Losses of Agricultural Product Processing By-products Are Staggering, While the Benefits of Comprehensive Utilization Are Considerable
Recently, the Agricultural Product Processing Bureau of the Ministry of Agriculture conducted a special survey on the comprehensive utilization of by-products from agricultural production and processing. The survey shows that the quantity of by-products from agricultural production and processing has been increasing year by year. Because development has remained only at the primary and secondary stages and the resources have not been fully exploited, this directly affects resource conservation, environmental protection, quality and safety, and farmers' income growth. It is recommended that great importance be attached to the comprehensive utilization of agricultural product processing, that policy support be increased, that scientific and technological research be strengthened, that waste be turned into treasure and harm into benefit, and that the full utilization of agricultural product resources be achieved. This edition specially publishes a feature on the comprehensive utilization of by-products from agricultural production and processing for the reference of practitioners.
——The Editor
Low Comprehensive Utilization Rate Has Huge Negative Impacts
It wastes resources and pollutes the environment; it reduces income and also increases safety hazards
●Agricultural by-products are non-primary products generated during agricultural production or processing, including straw, rice bran, rice husk, wheat bran, oilseed meal, fruit pomace, vegetable trimmings, livestock and poultry bones and blood, potato residue, distillers' grains, vinegar residue, and so on. In 2013, China's crop straw was about 800 million tons, accounting for 50% of total agricultural biomass output; by-products from the processing of grain, oil, fruits and vegetables, livestock and poultry, and aquatic products totaled 580 million tons, of which 60% (far lower than the 10% in developed countries) was discarded as waste or simply piled up, forming several “mountains” of agricultural by-products such as straw, rice husk, distillers' grains, fruit pomace, vegetable trimmings, and bones and blood. This is equivalent to the input and output of 700 million mu of land and 600 billion yuan in income being lost.
The comprehensive utilization rate of grain processing is very low. At present, grain processing by-products exceed 180 million tons, including 20.42 million tons of rice bran, 40.85 million tons of rice husk, 21.78 million tons of wheat bran, 40 million tons of corncob, 41.12 million tons of corn husk, and 18 million tons of residues (15 million tons of distillers' grains and 3 million tons of vinegar residue). Among these, the output of rice bran, rice husk, and rice germ increased by an average of 1.6% annually, while the output of wheat bran and wheat germ increased by 3.1% year on year; the output of corncob and corn husk increased by an average of 6.7% annually. Rice husk is less than 5%, broken rice is 16%, and rice bran is less than 10%, with broken rice the highest and rice husk the lowest.
The comprehensive utilization rate of oilseed processing is relatively low. At present, oilseed processing by-products total 90 million tons, growing at an average annual rate of 3.9%, including more than 10 million tons of hulls and more than 80 million tons of cake, meal, oil sediment, soapstock, and so on, with a comprehensive utilization rate of more than 20%.
The comprehensive utilization rate of fruit and vegetable processing is the lowest. At present, fruit and vegetable processing by-products exceed 240 million tons, up 4.4% year on year, including 212.65 million tons of leaves, vines, stems, roots, peels, and residue, and 30.21 million tons of peels, residue, seeds, shells, and cores (15.84 million tons of citrus, 11.55 million tons of apple, and 2.64 million tons of grape), with a comprehensive utilization rate of less than 5%.
The comprehensive utilization rate of livestock, poultry, and aquatic products is slightly higher. The main by-products of livestock and poultry slaughtering and processing are bones, blood, viscera, feathers, and hides, with a total output of 56.2 million tons, up 5.4% year on year. The main by-products of aquatic product processing are heads, skins, tails, bones, and shells, with total by-products of 15.69 million tons, up 5.4% year on year. The comprehensive utilization rate is 29.9% for livestock, 59.4% for poultry, and more than 50% for aquatic products.
●The low comprehensive utilization rate of agricultural product processing by-products has a huge impact on resources, the environment, and farmers' income
Resources are wasted. China's comprehensive utilization rate of agricultural product processing is only 40%, while developed countries reach 90%, among which Japan's comprehensive utilization rate of rice bran reaches 100%, and even less-developed India has reached 30%. The abundant carbohydrates, proteins, fats, and other effective substances in by-products are raw materials for food, medicine, health products, energy, chemical products, and so on. A low comprehensive utilization rate directly leads to lower product added value, and a large amount of resources cannot be put to full use and is wasted in vain.
The environment is polluted. China produces nearly 1.4 billion tons of by-products from agricultural production and processing each year. As pollution accidents and incidents involving these by-products increase year by year, they have attracted more and more attention in recent years. For example, straw burning increases the air pollution index and affects transportation and aviation; around some processing enterprises, sewage flows everywhere and the stench is overwhelming, seriously affecting the ecological environment, landscapes, residents' daily lives, and health, and directly leading to non-point source pollution and water eutrophication; some by-products among livestock and poultry by-products that are not suitable for consumption (bones, lungs, glands, pancreas, etc.) and by-products such as potato residue from potato starch production are discharged or discarded into urban sewers, rivers, lakes, oceans, abandoned wells and mines, quarries, or caves, polluting water bodies, causing the death of aquatic organisms, and also producing odors that affect residents' lives; in major vegetable-producing areas, large vegetable wholesale markets, and processing plants, vegetable trimmings pile up like mountains and rot, seriously polluting soil, groundwater, and the environment, and consuming large amounts of funds to treat environmental pollution problems.
Income is reduced. For example, if 50% of China's 800 million tons of straw were used for energy processing, it would be equivalent to building another Daqing Oilfield; if 30% of straw and 70% of the more than 510 million tons of by-products from grain, oil, fruit, and vegetables were used as feed, based on 1 ton of dry alfalfa produced per mu, it would be equivalent to adding 580 million mu of land. Based on Daqing's 2012 production of 40 million tons of crude oil and 3.3 billion cubic meters of natural gas (at 4,005 yuan per ton of crude oil and 2.05 yuan per cubic meter of natural gas) and the alfalfa output and price of that year (1,000 yuan per ton of dry alfalfa), the output value would be 746.965 billion yuan, most of which can be turned into economic benefits and farmers' income.
Food safety hazards are increased. China feeds 22% of the population with 7% of the world's arable land, and food security has become an important strategy related to national security. The national food security strategy requires that the self-sufficiency rate of China's main grain varieties must be above 90% in order to maintain national food security. To meet this requirement, it is necessary to rely further on science and technology and continuously improve the land output rate, resource utilization rate, labor productivity, and scientific and technological contribution rate of grain production. However, the effective utilization rate of by-products in China is low, failing to provide people with more food energy and food nutrition, which affects the effective supply of food and national food security.