Physical And Chemical Characterization Of Substrates Formed By Different Source Material

Background: The search for the ideal substrate that does not burden the production system is the key to discovering different components that, together, may have all the physical and chemical characteristics suitable for full plants development. Therefore, it is essential to find cheap, local alternatives and, at the same time, dispose of materials with high pollutant potential, such as agro-industrial waste. The present study aimed to characterize the physical and chemical characteristics of substrates formed by different materials of different origin and quantities. Materials and Methods: The experiment was developed at the Experimental Farm Laboratory of the Federal University of Grande Dourados, in a completely randomized design, with four substrates (treatments) and five replicates. All substrates were formed by the same quantities of sugarcane ash (20%), coarse sand (10%) and swine biological sludge (10%). Substrate A was formed by 30% sugarcane bagasse, 10% vermiculite, 10% sugarcane filter cake and 10% chicken litter; substrate B was formed by 20% sugarcane bagasse, 20% sugarcane filter cake and 20% chicken litter; substrate C was formed by 10% vermiculite, 10% sugarcane filter cake, 10% chicken litter and 30% sugarcane straw; finally, substrate D was formed by 20% sugarcane filter cake, 20% chicken litter and 20% sugarcane straw. The characteristics evaluated were: current moisture content, wet density, dry density, water retention capacity at 10 cm, total porosity, aeration space, available water, particle size, percentage of moisture loss, pH and electrical conductivity. Results: Substrates A and B may be indicated for use in pots measuring 20 to 30 cm in height, depending on the dry density, while substrates C and D may be used in pots larger than 30 cm. Total porosity and available water of all substrates presented values considered ideal. Conclusion: The values indicated in the theoretical reference of the literature indicate the substrates as nonadequate due to the high pH value, however, this indication may be reassessed depending on the species of plant that will be cultivated, while the electrical conductivity is in the range considered ideal for cultivation.