Características del sustrato y calidad de plantines delechuga (Lactuca sativa L.) según dosisde lombricompuesto

Abstract

Substrates with vermicompost added promote growth in horticultural crops. Therefore, it is important to know its properties in order to apply proper amounts of it. This work aims to analyze substrate changes according to vermicompost doses and evaluate the effect of the mixtures on letuce seedling quality. The essay was carried out under greenhouse conditions in Luján, Argentina (34°36′ S, 59°04′ W). Buterhead letuce cv. Tizona was sown using substrates with different amounts of vermicompost added and a commercial mix of peat and perlite: 1) 0% vermicompost, 2) 20% vermicompost, 3) 40% vermicompost. The substrates were analyzed physically and chemically. The number of leaves and both fresh and dry weights of leaves, roots and plant were determined. The treatments were established in a complete randomized block design with four replications. Data were evaluated by analysis of variance, while the difference between means was studied by Tukey's Test. Regression analysis was used to study the response of substrate physical and chemical parameters to the addition of vermicompost, ranging from 0 to 40%. The addition of vermicompost resulted in a linear increased in pH, electrical conductivity, nutrient level, bulk density and total porosity of the substrate, while organic mater decreased linearly and quadratically the percentage of pores occupied by water. The plants responded to the addition of vermicompost, with a 20% increase in size.