NAPERVILLE, (Ill.): China, which plants more corn than any other country, has launched plans to begin sowing genetically engineered corn this year in order to boost food security and reduce reliance on imports.

But it could be many years before the desired result is achieved as soil health is taxed and arable land is constrained. That could cause China to lean more heavily on grain imports if its own production costs become too high or if overseas supply becomes cheap again.

Beijing last week approved planting of genetically modified (GM) corn for this year, though GM acres will likely account for less than 1% of the total corn area. China said on Tuesday it would expand the scope of its trials on GM crops, which have long faced opposition in the country.

Almost all arable land in China is already in use, and that area is declining. The country’s latest land use survey published in 2021 showed a 6% decline in arable land from 2009 to 2019, so higher yields hold the key to the planned crop production growth. The lack of plentiful high-quality topsoil, something that can take centuries to replenish if lost, is perhaps China’s biggest limitation when it comes to boosting yields.

One Chinese scientist recently estimated that the content of organic matter in China’s fertile Northeast soils has fallen by up to 75% over the last several decades. Poor practices, such as the overuse of synthetic fertilizers, have sped up erosion and acidification of the soil.

Beijing a year ago launched its first national soil quality survey in more than 40 years, and data collection will last through 2025. But government researchers said last month the area and intensity of soil erosion had significantly declined in the last 10 years.

Corn yields in China have increased by more than 10% in the last decade, and yield growth in the last few years has actually outpaced the United States. This could partially stem from excessive fertilizer and chemical use, which sacrifices soil health for a small bump in yields.

Additionally, state media reported in 2021 that up to 70% of corn acres in China’s main grain belt may be illegally sown with GM seed. Beijing is not shy when it comes to spending on food security, as it dedicates large funds to things such as farmland preservation, land consolidation and production subsidies.

But global grain and oilseed prices have been high for more than two years, heightening China’s urgency to invest more heavily in its own crop production. It is uncertain if these efforts will still be prioritized if prices ease. During lower price periods in the past, it was sometimes cheaper for Chinese buyers to import foreign grain instead of transporting domestic supplies from production areas to livestock areas further south.

China harvests the second largest combined grain and oilseed area in the world after India, some 33% more than in No. 3 United States. On average, China’s area has remained steady over the last decade but is now about 11% higher versus 40 years ago.