Nitrogen mangement under different compost levels for lettuce plant grown in coconut fiber [electronic resource].

Includes reference.

Two experiments were conducted at the roof of central laboratory for agricultural climate, Dokki, Giza-Egypt. two lettuce types (Lactuca sativa L.) iceberg and romaine were transplanted at october during the two seasons (2006 and 2007) into white polyethylene container filled with coconut fiber media. the experiments aimed to study the effect of three nitrogen levels (50, 100 and 150 ppm) applied by fertigation a d three compost levels (0, 2 and 4% by volume). the experimental design was a completely randomized factorial design with three replications. using different nitrogen and compost levels were affected vegetative growth,' nutrients content (N, P, K, Ca, Mg and NO) and yield. the obtained results indicated that the increasing nitrogen level up to 150 ppm significantly increased plant height, number of leaves per plant, dry weight and yield. compost 4% level gave the highest vegetative growth and yield comparing with the other compost treatments. The highest nitrogen level (!50ppm) combined with compost 4% increased vegetative growth and yield significantly. On the other hand, 50 ppm nitrogen gave the highest nitrogen use efficiency (NUE) and the least value of nitrate content in leaves followed by 100 ppm. The highest nitrogen level (150ppm) led to increase nitrate content over the healthy save line with different compost levels.

Summary in arabic.

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