• Authors:
    • Muni, R.
    • Saudan, S.
    • Aparbal, S.
    • Man, S.
  • Source: Archives of Agronomy and Soil Science
  • Volume: 58
  • Issue: 4
  • Year: 2012
  • Summary: The objective of the study was to determine the profitability and employment-generation potential of different cropping systems involving menthol mint ( Mentha arvensis L.) as a component of sequential/intercropping in comparison with the most common paddy-wheat-green gram cropping system. Field experiments were conducted at Lucknow, India (26°5′N, 80°5′E and 120 m above mean sea level) for three years from July 2004 to June 2007. Menthol mint yielded the maximum fresh shoot biomass and essential oil (21.0 t and 151 kg ha -1, respectively) grown after sweet basil ( Ocimum basillicum)-potato followed by paddy-potato-menthol mint (18.9 t and 136 kg ha -1, respectively) and maize-mustard-menthol mint (17.7 t and 131 kg ha -1, respectively). Net returns of all the menthol-mint-based cropping systems were 82.6-354% higher than traditional paddy-wheat-green gram cropping system. Maize-garlic-menthol mint+okra was found to be most profitable (77,200 Rs ha -1) followed by pigeon pea+sweet basil-menthol mint+okra (76,120 Rs ha -1). Employment-generation efficiency was much higher in cropping systems involving menthol mint and vegetable crops, the highest (2.21 man days ha -1 day -1) being in a maize-cauliflower-onion-menthol mint+okra cropping system.
  • Authors:
    • Bem, C.
    • Horst, T.
    • Agnolin, C.
    • Fontaneli, R.
    • Olivo, C.
    • Meinerz, G.
  • Source: REVISTA BRASILEIRA DE ZOOTECNIA-BRAZILIAN JOURNAL OF ANIMAL SCIENCE
  • Volume: 41
  • Issue: 4
  • Year: 2012
  • Summary: The objective of this research was to evaluate early growth, yield and canopy characteristics of 12 genotypes of six species of winter cereals with double purpose (forage and grains) submitted to harvest at Depressao Central region of Rio Grande do Sul state, South Region of Brazil. Species and genotypes tested were: BRS 277, BRS Guatambu, BRS Taruma and BRS Umbu wheat; Agro Zebu, UPFA 21 - Moreninha and Commom black-oat; UPF 18 white-oat; BR 1 and BRS Serrano rye; BRS Marciana barley; and BRS 148 triticale. The genotypes were distributed in 36 experimental plots, in a completely randomized design with 12 treatments, three replications and repeated measure. Studied variables were herbage mass, botanical and structural composition, forage and grains production. The earliest genotypes for forage production were BR 1 rye and BRS 148 triticale. BRS Taruma wheat presented higher forage and leaf blade production. BRS Umbu wheat presented higher grains yield and hectoliter weight. Among the genotypes evaluated, BRS Taruma wheat is the most suitable for double purpose in Depressao Central region of Rio Grande do Sul state.
  • Authors:
    • Hirata, T.
    • Komatsuzaki, M.
    • Nakamoto, T.
    • Araki, H.
  • Source: Soil Science and Plant Nutrition
  • Volume: 58
  • Issue: 1
  • Year: 2012
  • Summary: We hypothesized that cover cropping could increase soil microbial activities under various tillage systems and that increased microbial activities would improve soil properties. Soil sampling was conducted at two fields in Japan in 2009. At the Ibaraki field (Andosol, clay loam), three tillage practices (no-tillage, plowing to 30 cm, and rotary tillage to 15 cm) and three types of winter cover cropping [bare fallow as control, hairy vetch ( Vicia villosa Roth), and rye ( Secale cereale L.)] were conducted from 2003 to 2009. At the Hokkaido field (Fluvisol, light clay), two tillage practices (autumn tillage and rotary tillage with a rotary tiller to a depth of 15 cm once in autumn and twice in a year, respectively), and four types of winter cover cropping (bare fallow, hairy vetch, bristle oat ( Avena strigosa L.), and a mixture of hairy vetch and bristle oat) were conducted from 2006 to 2009. Soil microbial activities and the fungal-to-bacterial activity ratio (F/B ratio) were estimated by the substrate-induced respiration (SIR) method with the use of selective antibiotics. At the Ibaraki field, rye cover cropping showed higher microbial SIR than bare fallow at depths of 0-30 cm and rotary tillage maintained higher microbial SIR than no-tillage or plowing at depths of 7.5-15 cm. There was no meaningful interaction effect between cover cropping and tillage on microbial SIR. At the Hokkaido field, cover cropping and tillage had only limited effects on microbial SIR. High F/B ratios (indicating fungal dominance) were recorded with the use of cover crops in both fields. Fungal SIR, estimated from the microbial SIR and F/B ratio, was closely related to the content of total soil organic carbon (SOC) and the mean weight diameter (MWD) of water-stable aggregates. Based on SOC, fungal SIR was significantly higher under rye cover cropping. The relationship between fungal SIR and MWD was affected by tillage. We conclude that rye cover cropping and rotary tillage were very effective in increasing fungal SIR, SOC, and MWD in the Ibaraki soil. Field practices that enhance fungal activities might be effective in improving certain types of arable soil.
  • Authors:
    • Chimbizi, A.
    • Chimphero, L.
    • Mwale, C.
    • Mhango, W.
    • Kambauwa, G.
    • Kabambe, V.
    • Ngwira, A.
    • Mapfumo, P.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 6
  • Year: 2012
  • Summary: Maize ( Zea mays L.) is a major staple food in Malawi. However, low soil fertility resulting from low and inappropriate use of fertilizer practices, continuous monocropping and inappropriate crop residues management coupled with limited resources and droughts keep yields low. This had led to a quest for sustainable solutions such as maize-legume intercropping or rotation including more efficient use of crop residues in smallholder farming systems. Innovation platforms (IP) built around learning centres (LC) located on smallholder farmers' fields in target locations were used as an approach to disseminate integrated soil fertility management (ISFM) technologies and build capacity of farmers, extension staff and other stakeholders. Rotating maize with either groundnut or groundnut intercropped with pigeonpea increased maize grain yield (3678 and 3071 kg ha -1 respectively) compared to sole maize (2260 kg ha -1). These preliminary findings were linked to farmer assessment of technologies where farmers participating in the LCs expressed strong interest in the maize legume rotation technologies. Associated farmer field days outlined constraints underlying technology choice, information that is not usually considered in conjunction with on-farm experimentation. Although, the legumes were highly productive, farmers expressed worries about legume seed availability, disease incidences, weeds infestations and livestock damage. Participating farmers commonly manage residues by burning. Promotion and experimentation with more efficient use of legume residues have shown short-term positive impacts in efforts to promote scaling-out of best fit legume technologies. This study reports the value of multi-stakeholder partnering in scaling-out and evaluation of best fit legume technologies and adoption constraints.
  • Authors:
    • Kalburtji, K.
    • Tsirakoglou, V.
    • Tsatsarelis, C.
    • Menexes, G.
    • Mamolos, A.
    • Michos, M.
  • Source: Ecological Indicators
  • Volume: 13
  • Issue: 1
  • Year: 2012
  • Summary: Energy analysis in peach orchards is useful to decide best management strategies. The objectives of this study were to evaluate (a) the energy flow among conventional, integrated and organic farming systems and (b) the effect of farming system to greenhouse gas-emissions. Sixteen farms (four conventional, nine integrated, three organic) at six locations in northern Greece were selected randomly during the years 2008 and 2009. Multidimensional data analyses were used to detect (a) clusters of farming systems and (b) associations between farming systems and production coefficients variables. Three groups of farming systems and three groups of variables were revealed. Farming systems in the same group respond more or less similarly to the production coefficients variables. Non-parametric tests concerning external variables (outputs, energy efficiency, fruit production, CO2, CH4 and N2O) showed that the variables in organic farming cluster were at average significantly lower. Similarities and/or dissimilarities among farming systems, can probably be related to farm topography, production coefficients and local farming practices. The results showed that organic farming could reduce inputs and gas-emissions. (C) 2011 Elsevier Ltd. All rights reserved.
  • Authors:
    • Crosson, E.
    • Bandaru, V.
    • West, T.
    • Andrews, A.
    • Lauvaux, T.
    • Davis, K.
    • Richardson, S.
    • Miles, N.
  • Source: Journal of Geophysical Research-Biogeosciences
  • Volume: 117
  • Issue: G1
  • Year: 2012
  • Summary: This study presents observations of atmospheric boundary layer CO2 mole fraction from a nine-tower regional network deployed during the North American Carbon Program's Mid-Continent Intensive (MCI) during 2007-2009. The MCI region is largely agricultural, with well-documented carbon exchange available via agricultural inventories. By combining vegetation maps and tower footprints, we show the fractional influence of corn, soy, grass, and forest biomes varies widely across the MCI. Differences in the magnitude of CO2 flux from each of these biomes lead to large spatial gradients in the monthly averaged CO2 mole fraction observed in the MCI. In other words, the monthly averaged gradients are tied to regional patterns in net ecosystem exchange (NEE). The daily scale gradients are more weakly connected to regional NEE, instead being governed by local weather and large-scale weather patterns. With this network of tower-based mole fraction measurements, we detect climate-driven interannual changes in crop growth that are confirmed by satellite and inventory methods. These observations show that regional-scale CO2 mole fraction networks yield large, coherent signals governed largely by regional sources and sinks of CO2.
  • Authors:
    • Bernhardt, E.
    • Ardon, M.
    • Morse, J.
  • Source: Ecological Applications
  • Volume: 22
  • Issue: 1
  • Year: 2012
  • Summary: Whether through sea level rise or wetland restoration, agricultural soils in coastal areas will be inundated at increasing rates, renewing connections to sensitive surface waters and raising critical questions about environmental trade-offs. Wetland restoration is, often implemented in agricultural catchments to improve water quality through nutrient removal. Yet flooding of soils can also increase production of the greenhouse gases nitrous oxide and methane, representing a potential environmental trade-off. Our study aimed to quantify and compare greenhouse gas emissions from unmanaged and restored forested wetlands, as well as actively managed agricultural fields within the North Carolina coastal plain, USA. In sampling conducted once every two months over a two-year comparative study, we found that soil carbon dioxide flux (range: 8000-64 800 kg CO2.ha(-1).yr(-1)) comprised 66-100% of total greenhouse gas emissions from all sites and that methane emissions (range: -6.87 to 197 kg CH4.ha(-1).yr(-1)) were highest from permanently inundated sites, while nitrous oxide fluxes (range: -1.07 to 139 kg N2O.ha(-1).yr(-1)) were highest in sites with lower water tables. Contrary to predictions, greenhouse gas fluxes (as CO2 equivalents) from the restored wetland were lower than from either agricultural fields or unmanaged forested wetlands. In these acidic coastal freshwater ecosystems, the conversion of agricultural fields to flooded young forested wetlands did not result in increases in greenhouse gas emissions.
  • Authors:
    • Torbert, H.
    • Watts, D.
    • Way, T.
    • Mays, D.
    • Nyakatawa, E.
    • Smith, D.
  • Source: Journal of Sustainable Agriculture
  • Volume: 36
  • Issue: 8
  • Year: 2012
  • Summary: Soil management practices can alter the natural balance at the soil-plant-atmosphere ecosystem interface, which can significantly affect the environment. This study compared CO2 fluxes in conventional tillage (CT) and no-tillage (NT) corn (Zea mays L.) production systems receiving poultry litter (PL) and ammonium nitrate (AN) fertilizers on a Decatur silt loam soil in the Tennessee Valley region of North Alabama from Spring 2008 to Fall 2009. Soil CO2 flux in CT plots (9.5 kg CO2 ha(-1) day(-1)) was significantly greater than that in NT plots (4.9 kg CO2 ha(-1) day(-1) in summer. Soil CO2 fluxes were lowest in fall where CT plots had a mean soil CO2 emission of 0.8 kg CO2 ha(-1) day(-1), while plots under NT and grass fallow system were sinks of CO2 with fluxes -0.6 and -1.0 kg CO2 ha(-1) day(-1), respectively. Mean soil CO2 flux averaged over seasons in NT plots was 36% lower than that in CT plots. Grass fallow plots were net sinks of CO2 with a mean CO2 flux of -0.4 kg CO2 ha(-1) day(-1). Our study showed that application of PL or AN fertilizer in NT systems can significantly reduce soil CO2 emissions compared to CT systems in corn production.
  • Authors:
    • Romic, D.
    • Rengel, Z.
    • Ondrasek, G.
    • Savic, R.
  • Source: European Journal of Soil Science
  • Volume: 63
  • Issue: 5
  • Year: 2012
  • Summary: Soil degradation processes, such as organic matter (OM) depletion, accompanied by metal contamination and salinization are becoming a serious threat to crop production and human food security. A glasshouse study was conducted to assess a factorial combination of salinity (0, 20, 40 and 60 mm NaCl) and cadmium (Cd) (0.3, 2.5 and 5.4 mg Cd kg-1) in organic soil (>90% OM) and their influence on dissolved organic carbon (DOC) in the rhizosphere and phyto-accumulation in radish (Raphanus sativus L. var. sativus). A 34-day exposure to increasing NaCl salinity significantly decreased DOC concentration in the radish rhizosphere solution and increased trace element (copper, Cu; zinc, Zn; and Cd) concentrations in the rhizosphere as well as in leaf/fruit tissues of radish. Soil contamination by Cd progressively raised concentrations in soil solution, but markedly reduced total concentration of Cu and Zn in the rhizosphere and leaves of radish. The NICA-Donnan chemical speciation/distribution modelling confirmed the predominance of dissolved organic reactive surfaces (from fulvic acid for example) in Cu and Cd chemisorption/complexation processes over the whole range of applied NaCl and Cd treatments. In contrast, Zn speciation was dominated by an organically-complexed pool at low salinity (020 mm NaCl), and free Zn2+ was the most important species at increased salinity (=40 mm NaCl). In conclusion, because of the diminished pool of DOC under excessive salinity, the biogeochemistry of Cu, Zn and Cd in the rhizosphere can be affected in a way that would enhance solubility and phyto-accumulation of these trace metals in food crops.
  • Authors:
    • Bellotti, B.
    • Ridoutt, B.
    • Page, G.
  • Source: Journal of Cleaner Production
  • Volume: 32
  • Year: 2012
  • Summary: There is growing interest in carbon footprints of products but for horticulture water use can also be important, hence we studied both for fresh tomatoes supplied to the Sydney market. Carbon and water footprints for each kg of fresh tomato supplied to Sydney depend on the season and the type of production system (ranging from 0.39 to 1.97 kg CO(2)e; 5 to 53 L). Energy use of the systems was also reported which ranged from 6.16 to 27.42 MJ for each kg of fresh tomato supplied to Sydney. Tradeoffs exist within studied production systems such that a system which had higher carbon footprint had lower water footprint; this complicates setting priorities for overall environmental improvement. To address this limitation, life cycle impacts of greenhouse gas (GHG) emissions and water use were subsequently modelled using endpoint indicators and compared. The results indicated that in all cases the climate change impacts were most important representing 84-96% of the combined scores on damages to the environment. As such the vegetable industry's priority to reduce GHG emissions is confirmed. In case of field production, transportation of tomatoes to market was the hotspot in carbon footprint, while for the medium and high technology greenhouses it was artificial heating. Although the results indicated priority to reduce carbon footprint, further development and harmonisation of LCA impact assessment models for water use at the endpoint level is considered essential. (C) 2012 Elsevier Ltd. All rights reserved.