Expanding legume-rhizobia system is the most effective way to reduce the amount of chemical nitrogen fertilizer in China. The report of Academician Chen Wenxin of China Agricultural University made the participants feel refreshed. Academician Chen Wenxin has devoted himself to the research and popularization of soybean rhizobia for 30 years, and has put forward suggestions to the Central Committee to strengthen this research and popularization more than once.
At the beginning of the founding of the People's Republic of China, under the leadership of several agricultural microbiology predecessors who returned to China, rhizobia inoculation experiments of soybean, peanut and Chinese milk vetch were widely carried out in China, and the results were very good, especially the inoculation effect of Chinese milk vetch was excellent, and the inoculation of rhizobia had a prosperous period. However, with the extensive application of chemical fertilizers, biological nitrogen fixation technology gradually faded out and was no longer taken seriously.
According to statistics, the annual consumption of nitrogen fertilizer in China accounts for 30% of the world. Taking the statistical data in 2004 as an example, the production of 33 million tons of nitrogen fertilizer in China needs to consume more than 654.38 billion tons of standard coal, while the utilization rate of nitrogen fertilizer is only 654.38+00% ~ 30%. According to the amount of chemical fertilizer and planting area in 2002, the average amount of nitrogen fertilizer applied in China is 2.88 times that of the United States, 5.79 times that of Brazil and 8.85 times that of Australia. Not to mention the harm of excessive application of chemical nitrogen fertilizer, only from the perspective of energy saving, biological nitrogen fixation technology should also be vigorously promoted.
Ge Cheng, a researcher at China Academy of Agricultural Sciences, shouted: Our oil will run out one day. Then where can we find nitrogen fertilizer? As we all know, nitrogen fertilizer is a product with high energy consumption, and reducing the input of chemical nitrogen fertilizer is of great significance to alleviate the energy shortage in China. Biological nitrogen fixation of leguminous plants is recognized as an effective technology in the world. Rhizobia of leguminous plants has the function of nitrogen fixation, and this technology has been adopted all over the world. Why not promote it vigorously?
"One Kilometer" Popularization of Rhizobia Agent
In the popularization of soybean rhizobia, the process from product to soil is called "one kilometer" problem of rhizobia popularization. "Experimental demonstration is the foundation, publicity and training is an important means, policy support is the key, and' fool' integration can really put technology in place", which is the successful experience of Heilongjiang Land Reclamation. The so-called "fool-like" integration refers to a set of convenient and simple fertilization models summed up in the reclamation area-soybean rhizobia+diammonium phosphate+potassium fertilizer.
It is exciting that from 2003 to 2007, the area of soybean rhizobia in Heilongjiang reclamation area was 8.2 million mu, and the urea input was reduced by nearly 40 thousand tons. The concept of biological nitrogen fixation is increasingly accepted by workers in reclamation areas. First, increasing production and increasing efficiency is obvious, which is a driving measure of soybean revitalization plan; Second, in the current situation of soaring fertilizer prices, the effect of reducing costs is considerable. The technical problems to be solved now are: first, to prolong the survival time or shelf life of rhizobia in packaging; Second, under open conditions, such as after seed dressing and before sowing, the survival time of rhizobia can be prolonged and the number of rhizobia can be increased.
The important position of soybean in planting structure is irreplaceable. In the United States, soybean planting area accounts for about 30%~40% of cultivated land, while in China, especially in the Northeast, soybean plays a very important role. In recent years, the price of soybean has risen, which has improved farmers' enthusiasm for planting; The soaring price of chemical fertilizer provides a very good opportunity for the popularization of rhizobia.
Gao, director of the Soil and Fertilizer Technology Division of the Agricultural Technology Extension Service Center of the Ministry of Agriculture, said that in recent years, the planting area of green manure and soybeans in southern China has been decreasing, and now is an excellent opportunity to popularize this technology on a large scale. On the one hand, it directly reduces the input of chemical nitrogen fertilizer and relieves the energy pressure in China; At the same time, it also contributed to the revitalization of soybean industry and provided technical support.
According to statistics, biological nitrogen fixation is about 200 million tons every year in the world, and leguminous nitrogen fixation accounts for 65%~80%, providing 50%~ 100% of the nitrogen needed by plants. Academician Chen's research for many years shows that the intercropping effect of leguminous plants and gramineous plants is obvious. Gramineae solved the obstacle of nitrogen repression for legumes, which not only increased the amount of nitrogen fixation, promoted the high yield of beans and Gramineae, but also reduced the harm of pests and diseases. If we observe the rotation process, leguminous crops in the previous crop provide considerable nitrogen fertilizer for the following crop, and biological nitrogen fixation contributes more.
Study on industrialization of rhizobia agent
At present, Qinhuangdao Leading Science and Technology Development Co., Ltd. is the most representative of the industrialization level of rhizobia production in China. After years of efforts, the company achieved technological equipment innovation and technological breakthrough in the production of leguminous rhizobium agents in 200 1 year; In 2006, "liquid rhizobia agent industrialization process" passed the provincial scientific and technological achievements appraisal; The national high-tech industrialization demonstration project undertaken by the company-"20,000 tons of leguminous rhizobia agent industrialization demonstration project" passed the national acceptance in Qinhuangdao in June 2007. The production line has reached the GMP production standard, the equipment level has reached the international advanced level, and the construction of the first rhizobia industrialization base in China has been completed.
Soybean is a moderately salt-tolerant plant. Salt stress will hinder soybean seed germination and plant growth, reduce nodules, inhibit the accumulation of biological yield, and lead to a decline in yield. Li Jun, director of the microbial fertilizer quality supervision, inspection and testing center of the Ministry of Agriculture, believes that it is the research direction of rhizobia industrialization to study and screen excellent strains of soybean nodules with salt tolerance and high nitrogen fixation efficiency and apply them to production practice. Excellent strains with strong nitrogen fixation ability and competitive nodulation ability suitable for a certain soil type in a certain area should be selected. Determine the stable and high-yield fermentation process of the strain, including the best fermentation medium formula and the best fermentation parameters. Screening suitable carriers and stabilizing additives can make the functional strains in the product survive stably, prolong the shelf life of the product and reduce the cost.
Academician Chen believes that it is urgent to strengthen the basic research on leguminous plant breeding and rhizobia application, such as optimizing the matching between leguminous plant varieties and high-efficiency rhizobia; Break through the bottleneck that rhizobia can be preserved for a long time; The most effective application technology of rhizobia agent and the corresponding machine transformation. She believes that at present, China has prepared sufficient germplasm resources and new knowledge for inoculating leguminous crops with rhizobia, and the large-scale popularization of soybean biological nitrogen fixation is just around the corner. It is suggested that many leguminous plants should be inoculated with rhizobia in the cause of returning farmland to forest and grassland in the west; In the vast agricultural areas, the intercropping rotation system of leguminous plants-rhizobia and Gramineae and other cash crops should be established to give full play to biological nitrogen fixation and minimize the amount of chemical nitrogen fertilizer.
Director Li Jun said that the national high-tech industrialization demonstration project (National Development and Reform Commission) and the national pilot subsidy project for improving soil organic matter (Ministry of Agriculture) are conducive to promoting the industrialization of rhizobia agents. It is reported that in 2008, the state will start planting 50,000 mu of leguminous green manure in five provinces (regions) of Shanxi, Jiangxi, Hunan, Guangxi and Anhui, and give financial subsidies. At the same time, the development of bio-industry has been written into the Eleventh Five-Year Plan-the special implementation plan of green agricultural bio-products: promoting the industrialization of new and efficient bio-fertilizers and developing efficient nitrogen-fixing products. The Ministry of Agriculture has set up a pilot project of soybean planting technology system to promote inoculation of rhizobia.