Xinhua News Agency, Changsha, August 25 - Question: why the particle positions difficult to achieve? The loss of my country's grain harvesting link is staggering
Xinhua News Agency reporters Zhou Nan, Wang Jian, Song Xiaodong, Dong Jun
Recently, food waste has become a hot spot of public concern. However, compared with the commonplace "waste on the tip of the tongue," the loss of my country's grain from production to processing chain is less known, but it is equally shocking.
Data from the National Bureau of Grain and Material Reserves shows that the annual loss of my country's grain in the storage, transportation and processing links amounts to 70 billion jin. The food output of Sichuan Province in 2019 was more than 69.9 billion catties.
In a recent survey conducted by reporters from Xinhua Viewpoint, grain farmers, agricultural cadres, and agricultural experts generally reported that the loss of grain harvesting is very prominent. Not to mention the return of pellets to warehouses, some machine harvest loss rates are even as high as 10%.
The loss of food in the fields that the harvester drives through is heartbreaking
After the summer, harvesters roared on the plain of Dongting Lake, tractors came and went, and grain farmers were rushing to harvest early rice.
Yu Zhongyong, chairman of the Honesty Rice Cultivation Cooperative in Yueyang County, Hunan Province, looked at the busy farming scene in front of him, but felt a little heartbroken. In the fields where the harvester drove, many ears of rice were often left behind, and the rice was scattered everywhere. He picked up a full ear of rice and sighed: "Mechanization has indeed improved the efficiency of grain harvesting, but the operation is not detailed enough, resulting in a lot of grain loss."
When reporters interviewed in Hunan, Heilongjiang, Henan and other major grain producing provinces, grain farmers generally reported that the problem of grain loss in the harvesting process is still quite prominent.
First of all, mechanical contact caused some losses during harvesting. "The rolling of the harvester's puller wheel can easily cause the rice at the end of the ear to fall off, and the loss rate ranges from 3% to 5%." A large grain grower in Hunan Province told Tie Qing.
Secondly, incomplete threshing can also cause losses. The reporter had interviewed many soybean harvesting sites in Heilongjiang Province and saw some soybeans left in the field. He grabbed a handful of pods on the ground, and there were more than 10 soybeans in it, showing that the threshing was not complete. Mao Zhijiang, a villager in Xiaonanhe Village, Raohe County, Heilongjiang Province, said that in the past, manual harvesting resulted in fewer losses, but now the harvesting progress is faster and losses have increased significantly.
The loss of machine harvested corn is also more obvious. Liu Guoming, a large grain grower in Lanxi County, Heilongjiang Province, has planted more than 5,000 acres of corn. He said that corn kernels are relatively dry and crisp, and corn kernels are easy to fall when harvesting corn cobs. If the corn falls down, some corn cobs will fall and lose. Further increase.
Chen Zhi, president of the China Agricultural Machinery Industry Association, believes that at present, my country's agricultural harvesters mainly suffer from two general technical problems of crop loss and damage. The total loss rate and total damage rate of some corn machines are as high as 10%. A scholar from China Agricultural University Wulaping Pingtong found in the survey that the loss rate of the mechanical harvesting link of rice and wheat was 3.83% and 4.12%, respectively.
"The loss rate in actual operation is higher than theoretically." Zhu Qizhen, director of the Institute of Farmer Issues of China Agricultural University, believes that theoretically the loss rate is calculated according to the best harvesting conditions, but in reality it is difficult to fully achieve the best harvesting conditions. For example, over-maturity of grain makes it easier to fall off, and rainy weather causes grain adhesion to affect threshing.
And the losses due to cost considerations cannot be ignored. Zhou Bo, a major grain grower in Yuanjiang City, Hunan Province, said: “Rice that is close to maturity is prone to lodging in strong winds. If the lodging is severe, the harvester is difficult to harvest, and manual harvesting costs are high, so they often give up. ."
In addition, the problem of mechanical harvesting caused by irregular fields has also led to a lot of waste. Ma Wentian, a farmer in Puyang County, Henan Province, lives in the Yellow River beach area. The land is irregular, and the corners are small and cannot be harvested by machine. He said: "When you are free, you can collect it with your sickle. If you are too busy, just ignore it."
The level of refined operation of the harvester is not high
Large grain growers such as Zhou Bo reported that among the main reasons for grain loss in the harvesting process, the low level of refined operations of harvesting machinery is more prominent.
Chen Zhi believes that many current harvesters are difficult to perform efficient and high-quality processing of crops. For example, they cannot accurately strip corn grains, mandrels, stalks, and bracts. The cleaning process of rice harvesters has long been serious. The problem of adhesion and blockage, the grains cannot be separated in time; the head of the wheat harvester hits the head of the ear at high speed, resulting in serious loss of grain loss.
Chen Zhi told reporters that high-speed collisions in the ear picking and threshing processes will cause serious grain breakage. Once the grains are broken, especially cracks, they will have a greater impact on the later storage. As long as the storage environment has a slightly higher moisture content, it will easily produce mildew and can no longer be used as a ration.
He said: "There are national standards for the loss rate of harvesters, but grain breakage caused by collisions, especially cracks, is difficult to measure, and there is a long lack of relevant national standards."
Many grain farmers and agricultural experts reported that the problem of insufficient refinement of domestic harvesters is more prominent. Xia Zhaoyou, head of the Qiangsheng Agricultural Machinery Cooperative in Hegang City, Heilongjiang Province, said that as an important transmission transmission system gear in agricultural machinery equipment, some domestic products have relatively low gear grinding accuracy and poor meshing tightness, which results in shifting, shifting, and turning. In actual operation, problems such as jamming and operation delay are likely to occur, which will affect the quality of the operation and the safety of the operation.
Chen Zhi believes that the design and manufacture of foreign harvesters have a solid theoretical foundation and a large number of field tests, and some mechanical properties are relatively better. However, it should also be noted that foreign harvesters are mostly faced with highly intensive fields, the working environment is relatively single, the variable factors are few, and the operation is relatively stable.
He said: "The diversity of food varieties, agronomy, climate, etc. in China has formed natural and variable agricultural conditions, which makes it difficult for harvesters to be standardized and universal. Take corn as an example, the planting row spacing in China is 30 to 65 The difference between centimeters and different regions has resulted in a high rate of mechanized ear picking and missed picking. In some developed countries, the corn planting row spacing is uniform. One type of machine can work on corn in various regions with a low loss rate."
Strengthen scientific research on agricultural machinery and accelerate the construction of high-standard farmland
"my country's agriculture needs to accelerate its transformation and upgrading. There is still a lot of room for development, such as improving the performance of harvesters, building high-standard farmland, optimizing the quality of agricultural machinery operators, and researching and developing anti-lodging grain varieties." Zhu Qizhen told reporters.
-It is necessary to actively integrate scientific research forces and strengthen basic scientific and technological research in the grain harvesting process. Chen Zhi suggested that it is necessary to speed up the construction of a batch of technology R&D integration platforms, make full use of the principle of agricultural machinery and agronomic integration, design and manufacture harvesters that can adapt to agronomic characteristics, and improve the matching of mechanical structure and working condition parameters to crop mechanics.
-It is necessary to make breakthroughs in a number of key technologies and cross-integrate artificial intelligence technologies. Chen Zhi suggested that it is necessary to ascertain the laws of crop adhesion and fracture under different mechanical actions, accurately construct crop-mechanical interaction models, develop new algorithms and new sensors that can characterize the above models, and form adjustments to various operating conditions. Technology to achieve crop harvesting to reduce losses and increase efficiency.
-To further accelerate the construction of high-standard farmland. Li Guoxiang, a researcher at the Institute of Rural Development of the Chinese Academy of Social Sciences, suggested that the degree of land fragmentation should be reduced. The larger the planting scale, the more systematic the field, the more conducive to the operation of the combine harvester and the reduction of losses.
——Strengthen professional skills training and improve the service level of agricultural machinery. Li Guoxiang suggested that agricultural machinery operators should be trained regularly to enhance their awareness of saving food. At the same time, they should improve the content of the socialized service contract for mechanical collection and include the loss rate in the service terms.