摘要:

Corn yields and leaf samples were obtained from experimental plots receiving varying rates of N, P and K. Yields were regressed on leaf levels of N, P, K, Ca, Mg, B, Cu, Fe, Mn and Zn as independent variables. Various polynomial regressions were fitted to the yields and “goodness of fit”; of particular mathematical models was used as a basis for evaluating particular biological and statistical concepts.

ISSN:0010-3624    

DOI:10.1080/00103627009366250

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

The apparent boron content of plant tissues was found to vary with the amount of tissue used. The effect was observed in both ashed and acid extracted plant tissue and is related to the salt content of the material which affects the value of boron obtained in the absence of salts.

ISSN:0010-3624    

DOI:10.1080/00103627009366251

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

White Rose potato plants (Solanum tuberosum, L.) were grown outdoors, without tuber formation, in a modified Hoagland's nutrient solution with 9 treatments of KH2PO4ranging from 0 to 4.0 mmoles per liter. Deficiency symptoms ranged from very severe to none at harvest after 27 days of growth. Growth of the potato plants increased with increased P supply and was associated with an increased P content of the plant tissues. The critical H2PO4‐P concentration at a 10% reduction of top growth, based on a second leaf analysis, was about 1,000 ppm for the petiole and terminal bladelet and about 1,200 ppm for the lateral bladelet, dry weight basis.

ISSN:0010-3624    

DOI:10.1080/00103627009366252

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

A procedure for the rapid and accurate determination of water‐extractable soil nitrates is described. Use of this procedure resulted in quantitative recovery of nitrates added to soil. Reproducibility of results was high, with nitrate‐nitrogen in 40 soil samples determined on successive days differing by a maximum of 4 ppm with 33 determinations differing by 2 ppm or less. Comparison with a phenoldisulfonic acid method on 513 soil samples had a maximum difference of 7 ppm with a majority of determinations having a difference of 4 ppm or less.

ISSN:0010-3624    

DOI:10.1080/00103627009366253

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Leaf and petiole samples from 16 cotton (Gossypium hirsutumL.) varieties at three Southeastern soil series locations were analyzed for elemental composition. The concentrations of six micronutrients were found to vary between varieties at any one of the locations as well as from one location to another. Mn and Fe contents of the varieties were significantly different (P = .01 and P = .05, respectively) for plants grown on a Farragut sil (Calhoun, Ga.) but not on a Cecil cl (Griffin, Ga.) or a Greenville sl (Plains, Ga.). Correlation coefficients indicated a significant (P = .01) positive relationship for Mn and Fe among varieties grown on the Farragut and Greenville soils. Among all varieties and all locations, positive correlations occurred between Mn, Fe, Zn, B, Cu, and K whereas Mo was negatively correlated with the same elements. Levels of Mn and Fe found in the plant tissue could not be explained in terms of total soil Mn and Fe or soil pH.

ISSN:0010-3624    

DOI:10.1080/00103627009366254

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

摘要:

Ammonium nitrate fertilizer, whether applied in spring, summer or autumn, resulted in a rapid increase in the total N content of most tree tissues, although autumn‐applied N remained mainly in the tree roots through the winter. The total P content of the trees was increased by added N fertilizer but the total K content was decreased. Analysis showed that significantly more N was lost in the leaves abscissing from the spring and summer‐N trees than from the autumn‐N trees or controls; also more P was lost from trees given spring N.

ISSN:0010-3624    

DOI:10.1080/00103627009366255

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627009366249

出版商:Taylor & Francis Group    

年代:1970

数据来源: Taylor