ISSN:0010-3624    

DOI:10.1080/00103627409366492

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Phosphate desorption isotherms were constructed for four tropical and one British soil with different chemical properties. Phosphate was released with a oitric acid solution (0.0025M) adjusted to pH 5.7 and by using different soil/ solution ratios during 18 hours. This citrate level does not operate efficiently for high phosphate sorbing soils (i.e. Bowden Series), so that there is a competition between oitrate and phosphate for sorbing places and some disturbances in the shape of the desorption isotherms appeared. In moderated phosphate sorbing soils (Rengam Series) fairly reasonable desorption isotherms were obtained even at this low oitrate concentration (0.0025M). An almost linear isotherm curve was obtained when a higher concentration of citrate (0.1M) was used.

ISSN:0010-3624    

DOI:10.1080/00103627409366493

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Alfalfa(Medicago sativa)yields were determined for five years on Davidson clay loam at Orange, Virginia. The effects of irrigation and K application on the yield and chemical composition of alfalfa and on the available soil K content were determined. Seven rates of K were applied annually.

ISSN:0010-3624    

DOI:10.1080/00103627409366494

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Cation exchange capacity increased with both air drying (25°C) and oven drying (105°C). The initial value of exchange acidity at field moisture determines whether exchange acidity increases or decreases after drying. Exchangeable bases, particularly calcium, increase with oven drying.

ISSN:0010-3624    

DOI:10.1080/00103627409366495

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Analyses of deionized, distilled, water‐washed grain sorghum (Sorghum bicolor(L.) Moench) plant‐tissue parts throughout the plant's growth cycle for Zn, Cu, Fe, Mn, Mg, and Ca contents showed no significant change, except for Fe, in nutrient concentrations from those of unwashed tissue. Iron concentrations were considerably higher in unwashed blade, sheath, and head tissue than in washed parts. Differences between unwashed and washed tissues varied throughout the plant's growth cycle. Iron concentrations in the culm were affected only slightly by washing. Zinc, Cu, and Mn concentrations in plant tissue were affected least by washing. Average Zn concentrations of washed tissue were higher in all plant parts, but not consistently higher from one sampling date to the next. Average Mg and Ca concentrations were slightly higher in unwashed than washed blade and sheath tissue, primarily because concentrations in unwashed tissue tended to be higher late in the growth cycle.

ISSN:0010-3624    

DOI:10.1080/00103627409366496

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Analysis of the salt and nutrient status of potting composts and growing substrates with the aid of the 1:25 weight extract ‐ previously used in the Netherlands ‐ has several disadvantages. The interpretation of analytical data based on the organic matter content is not very accurate because this content does not provide a true estimation of the moisture capacity. In addition the conductivity of growing media rich in gypsum gives an unfavourable impression of the salt status.

ISSN:0010-3624    

DOI:10.1080/00103627409366497

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

In a fertilizer trial in a Valencia orange orchard, two soil types were distinguished: a poorly aerated loamy sand (A) and sandy clay loam (B). Mineral composition of leaves and fruit quality characteristics differed significantly in the two soil types, regardless of the fertilizer treatments. Fruits on the sandy clay loam were larger, had a thicker peel, and contained more total acids and vitamin C in the juice, and were less affected by a peel disorder (creasing). The leaves of such trees contained more K and Mg and less Ca and P.

ISSN:0010-3624    

DOI:10.1080/00103627409366498

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Maize (Zea maysL.) inbreds were grown on soils known to produce Fe, Zn, Mg, Ca, and Cu deficiency and Al and Mn toxicity. The inbreds were assessed for their differential responses to the elemental problem induced by each soil. Marked differences in susceptibility and/or tolerance to limited or excess amounts of mineral nutrients were noted among the inbreds. Information on differential responses of plants to the various mineral elements should be beneficial for overcoming particular element problems and for developing plants which utilize mineral elements more efficiently.

ISSN:0010-3624    

DOI:10.1080/00103627409366499

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Significant varietal differences in plant nutrient content have been reported in the literature which would make extremely difficult the interpretation of plant analysis results for diagnosing plant nutritional problems. This investigation was conducted to analyze a relatively large number of uniformly fertilized commercially grown corn (Zea mays) varieties for possible differences in N, P, K, Ca, and Mg concentrations. Whole young plants 60 to 90 cm tall and ear leaves collected at tassel ling were chemically analyzed.

ISSN:0010-3624    

DOI:10.1080/00103627409366500

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627409366501

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor