• Authors:
    • Kasimir-Klemedtsson, A.
    • Rutting, T.
    • Weslien, P.
    • Klemedtsson, L.
  • Source: Nutrient Cycling in Agroecosytems
  • Volume: 94
  • Issue: 2-3
  • Year: 2012
  • Summary: The emissions of the greenhouse gas nitrous oxide (N2O) were measured from a non nitrogen fertilized carrot (Daucus carota ssp. sativa) field on an organic soil in Sweden during one cropping and post-harvest season. The cumulative emission during the measuring period of 149 days was 41 (+/- 2.8) kg N2O ha(-1). Dividing the measuring period into a cropping and a post-harvest period revealed that the presence of carrots strongly stimulated N2O emissions, as the emission during the cropping period was one order of magnitude higher compared to the post-harvest period. The N2O emission from the carrot field were higher than fluxes reported from cereal crop and grass production, but in the same order as reported fluxes from vegetable cropping on organic soils. In conclusion, our results indicate that the cultivation of root vegetable, such as carrots, on organic soil can be a high point source for N2O emissions.
  • Authors:
    • Akbarpour, M.
    • Taki, M.
    • Abdi, R.
  • Source: International Journal of Natural and Engineering Sciences
  • Volume: 6
  • Issue: 3
  • Year: 2012
  • Summary: The aim of this study was to examine the energy use patterns and energy input-output analysis of some field crops and vegetables in the Esfahan province of Iran. The data were collected using a face-to-face questionnaire method. The results indicated that total energy input for wheat, corn silage, cucumber and tomato production was to 69373, 109659, 152553 and 147108 MJ ha -1, respectively. Among all inputs involved, fertilizer and machinery had the highest energy values per 1 hectare for field crops; furthermore, diesel fuel had the highest share of total energy consumption for vegetable productions. The value of energy ratio for cultivating wheat, corn silage, cucumber and tomato crops were calculated at 0.74, 2.55, 0.46 and 0.73, respectively. The results of CO 2 emission analyzes showed that the total amount of CO 2 emission for wheat, corn silage, cucumber and tomato production was 2.07, 4.35, 4.99 and 4.66 tones ha -1, respectively. In the research area, greenhouse operators are still increasing the amount of inputs used in vegetable production. However, the timing of any applications and use of the inputs are not significant issues for the Iranian greenhouse producer. This inevitably leads to problems associated with energy use such as global warming, nutrient loading and pesticide pollution, as indicated above. Therefore, there is a need to develop a new policy to force producers to use all inputs on time and enough undertake more energy-efficient practices.
  • Authors:
    • Abou-Hussein, S. D.
  • Source: Journal of Applied Sciences Research
  • Volume: 8
  • Issue: August
  • Year: 2012
  • Summary: Global climate change, rated as the most serious threat to the environment, has been the center of debate among environmentalists and policy makers as it has become not only an environmental, a political and an economic issue, but also a global problem, of which agriculture is the major target. Therefore, the exponential growth of CO 2 and other greenhouse gasses in the atmosphere is causing climate change and it will be affected on agriculture, forestry, human health, biodiversity, snow cover and aquatic to mountain ecosystems. Changes in climatic factors like temperature, solar radiation and precipitation have potentials to influence crop production. Plants have been directly affected by rising atmospheric CO 2 concentration because they are the first molecular link between the atmosphere and the biosphere. The role of CO 2 in agriculture is complex in that it can be positive in some respects such as increasing [CO 2] will enhance photosynthesis and improve water use efficiency, thus increasing yield in most crops and negative in other respects. CO 2 concentration affects crop production directly by influencing the physiological processes of photosynthesis. The impact of increasing temperatures is more difficult to predict. Seed germination will probably be improved for most vegetables, as will vegetative growth in regions where mean daily temperatures during the growing season remain under 25°C, assuming adequate water is available. Reproductive growth is extremely vulnerable to periods of heat stress in many important vegetable fruiting crops, such as tomato, pepper, bean and sweet-corn, and yield reductions will probably occur unless production is shifted to cooler portions of the year. In many crops, high temperatures may decrease quality parameters, such as size, soluble solids and tenderness. For fresh-market vegetable producers, even minor quality flaws can make their crops completely unsaleable in some markets. Reduced or more irregular precipitation will also decrease vegetable yields and quality, although soluble solids and specific weight may increase in some crops. Leafy greens and most Cole crops such as broccoli, cabbage, cauliflower, are generally considered to be cool-season crops, so heat stress during the growing season would be detrimental to these species. Thus, planting dates, production areas and cultivars may need to be adjusted if temperatures change.
  • Authors:
    • Hastings, A.
    • Sim, S.
    • King, H.
    • Keller, E.
    • Canals, L. M. I.
    • Flynn, H. C.
    • Wang, S.
    • Smith, P.
  • Source: Global Change Biology
  • Volume: 18
  • Issue: 5
  • Year: 2012
  • Summary: Many assessments of product carbon footprint (PCF) for agricultural products omit emissions arising from land-use change (LUC). In this study, we developed a framework based on IPCC national greenhouse gas inventory methodologies to assess the impacts of LUC from crop production using oil palm, soybean and oilseed rape as examples. Using ecological zone, climate and soil types fromnatural the top 20 producing countries, calculated emissions for transitions from vegetation to cropland on mineral soils under typical management ranged from -4.5 to 29.4 t CO2-eq ha-1 yr-1 over 20 years for oil palm and 1.247.5 t CO2-eq ha-1 yr-1 over 20 years for soybeans. Oilseed rape showed similar results to soybeans, but with lower maximum values because it is mainly grown in areas with lower C stocks. GHG emissions from other land-use transitions were between 62% and 95% lower than those from natural vegetation for the arable crops, while conversions to oil palm were a sink for C. LUC emissions were considered on a national basis and also expressed per-tonne-of-oil-produced. Weighted global averages indicate that, depending on the land-use transition, oil crop production on newly converted land contributes between -3.1 and 7.0 t CO2-eq t oil production-1 yr-1 for palm oil, 11.950.6 t CO2-eq t oil production-1 yr-1 for soybean oil, and 7.731.4 t CO2-eq t oil production-1 yr-1 for rapeseed oil. Assumptions made about crop and LUC distribution within countries contributed up to 66% error around the global averages for natural vegetation conversions. Uncertainty around biomass and soil C stocks were also examined. Finer resolution data and information (particularly on land management and yield) could improve reliability of the estimates but the framework can be used in all global regions and represents an important step forward for including LUC emissions in PCFs.
  • Authors:
    • Inubushi, K.
    • Bakar, R.
    • Affandi, D.
    • Hadi, A.
  • Source: Jurnal Tanah Tropika (Journal of Tropical Soils)
  • Volume: 17
  • Issue: 2
  • Year: 2012
  • Summary: Presently, about 20% of oil palm ( Elaeis guineensis Jacq) fields in Indonesia are on peat soil, in addition to that other area of peat soil has been conventionally used for rice field and vegetables. To elucidate the global warming potentials of peat soils cultivated to oil palm, vegetable or rice field, field experiment has been carried out in South Kalimantan. Air samples were taken from rice field, oil palm and vegetable fields in weekly basis for six month period and analyzed for concentrations of N 2O, CH 4 and CO 2. The global warming potentials (GWP) of the three gases were calculated by multiplying the emission of each gas with their respective mole warming potential. This step was followed by the addition of the three gases' GWP to have the total GWP. The results showed that the emissions of greenhouse gases from peat soils changed seasonally and varied with the crops cultivated. Oil palm has resulted the highest GWP, mostly contributed by N 2O. There was no statistical different in total GWP of paddy and vegetable fields. The annual N 2O emission from oil palm field was 4,582 g N ha -1 yr -1. Water, nutrients and organic matter managements are among the potential techniques to minimize gas emissions from oil palm field which need field trials.
  • Authors:
    • Xiong, Z. Q.
    • Ma, Y. C.
    • Jia, J. X.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 150
  • Year: 2012
  • Summary: The net ecosystem carbon budget (NECB), global warming potential (GWP) and greenhouse gas intensity (GHGI) of vegetable ecosystems are not well documented. The net GWP and GHGI either including the carbon emissions from agricultural management (net mGWP/mGHGI) or not were estimated from an intensive vegetable production system in Nanjing, China between 2009 and 2010. The four typical consecutive rotations included celery-tung choy-baby bok choy-amaranth (C-T-Bb-A), choy sum-celery-tung choy-bok choy (Cs-C-T-Bc), garland chrysanthemum-tung choy-bok choy (G-T-Bc), and celery-choy sum-lettuce-bok choy (C-Cs-L-Bc). A net sink was observed and estimated at crop seasonal time scale for both the NECB and the soil organic carbon change (delta SOC) from the four vegetable rotation fields. The mGWP, net GWP, net mGWP. GHGI and mGHGI all showed nearly consistent changes among the rotations and among the vegetables within each rotation. The global warming potential ranged from 26 Mg CO2 equiv. ha(-1) to 109 Mg CO2 equiv. ha(-1) for net GWP and 36 Mg CO2 equiv. ha(-1) to 131 Mg CO2 equiv. ha(-1) for mGWP. The GHGI and mGHGI ranged from 0.17 kg CO2 equiv. kg(-1) vegetable to 0.41 kg CO2 equiv. kg(-1) vegetable and from 0.22 kg CO2 equiv.kg(-1) vegetable to 0.49 kg CO2 equiv. kg(-1) vegetable, respectively. The mGWP, net GWP, net mGWP, GHGI and mGHGI were dominated by the GWP resulting from N2O emissions. Annual cumulative direct N2O emissions were 374 kg N2O ha(-1) for G-T-Bc, 216 kg N2O ha(-1) for C-T-Bb-A, 159 kg N2O ha(-1) for Cs-C-T-Bc and 89 kg N2O ha(-1) for C-Cs-L-Bc, respectively. High N fertilizer input was likely responsible for the high N2O emissions. Increasing fertilizer use efficiency and adoption of best practices are effective measures for sustainable intensive vegetable production.
  • Authors:
    • Shan, W. H.
    • Jie, G. D.
    • Zhou, C. Z.
    • Mei, J. H.
  • Source: Acta Pedalogica Sinica
  • Volume: 49
  • Issue: 1
  • Year: 2012
  • Summary: Ammonia (NH 3) volatilization is a major pathway for gaseous nitrogen loss from fields applied with manure. To explore effects of topdressing of bio-digested manure slurry on ammonia volatilization, a field experiment was carried out in a vegetable greenhouse, applying bio-digested pig manure slurry (DPS) on winter vegetable, cress ( Oenanthe clecumbens L.) and radish ( Raphanus sativus L. Var. Radiculus pers.), and summer vegetable, pak choi ( Brassica chinensis L.) and crown daisy ( Chrysanthemum carinatum Schousb.). The topdressing rates of nitrogen were 72 kg hm -2, 54 kg hm -2, 42 kg hm -2 and 63 kg hm -2, respectively, during the growing periods of vegetables. Results showed that (1) topdressing of DPS led to explosion of ammonia volatilization within 48 h; (2) the accumulative ammonia release of the growing season reached 8.68 kg hm -2 and 9.90 kg hm -2 in cress and radish fields, respectively, which were significantly higher than those in the plots topdressing with chemical fertilizer (CF) (4.06 kg hm -2 and 5.59 kg hm -2); however, in the pak choi and crown daisy fields, the value was 10.40 kg hm -2 and 11.61 kg hm -2, respectively, which were not so significantly higher than those in the plots topdressing with CF (9.81 kg hm -2 and 10. 09 kg hm -2); (3) ammonia volatilization contributed 11.7% and 17.7% to the total N loss, respectively in the cress and radish plots topdressing with DPS in winter, and 23.3% and 26.8% in the pak choi and crown daisy plots in summer. The former was significantly lower than the latter; (4) temperature, water content, content of soluble organic carbon, form and concentration of nitrogen, biomass and activity of microbes in the surface soil at 0-10 cm depth were found to be the main contributors to ammonia volatilization. Application of bio-digested manure slurry in the vegetable field increased nitrogen loss through ammonia volatilization from DPS per se and its stimulative effect on decomposition of soil organic nitrogen. It is, therefore, essential to pay adequate attention to effects of temperature and application method in using bio-digested manure slurry as a soil amendment.
  • Authors:
    • Chung, S. O.
    • Choi, J. M.
    • Cho, Y. J.
    • Choi, C. H.
    • Lee, K. S.
    • Lee, D. H.
  • Source: KOREAN JOURNAL OF HORTICULTURAL SCIENCE & TECHNOLOGY Pages:
  • Volume: 30
  • Issue: 3
  • Year: 2012
  • Summary: Greenhouse industry has been growing in many countries due to both the advantage of stable year-round crop production and increased demand for fresh vegetables. In greenhouse cultivation, CO2 concentration plays an essential role in the photosynthesis process of crops. Continuous and accurate monitoring of CO2 level in the greenhouse would improve profitability and reduce environmental impact, through optimum control of greenhouse CO2 enrichment and efficient crop production, as compared with the conventional management practices without monitoring and control of CO2 level. In this study, a mathematical model was developed to estimate the CO2 emission from soil as affected by environmental factors in greenhouses. Among various model types evaluated, a linear regression model provided the best coefficient of determination. Selected predictor variables were solar radiation and relative humidity and exponential transformation of both. As a response variable in the model, the difference between CO2 concentrations at the soil surface and 5-cm depth showed are latively strong relationship with the predictor variables. Segmented regression analysis showed that better models were obtained when the entire daily dataset was divided into segments of shorter time ranges, and best models were obtained for segmented data where more variability in solar radiation and humidity were present (i.e., after sun-rise, before sun-set) than other segments. To consider time delay in the response of CO2 concentration, concept of time lag was implemented in the regression analysis. As a result, there was an improvement in the performance of the models as the coefficients of determination were 0.93 and 0.87 with segmented time frames for sun-rise and sun-set periods, respectively. Validation tests of the models to predict CO2 emission from soil showed that the developed empirical model would be applicable to real-time monitoring and diagnosis of significant factors for CO2 enrichment in a soil-based greenhouse.
  • Authors:
    • Reardon-Smith, K.
    • Mushtaq, S.
    • Maraseni, T. N.
  • Source: Journal of Environmental Management
  • Volume: 111
  • Year: 2012
  • Summary: The Australian Government is meeting the challenge of water scarcity and climate change through significant on-farm infrastructure investment to increase water use efficiency and productivity, and secure longer term water supplies. However, it is likely that on-farm infrastructure investment will alter energy consumption and therefore generate considerable greenhouse gas (GHG) emissions, suggesting potential conflicts in terms of mitigation and adaptation policies. In particular, the introduction of a price on carbon may influence the extent to which new irrigation technologies are adopted. This study evaluated trade-offs between water savings, GHG emissions and economic gain associated with the conversion of a sprinkler (hand shift) irrigation system to a drip (trickle) irrigation system for a lettuce production system in the Lockyer Valley, one of the major vegetable producing regions in Australia. Surprisingly, instead of trade-offs, this study found positive synergies - a win-win situation. The conversion of the old hand-shift sprinkler irrigation system to a drip irrigation system resulted in significant water savings of almost 2 ML/ha, as well as an overall reduction in GHG emissions. Economic modelling, at a carbon price of $ 30/t CO(2)e, indicated that there was a net benefit of adoption of the drip irrigation system of about $ 4620/ML/year. We suggest priority should be given, in the implementation of on-farm infrastructure investment policy, to replacing older inefficient and energy-intensive sprinkler irrigation systems such as hand shift and roll-line. The findings of the study support the use of an integrated approach to avoid possible conflicts in designing national climate change mitigation and adaptation policies, both of which are being developed in Australia.
  • Authors:
    • Boyd, N. S.
    • Brennan, E. B.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 3
  • Year: 2012
  • Summary: Long-term research on cover crops (CC) is needed to design optimal rotations. Winter CC shoot dry matter (DM) of rye (Secale cereale L.), legume-rye, and mustard was determined in December to February or March during the first 8 yr of the Salinas Organic Cropping Systems trial focused on high-value crops in Salinas, CA. By seed weight, legume-rye included 10% rye, 35% faba (Vicia faba L.), 25% pea (Pisum sativum L.), and 15% each of common vetch (V sativa L.) and purple vetch (V. henghalensis L.); mustard included 61% Sinapis alba L. and 39% Brassica juncea Czern. Cover crops were fall-planted at 1x and 3x seeding rates (SR); 1x SR were 90 (rye), 11 (mustard), and 140 (legume-rye) kg ha(-1). Vegetables followed CC annually. Cover crop densities ranged from 131 to 854 plants m(-2) and varied by CC, SR, and year. Year, CC, and SR affected DM production, however, the effects varied across the season and interactions occurred. Averaged across years, final DM was greater in rye and legume-rye (7 Mg ha(-1)) than mustard (5.6 Mg ha(-1)), and increased with SR through January. Dry matter production through the season was correlated significantly with growing degree days (GDD). Legumes contributed 27% of final legume-rye DM. Season-end legume DM was negatively correlated with GDD at 30 d, and legume DM in the 3x SR increased during years with frequent late-season rainfall. Seed costs per Mg of final CC DM at 1x SR were approximately three times higher for legume-rye than rye and mustard.