摘要:

A digestion mixture suitable for the decomposition of soil and plant materials is described. This is based on sulphuric acid and hydrogen peroxide as oxidants with the addition of lithium sulphate to elevate the digestion temperature and selenium as catalyst. The subsequent solution is suitable for the determination of nitrogen, phosphorus and most mineral ions. A series of tests have been carried out to determine optimum conditions and check elemental recoveries and the procedure is compared with alternative systems.

ISSN:0010-3624    

DOI:10.1080/00103627509366539

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Total concentration of Ca in the foliage samples of several tree species in forestry was determined by HCl extraction of ashed samples and ammonium EDTA extraction of un‐ashed samples. The results for ammonium EDTA extracts without the addition of La were comparable with the commonly employed method for HCl extracts with La addition when air‐acetylene flame was used for atomic absorption analysis.

ISSN:0010-3624    

DOI:10.1080/00103627509366540

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Container soil water relations are reviewed relative to the extrapolation of container experiments to the field. The use of soil mixtures for the experimental control of container soil water relations is also discussed.

ISSN:0010-3624    

DOI:10.1080/00103627509366541

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Elemental concentrations were determined in leaflets of a living, intact bushbean plant by x‐ray fluorescence analysis. Precision levels were limited principally by the counting statistics, although other considerations were discussed. Some significant changes in elemental content were associated with heat treatment. Following heat treatment there was an increased concentration of K, Ca, Zn, and Br, decreased concentration of Fe, and unchanged concentrations of Mn and Cu. There were no significant differences in mobility rates following heat treatment. However, there seemed to be different degrees of elemental mobility in the leaflets.

ISSN:0010-3624    

DOI:10.1080/00103627509366542

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The effect of NaCl salinities of 1 atm. and less on elemental relationships in bean leaves was determined in situ by α‐induced x‐ray fluorescence. The method was excellent for detecting light Z elements ranging from 10 to 22. The results showed that Mg and P levels were good indicators of 0.5 atm NaCl salinity, whereas Cl concentration was a good indicator of at least 1.0 atm NaCl salinity. Mg and P levels decreased, whereas Cl level increased with increasing salinities. S,K, and Ca levels were not affected by low salinities. Leaves from both control and test plants were characterized by positive P‐Ca and K‐Ca correlations. In addition, negative P‐Cl and S‐Ca correlations were associated with salinity treatment.

ISSN:0010-3624    

DOI:10.1080/00103627509366543

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Differential thermal analysis shows that in soils organic matter and carbonates react in very different temperature ranges. An automatic CHN Analyzer was therefore used to determine the organic and inorganic carbon content of soils. At 500°C complete oxidation of soil organic matter occurs without appreciable decomposition of carbonates. Because only elemental carbon is determined, interferences due to weight losses from structural water in clays are eliminated. Decomposition of carbonates begins above 500° and always is concluded before 1100°C. Total organic and inorganic carbon in soils thus may be determined by running replicates at 500° and 1100°C with the Analyzer.

ISSN:0010-3624    

DOI:10.1080/00103627509366544

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Maximum yields of corn depends on adequate and balanced supplies of essential nutrients. In order to elucidate some of the factors which influence yields, a study was initiated to evaluate K, Ca, and Mg balances as influenced by seasonal variation, age of plants, and rates of K application.

ISSN:0010-3624    

DOI:10.1080/00103627509366545

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The absorption mechanisms for Na, K, SO4and Cl were tested in a salt tolerant (PVR 1) and a salt sensitive (GEB 24) rice varieties. The salt tolerant variety accumulated significantly larger amounts of Na than the salt sensitive variety. Further, PVR 1 absorbed SO4from Na2SO4in preference to that from K2SO4. The absorption patterns for K and Cl were similar in both the varieties. It is concluded that the capacity of plant species to accumulate greater amounts of Na is a reflection of their halophytic feature.

ISSN:0010-3624    

DOI:10.1080/00103627509366546

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

An analysis is described for the rapid determination of nitrate‐N in plant extracts. The complex formed by nitration of salicylic acid under highly acidic conditions absorbs maximally at 410 nm in basic (pH>12) solutions. Absorbance of the chromophore is directly proportional to the amount of nitrate‐N present. Ammonium, nitrite, and chloride ions do not interfere.

ISSN:0010-3624    

DOI:10.1080/00103627509366547

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The forage crops corn(Zea Mays), sorghum‐sudangrass(Sorghum VulgarePers. xSorghum sundanesestapf.), and kenaf (Hybiscus cannabinusL.) were irrigated with municipal effluent at rates of 5, 10, 15, and 20 cm/week on Lakeland fine sand. Plant samples were collected weekly from each plot to measure green weight, dry matter, and nitrogen content. From these data crop nitrogen (kg/ha) was calculated for each week. Finally, uptake of nitrogen was calculated to determine efficiency of nitrogen recovery from the effluent as the crops matured. In all cases efficiency of uptake decreased with increasing application rates, as expected from fertility studies. For corn, efficiency of uptake continued to increase up to harvest. For sorghum‐sudangrass and kenaf a peak was reached at about 50 days after planting, after which efficiency of uptake declined rapidly.

ISSN:0010-3624    

DOI:10.1080/00103627509366548

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor