摘要:

Four greenhouse experiments were conducted to investigate nutritional relationships between P and Ca in cigar wrapper tobacco. Plants were grown in a soil‐peat mix in 2 of the experiments and in sand cultures in the others. Levels of P and Ca in the nutrient media were varied. Plant concentration and uptake of P and Ca were determined to evaluate nutritional relationships between the two elements. An inverse relationship between P and Ca concentrations in cigar wrapper tobacco was apparent in all 4 experiments. Phosphorus appeared to decrease Ca uptake by cigar wrapper tobacco when added in increasing amounts.

ISSN:0010-3624    

DOI:10.1080/00103627209366355

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Onions were grown on two areas of sphagnum peat. One (old area) had been fertilized and cropped for a 5‐year period and the other (new area) had not. Fertilizer treatments on both areas consisted of an N, a P and a K series. Each nutrient was applied at four rates in combination with constant rates of the other two.

ISSN:0010-3624    

DOI:10.1080/00103627209366356

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

For depletions of soil exchangeable potassium of between 15 and 50%, potassium concentrations in ryegrass and strawberry leaf were linearly related to pAROK√BCOwhere AROKis the equilibrium potassium activity ratio and BCOis the slope, measured at AROKof the curve relating the quantity of labile potassium and the activity ratio. Potassium supplying power as measured by pAROK√BCOcould also be expressed as a function of the equilibrium activity ratio and the mineral component of the cation exchange capacity of the soil.

ISSN:0010-3624    

DOI:10.1080/00103627209366357

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Eleven cultivars of snapbeans were grown on an acidic Tifton loamy sand to compare yielding ability and leaf and fruit mineral element composition and to determine if leaf composition was associated with yield. A strong cultivar effect on leaf mineral element composition at full bloom and harvest and in fruit tissue was noted. The Ca and Sr level of leaf tissue at harvest was positively associated with yield, and yields varied significantly with cultivars. Significant correlations were obtained among many of the elements.

ISSN:0010-3624    

DOI:10.1080/00103627209366358

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Cation exchange capacity (CEC) is just one of several mechanisms which regulate the availability of plant nutrients in a soil. The base saturation ratio of nutrient cations adsorbed on the CEC can affect the levels at which insufficiency and sufficiency of a nutrient occurs. Similarly, once sufficiency is reached, there usually is little point in adding one or the other of two cations just to adjust their ratio in the soil.

ISSN:0010-3624    

DOI:10.1080/00103627209366359

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Results of solution culture experiments on effects of N, P, and K deficiencies on S constituents of leaf blades, total S concentrations, and S uptake by soybean plants are reported. Nitrogen deficiency decreased the concentration of soluble protein S, had little effect on nonsoluble S, and increased concentrations of soluble nonprotein S, sulfate S, reduced non‐protein S, and total S of soybean leaf blades. Soluble protein and S content of soluble protein decreased under N‐deficient conditions. For whole plants, S concentration and S uptake increased while dry weight was unaffected by N deficiency.

ISSN:0010-3624    

DOI:10.1080/00103627209366360

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The distillation step in total N analysis of soil by the Kjeldahl method can be eliminated by use of the Orion ammonia electrode for determination of the ammonium formed by Kjeldahl digestion of the soil sample. The electrode method of analysis is rapid, simple, and precise, and it gives quantitative recovery of ammonium added to Kjeldahl digests of soils. The results by this method of determining ammonium in Kjeldahl analysis of soils agree closely with those obtained by the customary distillation‐titration method.

ISSN:0010-3624    

DOI:10.1080/00103627209366361

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

An inexpensive vacuum attachment for the standard laboratory grinding mill is described. Air forced through the mill aids in the grinding process and in the removal of material from the mill. Ground material is collected on a paper filter. A number of advantages are described for the technique; these include faster grinding, increased recovery, reduced dust, and lower contamination from samples labelled with radioisotopes.

ISSN:0010-3624    

DOI:10.1080/00103627209366362

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627209366363

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627209366354

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor