. With any N rate treatments, MT and NT could reduce CO2-C emission to 65.2%-67.6% and to 75.4%-87.6% as much of IT, respectively. While in soybean season, MT and NT could reduce CO2-C emission to 17.6%-46.7% and 42.0%-74.3% as much of IT, respectively. Prior to generative soybean growth, N fertilization with rate of 50 kg N ha -1 could reduce CO2-C emission to 32.2%-37.2% as much of 0 and 25 kg N ha -1 rates.
  • Authors:
    • Zhang, H.
    • Chen, F.
    • Kong, F.
    • Wei, Y.
    • Zhang, M.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 6
  • Year: 2012
  • Summary: Distribution of soil organic carbon in different soil layer can be transformed by tillage practices, and then soil carbon storage was changed. The four indices of soil organic carbon (SOC), soil carbon density (SCD), soil respiration (SR) and biomass carbon (BC) were selected to verify the adaptability of DNDC model in North China based on model adaptation and then the model was used to simulate local dynamic change of soil carbon storage (SCS) and characteristics of greenhouse gas emission. The result showed that there was a high similarity between simulated values and observed values and the model proposed was suitable to apply to the simulation research of soil organic carbon for winter wheat-summer corn in North China. SOC and SCS simulated by the model increased from 2001-2010, and simulated data in the next 100 years showed that SOC with rotary tillage (RT), conventional tillage (CT) and no-tillage (NT) showed a severe rising tendency in the first 15 years, and rising tendency of NT could sustain for 40 years. By comparing changes of soil carbon storage for 100 years between each treatment, it was found that SCS values with CT were the highest in the first 20 years and SCS values with NT was the highest after first 20 years. The sequence of global warming potential (GWP) for each treatment was CT > RT > NT. The results showed that DNDC model could work well for winter wheat-summer corn in North China, and NT was beneficial to increase SCS and decrease GWP of farmland in the long run. It provides a reference for fixing carbon and reducing discharge of winter wheat-summer corn in North China.