The impact of agriculture on regional air quality creates significant challenges to sustainability of food supplies and to the quality of national resources. Agricultural emissions to the atmosphere can lead to many nuisances, such as... more
The impact of agriculture on regional air quality creates significant challenges to sustainability of food supplies and to the quality of national resources. Agricultural emissions to the atmosphere can lead to many nuisances, such as smog, haze, or offensive odors. They can also create more serious effects on human or environmental health, such as those posed by pesticides and other toxic industrial pollutants. It is recognized that deterioration of the atmosphere is undesirable, but the short‐ and long‐term impacts of specific agricultural activities on air quality are not well known or understood. These concerns led to the organization of the 2009 American Chemical Society Symposium titled Managing Agricultural Gas and Particle Emissions. An outcome of this symposium is this special collection of 14 research papers focusing on various issues associated with production agriculture and its effect on air quality. Topics included emissions from animal feeding operations, odors, volat...
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Author: Tanji, Kenneth K, University of California, Davis Dahlgren, Randy A, University of California, Davis Ong, Colin, University of California, Davis Herbel, Mitchell, University of California, Davis Quek, Ann, University of... more
Author: Tanji, Kenneth K, University of California, Davis Dahlgren, Randy A, University of California, Davis Ong, Colin, University of California, Davis Herbel, Mitchell, University of California, Davis Quek, Ann, University of California, Davis Gao, Suduan, University of ...
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Research Interests: Environmental Science, Geochemistry, Arsenic, Agriculture, Evaporation, and 15 moreEnvironmental Chemistry, Medicine, Multidisciplinary, Dissolved organic matter, Metals, Dissolved Oxygen, Geologic Sediments, Arsenates, Arsenicals, Cacodylic Acid, Arsenate, Chlorides, High risk, Biogeochemical Cycle, and Arsenites
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Knowledge of carbon (C) and nitrogen (N) dynamics under different irrigation practices in pomegranate orchards is novel and essential to develop sustainable production systems. The aim of this research was to determine the effect of... more
Knowledge of carbon (C) and nitrogen (N) dynamics under different irrigation practices in pomegranate orchards is novel and essential to develop sustainable production systems. The aim of this research was to determine the effect of high-frequency drip irrigation and different rates of N fertilizer on C and N distribution in the soil and N uptake by pomegranate fruit and leaves. The main treatments were surface drip irrigation (DI) and subsurface drip irrigation (SDI), and the sub-treatments used were three initial N rates (N1, N2, and N3). As trees grew larger, the N application rate increased. From 2013–2015, trees received the following rates of N: 62–113 (N1), 166–263 (N2), or 244–342 kg/ha (N3). Soil and leaf total C (TC) and N (TN), soil dissolved organic C (DOC), soil nitrate (NO3−), and total N uptake by fruit were evaluated between 2012 and 2015. Soil samples were collected to 120 cm depth at 15 cm increments. DI resulted in higher concentrations of TN, TC, NO3−, and DOC in...
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Methyl bromide has been used extensively in open-field perennial crop nurseries to ensure the production of plants that are free of soilborne pests and pathogens. California regulations require that nursery stock for farm planting be... more
Methyl bromide has been used extensively in open-field perennial crop nurseries to ensure the production of plants that are free of soilborne pests and pathogens. California regulations require that nursery stock for farm planting be commercially clean with respect to economically important nematodes. Under the terms of the Montreal Protocol, the use of methyl bromide by developed countries was phased out 1 Jan. 2005. Although the perennial nursery industry in the United States largely continues to use methyl bromide under critical use exemptions and quarantine/preshipment criteria allowed under provisions of the Montreal Protocol, nursery growers need viable alternatives to this fumigant. Two fumigation trials in perennial crop field nurseries with sandy loam and clay loam soils, respectively, were conducted to compare the efficacy of fumigants applied through standard shank-injection equipment or as emulsifiable compounds applied through drip irrigation equipment. In the garden ro...
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Field studies were conducted to evaluate potential alternatives to methyl bromide (MBr) for the control of plant parasitic nematodes in shallow-rooted, bedded cropping systems such as strawberry and in perennial nursery cropping systems... more
Field studies were conducted to evaluate potential alternatives to methyl bromide (MBr) for the control of plant parasitic nematodes in shallow-rooted, bedded cropping systems such as strawberry and in perennial nursery cropping systems in central California. Chloropicrin (Pic), 1,3-dichloropropene (1,3-D or Telone), combinations of 1,3-D + Pic, iodomethane (IM) + Pic, propargyl bromide (PBr), and metam sodium (MS) were compared with untreated controls and industry standard MBr/Pic treatments. Materials were applied by both shank-injection and drip-application, except MS and PBr, which were applied only by drip. The efficacy on citrus nematode (Tylenchulus semipenetrans Cobb) and/or root-knot nematode (Meloidogyne spp. Chitwood) control was investigated in three trials conducted on soils ranging from sandy loam to silty clay loam. All treatments controlled nematodes near the injection point (center of bed and moderate depths) comparable to MBr/Pic. Drip-applied Pic provided somewhat...
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Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has... more
Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dynamics and N changes in soil profile (0-100 cm) were examined during 1990-2009 under chemical fertilization, manure incorporation with fertilizer, and fertilizer with straw return treatments. We employed a mass balance approach to estimate the N loss to the environment after taking into account soil N change. Results showed a significant increase in soil N storage under manure incorporation treatments, accompanied with the lowest N loss (ave.20-24% of total N input) compared to all other treatments (ave.35-63%). Both soil N distribution and mass balance data suggested higher leaching risk from c...
Research Interests: Environmental Science, Agronomy, Medicine, Straw, Nitrogen, and 3 moreFertilizer, Soil Fertility, and Manure
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Research Interests: Environmental Science, Chemistry, Air Quality, Irrigation, Pesticide Residues, and 15 moreEnvironmental Pollution, Medicine, Multidisciplinary, Emission reduction, Pesticides, Potassium, Pest control, Chloropicrin, Field Study, High Density Polyethylene, Environmental Pollutants, Amendment, Bare Soil, fumigation, and Field Test
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Research Interests: Earth Sciences, Environmental Science, Chemistry, Agriculture, Medicine, and 15 moreBiological Sciences, Environmental Sciences, Emission reduction, Pesticides, Cost effectiveness, Polyethylene, Chloropicrin, Environmental quality, High Density Polyethylene, Environment Quality, Soil Water, Soil Pollutants, Emission rate, fumigation, and Soil Fumigation
Research Interests: Earth Sciences, Environmental Science, Chemistry, Irrigation, Agriculture, and 15 moreEnvironmental Monitoring, Medicine, Biological Sciences, Insecticides, Environmental Sciences, Animals, Drip Irrigation, Chloropicrin, Environmental quality, Management Practice, Nematoda, High Density Polyethylene, Environment Quality, Air Pollutants, and fumigation
Research Interests: Earth Sciences, Environmental Science, Medicine, Biological Sciences, Environmental Sciences, and 14 morePest control, Chloropicrin, Soil Temperature, Environmental quality, Field Trial, San Joaquin Valley, High Density Polyethylene, Environment Quality, Soil Profile, Soil Water, Soil Pollutants, fumigation, Field Test, and Soil Fumigation
Research Interests: Earth Sciences, Chemistry, Soil, Carbon, Environmental Chemistry, and 15 moreMedicine, Biological Sciences, Environmental Sciences, Humic acid, Fulvic acid, Environmental quality, Total Organic Carbon, Soil Organic Carbon, Dissolved Organic Carbon, Organic carbon, Sodium Hydroxide, Peat Soil, Trihalomethanes, Organic Chemicals, and Fractional Derivative
Research Interests: Earth Sciences, Chemistry, Carbon, Filtration, Environmental Chemistry, and 15 morePublic Health, Medicine, Biological Sciences, California, Environmental Sciences, Drinking Water, Environmental quality, Electrolytes, Total Organic Carbon, Chlorine, Organic C, Soil Water, Electrolyte, Organic Chemicals, and Soil Pollutants
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Research Interests: Chemistry, Carbon, Environmental Chemistry, Medicine, Multidisciplinary, and 15 moreCalifornia, Drinking Water Treatment, Drinking Water, Conceptual Model, Dissolved organic matter, Soil organic matter, Electrolytes, Soil Organic Carbon, Dissolved Organic Carbon, Organic carbon, Organic Matter, Peat Soil, Electric Conductivity, Soil Water, and Soil Pollutants
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Research Interests: Environmental Engineering, Environmental Science, Air Quality, Irrigation, Agriculture, and 15 moreAtmospheric sciences, Pesticide, Soil moisture, Pesticides, Chloropicrin, Water Content, Soil Water Content, Soil Water, Field capacity, Volatilization, Cumulant, Fungicide, Atmospheric Environment, fumigation, and Soil Fumigation
Agricultural drainage from Delta islands is known to be a significant contributor of DOC (Dissolved Organic Carbon) that forms TI-IMs (Trihalomethanes) when drinking water is chlorinated. The current agricultural practices create seasonal... more
Agricultural drainage from Delta islands is known to be a significant contributor of DOC (Dissolved Organic Carbon) that forms TI-IMs (Trihalomethanes) when drinking water is chlorinated. The current agricultural practices create seasonal wet-dry cycles in ...