The first assignment received this year by the Kunjiang Crop Protection Team from Hegang City, Heilongjiang Province was to help Mr Zhang in the neighboring village to sow his paddy fields. “Labor cost has increased this year, and it’s been difficult to hire enough workers for our large fields. Nowadays, young people have gone to work in cities and only the elderly like us are left in the village,” said Zhang in a helpless tone.
In the past, to transplant with machines, farmers had to start building greenhouses, cultivating seedlings, and transplanting in early March––a cycle that lasts up to two and a half months. “Machine transplanting is cumbersome and time-consuming. During peak periods, our average labor cost is 450-500 yuan/day.”Counting with his fingers, Zhang was struggling to do the math for his expenses of machine transplanting.
For this mission, the Kunjiang Crop Protection Team chose to use the AGRAS T40 to sow Zhang’s fields directly. “The T40 can cover 3 hectares in an hour, and complete 33 hectares in a day.”
Flat and even fields
For direct sowing, a rice field must be flat and without stagnant water, with a maximum height difference of 3 to 5 cm. For the fertile lands in the three northeastern provinces, care must be taken to ensure the mud is not too soft, otherwise seeds may sink into the mud. After a field is leveled, if a seed cast from three meters in the air would sunk in the mud, the field should be left to dry in the sun for three to five days until the soil is hard enough for direct sowing by drones.
Seed soaking + forced germination
Before forced germination, the rice seeds must be bagged and then the bags filled and sealed. The seeds are then soaked in fungicides to eliminate all germs, to increase the chances of germination and the crop’s immunity against diseases. As for the forced germination process, the seeds only need to be planted in an intelligent water and temperature-controlled tank for seven days to induce their germination significantly.
Sprout Drying
After germination, the rice seeds must be laid flat in a cool, ventilated place until they no longer feel moist when held in your hands. Alternatively, you could let the seeds fall one by one through gaps in your hands, and if they do not stick together, it means they are dry enough.
If the seeds are not sufficiently dry after germination, they can easily clump together and result in uneven and inaccurate spreading.
Timing of Operation
The operation took place in early May, with the temperature on the day itself reaching 15°C. A conducive temperature is extremely important for direct sowing on paddy fields in colder regions, as it could affect the survival rate of the seeds.
Operation Parameter
Aircraft model |
T40 |
Flight speed |
6 m/s |
Relative height |
3.5 m |
Row width |
5 m |
Consumption per hectare |
189 kg/ha (after soaking) |
Spinner rotating speed |
1,000 r/min |
Operation mode |
Fully autonomous route (auto boundary coverage) |
Operation Results
May 12: Seeds spread using the T40 were evenly scattered on the soil.
June 2: Green sprouts were visibly growing from each seed 23 days after sowing.
June 24 - The seedings were thriving 44 days after sowing.
July 10 - 60 days after sowing.
Local farmers shared that seeds that are manually sown would often be distributed unevenly, and manual sowing was inefficient, with a worker only able to work five hectares a day. But with direct sowing from the air, the efficiency is 10 times that of traditional mechanical transplantation. It also does away with the need to purchase equipment for greenhouses, seedling cultivation, and other purposes, which reduces labor and production costs significantly. “Using the T40 to sow rice directly on 33 hectares of fields saves up to 36,500 yuan in costs. This is not including some miscellaneous costs.”
“It’s very convenient. With the drones, you don’t have to hire so many workers and it also makes the process simpler. They can also spray fertilizers and pesticides. I feel like we can rely on one aircraft to work the whole year round!”
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