摘要:

A measure of biologically available B (BAB) was obtained by assaying the amount of B removed from a small volume of soil by sunflowers grown until they displayed B deficiency symptoms. Four different mineral soils and one organic soil which had been treated in the field with variable lime and B applications 2 years prior to sampling were compared. The amount of B extracted with hot water from soils before cropping was well correlated with BAB. The B extracted by the more intensive hot water extraction methods was closely related to the absolute level of BAB. Digestion of soils with concentrated H3PO4resulted in the dissolution of larger amounts of B than that extracted with hot water. The proportion of H3PO4soluble B that was measured as BAB was quite variable. Thus H3PO4was a less suitable extractant than hot water for assaying the amount of soil B available to plants during a short growing period. In no case was the difference between the B extracted from soils before and after cropping as large as the BAB values.

ISSN:0010-3624    

DOI:10.1080/00103627109366320

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Four soils from southern Brazil were treated with four levels each of lime and P and cropped with corn (Zea maysL.) in the greenhouse. Zinc deficiencies occurred at soil pH values of 6.3 or greater and independently of the rate of P application. Application of P alone did not induce Zn deficiency.

ISSN:0010-3624    

DOI:10.1080/00103627109366321

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Corn yields and leaf samples vere obtained from experimental plots receiving various rates and combinations of N, P and K. Yields were regressed on leaf N, P, K, Ca and Mg as independent variables expressed in milliequivalents per 100 grams and percentages in three regression models. The fit of two models was shown to be equivalent regardless of method of expressing the independent variables. For the other model the choice of milliequivalents per 100 grams or percentages determines a unique function.

ISSN:0010-3624    

DOI:10.1080/00103627109366322

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Experiments were conducted to study the effects of various Zn carriers and rates on the growth and Zn uptake of Sanilac navy beans. Plants were grown under greenhouse and growth chamber conditions for 2, 4, 6 or 8 weeks on a Wisner silty clay loam soil low in available Zn. Plant growth responded to the various Zn fertilizers except at 4 weeks where no response was obtained. Only ZnZnEDTA and ZnNa2EDTA increased growth at 2, 6 and 8 weeks while ZnSO4, ZnHEIDA, ZnNTA and Zn(NO3)2did not give consistent responses at all of these periods. The Zn carriers did not influence uptake until 6 weeks after planting.

ISSN:0010-3624    

DOI:10.1080/00103627109366323

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Alkaline‐soluble, acid‐precipitable organic matter from the Ah and Bm horizons of Chernozemic soils developed on four parent materials in each of three soil zones was analyzed for total and carboxyl acidity, and methoxyl groups. The values are expressed as meq/g dry ash‐free organic matter.

ISSN:0010-3624    

DOI:10.1080/00103627109366324

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Growth‐chamber experiments on effects of light and temperature on S constituents of leaf blades, total S concentrations, and S uptake in whole soybean plants are reported. A 5‐day dark period decreased concentration of soluble protein S and increased concentrations of nonsol‐uble S, soluble nonprotein S, sulfate S, organic S, reduced nonprotein S, and total S of leaf blades. Soluble protein was decreased but S content of soluble protein was unaffected. For whole plants, dry weight and S uptake decreased and S concentration increased.

ISSN:0010-3624    

DOI:10.1080/00103627109366325

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A rapid colorimetric method for the determination of boron in soil extracts, plant materials, composts, manures, water and nutrient solution is proposed. The method is rapid, reliable and carried out in aqueous solution. A marked advantage is that boron can be determined in the same soil extract or plant material digest used for determination of other elements.

ISSN:0010-3624    

DOI:10.1080/00103627109366326

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The comparative availability toLolivm perenneof32Pmyo‐inositol hexaphosphate (IH32P) and KH232PO. added to soil could be determined unequivocally from the32P count of leaf material even when dry matter yields and total P content were not significantly different from the control.

ISSN:0010-3624    

DOI:10.1080/00103627109366327

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Analytical data for Al and Fe extracted by different reagents is presented. It is concluded from the data that in podsolisation Al migrates mainly as inorganic gel while iron moves as organic chelated complexes.

ISSN:0010-3624    

DOI:10.1080/00103627109366328

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Corn yields and leaf samples were obtained from experimental plots receiving varying rates of N, P, and K. Yields were placed in two groups. One group consisted of yields < 134 bu/A, and a second group consisted of yields ≥ 134 bu/A. Within each group yields were regressed on leaf levels of N, P, K, Ca, Mg, B, Cu, Fe, Mn and Zn as independent variables in a second order polynomial. Using stepwise regression procedures the fit of the polynomial was determined for each set of observations, and statistical significance of various effects was determined.

ISSN:0010-3624    

DOI:10.1080/00103627109366329

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor