Under the scorching heat, multiple unmanned harvesters operate at full capacity to harvest rice at the Wanlyu Intelligent Unmanned Farm in Dongyuan county, located in Heyuan, Guangdong province.

As the largest high-tech agricultural demonstration base in Guangdong, the farm has recently welcomed the start of the local summer grain harvest.

The unmanned harvesters are moving forward at a constant speed along a preset route. Their sharp cutting platforms neatly draw in the heavy rice sheaves, and processes such as threshing and straw crushing are completed in one go.

Amid the roar of machines, plump rice grains pour into transport vehicles through automatic unloading devices, while technicians monitor yield data and machine status in real time via a mobile app.

The local agricultural department has forecast the farm's yield per hectare at 9 metric tons this year, marking the fourth consecutive year the farm's yield per hectare has exceeded the national average since it was established in 2022, said Wang Jiankuan, the farm's manager.

Led by the Dongyuan county government, the farm was jointly developed by Guangdong Wanlyu Smart Agricultural Technology Co and a team led by Luo Xiwen, an academician with the Chinese Academy of Engineering.

Last year, the farm reduced labor costs by 30 percent compared with ordinary rice fields, while achieving an average yield per hectare of 8.8 tons, an increase of 11 percent year-on-year. China's average annual rice yield is 7.2 tons per hectare, according to Luo.

The farm uses new high-yield, high-resistance rice varieties alongside variable fertilization and dense planting methods to boost productivity, Luo said.

"Now the farm is the most advanced and largest unmanned rice farm in Guangdong, covering over 6.7 square kilometers, including 1 square kilometer of unmanned core area," Wang said.

The farm integrates internet of things systems, Beidou navigation, artificial intelligence and other technologies to facilitate fully unmanned operations across the entire rice farming process, including soil preparation, planting, management and harvesting. Its machinery includes unmanned rotary tillers, rice transplanters and harvesters.

The unmanned harvesters rely on Beidou navigation and multispectral sensors to identify field boundaries and crop density accurately, control harvest losses and improve efficiency.

While manual harvesting typically covers 533 square meters a day, unmanned harvesters paired with grain transport vehicles can cover 46,667 to 53,333 square meters daily, increasing harvesting efficiency nearly 100-fold, Wang said.

Through remote cloud-based control, crop production efficiency has increased by more than 50 times compared with manual labor, he added.

Beidou navigation ensures transplanting row spacing errors are within 2 centimeters, while seed planting machines can ensure precision for each seed and hole, increasing seeding rates by 15 percent.

By promoting high-yield, high-quality, highly resistant aerospace rice varieties, the farm has further reduced management costs while enhancing risk resilience, Wang said.

Beyond reducing the need for manual labor, the unmanned farm is seen as a step toward achieving agricultural sustainability. Efforts such as real-time monitoring of soil, weather, pests and disease, drone patrols, electrified drying and cold chain storage have advanced the development of local green agriculture.

The farm has become a technological benchmark for rural vitalization in the province, managing 20 square kilometers of surrounding farmland and helping drive the combined annual income of the villagers to over 2 million yuan.

He Siming, deputy director of Dongyuan county's bureau of agriculture and rural affairs, said the farm has cultivated multiple rice varieties while integrating seed production, seedling raising, drying and processing.

"The farm, a main rice production area for the county, has achieved an annual output of more than 4,000 tons of rice and over 500 tons of seed production, driving the county's breeding and seed production area to expand to more than 3.33 square kilometers," He said.

The unmanned farm model will be promoted in more than 20 townships across Heyuan in the coming months, she added.

zhengcaixiong@chinadaily.com.cn