Journal of the Indian Society of Soil Science
Year : 2010, Volume : 58, Issue : 3
First page : ( 309) Last page : ( 314)
Print ISSN : 0019-638X. Online ISSN : 0974-0228.

Effect of Different Organic Manures on Phosphorus Availability from Udaipur Phosphate Rock in an Alkaline Soil

Weerasinghe P.¹, Saroa G.S.*, Sidhu A.S.

Department of Soils, Punjab Agricultural University, Ludhiana, 141004, Punjab.

*Corresponding author (Email: gssaroa@yahoo.com)

¹Present address: Regional Agricultural Research Centre, Angunakolapelessa, Sri Lanka.

Received:  February,  2008; Accepted:  March,  2010.

Abstract

Phosphorus is a key fertilizer input required for crop production in the tropics where P deficiency is widespread. High cost of P fertilizers and indifferent crop response to P application prevents the optimum use of P, creating a negative P balance in cropping systems. Direct use of phosphate rock (PR) is a better alternative in acidic soils but it is not recommended for alkaline soils. Application of PR with organic manure might help the direct use as organic manures produce organic acids. This study was undertaken to evaluate the influence of combined application of Udaipur PR (UPR) with organic manures on an alkaline soil in a ricewheat sequence. Incubation and plant response studies were conducted using organic manures having varying levels of decomposition ranging from fresh cow dung to matured rice straw compost. Combined application showed release of P from the UPR but the effects were not large enough either in P nutrition of the crops or to improve the P fertility of the soil after three crop cycles. None of the organic materials used was capable of increasing the P fertility status of the soil when applied in combination over its individual application.

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Keywords

Udaipur phosphate rock, organic manures, alkaline soil, P balance.

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