Role of Some Agricultural and Industrial By-products in Modifying Soil Physical Properties     

U. S. Gupta  Ram K. Gupta 《植物养料与土壤学杂志》1980,143(2):215-220

In a pot culture study, saw dust, vermiculite, lignite, magnesium oxide, wheat straw, paddy shell, ground nut shell and farm yard manure (FYM) were incorporated in to wet sandy loam and clay soils at the rate of 30 g/kg. Relative changes in soil structure and moisture retention were evaluated at the end of 160 day incubation period. All the amendments except vermiculite, ground nut shell and FYM in sandy loam soil and except vermiculite, lignite, magnesium oxide in clay soil significantly increased MWD and aggregates > 1 mm. Structural index was significantly improved by all the amendments except vermiculite and FYM in sandy loam and vermiculite and magnesium oxide in clay soil. Moisture retention and release in clay soil in the wet range (0 to 0.33 bar) were considerably increased by soil amendments except magnesium oxide, vermiculite and lignite. Almost all the amendments significantly increased moisture retention in the wet range in sandy loam soil. However, moisture release at 50 mbar was reduced only by wheat straw in sandy loam soil.  相似文献   

Occurrence and infectivity of arbuscular mycorrhizal fungi in some norwegian soils influenced by heavy metals and soil properties     

Corinne Leyval  Bal Ram Singh  Erik J. Joner 《Water, air, and soil pollution》1995,84(3-4):203-216

Mycorrhizae are ubiquitous symbiosis which can mediate uptake of some plant nutrients. In polluted soils they could be of great importance in heavy metal availability and toxicity to plants. Mycorrhizae have also been reported to protect plants against toxic metals. We investigated the occurrence and infectivity of arbuscular mycorrhizal (AM) spores as affected by heavy metal levels and other soil properties in Norwegian soils collected from heavy metal polluted, high natural background and non-polluted areas. Spore numbers, mycorrhizal infectivity and spore germination of indigenous mycorrhizal fungi and of a reference strain (Glomus mosseae) in soils showed lower values in two soils with high metal concentrations and in one soil with a low pH. Mycorrhizal infectivity was negatively correlated with extractable metals. Spore number and mycorrhizal infectivity in a soil with naturally high heavy metal content were not different to in non-polluted soils, and indigenous AM fungi appeared more tolerant to metals than those in non-polluted soils. Mycorrhizal infectivity, expressed as MSI₅₀ values, was significantly correlated (r′=0.89, P< 0.05) with the percentage of germinating G. mosseae spores in the soils. However, the number of spores per volume of soil was not significantly correlated with infectivity or spore germination of the reference strain. The spore germination method is discussed as a bioassay of heavy metal toxicity in soil.  相似文献   

Effect of the type of frying culinary fat on volatile compounds isolated in fried pork loin chops by using SPME-GC-MS     

Ramírez MR  Estévez M  Morcuende D  Cava R 《Journal of agricultural and food chemistry》2004,52(25):7637-7643

The effect of the type of frying culinary fat (olive oil, sunflower oil, butter, and pig lard) on volatile compounds isolated from fried pork loin chops (m. Longissimus dorsi) was measured by SPME-GC-MS. Frying modified the fatty acid composition of lipids from pork loin chops, which tended to be similar to that of the culinary fat used to fry. Volatile compounds formed from the oxidation of fatty acids increased, such as aldehydes, ketones, alcohols, and hydrocarbons. Besides, each culinary fat used modified the volatile profiles in fried meat differently. Sunflower oil-fried pork loin chops presented the highest aldehyde aliphatic content, probably due to their highest content of polyunsaturated acids. Hexanal, the most abundant aldehyde in fried samples, presented the most elevated content in sunflower oil-fried pork loin chops. In addition, these samples presented more heterocyclic compounds from the Maillard reaction than other fried samples. Volatiles detected in olive oil-fried pork loin chops were mainly lipid-derived compounds such as pentan-1-ol, hexanal, hept-2-enal, nonanal, decanal, benzaldehyde, and nonan-2-one. Butter-fried pork loins were abundant in ketones with a high number of carbons (heptan-2-one, nonan-2-one, undecan-2-one, tridecanone, and heptadecan-2-one). Pig lard-fried pork loin chops presented some Strecker aldehydes isolated in only these samples, such as 2-methylbutanal and 3-(methylthio)propanal, and a sulfur compound (dimethyl disulfide) related to Strecker aldehydes.  相似文献   

Incorporation of glucose-14C and NH4 + in microbial biomass of alkaline saline soil     

E. Ramírez-Fuentes  M. Luna-Guido  A. Ponce-Mendoza  E. Van den Broeck  L. Dendooven 《Biology and Fertility of Soils》2002,36(4):269-275

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Determination of phytohormones of environmental impact by capillary zone electrophoresis     

Segura Carretero A  Cruces-Blanco C  Soriano Peña M  Cortacero Ramírez S  Fernández Gutiérrez A 《Journal of agricultural and food chemistry》2004,52(6):1419-1422

A test mixture of five phytohormones [naphthaleneacetic acid (NAA), naphthoxyacetic acid (NOA), indoleacetic acid (IAA), indolebutyric acid (IBA), and indolepropionic acid (IPA)] was investigated. These compounds were cleanly separated with good resolution by capillary zone electrophoresis with a UV diode array detector using 20 mM sodium phosphate buffer (pH 7.25). The lowest detection limit was obtained for IPA (0.45 mg L(-)(1) or 0.005 mg kg(-)(1)) and the highest for NAA (1.04 mg L(-)(1) or 0.014 mg kg(-)(1)). The method has been applied for tomato samples fortified with the five phytohormones using a liquid-liquid extraction procedure, obtaining recovery percentages ranging from 91 to 109.0%.  相似文献   

Analysis of volatiles in porcine liver pâtés with added sage and rosemary essential oils by using SPME-GC-MS     

Estévez M  Ventanas S  Ramírez R  Cava R 《Journal of agricultural and food chemistry》2004,52(16):5168-5174

The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils) and one synthetic (BHT) on the generation of volatile compounds in liver patés from Iberian and white pigs was analyzed using SPME-GC-MS. Lipid-derived volatiles such as aldehydes [hexanal, octanal, nonanal, hept-(Z)-4-enal, oct-(E)-2-enal, non-(Z)-2-enal, dec-(E)-2-enal, deca-(E,Z)-2,4-dienal] and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace of porcine liver patés. Patés from different pig breeds presented different volatiles profiles due to their different oxidation susceptibilities as a probable result of their fatty acid profiles and vitamin E content. Regardless of the origin of the patés, the addition of BHT successfully reduced the amount of volatiles derived from PUFA oxidation. Added essential oils showed a different effect on the generation of volatiles whether they were added in patés from Iberian or white pigs because they inhibited lipid oxidation in the former and enhanced oxidative instability in the latter. SPME successfully allowed the isolation and analysis of 41 volatile terpenes from patés with added sage and rosemary essential oils including alpha-pinene, beta-myrcene, 1-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of liver patés.  相似文献   

Aggregate associated carbon, nitrogen and sulfur and their ratios in long-term fertilized soils   总被引：3，自引：0，他引：3  

Zhihui Yang  Bal Ram Singh  Sissel Hansen 《Soil & Tillage Research》2007,95(1-2):161-171

Farmyard manure (FYM) and fertilizer applications are important management practices used to improve nutrient status and organic matter in soils and thus to increase crop productivity and carbon (C) sequestration. However, the long-term effects of fertilization on C, nitrogen (N) and sulfur (S) associated with aggregates, especially on S are not fully understood. We investigated the effects of more than 80 years of FYM (medium level of 40 Mg ka⁻¹ and high level of 60 Mg ka⁻¹) and mineral fertilizer (NPKS and NK) on the concentrations and pools of C, N, and S and on their ratios in bulk soil, dry aggregates and water stable aggregates on an Aquic Eutrocryepts soil in South-eastern Norway. A high level of FYM and NPKS application increased the proportion of small dry aggregates (<0.6 mm) by 8%, compared with the control (without fertilizer). However, both medium and high level of FYM application increased the proportion of large water stable aggregates (>2 mm) compared with mineral fertilizer (NPKS and NK). The total C and N pools in bulk soils were also increased in FYM treatments but no such increase was seen with mineral fertilizer treatments. The increased total S pool was only found under high level of FYM application. Water stable macroaggregates (>2 and 1–2 mm) and microaggregates (<0.106 mm) contained higher concentrations of C, N and S than the other aggregate sizes, but due to their abundance, medium size water stable aggregates (0.5–1 mm) contained higher total pools of all three elements. High level of FYM application increased the C concentration in water stable aggregates >2, 0.5–1 and <0.106 mm, and increased the S concentration in most aggregates as compared with unfertilized soils. Higher C/N, C/S and N/S ratios were found both in large dry aggregates (>20 and 6–20 mm) and in the smallest aggregates (<0.6 mm) than in other aggregate sizes. In water stable aggregates, the C/N ratio generally increased with decreasing aggregate size. However, macroaggregates (>2 mm) showed higher N/S ratios than microaggregates (<0.106 mm). We can thus conclude, that long-term application of high amounts of FYM resulted in C, N and S accumulation in bulk soil, and C and S accumulation in most aggregates, but that the accumulation pattern was dependent on aggregate size and the element (C, N and S) considered.  相似文献   

Ultrasensitive detection of genetically modified maize DNA by capillary gel electrophoresis with laser-induced fluorescence using different fluorescent intercalating dyes     

García-Cañas V  González R  Cifuentes A 《Journal of agricultural and food chemistry》2002,50(16):4497-4502

In this work, four different fluorescent intercalating dyes are compared for the ultrasensitive CGE-LIF detection of DNA from transgenic maize in flours. The fluorescent intercalating dyes compared are YOPRO-1, SYBR-Green-I, Ethidium bromide (EthBr), and EnhanCE. For all the four dyes optimum concentrations are established, and efficient separations of DNA fragments ranging in size from 80 to 1000 bp are obtained. The comparative study demonstrates that SYBR-Green-I and YOPRO-1 provide better limits of detection (LODs) than EnhanCE or EthBr (i.e., LODs are, respectively, 700, 1000, 11300, and 97400 zmol, calculated for a 200-bp DNA fragment). Separations using YOPRO-1 are faster than those using SYBR-Green-I (30 min vs 47 min for the analysis of the 80-1000 bp DNA fragments). Also, separations using YOPRO-1 are more efficient than those using SYBR-Green-I (e.g., 2.4 x 10(6) plates/m vs 1.6 x 10(6) plates/m, respectively, calculated for the 200-bp fragment). Also, buffer depletion and cost per analysis are worse with SYBR-Green-I than with YOPRO-1. Therefore, YOPRO-1 was selected as the preferred intercalating dye. Using this fluorescent compound, analysis time reproducibility for the CGE-LIF separation of the DNA fragments is determined to be better than 1.7% (% RSD, n = 10) within the same day, and better than 1.9% (% RSD, n = 30) for three different days. Moreover, the fluorescence signal obtained using this dye is shown to vary linearly with the DNA concentration in the range studied, i.e., 1-500 ng/microL. It is demonstrated that by using this method 0.01% of transgenic maize can be detected in flour by direct injection of the PCR-amplified sample.  相似文献   

Quantitative Measurement of Organic Carbon in Mine Wastes: Methods Comparison for Inorganic Carbon Removal and Organic Carbon Recovery     

Fang You  Ram Dalal  David Mulligan 《Communications in Soil Science and Plant Analysis》2015,46(4):375-389

The present study aims to evaluate carbon recovery and analytical precision of two methods based on dry combustion for organic carbon (OC) quantification in base metal mine tailings: (1) IC subtraction method (inorganic C(IC) measured and subtracted from total C) and (2) direct OC quantification after acid pretreatment. Results showed IC subtraction method effectively hydrolyzed a range of IC minerals [calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), dolomite, magnesite, calcite] with satisfactory IC (as CO₂ released) recovery (87–103 percent). In the direct OC quantification method, 5 M hydrochloric acid (HCl) pretreatment resulted in a satisfactory recovery (76–92 percent) of most organic compounds [ethylenediaminetetraacetic acid (EDTA), cellulose, plant litter, and charcoal], except for water-soluble OC (sucrose, 40 percent recovery). The precision of both methods declined when C levels were <5 g kg^?1 with RSD (Relative Standard Deviation) > 10 percent. The OC values in test samples of base metal mine tailings were comparable between the two methods. However, IC subtraction method is not applicable for tailings with low OC levels (<5 g kg^?1) until the precision is substantially improved. Moreover, compared to the IC subtraction method, OC values are significantly lower in direct OC quantification method for tailings with high OC levels.  相似文献   

Effect of transpiration on iron uptake and translocation in lowland rice   总被引：1，自引：0，他引：1       下载免费PDF全文

Ram K. Shrestha  Katrin Engel  Mathias Becker 《植物养料与土壤学杂志》2015,178(3):365-369

We evaluated six lowland rice (Oryza sativa L.) genotypes with contrasting responses to increasing Fe²⁺ concentrations under conditions of both low (0.3 kPa) and high (2.4 kPa) vapor pressure deficit. Dry atmospheric conditions generally enhanced transpiration with concomitant increases in Fe uptake and leaf bronzing. Some resistant genotypes were able to limit the water loss by transpiration under higher Fe concentrations thus attenuating negative effects associated with increased Fe²⁺ translocation at high vapor pressure deficit.  相似文献