Abstract

                                Leguminous crops require larger quantities of P than all other cultivated crops. The rhizobia in the soil also require more P for the synthesis of body cells. Therefore when a leguminous crop is fertilised with P, it serves the needs of both and the association between the host and the symbiont becomes more effective leading to the maximum fixation of atmospheric N under favourable conditions. This property of leguminous crops is widely employed in Agriculture to enrich the soil. A uniform recommen- dation of P is not possible for a particular crop under different soil conditions. The present investigation was taken up with a view to fix the effective dose of P for saunhemp in the red soils of Coimbatore, Madras State.

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