Kiev ( Ukraine ) - (AFP) - A Ukrainian official told AFP on Friday that the country's grain harvest had fallen by about 40 percent year-on-year due to the Russian invasion.

"We expect a grain harvest of 65-66 million tons" by the end of the year, after a record harvest of 106 million tons last year, said Sergei Ivashchenko, head of the Ukrainian Grain Association.

He added that "the main reason is the war," which led to a shortage of fuel and impeded sowing.

Ukraine is a major grain exporter, but the Russian invasion that began on February 24 disrupted exports, with 20 million tons of grain stuck in the country's ports.

"The ports were closed ... that cycle was broken," Ivashchenko said, by cutting off farmers' source of income.

"That, and the war of course, means that farmers did not have enough money to buy fertilizers as their yields decreased," he explained.

A landmark agreement in July brokered by the United Nations and Turkey created a safe passage for cargo ships, allowing exports to resume.

The head of the Ukrainian Grain Association confirmed that "the occupation of several regions, the battles in the fields and the destruction of the infrastructure" are all factors that are still hindering production.

And he added, "We usually grow grain in more than 25 million hectares. This year we harvested only 18 to 19 million hectares."

The historic agreement was extended for 120 days in November after intense negotiations with Russia, which temporarily withdrew from the agreement.

In total, 580 ships carrying about 15 million tons of grain have left Ukrainian ports since the deal was concluded, according to Ukrainian authorities.