摘要:

The design, materials and dimensions for constructing a coring device for sampling soil fauna and flora at different depths is described.

ISSN:0010-3624    

DOI:10.1080/00103628609367735

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A wide range of synthetic and natural materials can act as amendments to enhance soil physical properties. Novel materials purporting to be conditioners need to be agronomically evaluated prior to adoption for general use. Of particular concern in semi‐arid regions are those that influence water relations in sandy soils. A polyacrylamid hydrogel, “Aquastock”, was tested in the laboratory for moisture retention under varying environments to simulate field conditions, and in relation to soil properties. A companion greenhouse study considered the influence of both rate and method of application on cucumber yield, and on irrigation frequency. The material increased available water and reduced permeability, especially in the sandy soil. Moisture release under varying soil pressure or matric potential was favorably influenced by the conditioner. The material significantly increased fruit yield and related crop parameters as well as reducing the number of irrigations required; complete mixing with the soil volume was more effective than partial mixing. “Aquastock” appears to have potential in semi‐arid areas and with protected high value cropping. Commercial and economic evaluation is warranted.

ISSN:0010-3624    

DOI:10.1080/00103628609367736

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This study was conducted to measure season‐long uptake of P by corn grown under no‐till and conventional‐till management at three levels of P supply‐low, adequate, and high as defined by grain yield‐to test the feasibility of using whole‐plant P uptake as an indicator of the P supply in soil; and to calibrate soil P extractable with both Mehlich No. 1 (HC1 + H2SO4) and Mehlich No. 2 (HC1 + H2SO4+ NH4F) versus whole‐plant P uptake over the response region.

ISSN:0010-3624    

DOI:10.1080/00103628609367737

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Calcium analysis ofCucurbitaembryos was carried out on samples dry‐ashed in porcelain crucibles. The atomic absorption procedure gave precise and repeatable results for most sample sizes but very small samples in the range 0.025–0.05 g persistently gave higher measured Ca concentration. The problem originated from an interaction of the sample with the crucibles and was manifested in small samples because of the increased surface contact between the samples and the crucibles. The interaction produced a change in the ash mineral complement relative to that of the larger samples and this change resulted in enhanced Ca signal in atomic absorption analysis.

ISSN:0010-3624    

DOI:10.1080/00103628609367738

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

All cucurbit embryos analyzed showed a decrease in the ease with which calcium could be extracted from the ash as the ashing temperature increased beyond 600°C. After ashing at 500°C, the Ca in the cucurbit ash was fully extracted by 5% o HC1. After 650°C ashing, lower than expected Ca levels were obtained unless additional ash treatment with HNO3and HC1 was applied. Castor bean embryos plus endosperm showed the same effect but other oily embryos tested did not need ash treatment to fully extract Ca from either the 500 or 650°C ash. Neutron activation analysis indicated that the differences in ash characteristics were related to the differences in concentrations of K and P in the embryo tissues.

ISSN:0010-3624    

DOI:10.1080/00103628609367739

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

While occlusion of the elements in the carbonaceous ash residue has been found to be a problem, calcium is more readily extracted from the black ash containing 11% carbon than from the light gray, carbon free ash ofCucurbita maximaandCucurbita andreanaembryos. The temperature of 600° C seems to be the point at which a change in the ash occurs. At and above 600° C ash samples require additional digestion with dilute nitric and hydrochloric acids before giving the correct calcium levels. Plant materials such as NBS Tomato Leaves and Wheat Flour standards do not show a change in ash solulility at higher ashing temperatures.

ISSN:0010-3624    

DOI:10.1080/00103628609367740

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Five colorimetric methods; alzarin red, aluminon, catechol violet, ferron and 8‐hydroxyquinoline, and AAS were compared for measuring aluminium in KCl extracts of soils. An analysis of variance of the results against soils, methods and replicates showed that, apart from the predictably large soil effect, the three two‐way interactions and the method effect gave small but statistically significant differences.

ISSN:0010-3624    

DOI:10.1080/00103628609367741

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The objective of this study was to evaluate a fluxing salt residue (slag) produced 1n large quantities by a Mg reclamation process as a potential K‐Mg nutrient source (41% KC1, 33% MgO and 3.2% MgCl2) for cereal crops 1n the Pacific Northwest. Field studies were conducted at Sandpoint, Idaho in 1983 and 1984 to evaluate this fluxing salt residue on the following three criteria: (1) potential phytotoxicity problems associated with plant growth, (2) response (yield) of spring wheat (Triticum aestivumL.), spring barley (Hordeum vulqareL.) and oats (Avena sativaL.), and (3) comparison with commercial K and Mg fertilizers.

ISSN:0010-3624    

DOI:10.1080/00103628609367742

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103628609367734

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor