Aristo was riding in a car and noticed a pond that was covered in algal blooms. which of these other features in the landscape could be the reason for the high levels of phosphorus? many cars cow pasture solar panels forest

The algal blooms are a result of the increased levels of the phosphorus in the water. The largest source of the phosphorus in the water bodies is the runoff from the grasslands and pastures. The cow pasture near the pond that Aristo visited is the source of the phosphorus in the pond, which lead to the harmful algal blooms in the pond. The cow manure is rich in phosphorus, which runs off to the nearby water bodies.

Hence, the answer is 'cow pastures'.

your spelling is a little off : ]