BEIJING — China's grain output saw a mild increase in 2017 as per unit yield climbed, official data showed Friday.

The country's grain output stood at about 617.9 million metric tons in 2017, up by 1.66 million tons, or 0.3 percent, compared with last year, according to the National Bureau of Statistics (NBS).

This was the second highest output in history, according to NBS statistician Hou Rui.

Grain planting area shrank by 815,000 hectares, while the per unit yield was up by 54 kilograms per hectare, or 1 percent year-on-year.

The growth in output came despite a reduction in output of high-yield grain, indicating progress in the supply-side structural reform in the agricultural sector, Hou said.

Facing an oversupply of corn and rising demand for soy and other grain varieties, many areas reduced corn planting in favor of soy and used some grain for feedstuff.

Corn planting area shrank by 3.6 percent, while that for beans increased by 6.7 percent in 2017, NBS data showed.