CN115428610A - Method for returning biomass to field and application - Google Patents

Abstract

The method for returning the biomass to the field and the application thereof realize the operation of turning over the land and burying the biomass below the surface soil layer by combining the biomass and the root soil into a whole in a spatial layer arrangement way, so that the biomass is placed at the lower layer of the root soil, the defects caused by returning the straw to the field due to the mixing of the biomass and the soil are reduced, the requirement of crushing the biomass is avoided or reduced, the energy consumption and the economic cost are reduced, and the farmland is used as a large-scale carbon fixation tool to achieve the effects of realizing large-scale soil improvement, carbon fixation and carbon reduction.

Description

A method and application of returning biomass to fields

technical field

The invention relates to a method and application of biomass returning to the field, belonging to the fields of straw treatment, utilization of biomass resources, carbon fixation and reduction, and environmental protection. Placed in the lower layer of the root soil, reduce and avoid the disadvantages of straw returning to the field caused by the mixing of biomass and soil, avoid or reduce the need to crush biomass, reduce energy consumption and economic costs, and use farmland as a large-scale solid Carbon tools to achieve large-scale soil improvement, carbon sequestration, and carbon reduction.

Background technique

In recent years, the adverse impact of global climate change on human production and life has become more and more prominent, and addressing climate change has become one of the most severe challenges faced by human society. Many countries have clarified the time point of carbon neutrality, and the reduction of greenhouse gas emissions has gradually become a joint action of all countries and a self-help action of human beings.

Biomass-Combined Carbon Capture and Storage (BECCS) technology and other carbon dioxide removal technologies (CDR) are considered to be indispensable means of "negative emissions" in the future. To limit the increase in global temperature to 1.5°C, the world needs to rely on CDR to absorb 100-1 trillion tons of carbon dioxide and help industries that are difficult to achieve zero emissions to solve residual carbon emissions. Existing and potential CDR measures include afforestation, soil carbon sequestration, BECCS, direct air carbon capture and storage, enhanced weathering and ocean alkalization, etc., but these measures vary widely in terms of maturity, potential, cost, risk, etc. Only two technical routes of afforestation and BECCS are relatively mature.

BECCS involves two links of biomass energy (BE) and capture and storage (CSS). In order to reduce costs, the utilization link is added. The dilemma of BE lies in the source of sufficient biomass (including wood, grass, agricultural and forestry waste, etc.), and the cost of collection and transportation. Secondly, there are the high cost of the carbon dioxide capture and storage technology produced by the incineration of biomass as energy, as well as the lack of carbon dioxide utilization fields and the lack of effective economic benefit support. Therefore, the current BECCS cannot achieve sustainable operation and development.

Biomass, especially agricultural and forestry plants, such as straw, weeds, and trees, is an inexhaustible recycled resource and is related to carbon emissions or carbon neutrality, the result of which lies in the method of disposal. Incineration increases carbon emissions, while resource utilization becomes a means of carbon neutrality. Because of its huge amount, its impact may be decisive, so there is the aforementioned BECCS as an effective carbon neutral technology route.

The annual carbon exchange between forest photosynthesis and respiration and the atmosphere is as high as 90% of the total terrestrial ecosystem. It can be argued that forests control the dynamics of the terrestrial carbon cycle. By extension, the carbon cycle of biomass is the foundation of the earth's carbon cycle. Using the carbon cycle of biomass can solve the problem of carbon cycle imbalance. A technical approach to the carbon cycle of matter. According to the data of Whittaker (1975), the amount of carbon fixed by net photosynthesis per square meter of forest per year is 450-1600g in tropical forests, 270-1125g in temperate forests, and 180-900g in cold temperate forests. The reserves are 20-100 times that of farmland.

According to the above data, if farmland has both the role and effect of forest carbon sinks, farmland is used as a tool for carbon sequestration, forestry carbon sequestration is introduced at the same time, and forestry carbon sequestration products are buried in farmland, then the carbon sequestration effect of each mu of farmland will be It has increased by 20-100 times, and each mu of farmland not only provides agricultural products, but also has the role of forest carbon sequestration. It is equivalent to increasing the effective area of the forest in effect.

The development of agriculture is fundamentally inseparable from farmland, water conservancy, and fertilizers. The foundation of farmland is soil. Suitable soil is inseparable from the carbon-containing and nitrogen-containing organic matter contained in it. Increasing the organic matter content in the soil will improve soil fertility, water retention capacity, and reduce soil erosion. Biomass is originally the main source of soil fertilizer fertility. If biomass can be actively input into the soil, year after year, it will continuously improve the quality of cultivated land, and at the same time help to achieve the goal of carbon neutrality. That is, by combining the necessary agricultural production with carbon sequestration, agriculture can not only help solve the problem of carbon emissions, but also improve agricultural soil, reduce carbon sequestration and increase food production at the same time.

However, the current technology of directly returning straw to the field is mainly: crushing the straw, then plowing and burying it deeply in the soil, or covering the field naturally with the straw, as long as it does not affect the planting. However, the straw is broken and the cost of deep plowing (for example, 25 centimeters or less) is too high is a problem. Due to the current plowing and deep burial technology or method, a considerable part of the straw will be mixed with the surface soil where the crops germinate and grow. , Specially eating the young shoots of crops will also become the source of insect pests in the next year; at present, there is no effective solution to the insect pest problem caused by returning straw to the field. In addition, after the straw is placed in the soil, because the fermentation time is short, it will compete with the crops for nutrients and burn the roots during the subsequent fermentation process, so it is even more unfavorable for planting, and the nutrients in the soil are absorbed by the straw. The debris is blocked, it is difficult to reach the seeds, and eventually the crops are uneven and the harvest is reduced. In addition, many farmlands are also mixed with straw and soil, and the soil is loose and there are too many large gaps. The soil cannot be fit at all and the ridges are broken, making some land unable to be planted. Generally speaking, according to the current technical method of crushing and plowing and deep burial, the amount of crushed and pressed straws returned to the field per mu of land can only be controlled within 500 kg, so as not to affect subsequent planting. Calculated on the basis of 2 billion mu of arable land, if all the straw is returned to the field, 1 billion tons of straw can be used; if 1-5 tons per mu of land can be returned to the field, 2-10 billion tons of straw, grass, and forest waste can be used. It is expected to achieve carbon neutrality of my country's current annual carbon dioxide emissions of 10 billion tons through the return of biomass to the field. According to the data, in the plan, seeking natural solutions in agriculture, forestry, grasslands, wetlands and other systems, the guaranteed annual carbon dioxide absorption is only 800 million tons.

In addition, because the organic matter carried by the straw cannot be effectively returned to the field, the excessive use of inorganic fertilizers has continuously degraded the farmland and seriously affected agricultural production.

Therefore, from the perspective of carbon sinks, or from the perspective of sustainable agricultural production, actively explore the supporting science and technology of straw returning to the field, combine the improvement of national soil organic matter and national land management or standard fertile land construction projects, and strive to apply advanced technologies to straw returning In order to keep the cultivated land strong and fresh, it is a top priority. From a technical point of view, large-scale, overall, and disruptive technological innovations are required, which can use farmland as a tool for carbon reduction and emission reduction, not only solve the problem of returning straw to the field for carbon sequestration, but also introduce forestry carbon sequestration farmland. Because of its huge scale, cost control and profitability are the key to technical feasibility. Only low-cost, profitable and profitable technologies can be applied sustainably and proactively.

That is, only when the carbon reduction behavior becomes profitable, rather than a behavior that needs to be supervised and enforced, will it be operable and feasible for large-scale promotion. Water saving, fertilizer saving, and soil improvement are the interests of agricultural producers themselves. As long as there is a convenient means of returning biomass to the field and avoiding a series of problems caused by the current straw returning to the field, the straw returning to the field can become a voluntarily.

Contents of the invention

A method and application of biomass returning to the field of the present invention arrange the biomass and the root soil (i.e. the soil where surface plants germinate and take root) in layers in space, so that the biomass is placed in the lower layer of the root soil to reduce and avoid growth The above-mentioned disadvantages of straw returning to the field brought about by the mixing of materials and soil can avoid or reduce the need for crushing biomass, and reduce energy consumption and economic costs. In addition, stainless steel wire mesh is used to isolate the bottom biomass from the upper soil; it is convenient for the picking of tubers and the plowing of the root soil after planting is harvested, reducing the intensity and power input of plowing, and reducing the energy consumption of land plowing . There are reinforced edges and or reinforced rings around the stainless steel wire mesh, which are convenient for hooking up with the traction pull rope. The screen is turned sideways by manual or agricultural machine pulling, and the soil on it is plowed to one side. For example, by pulling a corner of the wire mesh, pull it along the direction of the field ridge, that is, the direction of the length of the wire mesh at approximately 45 degrees, and wind the wire mesh into a roll. During the pulling process, the soil above the wire mesh is turned to one side of the field ridge .

An agricultural machine tool for the above-mentioned biomass returning to the field and plowing the soil of the present invention uses two or more plow blades arranged in a wedge shape to push the front soil out of the field ridge in two directions outside under the traction of the agricultural machine. , a rectangular pit with a rectangular cross-section or a rectangular shape with arcs on both sides is formed on the path of the passage. The pit is filled with a layer of biomass, which can be compacted first, or backfilled directly above the biomass to cover the excavated soil, or covered with stainless steel wire mesh first and then covered with soil. In order to facilitate the excavation of pits, rotary tillage can be performed in front of the plow blades to loosen the soil. The backfilling soil can be pushed back to the field ridge by two or more inverted splayed plow blades under the traction of agricultural machinery, and covered with biomass or isolated wire mesh.

A combined agricultural machine tool for the above-mentioned biomass returning to the field of the present invention includes a straw cutting and crushing device, a straw biomass picking and conveying system, a biomass storage bin and a feeder, and a rotary tillage device. The surface soil is thrown to the rear and upward, and enters the soil conveying system. The wire mesh arrangement system is combined into a whole, and the operation of plowing the land and embedding the biomass layered under the surface soil is realized at one time. Among them, the straw cutting and crushing device , Biomass storage bin and feeder, and wire mesh layout system are optional installations. The main feature of the combined agricultural implement of the present invention is that, by separating the soil conveying system from the biomass conveying system, bypassing each other from the center of the agricultural machinery and one or both sides, the surface soil is conveyed from the biomass along the center of the agricultural machinery Conveyed sideways or around the path into the field ridge pit, mulch is conveyed on top of the biomass in the pit, or the surface soil is conveyed along the center of the agricultural machine into the field ridge pit, and the biomass is pretreated from one or both sides It is transported into the pit, and then covered by the soil sent later, that is, the position where the biomass needs to fall into the pit is selected before the position where the soil falls.

According to needs or convenience, the above-mentioned rotary tillage device can be replaced by a plow blade device, and the soil is lifted up by the plow blade and introduced into the soil conveying system. In order to improve working efficiency, the combined agricultural machinery of the present invention can also be equipped with a seeding system and, or a fertilization system.

In a broad sense, feces and leftover organic waste produced by the aquaculture industry are also a kind of biomass, which can also be covered under the root soil by the above-mentioned method to solve the pollution problem of the aquaculture industry.

The biomass completely covered under the root soil can collect rainwater as a reservoir, provide water and nutrients for the subsequent growth of plants in a slow-release manner, reduce irrigation water consumption, save agricultural water, and reduce the use of chemical fertilizers ( reduce pollution caused by fertilizer production, carbon emissions, and save resources), and solve the problem that straws have no place to stack and affect subsequent cultivation. The problem of the site, after the slow decay of renewable biomass, increases the organic matter and microorganisms in the soil, reduces soil compaction, continuously improves land fertility, and solves the problem of land degradation after cultivation. At the same time, during the composting process, especially after soaking in rainwater, the biomass layer has a large water content, and the diseases, insects and insect eggs in it can be effectively killed, which solves the problem that the current straw returning to the field cannot be controlled.

The technology of the present invention can also be used for ecological restoration, desert control, reclamation of non-suitable land, reduction of soil erosion, land degradation area, reduction of technical no-tillage, intercropping or policy-based conversion of farmland to forest, grass, and lakes, etc. , increase food security.

By using a large amount of farmland soil to bury biomass, farmland can play a carbon sequestration role similar to forests in an economically beneficial manner, which is equivalent to effectively expanding the forest area. In particular, through the coverage of root soil, mature forests, The old forest trees in the overmature forest are collected and buried to realize the restoration and renewal of the forest land and convert them into usable resources. Through biomass carbon capture, farmland soil fixes carbon pathways, which not only solves the resource constraints of carbon neutral technology pathways, but also creates "new" resources or the use of huge amounts of biomass resources. Reduce the impact of carbon reduction on energy security, industrial chain supply chain security, and food security. Because of its huge amount, this technology can be used to form a new pattern of low-carbon development, realize and promote circular economy, and realize sustainable economic development.

In short, the method and application of biomass returning to the field of the present invention can not only solve the problem of straw pollution in a low-cost, easy-to-operate, and profitable manner, but also provide a large-scale carbon fixation and carbon reduction in a profitable manner. s method.

Description of drawings

Fig. 1 and Fig. 3 are mainly the schematic diagrams of the front view and the top view of the biomass conveying system; Fig. 2 and Fig. 4 are mainly the schematic diagrams of the front view and the top view of the soil conveying system.

detailed description

The technical method of the present invention will be described in detail below in conjunction with the examples, but the protection scope of the present invention includes but is not limited thereto.

Example 1

Manually dig out a 15 cm deep pit with an area of 1 m x 1 m, fill it with a mixture of weeds, fallen leaves, and small branches about 15 cm thick, and place a 1 x 1 m stainless steel wire mesh on it, the wire mesh is 0.8 mm thick, Mesh 1 cm x 1 cm, retrieve part of the dug up soil and cover about 8 cm thick. The soil width is also plowed about 30 cm around the wire mesh. As a contrast, 4 lettuces were transplanted above the silk screen, and 4 lettuce seedlings were also transplanted on the soil next to the screen. The soil of the two was the same, and the only difference was the presence or absence of the biomass layer below the soil. Under the condition of all completely natural growth, the lettuce growth speed on the wire mesh is obviously faster than that of the lettuce next to the wire mesh (the photo is omitted), and after transplanting, it will grow naturally for ~ 63 days (the seedlings were transplanted on February 10, and the seedlings were transplanted on April 10). Harvest on the 15th), the gross weight of the lettuce above the wire mesh after root removal was 2.45 kg, and the lettuce gross weight by the wire mesh was 1.52 kg. It shows that the buried biomass is beneficial to the growth of plants, which is consistent with the expectations of theoretical analysis. For plants in season, including but not limited to, the water storage capacity in the soil is increased by collecting rainwater, the air permeability is increased, and the possible increase of organic fertilizer . At least, it means that the rainwater harvested by the biomass helps the plants grow.

After the lettuce is received, simply use manpower or agricultural machinery to pull up the wire mesh from one corner, and pull it up along the direction of about 45 degrees of the wire mesh area, then the soil on it can be plowed to one side and the wire mesh can be removed , Dig out the decayed biomass under the screen and mix it evenly with the soil plowed to one side. At this time, the organic matter in the soil obviously increases, making the soil more suitable for the growth of plants. When backfilling, you can further dig deep pits, fill the pits with various biomass, place wire mesh on the biomass layer in the above order, and cover the soil with increased organic matter above the wire mesh.

The same comparison was used in the growth of potatoes, sweet potatoes, and scatter greens, and similar results were obtained, that is, the growth rate of plants was significantly increased in the upper soil covered with biomass. As a comparison, the presence or absence of wire mesh itself does not affect the growth of plants, or has no significant impact, but the advantage of placing wire mesh is that it is convenient to isolate the biomass layer from the soil layer, avoiding the mixing of the two, and it is also convenient for harvesting. Especially the harvesting of tuber agricultural products, as well as the cultivation of small fields dominated by manpower, can reduce the labor intensity of plowing the land.

Example 2

When working in the field, the width of the field ridge can be 1-2 meters wide, limited to the width of the stainless steel wire mesh. The width of the stainless steel wire mesh is convenient for pulling the wire mesh to facilitate the overturning of the soil on the side of the field ridge. The stainless steel wire The length of the net is based on the weight of a bundle of wire mesh for portability. If the field ridge is long, the wire mesh can be spliced. The thickness of the soil layer above the wire mesh is optimally selected according to the root depth of the planted crops, considering that part of the root system penetrates into the biomass layer. The thickness of the biomass layer can be appropriately increased to increase the amount of carbon fixation.

In order to facilitate field operations, it is equipped with a pit excavation device or agricultural machinery, 2 wedge-shaped plow blades (not shown) or multiple plow blades, under the traction of the agricultural machinery, push the front soil to one side or both sides Finally, pits are formed, and the depth of the pits is selected as 10-30 cm according to needs. The width of the pits can refer to the width between the two wheels of the agricultural machinery, and then the biomass is filled into the pits manually or by agricultural machinery, and then the biomass Backfill above the layer to cover the pushed out soil, or cover the stainless steel wire mesh first and then cover the soil. The soil accumulated on one side or both sides of the field ridge can be backfilled by driving the inverted figure-eight plow blades under the traction of agricultural machinery.

Example 3

When working in the field, the surface of the field ridge is often covered with harvested straw or biomass waste. When digging a pit, a cage grass machine and a biomass and forage conveying device can be installed on the same agricultural machine to transport the forward biomass into the pit. In the pit, the soil excavated by the same machine is sent to the top of the biomass in the pit through the conveying system, realizing the effect of layering the biomass buried under the soil, and solving a series of problems existing in the current direct crushing of straw and plowing back to the field. disadvantages.

Figure 1-4 is a schematic diagram of the biomass conveying system and the soil conveying system, in which the fixing, driving, and interconnection structures of the facilities are common-sense structures and configurations, which are omitted in the figure, and the directions of the arrows in the figure are respectively The direction of material transport and the direction of soil transport. For easy understanding, Fig. 1 and Fig. 2 are mainly the front view and top view of the biomass conveying system, and Fig. 3 and Fig. 4 are the front view and top view of the soil conveying system. 1 in the figure is a biomass conveying system, 1-1 is a biomass collection circle with a toothed rake, 1-2 is a transmission circle with a toothed rake, 1-3 is a transmission channel, and the upper part of the channel can be a closed or open structure. Biomass is transported and falls into the pit of the field ridge. If the biomass layer is relatively loose, a heavy rolling roller (not shown) can also be configured to compact the biomass layer. In order to facilitate the burying of biomass outside the field into the soil, such as broken trees and weeds, a biomass storage bin and a feeding device can be configured at the position where the biomass falls, so that the foreign biomass can be evenly introduced into the pit automatically. (not shown). The feeding device can be a circular rake driven by the power of the agricultural machine, which automatically pulls the biomass evenly from the silo.

2 in the figure is the excavation and conveying system of the surface soil, 2-1 is a rotary tiller, which excavates the surface soil, and the soil flies to the 2-3 soil divider in the middle through the ramp 2-2 and flows symmetrically to both sides The soil conveying channel 2-4, 2-4 is downhill, so that the soil depends on the gravity and the vibration of the machine, automatically descends and falls on the biomass layer in the pit. An auxiliary soil pushing device can also be installed in addition, such as a rotating circle type pushing device, or a belt conveyor, or a vibrating plate pushing (not shown). The soil falling into the pit 3 can also pass through the weighted soil even distributor (carriage plate, shown in the figure) at the tail of the agricultural machine, so that the fallen soil is more evenly distributed on the biomass and compacted to some extent.

According to needs or convenience, the above-mentioned rotary tillage device can be replaced by a plow blade device, and the soil is lifted up by the plow blade and introduced into the soil conveying system (not shown).

In order to facilitate the introduction of stainless steel wire mesh between the biomass layer and the soil layer, a stainless steel wire mesh arranger is set between the biomass blanking position and the soil blanking position, which contains a wire mesh frame supporting a roll of stainless steel wire mesh. The grid frame rotates automatically (rotating speed matches the driving speed of the agricultural machinery), or passively rotates (not shown) by being pulled by the wire mesh buried in the soil.

The aforementioned conveying channel for biomass or soil can also be equipped with a conveyor belt to facilitate the conveying of biomass and soil. The wheels on both sides of the traction agricultural machinery walk within the size of the field ridge to avoid rolling the field ridge outside the excavated field ridge, that is, the width of the pit is greater than or equal to the distance between the outer sides of the two wheels. The aforementioned biomass transport path and soil transport path can be interchanged, but after the interchange, it is still necessary to select the position where the biomass falls into the pit before the position where the soil falls. That is, the surface soil is transported along the center of the agricultural machinery to the pit of the field ridge, and the biomass is first transported into the pit from one or both sides, and then covered by the soil sent later, that is, the position where the biomass needs to fall into the pit Select before where the soil falls (illustration omitted).

If straw such as cotton stalks, corn, sorghum, etc. are still standing upright in the field after harvesting, an automatic shearing and crushing device is installed before the 1-1 biomass collection circle, and after shearing, harvesting, and crushing, it is sent to the concave through the biomass conveying system. pit. Cutting can be carried out by disc shears or zigzag shears, etc. The cutting position is at the root of the straw above the soil. After cutting, the rotating straw collection circle is introduced into the crushing system. The crushing system can use rotating blades to cut powder Pure, the length of crushing can be 5-80 cm, the longer the length, the lower the energy consumption required for cutting. Of course, primary cutting and crushing can also be carried out first, so that the biomass such as straw and forestry waste is evenly distributed on the field surface in advance, and then the biomass layer is buried under the soil by using the above-mentioned method of returning to the field.

Through the above-mentioned agricultural machinery device, the upper and lower exchange of the surface soil and the biomass above the soil can be realized, and at the same time, the isolation wire mesh can be automatically placed between the soil and the biomass. In order to increase the amount of biomass buried under the soil, increase the effects of carbon fixation, water retention, and soil improvement, agricultural and forestry wastes, weeds, animal manure, and leftovers can be collected and evenly covered on the field in advance, and then treated by the present invention The method is buried under the soil, or directly through the storage bin and the feeder along with the excavation of the pit, and the introduction process of the surface biomass is evenly introduced into the pit.

After the above-mentioned soil containing the biomass layer is planted and harvested or harvested, it is plowed according to the above-mentioned method, but the depth of the rotary plowing layer is increased, and the previously buried and corrupted biomass is plowed to the surface layer together with the surface soil, Bury again with a new layer of biomass. The organic matter contained in the surface soil is gradually increased to achieve continuous improvement of the soil.

Claims (10)

1. A method and application of returning biomass to fields, characterized in that the biomass and root soil are arranged in layers in space, so that the biomass is placed in the lower layer of the root soil. 2. The method and application of biomass returning to the field according to claim, characterized in that the bottom biomass is isolated from the upper layer of soil by stainless steel wire mesh. 3. A stainless steel wire mesh used for returning biomass to fields, characterized in that there are reinforcing edges and/or reinforcing rings around the wire mesh, which are convenient for hooking with traction pull ropes. 4. An agricultural machine tool for returning biomass to the field and plowing the soil, characterized in that two plow blades arranged in a wedge shape, or a plurality of plow blades, are pulled by the agricultural machine to move the front soil to the outside in two directions Push out the field ridge, and form a rectangular pit with a rectangular cross section or a curved rectangular shape on both sides on the path of the pass. 5. The agricultural implement according to claim 4, characterized in that the rotary tillage is performed in front of the plow blades to loosen the soil. 6. An agricultural machine tool for returning biomass to the field to cover the soil, characterized in that, under the traction of the agricultural machine, the pushed out soil is pushed back to the field ridge through two or more inverted plow blades formed by Over biomass or barrier screens. 7. A combined agricultural machinery for returning biomass to the field, characterized in that it includes a straw cutting and crushing device, a straw biomass picking and conveying system, a biomass storage bin and a feeder, a rotary tillage device, and soil transportation System, wire mesh layout system combined into a whole, one-time land plowing, biomass layered buried under the surface soil operation, among them, according to needs, straw cutting, crushing device, biomass storage bin and feeder, The wire mesh layout system is optional. 8. The combined agricultural machinery for returning biomass to the field according to claim 7, characterized in that the soil conveying system transports the surface soil from the side of the biomass conveying path or around the way to the field ridges and pits, covering the pre-conveyed onto the biomass in the pit. 9. The combined agricultural implement for returning biomass to the field according to claim 7, characterized in that, the biomass conveying system is transported from the side of the soil conveying path or in a surrounding manner to the field ridge pit, and the biomass is kept in the pit where it is conveyed. beneath the soil. 10 . The combined agricultural implement for returning biomass to the field according to claim 7 , wherein the rotary tillage device is replaced by a plow blade device. 11 .

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