Fertilization and substrates influence Astronium balansae seedlings in the nursery: one step further for conservation

Abstract

Research regarding the conservation of species at risk of extinction is needed worldwide. In this context, the cultivation of seedlings for conservation purposes plays a pivotal role in meeting the demand of projects and the transplantation of these species into natural habitats. There is currently a lack of information regarding the optimal nursery inputs for cultivating high-quality seedlings of Astronium balansae, a forest species native to southern Brazil, Argentina and Paraguay. Therefore, this study aimed to investigate the effect of different substrates and fertilizer sources on the production of A. balansae seedlings in nurseries. At 130 days after sowing, the morphophysiological attributes of the seedlings were evaluated, revealing a significant influence of the chemical and physical characteristics of substrates on plant quality. Controlled-release fertilizer, particularly when used in specific proportions with carbonized rice husk, proved effective in enhancing production. The species exhibits tolerance to low fertility levels and high-porosity substrates; however, under such conditions, it did not exhibit optimal physiological and morphological features. The use of various fertilizers and different doses of carbonized rice husk impacted the quality and production time of A. balansae plants. Morphological and physiological characteristics demonstrated that the application of controlled-release fertilizer at 6 g L^-1, in association with 0 %, 20 %, and 40 % carbonized rice husk, enhanced plant quality within 130 days. All the evaluated attributes can be utilized to assess the quality of A. balansae plants.