LIQUID FERTILISER FROM NEST REFUSE OF LEAF-CUTTER ANT NESTS (ATTA SP.) IN LETTUCE SEEDLING PRODUCTION

The demand for bioinputs for use in agriculture is growing, and liquid biofertilisers have emerged as a practical and affordable tool for small-scale organic vegetable production. The use of liquid biofertilisers in lettuce cultivation represents an alternative to complement the nutritional needs of plants and reduce production costs using commercial formulations. The nest refuse (NR) of leafcutter ants is an agglomerate of discarded plant material along with residues from its symbiotic fungus. For this reason, it is rich in nutrients and has potential as a biofertiliser. This study aimed to evaluate the effect of a liquid formulation of nest refuse (NR), produced by the leafcutter ant Atta opaciceps (Hymenoptera: Formicidae), on the production of lettuce seedlings. The experiment was conducted following a randomized design, arranged into two treatments with five replicates. The treatments consisted of the following steps: control, composed only of a commercial substrate, and treatment (commercial substrate + liquid solution containing 10% NR). The seeds were sown in expanded polystyrene trays with 128 cells, each with a volume of 40 cm3. The biological parameters evaluated were fresh and dry weights, stem diameter, total length, number of leaves, and root length. Plants treated with biofertiliser showed higher fresh and dry weights, stem diameter, total length and number of leaves. In addition, the levels of macronutrients P, K, Ca and Mg were significantly higher in the biofertiliser when compared with the control substrate. Thus, the addition of biofertiliser to the substrate provided more vigorous plants, in response to the increase in macronutrient levels.