Differential Phenological Response of Quinoa to the Application of Vermicompost Leachate and Moderate Doses of Fish Hydrolysate under High Andean Rainfed Conditions

The farmers of Andes in rural areas commonly use fish hydrolysate and vermicompost leachate as cost-effective bio-inputs, either due to limited economic resources or a part of organic farming practices. However, their agronomic effectiveness for primary sources of plant nutrition under rainfed conditions remains insufficiently documented. This study evaluated the phenological response of quinoa (Chenopodium quinoa Willd.) to the applications of fish hydrolysate (1% and 2%) and vermicompost leachate (10%) at the Illpa Agrarian Experimental Station in Puno, Peru. Morphological parameters and yield components of quinoa and soil chemical properties were assessed at the end of the crop cycle. The results revealed a differentiated response by phenological stage: vermicompost leachate significantly enhanced plant height during the grain-filling stage, while 1% fish hydrolysate increased above ground dry weight without translating into significant yield gains compared to the control. Both biofertilizers improved soil parameters, including pH and cation exchange capacity, indicating a positive effect on soil quality. In conclusion, these inputs exert specific biostimulant effects during the vegetative stages, but do not entirely replace the function of comprehensive fertilization to achieve high yields. Nonetheless, their strategic use at key phenological stages of the cycle may support the development of more sustainable production systems in high Andean rainfed environments.