◎ Hong Hengfei Science and Technology Daily reporter Jiang Yun
Rows of tomato trees are placed in their respective "workstations", indoor environmental data is controlled by information platforms, and farmers only need to do some pruning work... Located in the Mizuki Moganshan Urban Agricultural Complex in Deqing County, Huzhou, a vegetable factory covering an area of nearly 40 acres operates all year round, with an annual output of about 1.2 million kilograms of tomatoes, which can meet the annual needs of nearly 50,000 people.
Efficient, high-quality plant factories like these are becoming known to the public.
In late August, the Zhejiang Provincial Agricultural High-quality Development Conference was held, proposing to vigorously implement the action of strengthening agriculture through science and technology, and seek breakthroughs in key core technologies of seed sources, green ecological breeding, agricultural biotechnology and factory agriculture, and change agricultural production efficiency.
"Plant factories achieve continuous crop production through high-precision environmental control in the facility, which represents the development direction of agriculture in the future and is also one of the important technologies to achieve agricultural emission reduction and carbon neutrality." Kong Dedong, director of the Digital Agriculture Factory Research Office of the Zhejiang Academy of Agricultural Sciences, said that as an integrated system of multiple technologies, the application of plant factories is not limited to planting melons, fruits and vegetables, and it may be useful to implement scientific and technological action to strengthen agriculture.
<h1 class="pgc-h-arrow-right" data-track="7" > get out of cost embarrassment Technological innovation can turn losses into profits</h1>
As early as the last century, the concept of "plant factory" was proposed. Over the decades, thanks to the iterative breakthroughs in hydroponics, LED artificial light sources and automatic control, plant factories have developed rapidly and are currently developed and applied in many countries in the world.
At the same time, operating energy consumption and equipment costs are the key factors affecting the benign development of plant factories.
It is not difficult to understand that plant factories usually carry out crop production in a closed environment, although they do not need to occupy a large area of land, and are not limited by environmental conditions, correspondingly, it is necessary to build supporting engineering and equipment including construction structures, air conditioning systems, artificial light sources, multi-layer cultivation systems, nutrient solution circulation and computer control systems.
"The plant factory initialized investment, and the construction cost per square meter ranged from thousands to 10,000 yuan. The energy consumption cost accounts for about 30% of the total production cost, mainly including artificial light sources and high-density plants, closed environment brought about by cooling and humidification energy consumption. Li Licensing, CEO of Hangzhou Hanhui Optoelectronics Technology Co., Ltd., introduced that the original LED lighting equipment has serious heat production, high drive energy consumption, low bio-energy efficiency, large power of lighting equipment, and additional increase in air conditioning workload. As the core equipment of the plant factory, the importance of light technology is self-evident.
In recent years, around the cost reduction of plant factories, corresponding technological breakthroughs have been made at home and abroad through industry-university-research cooperation.
Kong Dedong introduced that 2018 can be described as a watershed in the development of plant factories. Through technological innovation, on an international scale, plant factories have gradually got rid of cost embarrassment and actively explored business models.
"Photosynthesis is the most important biochemical reaction for plant growth, so developing bioenergy and decoding the plant digital environment has always been the most critical core technology in vertical agriculture." Li Licensing introduced that the fourth generation of plant photosynthetic LED chips and lighting systems developed by the company, the energy consumption per square meter is controlled between 50-150W, compared with the current mainstream WRB (white, red and blue mixed) or RGB (red, blue and green mixing) lighting equipment can save 30% to 50%, for leafy vegetables, fruits, strawberries and small grain crops and some crops breeding, in Zhejiang Academy of Agricultural Sciences, Anhui Academy of Agricultural Sciences, Shanghai Academy of Agricultural Sciences and other institutes have been promoted and applied.
Professor Zhou Hong, deputy dean of Zhejiang University Of Engineering College and expert of the International Semiconductor Lighting Alliance, said that the domestic more mature plant factory, its unit area output, can currently reach dozens of times that of traditional agriculture, but to be further promoted throughout the country, continuous reduction of equipment costs and operating energy consumption is still the focus of future research.
<h1 class="pgc-h-arrow-right" data-track="18" > try to breed grain Factory advantages to break the time and space limit</h1>
Not long ago, the Chinese Academy of Agricultural Sciences and the China Rice Research Institute jointly teamed to successfully achieve an important breakthrough in rice planting for about 60 days in a plant factory environment, shortening the rice growth cycle of more than 120 days in the traditional field environment by half.
Qian Qian, director of the Institute of Crop Sciences of the Chinese Academy of Agricultural Sciences, said in an interview with the media that for most crops, to cultivate new excellent germplasm, it takes several generations to propagate, usually taking years or even decades. Relying on plant factory technology, this time and space bottleneck has been broken.
In the flowering period, it is necessary to select the parent book for hybrid pollination, the asexual offspring need to be tracked throughout the process, the growth or yield of different growth periods is recorded one by one, and the performance of the plant field is observed. The long breeding cycle is a prominent problem in the breeding process of hybrid rice, and the reason is that the homozygous stability of the breeding material needs to be continuously self-inbred for multiple generations.
"In addition to meeting the needs of large-scale factory-based crop production applications, in terms of breeding, plant factories can give full play to the advantages of flexible and controllable factory environmental parameters, and reduce the breeding costs caused by time and space and climate limitations as much as possible." Li Licensing said that by adjusting the key indicators such as light, temperature, water, gas and fertilizer required by plants, we will accelerate crop photosynthesis, break through the restrictions of breeding by geography, season, and light and heat conditions, shorten the breeding period, accelerate the selection and breeding of new materials and new varieties, and solve the pain points in breeding research and development such as large investment in variety selection, long cycle, low efficiency, and large workload.
Li Licensing introduced that the company's team tried to grow rice indoors under the intelligent photosynthetic LED system last year, and the power of the lighting system required for 1m2 planting area was only 144W, and the two harvesting cycles were 90 days and 80 days respectively. Wheat planting research was conducted in an indoor laboratory in December last year, and wheat ear extraction was also two months earlier than in the northern field planting environment.
The so-called "orange is orange in Huainan, and orange in Huaibei is orange", plant varieties face a complex and changeable ecological environment in the process of promotion, and the conditions of light, temperature, water, gas, diseases and insect pests in various regions are different. For example, soybeans that are sensitive to light temperature are typical short-day and temperature-loving plants, which are quite sensitive to the response to the photoperiod and temperature, and the promotion range of varieties is limited, and the benefits of breeding are reduced.
"In the past, the outdoor selection of rapeseed, usually two seasons a year, after the use of intelligent LED spectroscopy system, although the cost of facilities increased slightly, but because of the use of accurately regulated spectra to simulate the original crop or planting ground light environment and climate, the crop cultivation cycle was significantly shortened, which can achieve 3 to 4 generations of breeding a year, so that the annual rapid breeding program increased by about twice; at the same time, it also saved the cost of off-site multi-generational breeding, greatly improved the research level and efficiency of scientific researchers, and effectively alleviated the "card neck" problem of breeding." Fei Weixin, a researcher at the Crop Research Institute of the Anhui Academy of Agricultural Sciences, believes.
<h1 class="pgc-h-arrow-right" data-track="27" > synergistic green energy Artificial forage alleviates ecological pressure</h1>
According to the Journal of the Chinese Academy of Sciences, in recent years, the dietary structure of Chinese residents has continued to upgrade, the demand for high-quality animal protein has increased, and the demand for forage grass has increased rigidly, and the demand for domestic forage feed will reach 10 million tons / year in the future. However, the quality of domestic forage products is poor, and livestock in more than 75% of areas are short of grass in winter, resulting in a large dependence on imports of forage hay.
At present, the protection of domestic forage germplasm resources basically adopts the method of off-site protection, resulting in the loss of genetic diversity of forage, and the protection and utilization of forage germplasm resources need to be strengthened. At the same time, due to natural disasters such as drought and little rainfall and human factors such as overload overgrazing, the phenomenon of "degradation", "desertification" and "salinization" in pastoral grasslands is widespread, and it is urgent to recuperate.
"Fortunately, containerized mobile forage factories were born on demand." Kong Dedong said that taking the results of joint development between the team and the enterprise as an example, a 40-foot standard container, covering an area of about 30 square meters, has a 7-day planting cycle of barley grass and can produce 270 tons of pasture in 9 months.
Professor Zhou Hong also said that the application of forage plant factories also needs to consider the problem of energy supply. In 2019, the curtailment rate in southern Xinjiang was as high as 14%, and the photovoltaic consumption was weak, and the high curtailment rate and power curtailment seriously restricted the development of the photovoltaic industry in the northwest. Therefore, the energy supply problem of the forage plant factory can be solved by comprehensively considering relying on wind power and photovoltaic power generation equipment to supply power nearby, or directly equipping the forage factory with photovoltaic panels. The team is actively docking pastoral areas in Inner Mongolia and other places, and will promote energy development and grassland and animal husbandry in a coordinated manner by abandoning wind and light.
Coincidentally, the State Power Investment Group has cooperated with plant factory enterprises in Inner Mongolia, Yan'an and other places to build photovoltaic + plant factories, plant vegetables and fruits in places where arable land resources are lacking, and forage grasses lacking in pastoral areas, so as to improve clean energy consumption and save cultivated land resources.
Zhou Hong said that whether it is factory-type forage or indoor cultivation of plants, the development and solution of plant factories need to constantly break through the existing structure of breeding + breeding, in the long run, this kind of "new energy + plant factory + animal husbandry" ecological cycle model can greatly reduce the pressure on land and water, alleviate the current situation of land desertification, promote carbon neutrality and carbon emissions of animal husbandry, achieve a virtuous cycle of ecological environment, and enhance the core competitiveness of agriculture.
Edited by: Huang Lei
Review: Yue Liang