Crescimento e nutrição de mudas de sisal cultivadas em campo com plantas de cobertura

Abstract

This study aimed to evaluate the growth and nutrition of sisal plants (Agave sisalana Perrine ex Engelm) from bulbils grown in a field nursery system with soil cover crops. The experiment was conducted at Aroeira farm, in Campo Formoso, Bahia, Brazil. The experimental design was in randomized blocks with the following treatments: T1- without cover crops; T2 – Pigeon pea (Cajanus cajan); T3 – Sunn hemp (Crotalaria juncea); T4 – Butterfly pea (Clitoria ternatea); T5 – Sorghum (Sorghum bicolor); T6 – Sorghum + Pigeon pea; T7 – Sorghum + Sunn hemp; T8 – Sorghum + Butterfly pea; T9 – Malva (Waltheria indica), and T10 – Capim-buffel (Cenchrus ciliares L.). The experimental plots were evaluated for growth and nutrition of sisal plants and the cover crops, and for soil available nutrients. The results show that the nursery field production system of sisal plants from bulbils and with cover crops, allows sisal plants to reach the recommended stage for field planting, with 180 days of growth. However, future studies should determine the best period for pre-planting of the bulbils in plastic trays before transplanting them to the nursery system or the elimination of this phase with bulbils being planted directly in the nursery beds. The cover crops grew well in soil with a pH 8.0. Under these growth conditions, the biomass of the consortium Sorghum + Sunn hemp accumulated high levels of Na, which should be further investigated with saline soils. Sorghum and the consortium Sorghum + Sunn hemp and Sorghum + Butterfly pea promoted the best results for plant biomass production and plant aerial part nutrient accumulation. However, a significant different effect of the cover crops on soil fertility and sisal plant growth was not observed. Long-term studies are necessary for the evaluation of the effects of cover crops in the growth and nutrition of sisal plants in the nursery phase and after field transplantation.