ISSN:0010-3624    

DOI:10.1080/00103627309366443

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Rate of superphosphate application significantly increased the Bray #2 (easily acid soluble plus adsorbed P) and “AlPO4”; fractions for 3 successive years. A single dolomitic limestone application increased “FePO4”; by an average of 36% one year after application. Crop P removal by the strawberry cv. ‘Acadia’ was approximately 2–3 ppm each year and it was not possible to relate this small amount to any of the soil P fractions determined.

ISSN:0010-3624    

DOI:10.1080/00103627309366444

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Leaf content of Ca remained fairly constant over three dilutions of nutrient solution. K content of the leaves fell with dilution. Porosity of the rooting medium had no effect on Fe, Cu, Mg, K in leaves but Ca and Zn decreased linearly with increasing porosity. Cation exchange capacity of the roots was not affected by porosity but there was a nutrient effect.

ISSN:0010-3624    

DOI:10.1080/00103627309366445

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

An investigation was conducted in the greenhouse to determine the effects of applications of zinc (Zn) and different sources of phosphorus (P) on the production of dry matter and on the concentration and uptake of P and Zn in plant tissue of rice,Oryza sativaL., cultivar Saturn, at the vegetative growth phase on Crowley silt loam, pH 5.3.

ISSN:0010-3624    

DOI:10.1080/00103627309366446

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Yield response of Idaho Russet Burbank potatoes to nitrogen fertilizer was related to soil test for inorganic N (NO3‐and NH4+) in a total of 27 field experiments over a 3‐year period using polynomial correlation and regression analysis. Nitrate plus ammonium nitrogen content in the surface foot of soil was found to be useful in predicting yield response of potatoes to applied nitrogen.

ISSN:0010-3624    

DOI:10.1080/00103627309366447

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A silica gel plating method for counting of nitrifying microorganisms in soils was found equally satisfactory to most probable number method.

ISSN:0010-3624    

DOI:10.1080/00103627309366448

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A simple steam distillation method of determining nitrate is described that is not subject to interference by substantial amounts of phosphate or silicate. It involves use of FeSO4and MgO for reduction of nitrate to ammonia. The method is rapid and precise, and tests reported show that it is satisfactory for nitrate analysis of soil extracts.

ISSN:0010-3624    

DOI:10.1080/00103627309366449

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Young corn(Zea maysL.) and sugar beet (Beta vulgarisL.) plants were sampled in plots fertilized with different types and rates of nitrogen fertilizer during the period 1969–72. The twenty six trial fields covered a dozen different types of soil from the Montreal to the lower St. Lawrence River regions. As revealed by nitrate analysis (NO3‐N) there was a marked positive correlation between crop yield, and nitrate nitrogen from the fifth to the seventh week for corn and from the seventh to the eight week for sugar beet. Sampling prior to this was not indicative. A negative correlation was found between NO3‐N and total sugar yield for sugar beet, before the seventh week. Regression analysis, including soil NO3‐N test, showed a positive soil participation from the seventh week for corn and from the fourth week for sugar beet. The critical concentration value suggested for corn, under very adverse climatic conditions, is not less than 150–200 ppm NO3‐N. As a rule, however, the 2,000 ppm value appears to be a minimum concentration. This value may be extended to 3,000 ppm under certain conditions. As for sugar beet, a range from 10,000 to 20,000 ppa in petioles during the initial 50–56 day period, gave maximum sugar yields. During this stage, values ranging from 20,000 to 30,000 ppm of NO3‐N were considered to be overabundant.

ISSN:0010-3624    

DOI:10.1080/00103627309366450

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

There has been a marked change in the soil testing procedures used in the United States by state soil testing laboratories since the early 1950's. In the Coastal Plain states of the south and east, the Double Acid extraction procedure is used for P, K, Ca, and Mg determinations. Bray P1is the most frequently used method for P extraction except for the alkaline soils of the west where the Olsen method is used. Neutral normal ammonium acetate is the most frequently used extractant for K, Ca, and Mg determinations. The Morgan extraction procedures for P, K, Ca, and Mg, commonly used in the 1950's, is used by only a few states in the northeast and west. Although similar extraction reagents are used in many sections of the United States, there is considerable variance among states regarding weighed versus volume sampling, soil to solution ratio, shaking speed and time, and extraction vessel size and shape. For soil water pH, there is little variance in method as most states are using a 1:1 soil to solution ratio. The only exception is in several western states where water pH's are read in a saturated soil paste.

ISSN:0010-3624    

DOI:10.1080/00103627309366451

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A resin coated fertilizer (Osmocote3) was tested at 2 rates in combination with a normal greenhouse liquid fertilization (LF) program. A low rate of Osmocote in combination with LF produced superior growth and had equivalent N, P and K leaf tissue levels compared to a high rate. Delayed application of LF for 3–7 waterings significantly improved the substance of leaf and root tissue probably because of decreased damage of tender young roots from high soluble salts. Growth and tissue analyses (N, P and K) indicated only the need of nitrogen in LF suggesting the remainder of fertilizer constituents contribute only to soluble salt problems.

ISSN:0010-3624    

DOI:10.1080/00103627309366452

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor