摘要:

The efficacy of 10 ppm phenylmercuric acetate (PMA), 2N KCl and 0.02N CuSO4in suppressing ammonification, denitrification and CO2accumulation was studied during short‐term anaerobic incubations of three soils at 25 C. KCl and CuSO4almost completely suppressed ammonification in two of the soils and decreased it markedly in the third. Ammonification was suppressed to a lesser extent by the addition of PMA. The KCl treatment was much more effective than either PMA or CuSO4in preventing NO3‐disappearance and denitrification. Appreciable amounts of NO3‐disappeared from the soils treated with PMA and CuSO4. N2and not N2O was the major denitrification product; the suppressors had only a small effect on N2O accumulation. The influence of the chemicals on CO2accumulation differed according to the soil. CuSO4was least effective at depressing the accumulation of CO2, and, in fact, stimulated it in one soil. Neither 0.02N CuSO4nor PMA (10 ppm) is recommended in the absence of a concentrated salt solution for preventing mineral nitrogen changes during extraction of inorganic soil nitrogen. The value of 2N KCl in suppressing such changes is emphasized by the results of the present study.

ISSN:0010-3624    

DOI:10.1080/00103627209366400

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Interference and recovery tests reported indicate that the Orion ammonia electrode can be used satisfactorily for determination of ammonium in soil extracts and water samples. The electrode method of analysis described is rapid, simple, and precise, and its results agree closely with those obtained by a distillation‐titration method of determining ammonium in soil extracts and water samples.

ISSN:0010-3624    

DOI:10.1080/00103627209366401

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Investigations were conducted to determine the cause of severe leaf quality deterioration of cigar wrapper tobacco in the Georgia‐Florida area. Studies indicated that Fe was associated with “purple leaf”;, a term used to describe brittle, tender, dark brown to purple cured leaves which have poor burning characteristics and an undesirable flavor. Excessive Fe was found to be absorbed by the leaves with some adsorbed on the surface of leaves following irrigation with pond water containing an excess of 1.5 ppm Fe. Iron content of the water was highest in ponds having an excessive growth of aquatic plants or in those that were pumped to a level where overflow was restricted.

ISSN:0010-3624    

DOI:10.1080/00103627209366402

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The NO3levels in cantaloupe (Cucumis meloL.) petioles relate closely to N treatment and reflect the N status of the cantaloupe plant. Suggested levels of petiole NO3in cantaloupes grown in Arizona are presented. Nitrogen treatment had little effect on melon size, earliness, or most storage quality factors that were evaluated except that deficiencies resulted in lower netting, poor general appearance and an increase in cull melons.

ISSN:0010-3624    

DOI:10.1080/00103627209366403

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The boron sorption isotherm method of soil testing may provide an estimate of the fertilizer required to bring the soil to an optimum boron level. Data from the boron isotherm experiment suggests that at low concentrations a plot of added boron vs equilibrium solution boron will be linear. The boron concentration at which this plot becomes linear will depend on the characteristics of the soil tested. The data, from this and other studies, suggest that 0.5 ppm boron in the equilibrium solution should be the approximate upper limit of boron concentration where this relationship is linear. Since boron added is linear with respect to boron in equilibrium solution, boron fertilizer required to adjust the equilibrium solution concentration can be calculated from the least squares regression equation of these two variables. This fertilizer requirement can only be determined when the optimum level of boron in equilibrium solution is known. Thus, further study is needed to establish this optimum level for all plant species.

ISSN:0010-3624    

DOI:10.1080/00103627209366404

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

NPK was applied to a Haynie, very fine, sandy loam as 89.6 MT/ha (40 T/ac) of OF (organic fertilizer as feedlot manure at 45% water content) and as MF (mineral fertilizer) with nutrients equivalent to the manure during 18 months.

ISSN:0010-3624    

DOI:10.1080/00103627209366405

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The influence of reaction time and ionic environments, on phosphate adsorption were studied using one calcareous soil from India, and one calcareous and two latosols from Hawaii.

ISSN:0010-3624    

DOI:10.1080/00103627209366406

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Selected organic and mineral analyses of common beans, peanut kernels, and cowpeas were determined. Simple correlations were computed between organic and mineral components to investigate possible linear relationships that might be useful. Most correlations between mineral and organic components were negative, and relatively low coefficients of determination (r2) indicated little merit in attempting to predict organic components from inorganic compositions and sample linear models. A positive correlation between stachyose and the N content of common beans was observed.

ISSN:0010-3624    

DOI:10.1080/00103627209366407

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The relationship between corn yield and nutrient composition of whole plants at two stages of growth, and between corn yield and nutrient composition of different plant parts at early tassel was investigated. It was found that chemical composition of plants about 10 inches in height was more closely associated with yield than chemical composition when plants were about 30 inches high. Chemical composition of lower stalk or lower leaves was more closely associated with yield than was the composition of other plant parts.

ISSN:0010-3624    

DOI:10.1080/00103627209366408

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627209366399

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor