Physical-Chemical characteristics of alternative substrates and fertilization on the growth and quality of Spondias macrocarpa seedlings

Abstract

The objectives were to determine the physical and chemical characteristics of different substrates, and assess the influence of different substrates, with and without the addition of controlled-release fertilizer, on the growth and morphological quality of taperebá (Spondias macrocarpa) seedlings. The experimental design adopted was a 2 x 6 factorial scheme, with the presence and absence of 8.0 g L-1 of encapsulated controlled-release fertilizer and six substrates [Sub1= soil; Sub2= soil + carbonized rice husk (2:1 v/v); Sub3= soil + organic compos (2:1 v/v); Sub4= soil + carbonized rice husk + organic compost (1:1:1); Sub5= soil + carbonized rice husk + organic compost (2:1:1); Sub 6= soil + carbonized rice husk + organic compost (2:2:1)], with five replicates, composed of 10 seedlings (one in each container). Formulations of substrates containing soil + carbonized rice husk + organic compost (1:1:1) and soil + organic compost (2:1 v/v) had total porosity ranging from 0.88 to 0.91 m3 m-3, aeration space from 0.33 to 0.35 m3 m-3 and available water from 0.27 to 0.29 m3 m-3, hence being suitable to obtain taperebá seedlings with superior quality. The substrate Cerrado soil (Sub1) is not viable for the production of taperebá seedlings, since it has acidic pH, an undesirable chemical characteristic for the cultivation of this species. Incorporation of controlled-release fertilizer into the substrates used in the present study led to better morphological characteristics, so it is indicated as an input for fertilization in the initial stage of growth of taperebá seedlings.

A reagent-free phosphate chemiresistive sensor using carbon nanotubes functionalized with crystal violet

“…2 Furthermore, the requirement for phosphorus varies depending on the plant and the growing methods, like aquaponics needing less phosphorus compared to hydroponics. 1,2,4–7 For instance, one study reported that the average concentrations of phosphate (PO 4 –P) used in the aquaponic and hydroponic systems were 20 mg l −1 (0.62 mM) and 149 mg l −1 (4.62 mM), respectively. 3 Therefore, the phosphorus content should be closely monitored in aquaponic and hydroponic systems.…”