1、 Promotion and Application of Rape Transplanter

(1) Successfully developed joint transplanting machine and achieved mass production and sales

In response to the difficult field conditions such as heavy soil viscosity and straw return in rice stubble fields, as well as the lack of effective tillage and land preparation equipment, it is difficult to meet the requirements before transplanting, which seriously affects the quality of planting. Since 2018, a 2ZGK-6 fully automatic transplanting joint operation machine integrating tillage and transplanting functions has been developed, achieving full return of rice straw, transplanting under complex soil moisture conditions, transplanting quality The efficiency has been greatly improved. The prototype has passed performance testing. At the observation meeting held in Suzhou in November 2020, Wang Hanzhong, the vice president of the Chinese Academy of Agricultural Sciences, academician of the CAE Member, the chief scientist of the national rape industry technology system, said in his speech at the meeting: "Japan, as a developed country, is the world's leading level in small agricultural machinery, and paying for our technology fully demonstrates our advanced technology". Zhang Hongcheng, a professor of Yangzhou University and an academician of the CAE Member, said in his speech that "there are two major breakthroughs in this technology on the spot: one is the blanket seedling technology of rape, and the other is the efficient mechanical transplanting technology". The attending experts and leaders gave high praise and were widely welcomed by the majority of farmers.

In 2021, the rapeseed blanket seedling combined transplanting technology was transformed in Jiangsu Yunma Agricultural Machinery Manufacturing Co., Ltd. Through optimization and improvement of the scientific research prototype, a 2ZGK-6 combined transplanting machine was created and mass-produced for sales, which was promoted and applied in Jiangxi, Jiangsu, Hunan, Sichuan, Anhui, Guangdong and other regions.

The picture shows the 2ZGK-6 combined transplanting machine and its operation effect

(2) The seedling cultivation technology has matured, forming standardization and localization.

After 10 years of research and development and improvement, the rapeseed blanket seedling cultivation technology has become relatively mature, forming standardization of seedling cultivation technology. Through experiments, improvements, and innovations in various regions, the technology has been localized. Farmers can cultivate blanket seedlings that meet the requirements of transplanting machinery according to the standardized operation of seedling cultivation technology.

The picture shows the cultivation of rapeseed seedlings in a carpet shaped field

2、 Feasibility Analysis of Existing Rape Transplanter Technology

1. Current situation and problems of rapeseed industry

Rapeseed is the most important oil crop in China, providing over 50% of domestic edible oil, and has unique advantages in diversified utilization such as vegetable, feed, honey, flower, and fertilizer use. Approximately 100 million acres are planted annually, with 90% concentrated in the rice oil rotation area of the Yangtze River Basin. In recent years, with the improvement of people's living standards, the requirements for the quality and taste of rice have become increasingly high. The traditional double season late rice and one season rice harvest periods have been generally postponed and intensified year by year. The rice harvest periods in the middle and lower reaches of the Yangtze River have been postponed from before the end of September and before October 20th to early October and mid November, and even in December, the rice harvest has seriously missed the optimal sowing time for rapeseed planting, The yield of barely sown crops is very low (a decrease of over 30% compared to normal yields), and most people choose to abandon their crops, resulting in a large number of winter fallow fields. According to statistics, there are over 64 million acres of winter fallow fields that can develop rapeseed nationwide. Developing winter fallow oilseed rape through innovative seedling and transplant methods, technologies, and equipment is of great significance for significantly improving China's self-sufficiency rate of edible oil and implementing the rural revitalization strategy.

2. Technological innovation

The main obstacles to the development of winter fallow field rapeseed are the contradiction between rice oil rotation and insufficient growth period of rapeseed, which leads to a significant decrease in yield. However, seedling cultivation and transplanting technology compensates for a growth period of more than 30 days, and has the most prominent effect on increasing yield and stabilizing yield among all relevant technologies (such as tolerant late sowing varieties, dense supplementary late sowing, and (rice) pre harvest aerial sowing).

Traditional manual seedling cultivation and transplantation have high labor intensity and low efficiency, and are no longer sustainable. The existing domestic and foreign transplanting machines cannot meet the requirements for efficient transplanting of rapeseed in rice stubble fields. There are two major problems: firstly, the field conditions are not suitable and cannot be planted. The existing domestic and foreign transplanting machines, including fully automatic transplanting machines from countries such as Australia and Italy, which represent the world's advanced level, are all in dry land and have been cultivated to achieve soil looseness and fragmentation. Then, they are transplanted by digging trenches or holes, relying on soil backflow to achieve seedling establishment. They cannot adapt to the field conditions of sticky soil and straw return in rice stubble fields, and cannot stand seedlings; The second is low efficiency and slow planting. The existing semi-automatic transplanting machines, such as chain clip, seedling guide tube, and flexible disc, have a planting frequency of 35-45 plants per minute, which is far from meeting the needs of high-density transplanting of over 10000 rapeseed plants per acre.

In response to major industrial demands, the Nanjing Agricultural Mechanization Research Institute of the Ministry of Agriculture and Rural Affairs and Yangzhou University have jointly developed a research team. Since 2010, after more than 10 years of research, they have solved the technical difficulties of full return of rice straw to the field, efficient and high-quality transplanting under high moisture content soil conditions, and achieved high-density, high-efficiency, and high-quality transplanting of rapeseed under complex soil moisture conditions. The main technological innovations are as follows:

(1) Pioneering rapeseed blanket seedling cultivation technology.

We have changed the traditional seedling cultivation methods of low density seedling bed and artificial bare root seedling transplantation, and pioneered a high-density standardized seedling cultivation technology for rapeseed blanket seedlings that prevents overgrowth, promotes full seedling growth, assists in carpet formation, and improves quality. For the first time in the world, we have cultivated rapeseed blanket seedlings with high density, good quality, and suitable for mechanical cutting and transplanting. The seedling density is 30 times higher than traditional field sowing seedling cultivation (100 plants/square meter), reaching 3000 plants/square meter, The seedling age is 30-45 days, making it easy for the transplanting machine to cut and transplant. It can be raised on site or in the field.

(2) Pioneering the new principle of transplanting by cutting seedlings and inserting them into gaps.

Breaking through the existing methods of digging holes and trenching for transplanting, a new transplanting principle of rapeseed blanket shaped seedling cutting and slot planting has been proposed. A differential dual control non circular gear planetary gear system transplanting mechanism has been innovatively designed to achieve high-speed, accurate, and stable planting movement with low speed seedling picking, rapid migration, pressing into soil, advance seedling pushing, and high-speed return. The transplanting mechanism carries seedling blocks and inserts them into the planting gap, relying on the squeezing between the seedling blocks and the planting gap to establish seedlings, eliminating the dependence of transplanting on soil fluidity, thereby improving the adaptability and planting efficiency of the transplanting machine to sticky soil.

(3) Create a joint plowing and transplanting machine (joint transplanting machine).

In order to solve the problems of large amount of straw returned to the field and heavy soil viscosity in the paddy field after tillage, it is difficult to smash the soil, bury the stubble, and open ditches and boxes, which seriously restrict the quality and efficiency of transplanting, we have innovated the seedbed preparation technology of overall reverse rotation broken straw burying, split side throwing, ditch cleaning and wall building, staggered soil straw implantation, flat border cutting, automatic matching technology of planting hole spacing, and planting depth control technology of unit profiling and ground pressure adaptation, We have created the 2ZGK-6 joint transplanting machine and put it into mass production in 2021. We have completed multiple processes in one go, including rotary tillage and stubble removal, straw burying, trenching, border planting, slot cutting, block seedling picking, slot planting, and soil cutting and pressing. This has achieved full return of rice straw to the field and high-density, high-efficiency, and high-quality transplanting of rapeseed under complex soil moisture conditions.

3. Technical advantages

(1) High transplanting efficiency. Mechanized block cutting, seedling picking, and slot planting method, with a transplanting frequency of 300 plants per row per minute, is the highest transplanting frequency in the world. The overall operating efficiency of the machine is 6-8 acres per hour, which is 60-80 times that of manual transplanting and 13 times that of existing chain clamp transplanting machines.

(2) Strong adaptability. The joint transplanting machine not only improves work efficiency, but also enhances the ability of straw shredding and soil processing. It can be directly transplanted on the rice stubble field after rice harvest, and the plowing and transplanting are completed in one go, that is, plowing and transplanting, with an absolute soil moisture content of 15% -35%. By using high moisture content to seize moisture and transplant, the plant can generally live without watering, achieving efficient and high-quality transplanting under conditions of full straw return and high moisture content fields, Extremely adaptable to field conditions.

(3) Transplantation yields high. Carpet shaped seedling transplantation of rapeseed has made up for the shortage of growth period caused by delayed stubble due to the seedling age of over 30 days. Transplanting with soil is easy to live and has a short slow seedling period. The transplant density reaches 10000 plants/mu, which has good conditions for high yield. The results of multiple field experiments show that carpet shaped seedling transplantation increases yield by more than 30% compared to late sowing rapeseed at the same period.

(4) Good comprehensive economic benefits.

The total depreciation cost, fuel consumption cost, and operator labor cost of the transplanting machine are about 50 yuan/mu, and the cost of seedling materials and management is 70 yuan/mu, totaling 120 yuan/mu. Compared with mechanical live broadcasting, the cost of seedling materials and management is 70 yuan/mu, which reduces the cost of seed saving by 25 yuan/mu. The actual increase in seedling cost is 45 yuan/mu, and the field operation cost is 10 yuan/mu, resulting in a total increase of 55 yuan/mu. According to the direct seeding rapeseed yield of 130 kg/mu and a 30% increase compared to the same period, an increase of 39 kg/mu is calculated, which is equivalent to 195 yuan/mu. After deducting the increased costs, the net profit per mu is 140 yuan/mu. Compared with manual transplanting, the yield remains the same, saving labor costs of 200 yuan/mu. It can be seen that the comprehensive economic benefits of this technology are good.

3、Economic feasibility analysis of existing rapeseed transplanting machines

Ensuring the safety of edible oil supply is a major issue that the government attaches great importance to. Among the four major oil crops (rape, soybean, peanut and sunflower), rape is the only one that does not compete with food crops for land. It is estimated that replacing 90 million tons of imported soybeans with assets each year would require an additional 700 to 800 million acres of arable land. Currently, arable land is decreasing year by year, and there is no way to increase it. Utilizing winter fallow fields to develop rapeseed without competing for land with grain can achieve both abundant grain and oil. Rapeseed is also a land nourishing crop, and planting rapeseed is more conducive to fertilizing the soil than fallow. It has unique advantages in diversified utilization such as vegetable, feed, honey, flower, and fertilizer use, and has enormous development potential. Preliminary estimation shows that the market demand is 160000 units.

This technology provides a new and feasible technical approach and equipment support for the development and utilization of winter fallow fields, expanding the planting area of rapeseed, and increasing the unit and total yield of rapeseed. It will develop 64 million acres of winter fallow fields into winter rapeseed, increasing the total yield of rapeseed by 10 million tons, an increase of over 80%. By then, it can increase China's self-sufficiency rate of edible oil from the current 31% to nearly 40%, which is of great strategic significance for improving China's self-sufficiency rate of edible oil. At the same time, this technology does not affect rice production, achieving both abundant grain and oil, and annual high yield and efficiency. Utilizing winter fallow fields to develop winter rapeseed is more conducive to improving soil fertility than fallow cultivation, and can combine unique advantages such as vegetable use, feed use, honey use, flower use, and fertilizer use to contribute to rural revitalization. This technology can also be applied to the transplantation of vegetables such as green vegetables, celery, leeks, mustard, etc., with a broader application prospect.

4、Measures to be taken for the large-scale promotion and application of rapeseed transplanting machines

Due to the high production cost and poor economic benefits of rapeseed in China, farmers' enthusiasm for planting is not high. Although the efficient transplanting technology of rapeseed blanket seedlings has high operational efficiency and good comprehensive economic benefits, farmers still feel troublesome due to the increased seedling raising process and cost, and the increased benefits (140 yuan/mu) are still insignificant compared to working in other industries to earn money, which cannot arouse farmers' interest. Therefore, the country should start from the strategic height of increasing the supply capacity of edible vegetable oil and support the promotion and application of this technology. It is recommended to introduce policies for seedling and transplant subsidies to enhance farmers' enthusiasm for using winter fallow fields to develop rapeseed.