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An investigation was carried out to study different forms of phosphorus under major cropping systems in Y.S.R. Kadapa district of Southern Zone of Andhra Pradesh. Five soil samples from each cropping system at 0-15 cm depth collected from each cropping system to study their physicochemical properties, status of available P2O5 and different forms of P. Majority of the soils were moderately alkaline in reaction, non-saline, free lime content indicating that these soils are moderately calcareous, medium to high in available P2O5. Highest mean values for available P2O5 (182.41 kg ha-1), Al-P (80.82 mg kg-1), Ca-P (118.55 mg kg-1) and total-P (434.35 mg kg-1) were recorded in groundnut monocropping system whereas for saloid P (23.01 mg kg-1), Fe-P (69.82 mg kg-1) and other forms of P (228.35 mg kg-1) highest mean values were recorded under sunflower-sesame, groundnut-groundnut and fallow-bengal gram cropping systems, respectively.
Olsen SR, Cole CV, Frank SW, Dean LA. Estimation of available phosphorus in soils by extraction with sodium bicarbonate. United States Department of Agriculture Circular. 1954;939.
Murphy J, Riley JP. A modified single solution method for determination of phosphate in natural waters. Analytical Chemistry. 1962;27:31-36.
Kovar JL, Pierzynski GM. Methods of analysis for soils, sediments, residuals and waters. Second Edition, Virginia Tech University. 2009;50-53.
Jackson ML. Soil chemical analysis. Prentice Hall of India Private Ltd., New Delhi. 1973;134-182.
Tomar NK, Khanna SS, Gupta AP. Transformation of phosphates varying in nitrate and water solubility in calcareous soil after incubation with cattle dung. Journal of the Indian Society of Soil Science. 1984;32:421-426.
Devra P, Yadav SR, Gulati IJ. Distribution of different phosphorus fractions and their relationship with soil properties in Western plain of Rajasthan. Agropedology. 2014;24(01):20-28.
Sarkar D, Mandal D, Haldar A. Distribution and forms of phosphorus in some red soils of Chotanagpur plateau, West Bengal. Agropedology. 2013;23(2):93-99.
Sacheti AK, Saxena SN. Relationship between some soil characteristics and various inorganic phosphate fractions of soils of Rajasthan. Journal of the Indian Society of Soil Science. 1973;21:143-149.
Viswanatha J, Doddamani VS. Distribution of phosphorus fractions in some vertisols. Journal of the Indian Society of Soil Science. 1991;39:441-445.
Jatav MK, Sud KC, Trehan SP. Effect of organic and inorganic sources of phosphorus and potassium on their different fractions under potato-radish cropping sequence in a brown hill soil. Journal of the Indian Society of Soil Science. 2010;58(4):388-393.
Sudhakaran SV, Patil SR, Kondvilkar NB, Naik RM, Pharande, Kadlag AD. Effect of 32 year long-term integrated nutrient management on soil p fractions and availability of phosphorus under sorghum-wheat cropping sequence in vertisol. Journal of Pharmacognosy and Phytochemisty. 2018;7(4):3410-3416.
Laxminarayana K, Rajagopal V. Relative contribution of different inorganic fractions of soil phosphorus to P uptake by rice. Journal of Research ANGRAU. 2002;30(4):17-26.
Sowjanya P, Rani PP, Vani PM. Distribution of inorganic phosphorus fractions in soils of Bobbili mandal, Vizianagaram District, Andhra Pradesh. Journal of Indian Society of Coastal Agricultural Research. 2017;35(1):1-7.