Biotechnologie et biomatériaux

Abstrait

Development of a biofertilizer for tea agriculture by using different organic materials

Esra Kutlu Sezer, Ayten Namli

Turkey is considered to be one of the rare countries that can produce large amount of tea in a narrow land area and tea has a crucial role in the agricultural economy of Eastern Black Sea, Turkey where the background of Turkish Tea Agriculture goes back to 1950’s. Although there has been no serious problem in tea soils of Black Sea Turkey for the last three decades, Turkish tea sector have been recently suffering from several soil problems such as acidification, surface compaction, nutrient leaching, decrease in cation exchange capacity, water retention and microbial diversity and increasing soil erosion. In light of these facts, the purpose of the present study was to develop a biofertilizer formulation that can be applicable to problematic tea soils.

The study consists of three main steps including (i) biochar production and characterization, (ii) experimental biofertilizer production and finally (iii) soil incubation step.  In the first step, biochars obtanied from poultry bedding and tea residue under different the pyrolysis conditions, i.e. between 300 and 700 C) were characterized to figure most appropriate one with the highest specific surface area and microporosity. In the second step, plant growth promoting rhizobacteria isolated from acidic tea soils (Pseudomonas fluorescens, Bacillus subtilis, B. licheniformis and B. pumilus) were properly propagated and loaded to potential biochar carrier(s) in order to obtain solid biofertilizer formula. Followingly, 6 months soil incubation experiment was conducted to screen the effect of different biofertilizer formula on a variety of soil physical and chemical characteristics and also to determine the suitable application dose. Within the stages of 30, 60, 120 and 180. days, soil samples were collected to perform soil analysis including pH, EC, SOM, total N, bioavailable P, exchangable K, Ca, Mg, Fe, Cu, Zn, Mn, Pb, Cd, Ni, B, Cr, microbial counting, enzyme analysis (acid phosphatase, B-glucosidase and urease), soil respiration and soil microbial biomass.