What is Agricultural Waste?

Agricultural waste refers to waste generated during agricultural production, agricultural product processing, livestock and poultry breeding, and rural residents' daily lives. It mainly includes crop straw, livestock and poultry manure, by-products of agricultural product processing, and agricultural film residues. Its resource utilization is of great significance for alleviating resource shortages, improving the rural environment, and promoting sustainable agricultural development.

Agricultural waste, also known as agricultural waste, refers to organic matter discarded throughout the entire agricultural production process. Currently, the academic community has a relatively unified understanding of the meaning of "agricultural waste," but there are different emphases on its specific content.

Unfavorable Factors of Agricultural Waste: 

1. Large Quantity of Agricultural Waste

Accurately estimating the total amount of agricultural waste is extremely difficult under current circumstances, and the total amount is indeed very large. my country's agricultural production development is relatively backward, and its scientific and technological level is lower than that of developed countries, resulting in a large quantity of agricultural waste.

2. Poor Quality and Relatively Low Price

Agricultural waste contains very low levels of useful substances, and the chances of recycling are slim, making it difficult to sell at a good price. In the long run, this will lead to a large accumulation of waste, causing serious harm to the living environment and human health.

3. Inadequate Resource Utilization Leading to Environmental Pollution

Most crop straw is directly burned, resulting in an energy utilization rate of only 1/10. Most of the energy, crude protein, and mineral salts are wasted. Specifically, only 1/3 of potassium can be utilized; the rest—heat, organic matter, nitrogen, and phosphorus—are wasted. The smoke from burning straw contains a large amount of sulfur dioxide, which pollutes the air and has adverse effects on the agricultural production environment and human health.

Based on their source, agricultural waste can be divided into four main categories:

1.Crop waste, mainly referring to crop stalks, vegetable residues, fruit tree and forest branches, weeds, fallen leaves, and fruit shells.

2.Livestock waste, including animal excrement and bedding materials.

3.Agricultural product processing waste, referring to residues of agricultural by-products, such as melon pulp, bean dregs, and slaughterhouse blood.

4.Domestic waste generated by rural residents, such as excrement and household waste. Generally speaking, agricultural waste mainly refers to crop and livestock waste, namely crop stalks, weeds, fallen leaves, and livestock manure.

Agricultural Waste Resource Management: 

1. Uncertainty Regarding the Quantity of Agricultural Waste

Currently, there is no precise statistical data on agricultural waste, nor is there data on its types, quantities, distribution, utilization, and environmental impact. Furthermore, there are no precise statistics on how the generated agricultural waste is utilized, the amount used through various pathways, the degree of utilization, and the operational status.

2. Lagging Integrated Treatment Technology in Agricultural and Forestry Waste Areas

In the process of agricultural modernization and industrialization in my country, traditional disposal methods can no longer meet the needs and should be adapted to the contemporary green development concept. Currently, the resource utilization of agricultural waste is still at a very basic level, with low technical levels and low utilization rates. For example, the industrial utilization technologies for ethanol production, building material production, and material packaging are not yet mature. Therefore, the resource utilization and comprehensive utilization of agricultural waste is a very arduous and challenging task.

3. Incomplete Socialized Service System for Agriculture

Agricultural production involves many stages and complex processes, resulting in a complex and diverse process for the resource utilization of waste. If relying solely on farmers without a complete industrial chain, each stage will struggle to operate effectively. This urgently necessitates an industrialized approach to promote the development of related industries, expand utilization channels, accelerate the development of downstream products, and gradually form a complete agricultural waste utilization industrial chain.

Agricultural Waste Management: 

1. Scientific Approach to Technology and Management

Practical technologies should be introduced in a targeted manner, taking into account the specific conditions of rural areas and the local economic capacity, to maximize resource utilization.

2. Improve the Efficiency of Agricultural Waste Recycling

In addition to central and local government funding, social capital should be encouraged to invest in agricultural waste recycling to alleviate the funding shortage in my country's agricultural waste recycling sector and to quickly establish a sustainable investment mechanism.

3. Establish and Improve the Relevant Policy System

The government should establish and improve the relevant policy system for agricultural waste recycling, clarifying its development direction. This is an important way to achieve the recycling and reuse of agricultural waste in my country.

4. Raise Farmers' Environmental Awareness

With economic development, farmers' living conditions have improved. However, their overall education level is relatively low, and they have a strong small-scale farming mentality. Coupled with long-standing habits, farmers do not pay much attention to agricultural waste pollution. Therefore, it is necessary to strengthen publicity on the recycling of agricultural waste and enhance farmers' awareness of its utilization.

Practical Application of Agricultural Waste：

Currently, mechanized harvesting is widely implemented in the plains of China. In the fields, when harvesters produce large amounts of straw, farmers quickly install straw crushers along the field edges through cooperatives or collective fundraising. These crushers or biomass shredding systems efficiently process the straw. Straw usable as feed is crushed and fermented to become high-quality fodder; straw unusable as feed is directly returned to the field.

Directly returning crushed straw to the field not only helps increase the organic matter content of the soil but also enhances soil microbial activity. Typically, this method of straw return significantly increases crop yields, generally achieving an increase of about 5% to 10%.

Modern Utilization of Agricultural Waste:

Agricultural straw can be used to produce biogas and as organic fertilizer, as well as roughage and bedding for livestock. Livestock manure and bedding, or chopped straw mixed with appropriate amounts of human and animal excrement, can be composted at high temperatures. After a short period of fermentation, pathogens, parasite eggs, plant pests hidden in the straw, and various weed seeds can be largely killed. The compost is then put into a biogas digester for fermentation to produce biogas.

This treatment method provides both biogas fuel and high-quality organic fertilizer; the sealed manure also prevents fly breeding. This method is widely used in rural China and has received attention worldwide. Earthworms are rich in protein and are excellent feed for poultry and fish. Earthworm castings are comprehensive organic fertilizer. Agricultural straw, livestock manure, and their bedding can be used as earthworm food, promoting the artificial breeding of earthworms.