Características físicas do solo e plantas espontâneas em plantio direto de beterraba sob diferentes densidades de cobertura de milho

Abstract

The bean belonging to the family Amaranthaceae is one of the main vegetables produced in Brazil. However, new techniques of cultivation and soil preparation are being employed, among them the SPDH (Direct Planting System in Vegetables). A soil cover option is corn, which due to its high amount of phytomass presents slower decomposition in no-tillage, which can be attributed to its high C / N ratio. The objective of the present work was to verify the physical characteristics of the soil and to evaluate the incidence of spontaneous plants in no - tillage system of beet with different densities of corn plants.The experiment was carried out in the municipality of Nova Laranjeiras (Pr) under no - tillage system, using corn as soil cover in different densities (0 40 60 80 and 100 thousand plants / ha) for the cultivation of the beet cultivar Early Wonder Tall Top. The experimental design used was in blocks intercalated in a uni factorial scheme. The variables evaluated were water retention capacity, soil basal respiration, straw decomposition index, area height, number of leaves and survival index of beet plants, incidence of phytophagous and phytopathogens, and survey of spontaneous plants. Data were submitted to analysis of variance (ANOVA) and in the significant cases the means were compared to 5% of probability, a regression analysis and Tukey's test were performed. The results for water retention capacity, soil basal respiration and spontaneous plant incidence were significant for densities and periods of evaluation. It is concluded that in relation to the soil water retention capacity and basal respiration of the soil in no-tillage systems, corn densities of 40, 60 (thousand plants / ha) are recommended. The use of corn cover on the beet beds reduced the incidence of spontaneous plants.