Efficiency of azotobacter, diluted sulfuric acid and vinasse on some calcareous soil properties and productivity of onion [electronic resource].

Includes references.

In an endeavor to alleviate the problems of calcareous soil, some possible manipulation of soil was evaluated. Two separate experiments were carried out to achieve the main objective of this research. The first was laboratory experiment, using qualitative and quantitative analyses to estimate the efficiency of Azotobacter spp isolate on dissolving CaC03, decreased pH and solubility of nutrients in both specific solid and liquid media, which were being inoculated with Azotobacter spp and Incubated at 30 'C for 0, 3, 5, 7, 10 and 14 days, results obtained increased with prolonging the incubation periods up to 10 days. The second was a field experiment, being carried out on a calcareous soil located at Cairo EI-.lsmailiya Desert Road (Km 38), during two successive seasons (2009-2010), to study the effect of certain treatments on amelioration of calcareous soil properties and its productivity.. The soil was amended with diluted sulphuric acid (5%) at rates of (5, 10, 15 m3fea-1 ), vinasse at rats of (1,2 and 3 ton fea-11) and/or Azotobacter Isolate carried on vlnasse as a carrier (with a final density of 10' cells mr1 liquid culture), applied at rates of (15, 30 and 45 L fe(1). Seedlings of Onion (Allium Cepa) cv. Giza 20 were transplanted and drip Irrigated with saline well water (ECw 4.2 dSm-1). The results obtained showed that the values of soil pH, , total CaC03, active CaCo3, bulk density and fine capillary pores trended to decrease with increasing the applied rates of each of Azotobacter spp. diluted sulphuric acid and vlnasse. On the other hand, EC, , available Ca +2, Aggregation %, percentage of stable aggregate (PSA), hydraulic conductivity and total porosity exhibited pronounced increases, and these were reflected on onion yield and quality, as well as increase enzyme activities (Nitrogenase and dehydrogenase) and Co2 evolution especially with adding Azotobacter spp. at any rate and vinasse 3 ton fed-1. Economically, cost of the treatment of 15 m3 fed-1 diluted sulfuric acid was 1200 L.E. for decreasing about 40% of total CaCo3 and 60% of active Caco3, while vinasse 750 L.E. for 3 ton fea1 decrease CaCo3 % about 30% and about 43% active CaCo3. Values concerning the Azotobacter treatment were 270 L.E. for 45 Lfea-1 to achieve about 27 and 37 % decreased in both total and active CaCo3, respectively. Such treatments provided favorable conditions for nutrients availability for the growing plants and microbial population in soil.

Summary in Arabic.

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