摘要:

Nine K‐rich soils belonging to three Orders often found in Southern Italy (Inceptisol, Alfisol, Vertisol) were extracted with H2O, CaCl2, NH4OAc, HCl, Mehlich, HNO3reagents for K and the results were compared to the EUF method. Significant correlations between the reagent extracted K and EUF K were found. The results allowed us to distinguish three basic K fractions: (i) actually available, (ii) quickly released reserve and (iii) slowly released reserve. The EUF provided both quantitative and qualitative data, suitable for a “dynamic” diagnosis of K soil fertility saving time and reagents. The EUF curves showed an unexpected strong K affinity for Inceptisol, the soil which was richest in K.

ISSN:0010-3624    

DOI:10.1080/00103628809367936

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Surface charge characteristics of several Spanish Andosols were investigated. The relationship between these characteristics and the mineralogical composition and organic matter content of the soils were also taken into account.

ISSN:0010-3624    

DOI:10.1080/00103628809367937

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The CEC of various Spanish soils derived from volcanic ashes was determined by using different procedures: (1) displacement with 1N NaOAc, pH 8.2 (2) effective CEC determined as the total exchangeable bases displaced with NH4OAc plus exchangeable Al extracted with 1N KCl and (3) compulsive exchange of Mg for Ba.

ISSN:0010-3624    

DOI:10.1080/00103628809367938

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Black walnut foliage samples collected from a wide range of sites during a national survey of the New Zealand (NZ) resource conducted in 1979 were analysed for N, P, K, Ca, Mg, B, Fe, Mn, and Zn. Provisional American standards applied to the foliar data indicate that only very small proportions of the field population (individually 1 to 2%) have foliar levels of N, P, Fe, Mn, or Zn rating deficient. For K, Ca, Mg, or B foliar levels consistently exceeded the deficiency threshold. The proportions of the population rating intermediate were very large (40 to 95%) for certain elements (P, Mg, Fe, Zn), and fairly large (16 to 27%) for the remainder. In this transitional bracket response to fertiliser is uncertain. As the applicability of the American criteria to NZ conditions is unproven, this evaluation must remain tentative.

ISSN:0010-3624    

DOI:10.1080/00103628809367939

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An inter‐laboratory study was conducted to determine the variability of three aglime analysis methods. The methods evaluated were; total Ca and Mg analysis, neutralization of 0,5 mol dm‐3HCl and a resin suspension method. It was found that the resin suspension method not only significantly gave the best reproducibility between laboratories, but it proved to be the most discriminatory between samples, as it is sensitive to all aspects involved, such as fineness, chemical purity and other physical properties.

ISSN:0010-3624    

DOI:10.1080/00103628809367940

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Soils in the Appalachian region are acidic and many have chemical properties which may inhibit the initiation of clover‐Rhizobium leguminosarumbiovartrifoliisymbiosis. The influence of soil properties on nodulation by, and competition between, an introduced strain (162X95) and a naturalized strain (WV22) ofRhizobium trifoliiwere studied in limed and unlimed portions of 10 subsoil horizons. Rhizobial strains were inoculated alone or in a 1:1 mixture in liquid form on germinating subterranean clover (Trifolium subterraneumL.). Nodulation by both strains was inhibited in soils with a combination of toxic properties: pH (1:1 H2O) 4.37 to 4.46, Ca saturation 1.1 to 9.2 %, and Al saturation 54.2 to 82.6 %. In the competition experiment strain 162X95 was detected in nodules by enzyme‐linked immunosorbent assay (ELISA) using a monoclonal antibody. Soil and soil solution chemical properties which were correlated with percent nodule occupancy by strain 162X95 were soil pH (1:1 H2O), soil solution pH, Al saturation, exchangeable Al, soil solution total Al, and soil solution reactive Al (as measured by 8‐hydroxyquinoline) (p ≤0.05). Soil pH gave the best estimate of nodule occupancy by strain 162X95 using a second order polynomial: % nodule occupancy = ‐481.40 + 176.05 soil pH ‐ 14.28 soil pH2(r2= 0.62**).

ISSN:0010-3624    

DOI:10.1080/00103628809367941

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A direct extraction method to estimate both soil microbial C and N, using a single extractant and chemical digestion stage was evaluated. Soils were fumigated overnight with EtOH‐free CHCl3, the CHCl3removed, and the soils extracted in 0.5MK2SO4. The flush of microbial C, measured as organic C, and microbial N, measured as NH4‐N, were estimated after acid‐dichromate treatment of the soil extract.

ISSN:0010-3624    

DOI:10.1080/00103628809367942

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The impact of a water treatment sludge on the fertility of a silt loam soil was assessed by monitoring the yield and elemental composition of tomato(Lycopersicon esculentum) shoots in a greenhouse study. Application of sludge at rates from 2–10% (air dry weight basis) raised the soil pH from 5.3 to 8.0 which enhanced plant growth. A substantial reduction in metal (Cd, Zn, Cu, Ni) uptake was observed with sludge amendments, even at the highest rates. The alkaline nature of this sludge (pH=9.3, calcium carbonate equivalence=53%) suggests its potential use as a liming material for agricultural soils. Overly alkaline conditions should be avoided however, as high application rates combined with ammonia fertilization had an antagonistic effect on plant growth, possibly from P deficiency induced by struvite (MgNH4PO4) formation.

ISSN:0010-3624    

DOI:10.1080/00103628809367943

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103628809367935

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor