International Journal of Environmental Sciences

Volume 5 Issue 5 2015- March 2015    Pages: 980- 987  <<Previous    Next>>

Direct and residual effect of organic manures, urea integration on okra grown in sandy regosol

Author Information:

W. Shanika and P. Premanandarajah
Department of Agricultural Chemistry, Faculty of Agriculture, Eastern University, Sri Lanka, Sri Lanka.


In modern agriculture over use of inorganic fertilizers causes dangerous effects on environment, human health and loss of soil fertility especially in sandy regosols, where the poor soil structure promotes heavy leaching of nutrients. A pot experiment was carried out at Eastern University, Sri Lanka during the period of March to July 2014, to evaluate the residual soil nitrogen and nitrogen uptake of okra (Abelmoschus esculentus (L.) Moench) in sandy regosol using variety EUOK - 2. There were thirteen treatments replicated four times in Completely Randomized Design. They include poultry manure, farmyard manure, Leucaena (Ipil ipil) leaves and paddy straw as organic nitrogen sources and urea as the inorganic nitrogen source. The organic nitrogen sources were evaluated solely and in combination with urea at the rate of 50% and 100% from each in weight basis. These all treatments were tested with control with no organic nitrogen or inorganic nitrogen sources and were evaluated among themselves also. Among these treatments, significantly highest nitrogen uptake was registered in sole poultry manure application, highest Residual Soil Nitrogen (RSN) was recorded in 100% paddy straw integrated with 100% urea and the highest available soil nitrogen at the time of planting was in 100% poultry manure integrated with 100% urea. So sole poultry manure can be suggested to the farmers especially for the cultivation of okra on sandy regosol in order to maximize the nitrogen uptake and indirectly induce the growth performance and to reduce use of chemical fertilizers.

Keywords: Farmyard manure, Leucaena leaves, okra, paddy straw, poultry manure.


© 2014 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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