Top PDF Methane, carbon dioxide and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain.

Methane, carbon dioxide and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain.

Methane, carbon dioxide and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain.

production-consumption dynamics in the subsoil had been adjusted to the experimental treatments. Seven subsurface soil air equilibration tubes were installed at each site with sampling ports at 30, 60, 90, 150, 200, 250 and 300 cm in December 2006 (for more details, see reference 16). Soil-air samples were taken twice a week between 9:00 AM and 11:00 AM, using 100 ml plastic syringes connected to the tubes via the three-way stopcocks at the surface. The surface air was concurrently sampled at a height of 5 cm above the soil surface. The gas samples were analyzed by gas chromatography (Agilent GC-6820, Agilent Technologies Inc. Santa Clara, California, US) with separate electron capture detector (ECD at 330 uC) for N 2 O determination
Mostrar mais

14 Ler mais

Nitrous Oxide Emission and Denitrifier Abundance in Two Agricultural Soils Amended with Crop Residues and Urea in the North China Plain.

Nitrous Oxide Emission and Denitrifier Abundance in Two Agricultural Soils Amended with Crop Residues and Urea in the North China Plain.

summer maize harvest from the fields in which winter wheat and summer maize were culti- vated in a one-year rotation system. The OAC soil was collected from the experimental farm at Henan Agricultural College (113.59E, 34.86N) in Zhengzhou, Henan, China on september 26th, 2014, and the HAV soil was collected within Zhumadian city (114.53E, 33.41N), Henan, China on september 28th, 2014. The OAC soil derived from Northwest Loess Plateau, which was rich in calcium carbonate of loess sediments with groundwater depth and about 1 g/L min- eralization degree. The annual mean temperature in this region is 14.1°C, and the annual mean rainfall is 641 mm. The HAV soil derived from quaternary lacustrine sediments on the semi hydromorphic soil, more than 40% montmorillonite clay mineral in 0-40cm tillage layer of this soil with less coarse sand usually leads to the too sticky and the large expansion coefficient in soil texture. The annual mean temperature in this region is 14.8°C, and the annual mean rain- fall is 852 mm. Texture and properties of the both soils were in Table 1.
Mostrar mais

15 Ler mais

Dataset on ammonia, nitrous oxide, methane, and carbon dioxide fluxes from two soils fertilized amended with treated and non-treated cattle slurry

Dataset on ammonia, nitrous oxide, methane, and carbon dioxide fluxes from two soils fertilized amended with treated and non-treated cattle slurry

measured from two different soils under a Mediterranean double- cropping system (oat in autumn/winter followed by maize in spring/summer). The two soils were fertilized using four different treatments: (i) Injection of raw cattle slurry (100 mm depth), (ii) application of raw cattle slurry followed by soil incorporation (20 mm depth), (iii) band application of acidified (pH¼5.5) cattle slurry followed by soil incorporation (20 mm depth), and (iv) band application of acidified (pH¼5.5) cattle slurry without soil incor- poration. A non-amended soil was also considered as control treatment. The data presented here were obtained over a three years experiment between 2012 and 2015. Fluxes were measured in a period between slurry applications to soil (before plant seeding) till crop harvest. The data presented here are supporting the research article “Band application of acidified slurry as an Contents lists available at ScienceDirect
Mostrar mais

10 Ler mais

Environmental and microbial factors influencing methane and nitrous oxide fluxes in Mediterranean cork oak woodlands: trees make a difference

Environmental and microbial factors influencing methane and nitrous oxide fluxes in Mediterranean cork oak woodlands: trees make a difference

Hanson, 1996). Methanotrophs are traditionally classified into Type I (aerobic Gammaproteobacteria) and Type II (aerobic Alphaproteobacteria) groups (Hanson and Hanson, 1996). Methanotrophs have the functional gene pmoA, which encodes a subunit of particulate methane monooxygenase (pMMO). This gene exists in all methanotrophs with the exceptions of Methylocella sp. and Methyloferula sp., which have soluble MMO (sMMO; Theisen et al., 2005; Vorobév et al., 2011). Therefore, MMO genes are widely used as a biological marker in molecular ecological studies of methanotrophs (McDonald et al., 2008). Methanotrophs are widely distributed in various environments: such as paddy soils (Bodelier et al., 2000), upland forest soils (Knief et al., 2006; Lau et al., 2007; Mohanty et al., 2007; Kolb, 2009), landfill soils, wetlands (Einola et al., 2007; Siljanen et al., 2011), alpine grassland soils (Abell et al., 2009), and extreme thermoacidophilic environments (Pol et al., 2007; Islam et al., 2008). Soil moisture is important for induction of CH 4 oxidation and regulation of CH 4 uptake
Mostrar mais

11 Ler mais

MITIGATION OF METHANE AND NITROUS OXIDE EMISSIONS FROM FLOOD-IRRIGATED RICE BY NO INCORPORATION OF WINTER CROP RESIDUES INTO THE SOIL

MITIGATION OF METHANE AND NITROUS OXIDE EMISSIONS FROM FLOOD-IRRIGATED RICE BY NO INCORPORATION OF WINTER CROP RESIDUES INTO THE SOIL

FORSTER, P.; RAMASWAMY, V.; ARTAXO, P.; BERNTSEN, T.; BETTS, R.; FAHEY, D.W.; HAYWOOD, J.; LEAN, J.; LOWE, D.C.; MYHRE, G.; NGANGA, J.; PRINN, R.; RAGA, G.; SCHULZ, M. & van DORLAND, R. Changes in atmospheric constituents and in radiative forcing. In: SOLOMON, D.; QIN, D.; MANNING, M.; CHEN, Z.; MARQUIS, M.; AVERYT, K.B.; TIGNOR, M. & MILLER H. L. Climate change 2007: The physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge, Cambridge University Press, 2007. p.129-234. FRAGA, T.I.; CARMONA, F.C.; ANGHINONI, I.; GENRO JUNIOR, S.A. & MARCOLIN, E. Flooded rice yield as affected by levels of water salinity in different stages of its cycle. R. Bras. Ci. Solo., 34:175-182, 2010.
Mostrar mais

12 Ler mais

Soil macrofauna in wooded pasture with legume trees

Soil macrofauna in wooded pasture with legume trees

Soil macrofauna samplings were performed in summer (December 2006) and in winter (July 2007) under half of the legume treetop shades, according to the method recommended by the Tropical Soil Biology Fertility program (ANDERSON & INGRAM, 1993), thus holding a total of 8 repetitions to each studied woody species within a pasture and to the area without the influence of treetops (reference area). To do so, it was used a 25cm x 25cm squared frame where the soil was collected from, within 0-10cm, 10-20cm and 20-30cm depths. During extraction, the soil was placed on a tray and, with the help of a tweezers, all the visible invertebrates were taken out from it. They were placed in identified pots comprising 70% alcohol. Once in the lab, the invertebrates were identified according to big taxonomic groups as by DINDAL (1990). For evaluating the soil macrofauna community, densities from different groups and from the total of individuals by area and time were estimated, thus extrapolating the average for individuals m -2 , also calculating the
Mostrar mais

7 Ler mais

Nitrous oxide fluxes at the air-sea interface in Guanabara Bay.

Nitrous oxide fluxes at the air-sea interface in Guanabara Bay.

c mar = [K 0 × c hs(f) ] + [(P/RT) × (c hs(f) – c hs(i) )] (4) onde c hs(f) e c hs(i) são, respectivamente, as concentrações de N 2 O (em ppb) final e inicial no headspace da seringa [Obs.: c hs(i) representa a concentração de N 2 O no ar ambiente, portanto, c hs(i) = c ar (Equação 11)], K 0 é o coeficiente de solubilidade do N 2 O 15 calculado para a temperatura e salinidade da água do mar in situ e pressão de 1 atm (Equação 11), P é a pressão (assume-se 1 atm), R é a constante universal dos gases (0,082 L atm K -1 mol -1 ) e T (em K) é a temperatura da água do mar in situ.
Mostrar mais

8 Ler mais

Soil fertility controls soil–atmosphere carbon dioxide and methane fluxes in a tropical landscape converted from lowland forest to rubber and oil palm plantations

Soil fertility controls soil–atmosphere carbon dioxide and methane fluxes in a tropical landscape converted from lowland forest to rubber and oil palm plantations

plots of oil palm plantations in each of the two landscapes, and in each plot we selected three trees separated by an in- terrow distance of 9 m (in total, 18 oil palm trees). At 0.8 m distance from the base of each tree, we applied the fertilizer manually to the area within 0.2 m around the tree using the same rate that smallholders applied to these oil palm plan- tations (i.e., equivalent to 2 kg fertilizer per tree, based on 300 kg NPK fertilizer ha −1 divided by 134–140 trees ha −1 ; Table A2). We used the same fertilizer forms that smallhold- ers applied, i.e., NPK complete fertilizer in the clay Acrisol landscape and a combination of KCl, ammonium sulfate and NPK complete fertilizer in the loam Acrisol landscape. One chamber base was placed at 0.3 m distance from the tree base (chamber location a); another chamber base, to which fer- tilizer was applied, was placed at 0.8 m distance from the tree (chamber location b); and a third chamber was placed at 4–4.5 m distance from the tree and served as a reference chamber without direct fertilizer application (chamber loca- tion c). In the clay Acrisol landscape, measurements in the three oil palm plots were done from mid-October to mid- December 2013, mid-February to mid-March 2014, and mid- February to mid-April 2013. In the loam Acrisol landscape, measurements were done from the end of October 2013 to mid-December 2013, mid-January to mid-March 2014, and mid-March to the start of April 2014. Shorter intervals of sampling days (Appendix Fig. B1) were conducted right af- ter the fertilizer application.
Mostrar mais

22 Ler mais

Response of CH4 and N2O emissions and wheat yields to tillage method changes in the North China plain.

Response of CH4 and N2O emissions and wheat yields to tillage method changes in the North China plain.

The North China Plain is one of the most important grain production regions of China. Harrow tillage (HT), rotary tillage (RT) and no-tillage (NT) are frequently used conservation tillage methods in this region because they not only improve crop yield but also enhance the utilization efficiency of soil moisture and nutrients [8–12]. However, successive years of shallow tillage (10– 20 cm) exacerbate the risk of subsoil compaction, which not only leads to the hardening of soil tillage layers and an increase in soil bulk density, but also reduced crop root proliferation, limited water and nutrient availability and reduced crop yield [13].
Mostrar mais

10 Ler mais

Crises and emissions : new empirical evidence from a large sample

Crises and emissions : new empirical evidence from a large sample

The response of emissions to financial crises may also depend on whether the government is engaging in expansionary or contractionary fiscal policy at the time the economy is hit. To our knowledge, the only paper relating fiscal policy and the environment is the one by Lopez et al. (2011). The authors model (and empirically test) the impact of fiscal spending patterns on the environment and find that there is a reallocation of government spending composition towards social and public goods that tend to reduce pollution when an economy is hit by a negative shock. They further conclude that increasing total government spending (that is, engaging in expansionary fiscal policy) without altering its composition, does not reduce polluting emissions. while our setting is not identical, we still aim to shed further light into the effects of crises on the environment conditioning on prevailing (at the time of the shock) fiscal conditions. To this end, we consider an alternative version of equation 2 where instead of the state of the economy, we use instead an indicator of fiscal policy stance. The indicator fiscal policy stance is a government consumption shock, identified as the forecast error of government consumption expenditure relative to GDP (for a similar approach see, e.g., Auerbach and Gorodnichenko 2012, 2013; and Abiad et al., 2015). 18
Mostrar mais

39 Ler mais

Dissolved greenhouse gases (nitrous oxide and methane) associated with the naturally iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean

Dissolved greenhouse gases (nitrous oxide and methane) associated with the naturally iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean

Bopp, L.,Bowie, A., Brunet, C., Brussaard, K., Carlotti, F., Chris- taki, U., Corbiére, A., Durand, I., Ebersbach, F., Fuda, J. L., Gar- cia, N., Gerringa, L. J. A., Griffiths, F. B., Guigue, C., Guillerm, C., Jacquet, S., Jeandel, C., Laan, P., Lefèvre, D., Lomonaco, C., Malits, A., Mosseri, J., Obernosterer, I., Park, Y. H., Picheral, M., Pondaven, P., Remenyi, T., Sandroni, V., Sarthou, G., Savoye, N., Scouarnec, L., Souhault, M., Thuillers, D., Timmermans, K. R., Trull, T., Uitz, J., Van-Beek, P., Veldhuis, M. J. W., Vincent, D., Viollier, E., Vong, L., and Wagener, T.: Effect of natural iron fer- tilization on carbon sequestration in the Southern Ocean, Nature, 446, 1070–1075, 2007.
Mostrar mais

16 Ler mais

Frozen soil parameterization in a distributed biosphere hydrological model

Frozen soil parameterization in a distributed biosphere hydrological model

Consequently, much of the snowmelt water freezes again at night before its departure from snowpack. Therefore, the snowmelt runoff in the early spring was rather small. From May to June (late spring), the air temperature increases to above 0 ◦ C stably, and the snowmelt runoff becomes very large. This is also attributed to the little permeability of the underlying seasonal frozen soil layers which have thawed only in upper soil layers

34 Ler mais

EMISSION OF NITROUS OXIDE AND CARBON DIOXIDE FROM SEMI-ARID TROPICAL SOILS IN CHIAPAS MÉXICO

EMISSION OF NITROUS OXIDE AND CARBON DIOXIDE FROM SEMI-ARID TROPICAL SOILS IN CHIAPAS MÉXICO

surface (Ferrusquía-Villafranca et al., 2000). Rocks protect the soil surface and reduce raindrop impact and surface sealing (Abrahams & Parson, 1991), but limit agricultural activity. Around 50 % of the surface is rock and the thin soil is predominantly Lithosol, 5–15 cm deep. The region is dominated by short-tree savannah and thorn woodland (Breedlove, 1978), dominated by A. angustissima (Timbre) and Byrsonimia crassifolia (Nanche), Swietenia macrophylla (Caobilla), Bucida macrostachya (Cacho de toro), Opuntia spp (Nopal), Acacia farnesiana (Huisache) and bushy old fields or secondary forest (acahuales) can be found in this area (Rzedowski, 1978). Traditionally, Acacia angustissima was used as fuel or for medicinal purposes by local people. Today, these bushes are mixed with agriculture and grasslands in cultivated areas (Rincón-Rosales & Gutiérrez, 2008).
Mostrar mais

12 Ler mais

Nitric oxide and nitrous oxide emissions from cattle-slurry and mineral fertiliser treated with nitrification inhibitor to an agricultural soil: a laboratory approach

Nitric oxide and nitrous oxide emissions from cattle-slurry and mineral fertiliser treated with nitrification inhibitor to an agricultural soil: a laboratory approach

The LF used in the present study was collected from a commercial dairy-cattle farm from Northwest Portu- gal where the diet is mainly based in maize silage. The raw slurry (10% dry matter) after being stored in a concrete storage open pit for five months, has been mechanical separated with a screw press separator equipment (FAN model S655, BAUER, Austria) gen- erating a LF with low dry mater content and average particle size <1 mm. The collected LF was homoge- nized and kept refrigerated (4 °C) to preserve N. At the beginning of the experiment, LF subsamples were analysed using standard laboratory methods to assess the following parameters: dry matter, 5.7%; pH, 8.0; total C, 25.0 g/kg; total N, 3.7 g/kg; NH 4 + -N, 2.1 g/kg;
Mostrar mais

9 Ler mais

Emissão de N2O do solo devido à aplicação de urina e o potencial de mitigação

Emissão de N2O do solo devido à aplicação de urina e o potencial de mitigação

This variability in reported EFs highlights the importance to determine specific EFs for each country or climatic region. The results from this study represent some of the first data for Brazil, but are limited in terms of duration (one month only), spatial representation (one site only) and seasonal representation (summer only). Extrapolating these results to regional or national emissions is therefore not appropriate. In addition, when expressing the EF per animal, the diet and level of productivity of the animal are also important factors to consider. To develop regional or national EF, many other studies are necessary to taking into account the range of soil, climate and management conditions within a country.
Mostrar mais

89 Ler mais

O EMISSIONS FROM A CULTIVATED MOLLISOL: OPTIMAL TIME OF DAY FOR SAMPLING AND THE ROLE OF SOIL TEMPERATURE

O EMISSIONS FROM A CULTIVATED MOLLISOL: OPTIMAL TIME OF DAY FOR SAMPLING AND THE ROLE OF SOIL TEMPERATURE

spread across the soybean field, were inserted into the soil to a depth of 0.05 m. This size of field chambers was described as optimal by other authors (Rochette & Eriksen-Hamel, 2008) and was already used by Jantalia et al. (2008) and Alves et al. (2012). After closing the chambers, gas samples were taken after 0, 20 and 40 min, with a vacuum pump, and injected into previously evacuated 25 mL vials with a rubber stopper fixed to the vial with an aluminum flange. Once sampling was finished, the top of the chamber was removed. This process was repeated every 3 h for three consecutive days beginning at 9:00 am on the first day. The N 2 O collected was always measured
Mostrar mais

6 Ler mais

A study on methane and carbon dioxide adsorption

A study on methane and carbon dioxide adsorption

Malek and Farooq (1997) measured mass and heat transfer data for methane, ethane and propane adsorption in both activated carbon and silica gel beds using the dynamic-column breakthrough method. This method was chosen due to the significant amount of adsorbent used which enables more representative data to be obtained. Their research concluded that using single-component kinetic data and the extended Langmuir-Freundlich equilibrium isotherm provides positive prediction of experimental breakthrough profiles. The correspondence between experimental and theoretical results can be compromised when recurring to the extended Langmuir isotherm but it greatly accelerates the process. [30]
Mostrar mais

48 Ler mais

Carbon allocation and carbon isotope fluxes in the plant-soil-atmosphere continuum: a review

Carbon allocation and carbon isotope fluxes in the plant-soil-atmosphere continuum: a review

The time lag caused by C translocation from leaves to be- lowground sites of respiration has been extensively reviewed (Davidson and Holbrook, 2009; Kuzyakov and Gavrichkova, 2010; Mencuccini and H¨oltt¨a, 2010) since photosynthe- sis has been identified as a key driver of soil respiration (H¨ogberg et al., 2001). Generally, time lags determined as propagation of fluctuations in δ 13 C at natural abundance in- crease with tree height, with transport rates between 0.07 and 0.5 m h −1 (Kuzyakov and Gavrichkova, 2010; Mencuccini and H¨oltt¨a, 2010), although carbon translocation velocities are often higher in tall plants (Lang, 1979; Thompson and Holbrook, 2003; Van Bel and Hafke, 2005; Mencuccini and H¨oltt¨a, 2010), potentially due to stronger root C sinks asso- ciated with a larger belowground biomass. In certain stud- ies, seasonal changes in belowground C allocation had no effect on the time lag between assimilation and use of as- similates in belowground respiration (Horwath et al., 1994; H¨ogberg et al., 2010), suggesting that phloem path length and structural differences were the main determinants of C transfer velocity. In contrast, other studies reported consid- erable variation of the time lag during the growing season in the same trees (Plain et al., 2009; Wingate et al. 2010; Dan- noura et al., 2011; Epron et al., 2011; Kuptz et al., 2011a) (Fig. 2). However, the mechanisms behind such variability are still unknown even though seasonal variations of carbon storage and remobilization in the trunk are the most likely mechanisms to affect the transfer of carbon as well as the conveyance of the carbon isotope signal from the canopy in basipetal direction over the growing season (Offermann et al., 2011).
Mostrar mais

33 Ler mais

Performance assessment of the FAO AquaCrop model for soil water, soil evaporation, biomass and yield of soybeans in North China plain

Performance assessment of the FAO AquaCrop model for soil water, soil evaporation, biomass and yield of soybeans in North China plain

Selected results relative to comparing the observed and sim- ulated ASW after appropriate model calibration are presented in Fig. 2. Also included the values simulated with the default param- eters listed in Table 4. ASW were observed and simulated for the maximum root depth. The target upper limit of ASW is the the total available soil water (TAW, mm) that corresponds to the ASW stored at field capacity in the root zone, and the target lower limit for ASW without water stress is the readily available water, RAW = p TAW, where p is the depletion fraction for no stress (Allen et al., 1998). In this application, p was previously calibrated with SIMD- ualKc (Wei et al., 2015). Results in Fig. 2 show that ASW generally varied between RAW and TAW, thus evidencing that only negligible water stress may have occurred. This is due to the fact that irrigation treatments T1 and T2 were designed for depletion fractions smaller than p.
Mostrar mais

15 Ler mais

Carbon dioxide efflux in a rhodic hapludox as affected by tillage systems in southern Brazil

Carbon dioxide efflux in a rhodic hapludox as affected by tillage systems in southern Brazil

corresponding to a 24 % higher volume than the mean monthly rainfall (136 mm). Five rainfall events were observed in the 30 day period when soil CO 2 -C flux was measured, where 63 % of the total rainfall volume of the period was recorded in only two events. As expected, higher WFPS values were found immediately after the stronger rains (Figure 1a). In general, the values of WFPS in the NT soil were higher than in the CT plot, which is in agreement with results reported by Linn & Doran (1984), with exception of May 28 (Figure 1a). These results confirm the higher capacity of NT system to infiltrate and hold soil moisture in relation to CT. Higher WFPS differences (Figure 1a) between tillage systems occurred just after the disk plow and harrow disk operations on the CT plot. It is noteworthy that around 85 % of the total rainfall volume occurred after soil tillage. Therefore, after soil tillage, smaller WFPS values were found in CT compared to NT. This result is probably associated to the wind effect that dried the bare soil surface of CT. A mean air temperature of 14 °C was registered during the studied period, which is 13 % below the mean temperature registered for this month (16 °C). Besides, a high thermal amplitude was verified, since the air temperatures ranged from 4 to 22 °C, with a declining trend throughout the experimental period. In May, the soil temperature was similar in the two tillage systems. However, measurements performed in the first week of June, after sowing, indicated a higher soil temperature in the CT than the NT plot (Figure 1b).
Mostrar mais

10 Ler mais

Show all 10000 documents...