Use of vermicompost as an organic fertilizerto stimulate phytoplankton production andimprove the productive performance ofwhite shrimp Litopenaeus vannamei inintensive culture at low salinity

Abstract

In Mexico, annual shrimp production is on the rise, which has increased demand for feed for farmed organisms. In shrimp farming, fertilization plays a key role in stimulating primary productivity. Among the organic fertilizers used, vermicompost made from Eisenia foetida worms stands out, as it promotes phytoplankton growth and thus contributes to the healthy development of aquatic organisms. The objective was to analyse and evaluate different vermicomposts as promoters of phytoplankton development. Six treatments were tested in 12-liter tanks with water at 10 ups: T-1 solid vermicompost from cattle manure and T-2 solid vermicompost from plant waste 0.5 g·L-1, T-3 liquid vermicompost from cattle manure and T-4 liquid vermicompost from plant waste 0.1 L· L-1, T-5 urea 0.45 g·L-1, T-6 control without fertilizer, lasting 33 days. Water quality parameters were within the optimal ranges for shrimp farming. Regarding phytoplankton, the highest concentration was found in treatment T-2 (551,500 cells/ml). The identified microalgae groups were diatoms, chlorophytes, and cyanophytes. T-2 had the highest weight gain and 100% survival; however, there were no significant differences (P>0.05). The highest survival rate was in the vermicompost treatment (92%).  The highest amount of phytoplankton was found in the treatments with vermicompost.