CN114431088B - Ultralow-carbon rice cropping method - Google Patents

Abstract

The invention discloses an ultralow-carbon rice cropping method, which comprises the following steps: starting from half a month before harvesting the previous crop, keeping the field to fully drain water, stopping water from spreading on the carriage surface, keeping the carriage surface dry, and allowing the straw after harvesting the previous crop to fall on the carriage surface to form a straw layer; an ecological ditch is formed on the straw layer; directly seeding rice seeds or transplanting rice seedlings on straw layers except the ecological ditch, covering soil around the rice seeds when directly seeding the rice seeds, and covering soil blocks on the roots of the rice seedlings when transplanting the rice seedlings; before the rice starts the spike period, horse race water is irrigated every 15-20 days without irrigating the carriage surface, half ditch water is reserved when meeting rain, and ecological ditch water is lack to form ecological means; filling water from the beginning of the rice spike period to ecological full, and keeping for 7-10 days; and (4) draining water from the start of the rice lactation period to the time of harvesting the rice, and keeping the ecological ditch moist. The invention can solve the problems of large methane emission, high carbon reduction cost and difficult stable yield after carbon reduction of the conventional rice cropping method.

Description

Ultralow-carbon rice cropping method

Technical Field

The invention relates to the technical field of rice cultivation, in particular to an ultralow-carbon rice cropping method.

Background

It is counted that the average annual total yield of the grains in the whole country from 2011 to 2020 exceeds 6.0 hundred million tons, the grain-stalk ratio is estimated to be 1:1.2, and the total annual yield of the grains in the whole country is over 7.2 hundred million tons, so that the grains contain a large amount of organic matters. The root stubble is arranged under 7.2 hundred million tons of stalks, the weight ratio of the root crowns of the crops is 0.1-0.2, namely 8.28 hundred million tons of stalks and root stubble. These stalks and stubs, if burned, produce 16.56 million tons of carbonaceous gas; if any of them decay, 9.11 hundred million tons of carbon-containing gas are produced, and the main gas discharged in the context of paddy rice planting in paddy fields is methane. At present, straw incineration is forbidden, and the main aim of straw and stubble after harvesting is to turn over or rotary tillage to a cultivated layer in the field, gradually rot and gradually release carbon-containing gas. At present, all countries in the world strive for early realization of carbon peak and carbon neutralization, and if the stalks and stubbles after the crops are harvested in China can be correctly utilized, most of carbon in the stalks is fixed in soil by treatment to form organic matters instead of carbon-containing gas through measures, so that the reduction of carbon emission in the rice production process is realized, and the method has important practical significance and historical significance.

The carbon emission of agriculture in China mainly comprises methane (CH 4), the carbon emission of rice crops is about 70%, and the warming potential formed by the carbon emission of rice crops is mainly about methane, so that the effect is more than 80%. Investigation shows that at present, crop stalks in China are turned over and pressed, rotary tillage is carried out, part of the stalks and root stubbles are changed into methane and carbon-containing gas under the action of microorganisms, and part of the stalks and root stubbles are changed into humus to remain in soil. Therefore, how to minimize the decomposition of straw and stubble into methane and carbon-containing gas, and to maximize the permanent retention of the decomposition products in the soil becomes an urgent problem to be solved in the crop field, especially in the rice field, in response to global greenhouse gas emission reduction actions.

In the rice farming production, the paddy field needs to be irrigated and soaked before tillage, 150 cubes are needed for each mu generally, the requirement is met in the shortest time to reduce the agricultural consumption, the irrigation requirement is met in a short time, on one hand, the electric power is greatly consumed, on the other hand, the reservoir inventory is reduced, if drought occurs, a large amount of energy is needed to supplement the reduced reservoir inventory, and the carbon emission is indirectly increased.

The average rice sowing area of nearly 10 years in China is 4.52 hundred million mu, and the water for soaking the fields is 678 hundred million cubic, so that the link is the main body of the water for rice production, the water for rice production is the main body of the water for agricultural production, and the agricultural production is the main body of water resource consumption in China, so that the water consumption of the link for saving the fields is related to the water consumption bureau and the energy conservation bureau in China.

In rice farming, carbon emission reduction and water saving are closely related, if water saving is carried out, wet irrigation and even semi-arid irrigation are carried out, and carbon emission is remarkably reduced besides water consumption, because oxidation-reduction potential in soil is increased under wet or semi-arid conditions, bacterial activity of methane is inhibited, and methane formed is reduced. Particularly, under the semiarid irrigation condition, compared with flooding irrigation, the carbon dioxide emission is obviously reduced.

The patent with publication number CN111919688A discloses a paddy rice micro-ridge mixed sowing cultivation method, which comprises S1, draining water in the mature period of previous crops, and reaching a state that a harvester can work; s2, harvesting previous crop, leaving stubble, crushing straw of the previous crop, and scattering the crushed straw on the left stubble to form a rhizosphere layer for rice growth; s3, ditching in the field to form an ecological ditch; s4, flattening the vertical stubble and crushed straws on a carriage surface to form a lower pad surface, forming the seed manure-soil compound into a ridge shape and falling on the lower pad surface to form an ecological belt, and forming a plurality of ecological belts between adjacent ecological ditches; the mass ratio of the seed manure composite is 6-14:50-70:6000-10000, and the chemical fertilizer and soil are evenly mixed. The ecological belt I is used as a medium for wrapping organisms and nutrient bodies, and is used for preserving heat, moisture, water and air; secondly, the biological nutrient is provided with moisture nutrition as a donor. The seeds which are sprouted and exposed in the ridge grow faster than weed seeds in the ridge and outside the ridge, and the long leaves root smoothly. In this patent, after sowing, the horse race water is irrigated once, and the water management in the cultivation process is: maintaining the water layer for 1-2 cm after the rice seedlings emerge; wetting irrigation is adopted in the tillering stage of the rice, and the depth of a water layer is 2-4 cm; the field is sunned when the number of the tillers reaches 80% of the effective spike number in the later tillering stage; wetting irrigation in heading and flowering periods and in milk ripening periods, wherein the depth of a water layer is 1cm, and water is irrigated after water is exhausted for 3-4 d; and (5) field sunning in the yellow ripeness period. In the rice cultivation process of the patent, although the water quantity in the rice field is lower than that of the conventional rice cultivation, the water in the rice field floods the compartment surface, the straw on the compartment surface is in an anaerobic state, and the straw is slowly decomposed in the anaerobic state and is in a carbon low-emission mode. The ecological ditch, the seed manure compound and the ecological belt in the application are all operated by adopting the cultivation method in the patent.

The rice crop production discharges carbon, and has three essential elements: carbon source, microorganism source and water source, wherein the carbon source is raw materials for forming carbon dioxide and carbon-containing gas, such as straw, and the straw is the most main carbon source for carbon emission in rice production; microbial sources refer to bacteria, fungi, etc., that convert raw materials into carbon-containing gases, such as methane bacteria; the water source is that bacteria utilize raw materials such as straw and the like to transform under the condition of proper humidity to form and discharge carbon-containing gas, and the bacteria can not complete the transformation under the dry state to form the carbon-containing gas.

Rice farming produces carbon emissions, which can be divided into three categories by the process and results of solving the three source problems: normal emission, low carbon emission and ultra low carbon emission. 1) Normal emission: the problems of three of carbon source, microorganism source and water source all exist. The flooding irrigation is mainly adopted, the wetting irrigation is assisted, chemical fertilizers such as nitrogen fertilizer and the like are applied to the cultivation layer, rotary tillage or turning over is carried out, the straws enter the cultivation layer, the straws and the stubble decompose and rot under the action of microorganisms, carbon dioxide and carbon-containing gas are discharged, and the yield of rice is high; 2) Low carbon emission: the problems of carbon sources and microbial sources and water sources are alleviated. The flooding intensity is larger than that of the conventional discharge mode, the wetting irrigation intensity is smaller than that of the conventional discharge mode, a rice-duck co-cultivation mode is generally adopted, ducks frequently move to increase the oxygen content of a water layer of a rice field, the oxidation-reduction potential of the surface layer of soil is improved, the growth and reproduction of microorganisms such as methane bacteria are inhibited, the metabolic capacity is reduced, the discharged carbon-containing gas is reduced, and the rice yield is equivalent to that of the conventional discharge mode.

The application adopts ultra-low carbon emission: the problems of carbon source and microorganism source exist, the water source problem is basically solved, the activity of the microorganism source is weakened, and most of the carbon source is converted into organic matters. No water layer is established in the whole growth period, and horse race water is irrigated once in 15 to 20 days; the water in the heading period is full and the water is not contained in the field surface, and the ecological zone is in a moist state after absorbing water; the ecological and ecological zone is established, the ecological layer on the symbiotic land of the chickens and the ducks and the underground ecological layer of the rice root group straw earthworms are constructed, no-tillage and semiarid cultivation is carried out, the growth and propagation of microorganisms are inhibited, the decomposition of the straw is inhibited, the digestion and half decomposition of the straw is inhibited, the conversion of the decomposed straw is inhibited, the discharged carbon dioxide and carbon-containing gas are obviously reduced, the rice yield is improved, the rice yield is increased, and the fertility of the rice field is improved.

Reduction of carbon emissions in production and life is a common concern for every country and each citizen worldwide. Rice crop production is an important point in crop production carbon emissions, and reduction of carbon emissions is significant in reducing carbon emissions in the agricultural industry. The carbon effect produced by methane emissions is the main component of rice production, and is secondarily carbon dioxide, nitrous oxide. Methane emissions have three essential elements: carbon source, microorganism source and water source, wherein the carbon source is raw materials forming methane, such as straw, and the straw is the most main carbon source for carbon emission in rice production; microbial sources refer to methane bacteria that convert raw materials to methane; the water source is that the raw materials such as straw and the like are utilized by the nail alkane bacteria, the raw materials are transformed under the condition of proper humidity to form methane and are discharged, and the methane bacteria can not complete the transformation action to form methane under the dry state.

The method for controlling the root cause of methane emission in rice production solves the problems of three sources. In a normal emission state, three problems of a carbon source, a microorganism source and a water source exist. In the low carbon emission state, the problems of the carbon source exist, and the problems of the microorganism source and the water source are relieved. Under the ultralow carbon emission state, the problems of carbon sources and microorganism sources exist, the water source problem is basically solved, the activity of methane bacteria is weakened, and most of the carbon sources are converted into organic matters.

Chinese patent CN200910272552.7 discloses a whole-course aerobic cultivation method of rice in fixed ditch without tillage seedling throwing, which comprises the following steps: (1) The rice seeds are coated by using a coating agent for dry-breeding and nursing, thick mud and dry fine soil, and the mass ratio of the components is as follows: 7.9 to 12.5 percent of dry-raising nursery, 25 to 26.3 percent of rice seeds, 12.5 to 13.2 percent of thick mud with the water content of 37 percent and 50 to 52.6 percent of dry fine soil with the water content of 3 percent; arranging seedling beds according to requirements and preserving soil moisture; keeping the seedling age for 15-18 days; (2) The compartment width of the stubble field is 1.2m, the ditch width is 0.3m, and the ditch depth is 0.25m; returning rape stubbles to the field; pure nutrient is applied to N15%, P ₂ O ₅ 15％，K ₂ O,15% of a ternary compound fertilizer, and applying 30kg of pure nitrogen per mu; applying 5.80kg of large-particle zinc per mu; applying 4.8kg of boron fertilizer per mu, and keeping the water full of the ditch; (3) 50-100 g/plant of 15-18 days seedling with soil is directionally thrown and planted according to the plant row spacing of 20 cm; (4) After seedling throwing, water is reserved in the ditch until the heading stage, the compartment surface is anhydrous, and dry-wet alternate cultivation is adopted from the grouting stage to the mature stage. The patent details the advantages of a no-tillage cultivation method in the background technology, is beneficial to improving the soil ventilation, reducing the greenhouse gas emission and the like, but adopts dry-wet alternate cultivation, water in a paddy field floods a compartment surface during wet cultivation, and earthworms in the paddy field cannot survive.

Disclosure of Invention

The invention aims to solve the technical problems of large methane emission, high carbon reduction cost and difficult stable yield after carbon reduction of the conventional rice cropping method.

In order to solve the technical problems, the invention adopts the following technical scheme: an ultra-low carbon rice cropping method comprises the following steps:

s1, arranging the field blocks out of a compartment surface and a compartment ditch before transplanting or directly seeding the previous crop, and planting the previous crop on the compartment surface;

s2, starting half a month before harvesting the previous crop, keeping the field sufficiently drained, stopping water from overflowing to the compartment surface, keeping the compartment surface dry, and enabling the straw after harvesting the previous crop to fall on the compartment surface to form a straw layer;

s3, an ecological ditch is formed in the straw layer;

s4, directly seeding rice seeds or transplanting rice seedlings on the straw layers except the ecological ditch, wherein soil is covered around the rice seeds when the directly seeding rice seeds are adopted, and soil blocks are covered on the roots of the rice seedlings when the transplanting rice seedlings are adopted;

s5, before the rice spike starting period, water is irrigated into the running horses every 15-20 days and is not irrigated onto the carriage surface, half ditch water is reserved when the water meets rain, and ecological ditches lack water to form ecological means;

s6, irrigating from the beginning of the rice spike period to ecological full, and keeping for 7-10 days; and (4) draining water from the start of the rice lactation period to the time of harvesting the rice, and keeping the ecological ditch moist.

The invention has the advantages that 1) the cultivation mode is changed, and the drought-seeding, seedling-to-booting drought-tube and heading-period ecology are implemented, the water is present, the compartment surface is anhydrous, and the drought-tube is used after the milk-maturing period; no ponding exists on the carriage surface, so that earthworms in the field can survive, and the earthworms promote the decomposition and digestion of straw; 2) Changing the vertical structure and the horizontal structure of the soil cultivation layer to form ecological devices, inlays and ecological ditches transversely; wherein the inlay is a structure formed by mixing straws together for many years; an ecological belt, a straw layer and a soil layer are formed longitudinally from top to bottom, and the air permeability of the soil cultivation layer and the straw layer is enhanced; 3) The environment for forming methane is changed, the water seepage, draining and water drainage of a cultivation layer and a straw layer are promoted, the water content of the straw is reduced, the air permeability of the straw is improved, the decomposition of the straw is prevented, and the methane gas formed by the straw is reduced. 4) The production mode is changed, and the three-way of the rice field production process is realized: no tillage, no burning of straw and no soaking of field water. And thirdly, reducing methane gas emission, irrigation water and operation energy consumption. Three increases: increase yield, enhance lodging resistance and increase the tillering ear forming rate.

The cultivation layer and the plough layer stubble treatment measures and the changing process: in-situ preservation of root stubbles, drying in the sun to open the soil surface, extending downwards for 40cm-60cm, ventilating, no effective nitrogen, mostly in an undegraded state, mostly in a semi-decomposed state, and rarely in a decomposed state, taking the root stubbles as underground habitats by earthworms, digesting the decomposed straw to become earthworm bodies or earthworm bodies, and releasing and discharging carbon dioxide and carbon-containing gas in an ultralow manner.

In S6, the ecological ditch is kept moist until the rice is harvested, and the moist ecological ditch is moist but no water is visible.

The previous crop is planted on the carriage surface; the furrows are kept normally drained during the growth of the previous crop and throughout the annual production period.

Further, chickens and muscovy ducks are bred in the paddy field in the tillering stage of the rice until the rice is harvested.

Soil surface straw treatment measures and changing processes: the method comprises the steps of placing straws on a soil surface, drying, no effective nitrogen, lifting straw layers by chicken using claws and Muscovy ducks every day, drying the straw layers, greatly reducing the temperature difference, and lacking the effective nitrogen, wherein the straw is decomposed in a hindered way, most of the straw is in an undegraded state, the rest of the straw is in a semi-decomposed state, and the rest of the straw is in a very small way, so that earthworms digest the straw in the semi-decomposed and decomposed state to become earthworm bodies or become wormcast, and the carbon dioxide and carbon-containing gas ultra-bodies are released and discharged.

Further, in order to reduce the moisture content of the straw after harvesting the previous crop, the moisture management before harvesting the previous crop in S2: semi-arid irrigation is mainly used for avoiding flooding irrigation; and when the water runs out of the horse when the water runs into drought, the flood irrigation is stopped. Semi-arid irrigation is where water is present in the ecological ditch, but the carriage surface is anhydrous. Flooding refers to flooding the surface of the car and maintaining a deeper layer of water. Flood irrigation refers to the direct placement of water on a deck, allowing water to flow along the deck to the deck without irrigation.

Further, the front crop in S2 is harvested for half a month, if in rainy days, the accumulated water in the dry ditch is required to be drained within 12 hours, the accumulated water in the ditch is not more than 6cm, and the water surface is stopped. The field drying is kept, which is beneficial to the operation of the harvester and the sowing of the next stubble.

Further, when the rice seeds are directly planted in the S4, the soil dug during ecological ditch opening is uniformly mixed with the fertilizer and the seeds wrapped by the soil sundry fertilizer after breast breaking, the seeds, the fertilizer and the soil compound are mixed into the seed, fertilizer and soil compound, and the seed, fertilizer and soil compound strips are sprayed on Tian Mianxing to form the ecological belt. The functions of drainage, water storage and ventilation are exerted; the ecological belt is constructed by mixing seed manure with a special mixed sowing machine and then discharging the mixed seed manure into a belt in a strip shape.

Further, in S4, the seed, fertilizer and mud compound is directly sown in a drought manner, and after seedling emergence, the field is kept dry, and if rain occurs, half ditch water in a ditch is kept. The dry direct seeding refers to that irrigation is not carried out when the seed, fertilizer and mud compound is sown, and horse race water is irrigated once after 15-20 days, and the upper carriage surface is not irrigated. The root system of the rice is forced to deeply prick and absorb water, the anti-lodging capability is enhanced, the growth center in the seedling stage is arranged at the middle and lower parts of the plant, long roots and low tillers are used as main materials, the growth vigor of early tillers in the seedling stage, early rooting and no tillers in the booting stage and long white roots are formed, the low tiller-ear specific gravity is high in the mature stage, and the tillering heading rate is increased.

And S4, when the rice seeds are directly sown, the stubble of the previous stubble crops is flattened, and then an ecological belt is formed on the stubble of the flattened previous stubble crops.

Further, building a chicken and muscovy duck shed on the field ridge; the middle of the field is provided with an overhead and a culvert for chickens and muscovy ducks to climb up and drill holes, the cross-country capability is cultivated, the whole field patrol is realized, and dead angles of insects and grass are eradicated.

Further, the width of the carriage surface is 150-600 cm; the width of the ditch is 10-25 cm, and the depth of the ditch is 40-50 cm.

Further, the total amount of three fertilizers produced by one season of rice is respectively as follows: nitrogen fertilizer pure N is 120.0kg/hm ² ～150.0kg/hm ² Potash fertilizer K ₂ O is 96.0kg/hm ² ～120.0kg/hm ² Phosphate fertilizer P ₂ O ₅ 60.0kg/hm ² ～75.0kg/hm ² 。

Further, the straws in the step S2 are crushed and uniformly scattered on the carriage surface.

The key technical measures are that no-tillage is carried out, and the straws are scattered on the carriage surface, dry sowing and semiarid cultivation at the same time, which is the core of the invention, and compared with the three methods of dry sowing flooding irrigation, dry sowing wetting irrigation and water sowing wetting irrigation in the past, the dry sowing semiarid mode of the invention is based on no-tillage straw carriage surface to prevent decomposition to form carbon-containing gas emission; the water does not go to the carriage surface, the flooding and wetting state is not caused, and the water content of the soil cultivation layer is low; the plow layer has a slightly higher moisture content but is significantly lower than the three modes of the previous. Under the state, the growth and the propagation of methane bacteria are inhibited, the decomposition of straw is inhibited, the half-decomposed straw is digested, the decomposed straw is converted, the discharged methane and carbon-containing gas are obviously reduced, the yield of rice is improved, the yield of rice is increased, and the fertility of a rice field is improved.

Adopts dry sowing and semiarid cultivation to realize ultra-low emission of methane gas, and has the precondition that three problems of difficult emergence, weed flooding and fertilizer loss must be solved. 1) The invention solves the problem that the seedling emergence is difficult, the seeds are sowed under the conditions of no irrigation and no rotary tillage, the seeds are prevented from being exposed on the soil surface and being damaged by sun-drying, low-temperature at night, rain water flushing, birds and mice, and the seedling emergence rate is reduced. In the scheme, when the stubble is harvested, the stubble straw is crushed (the common combine harvester is provided with the straw chopping function) and uniformly scattered on Tian Biao, germination is carried out until the chest is broken, a layer of organic fertilizer is wrapped before uniform mixing, then the fertilizer, moist ditch mud and the chest-broken seeds are uniformly mixed, and the seed, fertilizer and mud mixture strips are sprayed on Tian Biao by a special seeder to form an ecological belt, so that conditions of ventilation, moist, sun protection, rain erosion prevention and bird prevention are created for seed emergence, the seedling emergence rate is high, and the seedlings are even and strong. 2) The method for solving the problem of weed hazard is that weeds are extremely easy to flood and seriously influence the yield on the premise of carrying out arid-seeding semiarid cultivation, and the conventional method is to use herbicide at present. 3) The invention solves the problem that the fertilizer is lost, and the fertilizer application difficulty is increased on the premise of no-tillage and no-irrigation-foam field water, and the conventional method is that the fertilizer is applied to the surface layer of the field, is dissolved in the surface layer of the field when meeting rain, is gathered in high concentration, and is leaked vertically along with the rain to form a part of groundwater or leaked laterally to form a part of channel surface flow, and is lost completely. In this scheme, utilize chain ditcher ditching to throw out reserve with the earth in the field, mix chemical fertilizer, moist ditch mud and broken chest seed, spill seed, fertilizer, mud mixture strip in Tian Biao with special seeder, become the ecological area, chemical fertilizer evenly distributed in the ecological area, the ecological area tangent plane is triangle-shaped, lower end is wide, upper portion point, the chemical fertilizer in the area is protected, rain-proof erodees, difficult loss. 4) The invention solves the problems of no-tillage, ditching, compartment separation, soil taking and seed manure mixing to form a compound and strip spraying of the compound.

The technical principle of the invention is as follows: the invention uses a chain ditcher to ditche in a field which is not ploughed and not rotary tillage to form a compartment and a ditch, mixes ditch mud with seeds and chemical fertilizers wrapped by soil and sundry fertilizers after breast breaking in proportion, and then sows wine on the compartment surface to form an above-ground ecological layer and an underground ecological layer from top to bottom. The ecological layer on the ground is formed, the ecological zone is formed, seeds and chemical fertilizers are uniformly distributed in the ecological zone, the three-phase layout and the environment of seeds, the fertilizer and soil are changed, the three are integrated, no negative effect is formed, the high-concentration mixed mud application of the base fertilizer, the sowing of the seeds with the fertilizer and the ventilation and wetting of the soil between the seeds are realized, and the ecological layer on the symbiotic ground of the muscovy ducks is formed by the adaptation of animals and plants to the middle stage of the growth of the rice; the ecological layer is kept moist and breathable, the anaerobic decomposition of root stubbles is blocked, and the moist environment required by the normal life of earthworms is ensured. The formation of the above-ground ecological layer and the underground ecological layer promotes the accumulation of natural rainfall and the efficient drainage of a narrow compartment, improves the water utilization efficiency and the soil ventilation, realizes the effective coupling of organic fertilizer, chemical fertilizer and water resources, and achieves the purposes of methane emission reduction, water saving, water retention, fertilizer retention and yield increase. The technology can realize three reduction in the rice production: the total methane emission, especially the total greenhouse gas emission, the irrigation water and the operation energy consumption are reduced; three-way implementation is realized: no tillage, no stubble straw burning, no irrigation of field water, and obvious ecological benefit; three increases are realized: the whole growth period of the upper layer root group of the rice is in a fertile ecological zone, so that the nutrition condition is good and the yield is increased; the whole-course semi-arid cultivation is performed, the rice root system is forced to deeply prick and absorb water, and the lodging resistance is enhanced; the whole-course semi-dry cultivation is carried out, the growth center in the seedling stage is arranged at the middle and lower parts of the plant and mainly takes long-root and low-position tillering to form the growth vigor of early tillering in the seedling stage, no tillering in the early rooting stage and booting stage and long-white root, the low-position tillering to mature stage has high specific gravity, and the tillering and heading rate is increased. Specifically, as shown in fig. 1, the vertical structure: the ecological layer on the symbiotic ground of the rice chickens, the muscovy ducks and the two layers of the underground ecological layer of the rice root group straw earthworms are formed from top to bottom, and an ecological belt and an ecological device are formed.

The ecological simplicity has the following functions:

firstly, the methane emission reduction function: the ecological environment is good, the growth and development of methane bacteria of an overground ecological layer and an underground ecological layer are not facilitated, the straw and the rice stubble are mainly converted into organic matters, the activity of microorganism sources is weakened, most of carbon is converted into organic matters, and the methane emission is reduced by 75% -95% compared with the conventional mode;

secondly, the water draining function is realized, water vertically seeping from the ground surface to the plough layer is gathered to the ecological side and then enters the ditch;

thirdly, an oxygen supply function, wherein an air convection net channel is formed in the cultivation layer to supply oxygen to the root group of the crops;

the ecological belt and the field straw cooperatively play a role in:

firstly, the function of preventing organic matters from forming carbon dioxide is achieved, the straw of the previous stubble is paved on the field surface, the straw is in a semi-closed state and gradually carbonized to form organic matters, and the straw is prevented from forming carbon dioxide; the soil surface and the cultivation layer under the straw layer are rich in oxygen with little water, and the carbon-containing organic matters are gradually carbonized under the action of gravity to form organic matters which cannot form carbon dioxide;

secondly, the water-retaining function is achieved, the previous crop straw is paved on the field surface and is pressed by the upper ecological belt to form a water-retaining layer similar to a sponge body, so that the evaporation of the field surface is prevented, and the field surface becomes a small reservoir;

thirdly, the oxygen enrichment function, the similar sponge body formed by the straw flatly paved on the field surface can store air for the respiration metabolism of the rice roots extending out of the ecological zone;

fourthly, the fertilizer retaining function is that the fertilizer mixed with the ditch mud is firstly absorbed and accumulated by the ditch mud after being dissolved, the surface layer of the ecological belt forms a shell cover to avoid volatilization, and the surface soil layer lining which is not ploughed is arranged at the lower layer to delay infiltration;

fifthly, covering materials are provided for earthworms, the ecological belt linearly covers straw layers on the field surface, the straw layers are gradually settled and flaked, and the earthworms become barriers for protecting the earthworms against biological risks and natural risks;

sixth, clean straw function, the straw is returned to the field and is difficult to mechanically rotary tillage or turn over the farming industry, the invention is no-tillage and adopts the ecological belt to spread and press the straw, the straw is slowly dispersed in the aerobic state, form the straw clean utilization function.

Compared with the existing conventional rice production mode, the scheme of the invention has to solve two problems. 1) How to solve the problems of poor growth of paddy rice due to lack of water and yield reduction under semi-arid irrigation conditions: the scheme adopts drought sowing and seedling stage drought pipes, under the seedling stage condition, the root system of the rice develops to the depth of soil to obtain moisture, namely, a foundation for deep rooting is laid in the initial seedling stage. Although semi-arid irrigation is performed, the moisture content of the soil surface layer is higher below 30 cm, deep roots can absorb underground water, an effective water supply system is established, normal growth is ensured, stable yield is obtained, and even the yield is slightly increased. 2) How to solve the problem of grass damage in the semiarid state: the scheme is mainly based on semi-arid irrigation, no herbicide is applied, grass damage is controlled by two mechanisms, and grass is pressed, so that a large amount of straw is scattered on the surface layer of soil during harvesting of the previous crop, the straw tends to be uniformly distributed due to the grass spreading function of the seeder, and grass sheets are gradually formed by settling, so that the grass sheets have a stronger shielding effect and inhibit emergence of weeds; secondly, the chickens and the ducks are used for controlling grass, and the chickens and the ducks can freely move and walk in the whole journey due to semi-arid irrigation, and the stepping and pecking behaviors can effectively control tender grass which breaks through the grass sheets.

Compared with the prior art, the invention has the following beneficial effects:

1) The soil cultivation layer structure is changed, and the ecological layer on the rice, chicken, muscovy duck symbiotic land and the underground ecological layer of rice root group straw earthworm interaction are formed from top to bottom on the no-tillage basis.

2) On the basis of realizing the full-quantity returning and broadcasting of crop straws at one time, the ecological belt and ecological effect interaction is utilized to promote the decomposition of the straws in aerobic and dry environments and convert the straws into organic matters, prevent the formation of carbon dioxide and methane and play a role in ultralow emission of greenhouse gases.

3) By utilizing the good drainage capacity of the narrow compartment surface and the good water storage capacity of the deep groove, on one hand, the water content of the compartment soil is reduced, the soil ventilation is improved, and on the other hand, the utilization efficiency of natural water falling is improved.

4) Compared with the prior art, the method adopts dry sowing and semiarid cultivation, namely, no irrigation of field water is carried out, and horse race water is irrigated every 15-20 days instead of flooding, so that the method forms ecological and ecological bands in the field, and inhibits the respiration of cells and the fermentation of microorganisms under the environment with low oxygen and water content, remarkably reduces the emission of carbon dioxide and methane and plays a role of ultralow emission.

5) Compared with the prior art, the semiarid cultivation is adopted, and the invasion of weeds and pests is aggravated, so that the chickens, the muscovy ducks, the earthworms and the like are increased, the biological diversity is increased, and the weeds and the pests are prevented and controlled by a biological method; simultaneously, the agricultural method is adopted for prevention and control, the front stubble straw is paved in the paddy field, the ecological belt linearly covers the straw layer on the surface of the paddy field, the straw layer is gradually settled and formed into slices, the germination of weed seeds is restrained, namely, the germination is calculated, and the slices of straw restrain the growth of the leaves.

Drawings

FIG. 1 is a schematic view showing the structure of a cultivation layer for three years in succession according to an embodiment of the present invention.

The reference numerals in the figures are:

1. the plant growth and cultivation method comprises the steps of (1) carrying out primary integration on the first-year straws in the second year to form an undigested straw layer, a semi-decomposed straw layer and a decomposed straw layer (6) on the second-year straws in the third year to form an undigested straw layer, a semi-decomposed straw layer (3) carrying out primary integration on the second-year straws in the second year to form an undigested straw layer, a semi-decomposed straw layer, a decomposed straw layer (10) carrying out primary integration on the second-year straws in the second year to form the third-year straws in the third year to form the second-year straws, and (9) carrying out primary integration on the second-year straws in the third year to form the third-year straws, namely, 11 of cultivation layers, a bottom plow layer and the like, 12, tian Biao of earthworms (13) and 14 of earthworms in the field at the root stubble of the cultivation layers.

Detailed Description

An ultra-low carbon rice cropping method comprises the following steps:

1) And (3) carrying out ditch structure engineering all year round in the paddy field: the field blocks are arranged into a box surface before the previous crop is transplanted or directly sowed, and the width of the box surface is 150-600 cm; the width of the ditch is 10-25 cm, and the depth of the ditch is 40-50 cm; the previous crop is planted on the carriage surface; the normal drainage of the ditches is kept during the growth period of the previous crop and the whole annual production period;

2) And (3) water management: when the season is managed: dry sowing in the sowing period, dry pipe from the seedling period to the booting period, wet irrigation in the heading period and dry pipe after the milk ripening period are carried out; moisture management before harvesting of previous stubbles: wetting irrigation is mainly performed, and flooding irrigation is stopped; when the water is irrigated into the horse race water during drought, the flood irrigation is stopped; and the half month before harvesting starts, the field is kept to be fully drained, and the water surface is stopped.

The straw after harvesting the previous crop is scattered on the carriage surface uniformly to form a straw layer.

3) Planting and seedling management:

firstly, wrapping a layer of soil and sundry fertilizer on seeds with broken chest, then mixing the seeds, the fertilizer and the mud, directly seeding on drought, and continuously keeping the field dry after seedling emergence, if rain occurs, keeping half ditch water in a ditch.

4) And (3) fertilizer application: the total amount of three fertilizers produced by the paddy rice in one season is respectively as follows: nitrogen fertilizer pure N is 120.0kg/hm ² ～150.0kg/hm ² Potash fertilizer K ₂ O is 96.0kg/hm ² ～120.0kg/hm ² Phosphate fertilizer P ₂ O ₅ 60.0kg/hm ² ～75.0kg/hm ² ；

Evenly mixing soil lifted in ditching with seeds and fertilizers coated with soil and mixed fertilizers after breast breaking, and mixing to form a seed, fertilizer and soil compound, wherein the mass ratio is 10:60:12000; all fertilizers can be applied at one time in the proportion during sowing, and can be applied in two times as appropriate, wherein the first time is 85 percent and the second time is 15 percent.

5) Constructing field facilities;

constructing an ecological ditch in the field, and playing the drainage function of the ecological ditch to form an ecological river; and (3) uniformly mixing the ditch mud in the ditch ecological ditch with seeds and fertilizer for breaking the chest in the sowing stage, and sprinkling the mixed strips on the compartment surface straw layer to form the ecological belt. Building a chicken and muscovy duck shed on the field ridge; overhead is built in the middle of the field, culverts are arranged for chickens and muscovy ducks to climb up and drill holes.

6) And (3) field management: semi-dry irrigation is adopted in the whole growth period; the upper carriage surface is not irrigated, and horse race water is irrigated every 15-20 days; retaining half-ditch water when meeting rain; filling water from the beginning of the spike period to full, and keeping for 7-10 days; draining water from the period of milk ripeness to the harvest holding ditch, wherein water is not found.

As shown in fig. 1, the cultivation layer is an undigested straw layer 1, a half-decomposed straw layer 2 and a decomposed straw layer 9 formed by the straws of the third year from top to bottom after three years, the straws of the second year are primarily integrated 8 in the second year, the straws of the first year are integrated 7 in the third year, and the cultivation layer and the plough layer 10.

To explore the difference in the amount of methane gas discharged in the conventional, low and ultra-low discharge modes, the paddy field CH was measured and calculated using Yuan Weiling, cao Cougui, li Chengfang, etc. for 6 consecutive years from 2015 ₄ And N ₂ O emission method (China agricultural science, 2009,42 (6): 2052-2060, greenhouse effect and economic benefit evaluation of rice-duck and rice-fish co-cropping ecosystem) is carried out for three emission modes. Positioning observation CH by adopting closed static box ₄ And N ₂ O gas flux. The box body is made of transparent organic glass with the thickness of 5mm, and the size of the sampling box is 60cm multiplied by 110cm. The small electric fan is arranged in the box to make the gas in the box uniform. Sampling at the same place every 7d from the 3 rd day after transplanting the rice. When in sampling, the sampling box is lightly buckled on a stainless steel return base, and a water tank is arranged on the return base to isolate the water seal effect of the gas inside and outside the box. Each sample was taken from 9: and (3) starting at 00, sampling times are respectively 0, 10, 20, 30 and 40 minutes after closing the box, and placing 20ml of each sample into a vacuum glass bottle. CH (CH) ₄ The detection conditions of (2) are as follows: the temperature of the chromatographic column is 75 ℃; detector (FID) temperature 180 ℃; carrier gas N ₂ (> 99.999%) flow rate 2 ml.min ^-1 The method comprises the steps of carrying out a first treatment on the surface of the Gas combustionH ₂ (> 99.99%) at a flow rate of 30 ml.min ^-1 The method comprises the steps of carrying out a first treatment on the surface of the The gas is air with the flow rate of 300 ml.min ^-1 The method comprises the steps of carrying out a first treatment on the surface of the The sample injection amount is 1ml, the flow rate is 40 ml.min ^-1 。N ₂ The detection conditions of O are as follows: the temperature of the chromatographic column is 65 ℃; detector (ECD) temperature 300 ℃; the temperature of the sample injector is 100 ℃; argon methane carrier gas (95% argon +5% methane) with a flow rate of 40 ml/min ^-1 The method comprises the steps of carrying out a first treatment on the surface of the The sample injection amount is 1ml, the flow rate is 40 ml.min ^-1 。CH ₄ And N ₂ O-flux was calculated according to the following equation:

F＝ρ×h×dC/dt×273/(273+T) (1)

wherein F is the gas flow rate (mg.m) ^-2 ·h ^-1 ) ρ is the gas density in the standard state; h is the box height; dC/dt is the concentration change rate of the gas in the sampling tank, and T is the average temperature (DEG C) in the sampling tank during the sampling process. And calculating the gas discharge flux according to the relation curve of the gas sample concentration and time, wherein the seasonal discharge amount is the product of the average flux value and the total hours of the whole rice growing period.

Rice field ecosystem CH ₄ And N ₂ O gas emissions have an important impact on global warming, and the relative radiation effects of different greenhouse gases of the same quality on greenhouse effect enhancement are often expressed in terms of warming potential (GWPs, i.e. global warming potentials, GWPs for CO2 of 1). For climate change on the 100a time scale, CH ₄ And N ₂ GWPs for O gas are 21 and 310. CH of the same mass ₄ And N ₂ Conversion of O gas into CO of isothermal chamber effect ₂ And calculating the value of the greenhouse effect by using the average value of forestation cost and carbon tax law.

MC＝0.2729×α×M (2)

TC＝MC+DC (3)

Wherein MC is the temperature-increasing potential of CH ₄ And N ₂ O is converted to pure C (kg. Hm) ^-2 ) The method comprises the steps of carrying out a first treatment on the surface of the Alpha is GMP value; m is CH ₄ And N ₂ O emission (kg hm) ^-2 ) The method comprises the steps of carrying out a first treatment on the surface of the TC is CO ₂ Total amount of emissions (T/hm) ² ) The method comprises the steps of carrying out a first treatment on the surface of the DC is the classified emission of CO according to gas varieties ₂ Amount (T/hm) ² )。

The emissions for the last two years are shown in table 1, and the results of the study on the conventional emission mode, the low emission mode, and the ultra-low emission mode for 6 consecutive years from 2015 are substantially identical to the results for the last two years:

table 1 CH ₄ And N ₂ O、CO ₂ Emissions and total amount

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The invention influences the functions of carbon sources and microorganism sources to play by regulating and controlling the structure and functions of the surface layer covering object, the surface layer moisture state and functions, the plough layer moisture state and functions and the plough layer ventilation state and functions, and remarkably reduces the emission of carbon-containing gas, thereby forming an ultralow emission mode, and the difference between the three modes is shown in table 2.

TABLE 2 dissimilarity of ultralow carbon rice cropping method with conventional and low emission methods

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Claims (9)

1. An ultra-low carbon rice cropping method is characterized by comprising the following steps:

s1, arranging the field blocks out of a compartment surface and a compartment ditch before transplanting or directly seeding the previous crop, and planting the previous crop on the compartment surface;

s2, starting half a month before harvesting the previous crop, keeping the field sufficiently drained, stopping water from overflowing to the compartment surface, keeping the compartment surface dry, and enabling the straw after harvesting the previous crop to fall on the compartment surface to form a straw layer;

s3, an ecological ditch is formed in the straw layer;

s4, directly seeding rice seeds or transplanting rice seedlings on the straw layers except the ecological ditch, wherein soil is covered around the rice seeds when the directly seeding rice seeds are adopted, and soil blocks are covered on the roots of the rice seedlings when the transplanting rice seedlings are adopted;

s5, before the rice spike starting period, water is irrigated into the running horses every 15-20 days and is not irrigated onto the carriage surface, half ditch water is reserved when the water meets rain, and ecological ditches lack water to form ecological means;

s6, irrigating from the beginning of the rice spike period to ecological full, and keeping for 7-10 days; draining water from the rice milk ripening period to the rice harvesting time, and keeping the ecological ditch moist;

raising chickens and/or ducks in the rice field at the tillering stage of the rice;

the cultivation layer and the plough layer stubble treatment measures and the changing process: in-situ preservation of root stubbles, drying in the sun to open the soil surface, extending downwards for 40cm-60cm, ventilating, no effective nitrogen, mostly in an undegraded state, mostly in a semi-decomposed state, and rarely in a decomposed state, taking the root stubbles as underground habitats by earthworms, digesting the decomposed straw to become earthworm organisms or earthworm manure, and releasing and discharging carbon dioxide and carbon-containing gas in an ultralow manner;

soil surface straw treatment measures and changing processes: the method comprises the steps of placing straws on a soil surface, drying, no effective nitrogen, lifting straw layers by chicken using claws and Muscovy ducks every day, drying the straw layers, greatly reducing the temperature difference, and lacking the effective nitrogen, wherein the straw is decomposed in a hindered way, most of the straw is in an undegraded state, the rest of the straw is in a semi-decomposed state, and the rest of the straw is in a very small way, so that earthworms digest the straw in the semi-decomposed and decomposed state to become earthworm bodies or become wormcast, and the carbon dioxide and carbon-containing gas are released in an ultralow way.

2. The method of ultralow-carbon rice farming according to claim 1, wherein the pre-harvest moisture management of the previous crop in S2: wetting irrigation is mainly performed, and flooding irrigation is stopped; and when the water runs out of the horse when the water runs into drought, the flood irrigation is stopped.

3. The method for ultra-low carbon rice farming according to claim 2, wherein the harvesting of the previous crop in S2 is performed half a month before harvesting, and if in rainy days, the accumulated water in the dry ditch is required to be drained within 12 hours, the accumulated water in the ditch is not more than 6cm, and the water surface is stopped.

4. The method for ultra-low carbon rice farming according to any one of claims 1 to 3, wherein in S4, when rice seeds are directly planted, soil dug in ecological ditches is uniformly mixed with fertilizer and seeds wrapped with soil and miscellaneous fertilizer after breast breaking, and the mixture is mixed into a seed, fertilizer and mud compound, and the seed, fertilizer and mud compound is sprayed on Tian Mianxing to form an ecological zone.

5. The method of ultralow-carbon rice farming according to claim 4, wherein the seed, fertilizer and mud compound in S4 is directly sown in dry land, and the seedling is kept dry in the field after emergence, and half-furrow water in the furrow is kept if it is rained.

6. The method for ultra-low carbon rice farming according to claim 2, wherein a chicken shed and a muscovy shed are built on the field ridge; overhead and culvert are set in the middle of the field.

7. The ultralow-carbon rice cropping method according to any one of claims 1 to 3, characterized in that the width of the compartment is 150 to 600cm; the width of the ditch is 10-25 cm, and the depth of the ditch is 40-50 cm.

8. The method for ultralow-carbon rice farming according to any one of claims 1-3, wherein the total amount of three fertilizers produced by one season of rice is respectively: nitrogen fertilizer pure N is 120.0kg/hm ² ~150.0kg/hm ² Potash fertilizer K ₂ O is 96.0kg/hm ² ~120.0kg/hm ² Phosphate fertilizer P ₂ O ₅ 60.0kg/hm ² ~75.0kg/hm ² 。

9. An ultralow-carbon rice cropping method according to any one of claims 1-3, characterized in that the straw in S2 is crushed and uniformly scattered on the carriage surface.

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