Application Status and Development Measures of Biogas Fertilizer in Agricultural Production

Jing XIAO

Daiyue District Bureau of Agriculture and Rural Affairs, Tai’an 271000, China

Abstract Biogas fertilizer is widely used in agricultural production, and it can be used in a variety of ways, including liquid spraying, root fertilization, presoaking and biological pesticides, etc. It can improve soil structure, increase the content of soil organic matter and available nutrients, and increase crop yield. In addition, there are some problems in the utilization of biogas fertilizer. Some details that need to be paid attention to and can not be ignored should be further studied and discussed to achieve a final principle of harmonious, safe and efficient use, so as to ensure the benefit maximization of biogas fertilizer as an economic fertilizer source. Therefore, this paper summarizes the main ways and methods, existing problems and corresponding development measures concerning the application of biogas fertilizer in agriculture, in order to provide some reference for the utilization of biogas fertilizer in the field of agriculture and make it universal, safe and stable.

Key words Biogas fertilizer, Agricultural production, Application status, Development measures

1 Introduction

With the continuous promotion of rural urbanization, the farming and breeding industry is quickly transforming from large-scale development to intensive development. The contradiction between the increasing production of all kinds of crop straw and human, livestock and poultry manure and the current serious lack of collection and treatment capacity is becoming more and more prominent[1], especially the feces and sewage produced by large-scale farms. The biogas-based utilization is an effective way for the resource utilization of livestock and poultry manure[2]. However, how to make good use of biogas fertilizer is an urgent problem to be solved. As we all know, China is a large agricultural country, and the amount of chemical application accounts for one third of the total amount of chemical application in the world. Although the output of grain is increasing year by year, it also brings a series of eco-environmental problems. In view of this, the Ministry of Agriculture and Rural Affairs issued the2020ActionPlanforZeroGrowthofChemicalFertilizerUsein 2019 to implement the technical model of reducing the amount of chemical fertilizer and increasing efficiency throughout the country. Biogas fertilizer can replace inorganic fertilizer to a certain extent and become a new type of clean, high-quality and efficient fertilizer that meets the requirements of environmental protection. Based on the above situation, this paper summarizes the current application status of biogas fertilizer in agricultural production, and puts forward development measures, in order to provide some reference for the efficient utilization of biogas fertilizer in agricultural production in China.

2 Application of biogas fertilizer in agricultural production

Biogas fertilizer is the residue after biogas fermentation, and it is a kind of organic fertilizer with long fertilizer effect. It contains a lot of organic matter, humic acid, trace elements K, P, N, threonine, alanine, glutamic acid, methionine and so on, as well as gibberellin and ammonium salt. Among them, the bioactive substances of amino acids and vitamins play an important role in promoting seed germination, regulating plant growth and enhancing plant resistance. Related studies have shown that the application of biogas fertilizer has a significant effect on crop yield, quality and soil fertility[3]. Therefore, the application of biogas fertilizer in agricultural production is an effective way to ensure the recycling of biomass resources.

2.1 FertilizationThe application technology of biogas fertilizer in the fields of vegetables, fruit trees and food crops has made some achievements, realized extensive application and received theoretical recognition. It can significantly promote the growth of crops, and can improve the economic and commercial benefits of crops. When biogas slurry is applied to facility tomatoes, the number of fruits per tree will increase by 7% to 9%. The weight of the fruit will increase rapidly, the average yield will increase by 10% to 20%, and the commerciality of the fruit will be also significantly improved[4]. Wan Haiwen found that biogas fertilizer topdressing could increase the chlorophyll content of wheat and corn, thus improving the rate of photosynthesis and water use efficiency. The harvest time of wheat was advanced, the spike rate and grain weight of wheat were increased, and then the yield of wheat was increased[5]. Shandong Province is vigorously promoting the typical model of the combination of agriculture and biogas, such as farming waste-solid-liquid separation-diversified utilization-organic agriculture, crop by-products-feeding pigs with lees-biogas engineering-soil improvement-wheat or corn cultivation, rotten vegetables-biogas engineering-vegetable greenhouse, and large-scale farm-biogas power generation-biogas concentration-organic farming. They have all made good achievements[6], bringing remarkable economic, social and ecological benefits.

In addition, in the process of application of biogas fertilizer, the appropriate concentration and period should be selected according to different species, so as to give full play to the maximum benefit of biogas fertilizer.

2.2 PresoakingAs a simple, safe and efficient seed treatment technology, presoaking in biogas fluid has been gradually recognized by researchers and practitioners. At present, it has been widely used in the field of agriculture. Soaking seeds with biogas fertilizer has obvious effects of disease resistance, seedling enhancement and yield increase. Wei Suzhenetal. found that the germination rate of rape seeds soaked in biogas slurry with a concentration of 10% was significantly increased[7]. The studies of Yong Shanyuetal. have shown that soakingBupleurumseeds with biogas slurry with a concentration of 60% can significantly increase its germination rate[8]. After soaking the seeds in biogas fertilizer, compared with the control of clear water, the seedling rate was significantly increased (about 10% to 15%)[9]. Biogas slurry can also be used to soak rice seeds and significantly control diseases and pests[10].

2.3 BiopesticideBiogas fertilizer is considered to be a "biological pesticide" with no pollution, no residual poison and no drug resistance. It can be used to control diseases and pests and improve plant resistance, and the control effect can be significantly enhanced when biogas fertilizer is mixed with a certain volume of drugs. In the production, measures such as presoaking with biogas fertilizer, basic application of biogas fertilizer and topdressing are mainly used to control the disease. The main methods of pest control are direct application of biogas fertilizer and spraying biogas fertilizer. Zhang Xiaokangetal. found that the application of biogas fertilizer could significantly reduce the rate of diseases and pests in watermelon seedling stage and improve the yield and quality of watermelon[11]. Related studies have shown that biogas fertilizer has a good control effect on aphids, and the control effect of aphids on cabbage, cowpea,Zizaniacaduciflora, cabbage and other vegetables has reached 90%[12]. When the potato plants were sprayed with biogas slurry, it was found that the withering period was delayed, and the photosynthetic rate and productivity per plant were significantly increased. The incidence of late blight decreased by 1.6% and black stem rot decreased by 10.6%[13].

3 Development measures

Through the construction of biogas engineering, the wastes in agriculture and animal husbandry can be utilized comprehensively. As an organic fertilizer, biogas fertilizer can reduce the application amount of chemical fertilizer in farmland and achieve the purpose of reducing quantity and increasing efficiency, and its ecological benefit is also inestimable. It is necessary to make overall use of biogas fertilizer, solve the problem of appropriate use, fully evaluate environmental safety, and optimize the corresponding management mechanism.

In the actual application of biogas fertilizer, the corresponding concentration should be selected according to the different types of crops, and the appropriate application period and mode should be determined according to the characteristics of crops, so as to maximize its benefits. It is necessary to scientifically determine, strictly control, and control the content of organic matter such as total nitrogen and total phosphorus from the source. It is necessary to formulate an appropriate substitution ratio to ensure that biogas fertilizer is scientific and reasonable in the process of combined application with straw or inorganic fertilizer. It is necessary to ensure that there is no pollution in the application process and balance the relationship between the application of biogas fertilizer and a healthy ecological environment.

Farmers are the main body of the use of biogas fertilizer. In the process of biogas fertilizer utilization and promotion, we need to do a good job in publicity and popularize the ecological benefits and economic benefits of biogas fertilizer utilization to farmers. In this way, farmers can be from unfamiliar to familiar with it, and finally accept it, so that biogas fertilizer can be used in daily agricultural production. We can also fully mobilize the enthusiasm of farmers through the establishment of demonstration parks, cooperation with major grain growers, financial subsidies and other measures. Innovation is the first driving force to lead the development. It is necessary to fully mobilize the subjective initiative of the enterprise and make use of its advanced scientific research technology and strong R & D team to develop practical products in production. For example, by concentrating the volume of biogas slurry products and adding preservatives to prolong the shelf life of biogas slurry, we can achieve the effect of maintaining biogas fertilizer’s long-term biological activity and fertility. It is necessary to improve biogas slurry transport equipment, improve transportation quality and efficiency, and solve the contradiction between supply and demand of biogas fertilizer in a timely and efficient manner.

In addition, we need to modestly learn from foreign advanced ideas and experience, and develop standard procedures and technical specifications according to local conditions. It is necessary to improve the system of resource utilization of biogas slurry, and strictly control the pollutants in fermentation broth and ensure that the final biogas slurry will not exceed the standard. It is necessary to optimize the anaerobic fermentation process, reduce the diffusion of pollutants in the utilization process, and achieve the green goal of healthy development.

4 Prospect

Biogas fertilizer is a kind of high-quality biological resources, which has high economic and ecological benefits.

The application of biogas fertilizer is also the practice of building green water and green mountains, that is, the "construction of ecological civilization". Rational use of biogas fertilizer is an important link in building a resource-saving and environment-friendly society. For this reason, researchers need to further study the harmless and comprehensive utilization of biogas fertilizer.

First of all, in the early stage of biogas fertilizer utilization, we should fully investigate, consider the local resources, scientifically formulate the development model, and take the green and ecological industry development model according to local conditions. It is necessary to fully live up to the concept that "green water and green mountains are golden mountains and silver mountains". Secondly, it is necessary to establish a corresponding team of experts and improve the detection mechanism to provide a strong guarantee for the realization of harmless resource utilization of biogas fertilizer. Finally, it is necessary to develop the R&D model of the combination of production, learning and research, concentrate on the development of large and medium-sized biogas projects, and promote the resource reuse of agricultural and livestock wastes. It is believed that biogas fertilizer will have a bright future in agriculture in the near future, and it can help to further realize the large scale, industrialization and commercialization of biogas in our country.