PUEBLO LLANO, Venezuela — In Venezuela, where hunger is rampant, a farmer recently had to abandon his entire crop. Guiding a pair of oxen, he drew a wooden plow over his field, turning over thousands of shriveled carrots.

The trucks that would pick up his harvest never came, he said.

A fuel shortage has been gripping the country since May, bringing the nation’s already struggling agriculture industry to the brink of collapse and threatening more hunger and malnutrition in a nation where nearly half the population is already eating fewer than three meals a day.

“It’s all lost,” said the farmer, Joandry Santiago, pointing to the spoiled vegetables which cost him months of wasted labor.

Venezuela is an oil-rich nation. But years of mismanagement and corruption in the oil industry, worsened by American sanctions, have dried up gasoline pumps at a crucial moment. First, the shortage prevented farmers like Mr. Santiago from getting their produce to markets. Now, it is making it hard for them to sow new crops.