Nitrogen and/or phosphorus fertilization effects on organic carbon and mineral contents in the rhizosphere of field grown sorghum

Lee, K K and Wani, S P and Sahrawat, K L and Trimurtulu, N and Ito, O (1997) Nitrogen and/or phosphorus fertilization effects on organic carbon and mineral contents in the rhizosphere of field grown sorghum. Soil Science and Plant Nutrition, 43 (1). pp. 117-126. ISSN 0038-0768

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Abstract

The effects of N and/or P fertilizers on the nutritional status in the rhizosphere were studied by monitoring throughout the growth period the concentrations of organic C, inorganic N, NaHCO3 extractable P, exchangeable K, Ca, and Mg in sorghum (Sorghum bicolor) in an Alfisol field, and of all these elements except for extractable P, and exchangeable Ca in a Vertisol field in semi-arid tropical India. Concentrations were compared between the rhizosphere soil and bulk soil of sorghum grown in both fields. Organic C content of the rhizosphere increased with plant age and was higher than that in the bulk soil throughout the growth of sorghum, but it was not affected by the rates of N or P fertilizer. Inorganic N concentration in the rhizosphere was higher than that in the bulk soil until maturity in sorghum. Available P content in the rhizosphere was higher than in the bulk soil after the middle of the growth stage and its average concentration in the rhizosphere across growth stages was higher than in the bulk soil, which contradicts the observation in many reports that there is a depletion of P in the rhizosphere soil. The concentration of three exchangeable cations, K, Ca and Mg, showed different patterns in the rhizosphere and the bulk soils. Potassium was higher in the rhizosphere soil than in the bulk soil, Ca concentration was not different between the two soils, and Mg concentration was higher in the bulk soil than in the rhizosphere soil. The concentrations of these cations were not affected by the rate of N or P fertilizer except for Mg at a later growth stage. Differences between rhizosphere and bulk soils in Alfisol were similar to those in Vertisol with respect to the concentration of organic C, inorganic N, and exchangeable K and Mg.

Item Type:	Article
Divisions:	UNSPECIFIED
CRP:	UNSPECIFIED
Uncontrolled Keywords:	mineral content; N/P fertilization; organic C content; rhizosphere; sorghum
Subjects:	Mandate crops > Sorghum
Depositing User:	Library ICRISAT
Date Deposited:	10 Sep 2011 13:53
Last Modified:	04 Sep 2013 13:01
URI:	http://oar.icrisat.org/id/eprint/1289
Official URL:	http://dx.doi.org/10.1080/00380768.1997.10414720
Projects:	UNSPECIFIED
Funders:	UNSPECIFIED
Acknowledgement:	UNSPECIFIED
Links:	Author

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