摘要:

Leaf samples were taken from corn and grain sorghum being grown in adjacent fields with the same soil type and with the same cultural practices insofar as possible. The samples were analyzed for N, P, K, Ca, Mg, Fe, Zn and Mn. Results show that the nutrient composition of the leaves of corn and grain sorghum were consistently different for most nutrients. The differences were sufficiently great and consistent to strongly suggest that critical nutrient levels need to be established for grain sorghum instead of using diagnostic criteria established for corn.

ISSN:0010-3624    

DOI:10.1080/00103627109366331

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Sanilac and Saginaw varieties of navy beans were grown on Wisner silty clay loam. Treatments of no added Zn and 3 ppm Zn were applied to the soil fertilized with N, K, and 500 ppm P. Selected plant tissues were harvested two, four, six, or eight weeks after planting.

ISSN:0010-3624    

DOI:10.1080/00103627109366332

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The usefulness of the nitrate‐specific ion electrode (NE) for the determination of nitrate nitrogen (NO3‐N) in surface and ground water was determined. The NE method had several advantages that made it superior to the phenoldisulfonic acid (PDS) method in our environmental quality studies. Samples could be analyzed quickly and with a minimum of sample preparation. Sample coloration and soluble salts did not interfere with the performance of the electrode. Range of detection without dilution was much wider than by the PDS method. Also, the values obtained by the NE method, although slightly greater than those obtained by the PDS method, were satisfactory.

ISSN:0010-3624    

DOI:10.1080/00103627109366333

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The release of CO2from fresh soil at medium moisture was examined for 14 days after the application of gamma‐radiation over the range 0.025 ‐ 10 Mrad. All doses stimulated the release of CO2compared with non‐irradiated soil, but there was no extra yield of gas between 4 and 10 Mrad. Rapid evolution occurred during irradiation and over the next 24 hours, but towards the end of incubation both irradiated and untreated soil produced CO2at similar rates.

ISSN:0010-3624    

DOI:10.1080/00103627109366334

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The effect of including charcoal during extraction on the amount of manganese brought into solution was measured on soils from the Coastal Plain, Piedmont, and Mountain physiographic regions. The presence of charcoal increased the level of Mn extracted with dilute acid by a factor of 1.23 for soils with less than 40 ppm extractable Mn. This value was used to adjust the interpretation of the manganese soil test for soybeans based on previous correlation data so that charcoal may be omitted if desired.

ISSN:0010-3624    

DOI:10.1080/00103627109366335

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Three experiments were conducted to determine the critical meq NH4/meq K ratio in fresh tissue indicative of ammonium toxicity and the symptoms of the same under winter and summer conditions. Three and four levels each of ammonical N and K fertilization were employed in factorial designs. The chrysanthemum cultivars Bright Golden Anne and Yellow Mandalay were studied.

ISSN:0010-3624    

DOI:10.1080/00103627109366336

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Experiments were conducted on Congaree loam at Orange, Virginia, in 1963, 1964, and 1965 to measure the response of corn to irrigation and to 3 levels of P. Rate of N was 140 kg/ha. Levels of P were 0, 37.5, and 75 kg/ha; while the rate of K. was 70 kg/ha. All micronutrients were applied in recommended amounts. Excellent corn silage and grain yields were obtained and there was no response to addedVexcept for grain yields on irrigated plots. Cropping with corn, irrigation, and fertilization appeared to have little effect on the P content of the 0‐ to 15‐cm soil layer. Irrigation and P fertilization did not affect the P content of the corn leaves. Fractionation of P indicated appreciable amounts of A1‐P, Fe‐P, and Ca‐P to a depth of 140 cm with less Al‐P than the other forms.

ISSN:0010-3624    

DOI:10.1080/00103627109366337

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Leaf lettuce (Lactuca sativavar.crispaL.), radish (Raphanus sativusL.), and spinach (Spinacea oleraceaL.) plants were grown in sand culture under variable N concentrations from 0.187 to 48.0 meq/l. The plants were harvested when those grown at 12 meq N/l had attained approximate market maturity. Growth was restricted, and symptoms of N deficiency were evident at the low levels of N. Growth was also restricted at the highest N level. Approximate critical levels for leaf lettuce, radish roots, and spinach are 2000 ppm, 5000 ppm, and 4000 ppm, nitrate‐N respectively, on a dry weight basis.

ISSN:0010-3624    

DOI:10.1080/00103627109366338

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Moderate deficiencies of P, K, Ca, and Mg had no effect on nitrate accumulation inSpinaoea oleraceacv. America, a savoyed‐leaf type of spinach. Nitrogen supply had a marked effect on nitrate concentration in spinach leaves, but deficiencies of the other nutrients did not interact with N deficiency. Length of exposure of plants to nitrate nutrition was an important factor governing nitrate accumulation in the leaves.

ISSN:0010-3624    

DOI:10.1080/00103627109366339

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Phosphate interfered markedly with a Devarda's alloy distillation method for the determination of nitrate. Only 9% of added nitrate was recovered by this method when 200 mg P was present. This interference can be overcome by the addition of calcium ions, to precipitate the phosphate, and an extended distillation time.

ISSN:0010-3624    

DOI:10.1080/00103627109366340

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor