BUENOS AIRES, April 17 (Reuters) - Drought-wary Argentine farmers are expected to plant 5.9 million hectares (14.6 million acres) with wheat in the 2024/25 season, the Buenos Aires grain exchange said on Wednesday, a forecast below the five-year average.

Argentina is a key global supplier of wheat, but fears over the return of La Nina as soon as July have influenced some farmers to forgo wheat planting and save moist soil for corn and soy crops.

La Nina, a climate phenomenon that usually brings dry weather with lower rainfall, contributed to the historic drought that battered the 2022/23 harvest, cutting the wheat crop in half.

In recent weeks, Argentine farmlands have been soaked by above-average rainfall.

"The forecast of a year hit by the La Nina phenomenon leads many producers to choose to leave lots fallow (unplanted), with the aim of preserving recently stored moisture for the next cycle's corn and soy," the exchange said in its pre-season wheat report.

The exchange's projected wheat area, its first for the season that begins in late May, is below the 6.34 million hectares planted on average each season for the last five years.

The exchange cited increased production costs another factor in the smaller area estimate, adding that government measures to mitigate price hikes, including reduced tariffs on certain herbicides and fertilizers "will likely have a limited effect."

In the 2023/24 season, Argentine producers also planted 5.9 million hectares with wheat, harvesting 15.1 million metric tons. In the 2021/22 campaign, Argentina hit a production record of 22.4 million tons after planting 6.7 million hectares. (Reporting by Maximilian Heath; Editing by Chris Reese and Sandra Maler)