Impact of Neem Seed Cake on Soil Microflora and Some Soil Properties

Asereis of Laboratory experiments was conducted to evaluate the effects of Neem seed cake on the main groups of soil microflora and some soil properties. Soil samples were collected from El Rawakeeb Desertification Research Station Farm. Four treatments,replicated three times, were included with the application of 0, 2, 4 and 6 mg of Neem seed cake calculated as 0, 5, 10 and 15% of the basal dose of urea (40 mg/ bottle). A composition of 60 grams soil, Urea, Neem seed cake and a moisture level of 2/3 field capacity were incubated at room temperature. After 2, 4, 6 and 8 weeks from incubation soil samples were with drawn for determination of soil microflora. At the end of incubation , soil samples were taken for determination of exchangeable calcium, iron, manganese, copper and zinc. Another experiment was conducted with the same components and under the same conditions for the determination of electrical conductivity in 1:5 soil water ratio after 1,3,7,9,13 and 19 days. The results revealed that Neem seed cake positively affected the population of organic nitrogen users and actinomycetes and affected negetatively the population of fungi, Nocardia, Bactodermaand the whole population of inorganic nitrogen users which include nitrifying bacteria. On the other hand, it exerted fluctuating effects on Mycobacterium, Micromonosporaand Arthrobacter. Moreover, Neem seed cake significantly increased electrical conductivity, exchangeable calcium, iron, manganese, copper and zinc content.