ISSN:
1573-5036
Keywords:
Extractants for available Zn
;
Hill and forest soils
;
Rice
;
Threshold value
;
Zinc response
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary The available Zn in 25 soils of Sub-Himalayan hill and forest region was determined by using some chemical extractants to evaluate its critical limit in soils and rice plant. The critical limit of soil available Zn using DTPA-CaCl2, DTPA-NH4HCO3, EDTA-NH4OAc and EDTA-(NH4)2CO3 was 0.76, 0.86, 0.85 and 1.18 ppm, respectively. The amount of Zn extracted by these extractants was positively and significantly correlated with per cent dry matter yield. In addition to per cent dry matter yield, the Zn extracted by DTPA-CaCl2, DTPA-NH4 HCO3 and EDTA-(NH4)2CO3 was also positively correlated with Zn concentration in 3rd leaf of rice, Zn concentration in rice shoots, Zn uptake by rice shoots and organic carbon content of the soil, and negatively correlated with soil pH.The 2N MgCl2 and 0.1N HCl extractants were found to be not suitable for these soils. Among the four promising extractants, EDTA-(NH4)2CO3 was most efficient as the value of critical limit determined by it expressed 82.4% predictability in the degree of accuracy against 36.8% with EDTA-NH4OAc. Hence EDTA-NH4OAc is the least efficient extractant for estimation of available Zn in such soils. The critical Zn concentration in 3rd leaf of rice was worked out to be 21.5 ppm below which economic responses to Zn application can be expected.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02184332
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