摘要:

The frequent concentration‐ranges of various nutrient elements in soils and in plants are compared. Iron is different from almost all other nutrient elements in the fact that its optimal concentration range in plants is much lower than its frequent concentration range in soils. It is suggested that this observation is related to a chemical‐physiological mechanism of control on the uptake of iron by plants which in turn may explain the situations in which iron deficiency conditions in plants arise.

ISSN:0010-3624    

DOI:10.1080/00103627209366365

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Brucine, an organic reagent used for nitrate determinations, proved stable for at least one year when dissolved in methanol. This makes possible a consistently accurate and rapid method for field determinations of nitrate in clear solutions with a minimum of equipment. The method is also useful in the laboratory for determining nitrate in water or soil extracts. It is quicker and simpler than other colorimetric methods and more sensitive to low concentrations than the nitrate electrode.

ISSN:0010-3624    

DOI:10.1080/00103627209366366

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A field experiment was conducted to determine whether Zn applied for pathogen control could accumulate to a level which would be toxic to snapbeans, cucumbers, or corn. Zinc sulfate (ZnSO4) was applied at rates varying from 0 to 363 kg Zn/ha on a Flainfield loamy sand to approximate 3, 9, 27 and 81 years of fungicidal treatment.

ISSN:0010-3624    

DOI:10.1080/00103627209366367

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Adsorption of a small amount of P by soil from a solution, which delivers concentrations approximating the composition of soil solution systems, was measured for a heterogeneous group of 343 soils using32P‐labelled KH2PO4solution. The method allowed accurate determination of small quantities of P and identified the P under consideration as that added from solution. Simple correlations and stepvise linear regression analyses indicated that soil pH, Ca, P, Al, Fe, organic matter and particle size significantly influenced the amount of P adsorbed by the soils.

ISSN:0010-3624    

DOI:10.1080/00103627209366368

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Methylation of carboxyl groups reduced the cation exchange capacity of plant roots to almost zero. Deamination of the roots did not affect their cation exchange capacity.

ISSN:0010-3624    

DOI:10.1080/00103627209366369

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An established stand of alfalfa (Medicago sativaL.) was topdressed with two rates each of borax, zinc sulfate, and copper sulfate at two levels of applied P and K. Yields and plant composition were determined at five harvests over two seasons. Treatments were not effective in increasing yields but topdressing with B and Zn increased the concentration of these elements in the plant tissue. The Cu concentration in alfalfa tissue was not affected by topdressing with copper sulfate. Phosphorus application rates of about four times removal rates were needed to maintain the Bray 2 soil test level of the soil.

ISSN:0010-3624    

DOI:10.1080/00103627209366370

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

One‐year‐old slash pine seedlings (Pinus elliottiiEngelm.) accumulated more radioactive phosphorus in needles at a 15–10°C day‐night temperature and 2500 foot candles than at higher temperatures and reduced light. Rate of phosphorus uptake was related to concentrations of ethanol‐soluble carbohydrates but not to those of starch or all carbohydrates. Results suggest that temperature and light can be important for optimum phosphorus nutrition of slash pine.

ISSN:0010-3624    

DOI:10.1080/00103627209366371

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Corn (Zea maysL.) was grown for five consecutive years on Cecil fine sandy loam to measure the effects of irrigation and fertilization on leaf composition, yields, and on the changes in available K in the soil. Plant nutrients consisting of 0, 56, 140, 224 and 280 kg N/ha: 0, 15, 37.5, 60 and 75 kg P/ha, and 0, 28, 70, 112 and 140 kg K/ha were applied in a central composite rotatable design in each of the five years. All plant residue was removed each year when the corn was harvested and the plots were seeded without fertilization to rye each year as a cover crop. One‐half of the experiment was irrigated when there was a 50% depletion of available soil moisture in the 0‐ to 45‐cm soil depth.

ISSN:0010-3624    

DOI:10.1080/00103627209366372

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Elemental analyses of soybean leaf tissue from B & Mn field studies Indicate that washing tissue in deiontzed water did not appreciably change the concentration of most elements in the tissue. An exception was N which was decreased 0.54 per cent for one location and 0.33 per cent for the average of 3‐ sites when washed in deionized water prior to analyses. Although the tissue did not Indicate appreciable change tn K content when washed, the water In which the tissue had been washed Increased In K content by 6 ppm. The content of four of the micro elements in the plant tissue was affected by washing as compared to the unwashed samples. Mo and Ni were decreased while Zn andCuwere Increased.

ISSN:0010-3624    

DOI:10.1080/00103627209366373

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Supplemental N fertilization significantly increased survival and yield of Elberta peach trees growing in a severe decline area. There was a trend for supplemental N plus dolomitic lime to give further increases in tree survival and individual tree yields but did not significantly influence nutrient content of leaves. Trees did not respond to peach root residue applications.

ISSN:0010-3624    

DOI:10.1080/00103627209366374

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor