摘要:

The determination of chloride ion in soil extracts for cation exchange capacity in the presence of ammonium ions of nearly equal concentration (∼5 x 10‐2M) and excess sodium sulphate (0.5 M) by an Orion solid state selective ion electrode is reported. Ammonium ions were found to interfere by reducing the determined value of the chloride ion by up to 20%. This interference effect was compensated by the determination of a mean activity coefficient for ammonium chloride in the sodium sulphate medium. This method was accurate to ±7%. No interference effect was found for the chloride ion determination of a mixed sodium chloride‐sodium sulphate solution.

ISSN:0010-3624    

DOI:10.1080/00103627409366475

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The occurrence of blossom‐end rot of tomatoes is correlated with a low Ca content. The disease incidence can be aggravated by water stress. An attempt was made to study the effects of water stress under conditions of equal concentration of ions by addition of polyethylene glycol in water culture. These treatments gave a higher incidence of blossom‐end rot and withering of the plant tops. Although direct effects of water stress on blossom‐end rot cannot be excluded a restricted uptake of most ions was demonstrated, Mg excepted. Calculation of the indexes (K+Mg)/Ca for uptake and for the leaf show that under influence of osmotic stress the relative Ca‐content is indeed lowered.

ISSN:0010-3624    

DOI:10.1080/00103627409366476

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627409366477

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Suggestions are made for the elimination of some interferences with the azomethine‐H method for boron analysis of soil extracts, leaves, plants, manures, composts, nutrient solutions and irrigation waters.

ISSN:0010-3624    

DOI:10.1080/00103627409366478

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The objective of this study was to ascertain variability with multiple analyses by emission spectrography for 24 different elements in samples of plant material. The plant materials were obtained from plants grown to give a wide range in concentrations for each of the 24 elements. The coefficient of variation was obtained for each sample and each element for six analytical replicates. In general, the coefficient of variation was increased when concentrations of elements were very low. The coefficient of variation was generally around 10% or less in the range of most interest for most of the essential elements. For some nonessential elements, the coefficient of variation was 20 to 50% and the variability was due mostly to low concentrations near the limits of detectability.

ISSN:0010-3624    

DOI:10.1080/00103627409366479

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Ammonium nitrogen in animal slurries can be determined using an Orion ammonia electrode. Dilute hydrochloric acid (0.1N HCl) is used to extract the ammonium nitrogen from the slurries. The electrode method of analysis is simple, rapid and precise and gives quantitative recovery of added ammonium. Results agree closely with the standard steam distillation‐titration method.

ISSN:0010-3624    

DOI:10.1080/00103627409366480

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A field experiment was conducted to determine the effects of fertilization and irrigation on the yield and chemical composition of corn (Zea mays L.) and on the available soil K. The soil type was Davidson clay loam. Five rates of N, P, and K were applied annually. All plant residue was removed from the plots each year when the corn was harvested.

ISSN:0010-3624    

DOI:10.1080/00103627409366481

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627409366473

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor