Nader R. Habashy, Amal W. Abou El-Khair and Raafat N. Zaki( 2008). Effect of Organic and Bio-fertilizers on Phosphorus and Some Micronutrients Availability in a Calcareous SoilJournal of Agriculture and Biological Sciences, 4(5): 545-552, 2008
Abstract: Poor performance of particularly phosphorus and micronutrients availability is one of the major factors related to crop productivity in the soil calcareous in nature. This investigation was, therefore,carried out on a calcareous sand clay loam soil under field conditions of Bangar El-Sukar area, El Nubariya region, Egypt to evaluate the efficiency of organic manure (composted rice straw) and biofertilizer (arbuscular mycorrhizal fungi, AM) for improving phosphorus (P) and some micronutrients availability in a calcareous soil cultivated with maize. To achieve this target, P was applied at the rates 0 1 2 2 5 of 0 (P , inert phosphorus content), 15 (P ) and 30 (P ) kg P O /fed, in combination with mycorrhiza inoculum (AM multiplied in peat : vermiculite : perlit, 1:1:1) or organic compost at the rate of 10 ton/fed added as solely or combined treatments. All applied treatments received the recommended doses of
nitrogen and potassium fertilizers. The results obtained clearly show that the combined treatment of (AM + organic compost) significantly increased the released P and micronutrients in the soil. This may be due to lowering soil pH and favourable air-water balance, which considerably showed a positive reflection on maize yield. This beneficial effect was more pronounced for the combined treatment in case of applying 2 5 2 5 15 kg P O /fed plus AM inoculum, with insignificant difference for the applied rate of 30 kg P O /fed.
That was true, since the pronounced increases in mycorrhizal root colonization percent and number of spores/g soil led to easily mobility of phosphorus and micronutrients, and then their uptake by maize plants as compared to the control treatment. Moreover, the data obtained reveal that integrated effect of AM fungi in combination with organic compost was the best treatment as compared with the solely ones, such finding is emphasized by phosphorus recovery.
Keywords: (Arbuscular mycorrhizal fungi (AM infection), organic compost, phosphorus, micronutrients , calcareous soil.)
