Method for integrally planting avicennia marina by using vegetation concrete

Abstract

The invention discloses a method for integrally planting avicennia marina by utilizing vegetation concrete, which comprises the following steps of: uniformly stirring and mixing sea mud, cement, seawater and fertilizer to prepare vegetation concrete slurry, then pouring the vegetation concrete slurry into a seedling raising pipe, pre-culturing to form a blank, implanting avicennia marina seeds into the seedling raising pipe at a position 1-2cm away from the soil surface, curing and curing for 7 days, and finally, transplanting the seedling raising pipe into the seedling raising pipe. And then the Avicennia marina is directly planted on the mud flat wetland so as to realize integrated planting of seed germination, seedling breeding and field planting application of the Avicennia marina. According to the method, the vegetation concrete and the seedling raising pipes are used for constructing an integrated structure, the specific growth rate and the survival rate of the avicennia marina seedlings can be effectively increased, and the cultivation process of the avicennia marina seeds is greatly simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering materials, and in particular relates to a method for planting Avicennia marina in an integrated manner by utilizing vegetation concrete. Background Art

[0002] Mangroves are woody plant communities composed of evergreen shrubs or trees, mainly mangroves, that grow in tropical and subtropical intertidal zones and are periodically flooded by seawater. They are an important type of wetland ecosystem on Earth and play a key role in the ecological restoration and recovery of coastal wetlands. Mangroves have the functions of preventing wind and waves, promoting siltation and land reclamation, and purifying water quality. They are important habitats and breeding places for fish, shrimp, crabs, shellfish, waterfowl and seabirds. They have strong carbon sequestration capacity and important ecological functions and values.

[0003] Since mangroves have special requirements for their growth environment, they only grow on tidal flats between the average sea level (or slightly above) and the average high tide level of the regression tide (or the high tide level of the spring tide). Too high or too low a frequency of tidal flooding will lead to the degradation, death, or difficulty in natural regeneration of mangroves. Therefore, it is urgent to carry out seedling cultivation and afforestation of mangroves.

[0004] Traditional mangrove afforestation methods mainly include natural seed hypocotyl afforestation, natural viviparous seedling afforestation and artificial container seedling afforestation. Natural seed hypocotyl or viviparous seedling afforestation have problems such as slow seedling development and low seedling survival rate. Artificial container seedling afforestation has problems such as the seedling transplanting process easily damages the root system, resulting in low planting survival rate and low stand retention rate.

[0005] Avicennia marina is an evergreen shrub or small tree of the genus Mangrove in the Verbenaceae family. It has well-developed finger-like breathing roots, and often has aerial roots and prop roots. Avicennia marina is a mangrove plant with the strongest tolerance to salt and flooding, but not to low temperatures. It is a pioneer species of succession and is mostly distributed on the outer edge of mangroves. It can also appear in the inner beach. Fuqing City, Fujian Province (25°72ʹN) is the northern boundary of its natural distribution. Avicennia marina can reach a maximum height of 8~10 m in tropical areas. Avicennia marina plays an important role in preventing wind and waves, promoting siltation and consolidation of banks, protecting embankments, and regulating ecological balance. It is a pioneer species of afforestation with a wide distribution area and strong resistance among mangrove plants in my country. Avicennia marina is a cryptoviviparous mangrove plant that reproduces sexually by seeds. The flowering period is from May to September, and the fruit ripening period is from August to November. The cryptoviviparous capsule is nearly oblate, and the seeds are flat and weigh about 3 g. Since the natural seeds of Avicennia marina have no hypocotyls and the viviparous seedlings are too small to withstand the impact of waves, they are not suitable for afforestation with natural seeds or viviparous seedlings. Traditionally, artificial container seedlings are used for afforestation: Avicennia marina seeds are first used as seedbeds for seedlings, then transplanted into nutrient bags for cultivation, and after being planted in the nursery until qualified seedlings, they are transplanted and planted on the tidal flats of coastal wetlands. However, the roots of artificial container seedlings are easily damaged during the transplanting and planting process, which will lead to low survival rate and retention rate of seedlings. Therefore, it is particularly necessary to develop new models for seed germination, rapid seedling propagation and planting of Avicennia marina. Summary of the invention

[0006] The purpose of the present invention is to provide a method for planting Avicennia marina in an integrated manner using vegetation concrete, which uses commonly available raw materials to prepare a vegetation concrete seedling system with an integrated structure and stable performance. It is a new model for Avicennia marina seed germination, seedling rapid propagation and planting application, and can significantly improve the rate and survival rate of Avicennia marina seedling cultivation.

[0007] To achieve the above object, the present invention adopts the following technical solution: A method for planting Avicennia marina in an integrated manner using vegetation concrete comprises the following steps: pouring vegetation concrete slurry into a seedling tube, pre-growing the tube into a blank for 1 day, implanting a seed of Avicennia marina in the tube at a distance of 1 to 2 cm from the soil surface, curing and maintaining the tube for 7 days, and then directly planting the seed in a tidal flat wetland, so as to realize the integrated planting of seed germination, seedling breeding and planting application of Avicennia marina.

[0008] Furthermore, the vegetation concrete slurry is composed of sea mud, cement, seawater, and fertilizer, wherein, based on the mass of sea mud, the cement content in the vegetation concrete slurry is 3.0-9.0%, the water-cement ratio is 2.3-4.6, and the fertilizer content is 1‰. Preferably, by mass, the amount of sea mud in the vegetation concrete slurry is 1017-1400 parts, the amount of cement is 34.5-105 parts, the amount of seawater is 240-353 parts, and the amount of fertilizer is 1.05-1.37 parts.

[0009] Specifically, when the cement content is 7.5% and the water-binder ratio is 2.3-4.6, the compressive strength of the vegetation concrete after curing is 1.039-1.641 MPa, the porosity is 19.23-28.76%, and the density is 1268-1542 kg / m 3 When the cement content is 3.0-9.0% and the water-binder ratio is 3.5, the compressive strength of the solidified vegetation concrete is 0.777-1.69870 MPa, the porosity is 24.50-27.38%, and the density is 1350-1386 kg / m 3 .

[0010] Furthermore, the sea mud particle size is 0.5~1.0 mm.

[0011] Furthermore, the total nutrient content of the fertilizer is 35%, wherein the ratio of N, P2O5, and K2O is 16:10:9%.

[0012] Furthermore, the seedling tube is a bamboo tube, metal tube, ceramic tube or plastic tube with openings at both ends, an inner tube diameter of 10-12 cm and a length of 32-36 cm.

[0013] The present invention uses a seamless seed system constructed by vegetation concrete and seedling tubes to slow down the scouring of sea waves and tides; the appropriate strength and density of vegetation concrete can help the fixation and anti-lodging of seeds and seedlings, and prevent the loss of seedling matrix, seeds and seedlings; the appropriate porosity can effectively improve the water permeability and air permeability of the matrix; the addition of fertilizers can make up for the deficiency of nitrogen, phosphorus and potassium in sea mud raw materials. Therefore, this new model can improve the specific growth rate and survival rate of Avicennia marina seedlings, and it is simple to operate, low in production cost, and can produce good social, ecological and economic benefits.

[0014] The beneficial effects of the present invention are: 1. The present invention provides a new afforestation model integrating natural seed germination, container seedling rapid propagation and field transplant-free planting, which not only overcomes the defect that natural seeds and seedlings of Avicennia marina are too small to withstand the impact of waves and are damaged, but also avoids the problem of low seedling survival rate and low retention rate due to root damage when Avicennia marina container seedlings are transplanted to coastal wetland tidal flats, and can significantly improve the rate and survival rate of Avicennia marina seedling cultivation.

[0015] 2. The present invention solidifies sea mud with cement and casts it into a stable vegetation concrete. Its high strength and high density can reduce the scouring of waves and tides, effectively improve the retention rate of Avicennia marina plants, and protect the Avicennia marina plants planted on the tidal flats of coastal wetlands from being scoured by waves and eaten by aquatic animals.

[0016] 3. The solidified vegetation concrete of the present invention has suitable strength and density, which can effectively improve the fixation of the seedling cultivation matrix, help the fixation of seeds and seedlings, prevent the loss of the seedling cultivation matrix, seeds and seedlings, and avoid the problem that the seeds and seedlings of Avicennia marina are washed away by periodic tides and waves due to insufficient fixation of muddy soil.

[0017] 4. The solidified vegetation concrete of the present invention has a suitable porosity, which can effectively improve the water permeability and air permeability of the seedling cultivation matrix, improve the efficiency of seed germination, seedling breeding and afforestation, and avoid the problem that the seedlings are difficult to retain due to lack of oxygen and death due to the poor water permeability and air permeability of muddy soil, which causes the aerial roots of the seedlings to be buried and the water permeability and air permeability to decrease.

[0018] 5. The present invention adds fertilizers when pouring the nursery tube, which makes up for the deficiency of nitrogen, phosphorus and potassium in the sea mud raw material, and can improve the specific growth rate and survival rate of the seedlings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a real picture of Avicennia marina seeds.

[0020] Figure 2 This is a real picture of Avicennia marina seedlings. DETAILED DESCRIPTION

[0021] A method for planting Avicennia marina by using integrated vegetation concrete, which specifically comprises the following steps: stirring and mixing sea mud and cement according to a proportion for 1 minute, then successively adding fertilizer and seawater and stirring until uniform to prepare concrete slurry, and then pouring the slurry into a seedling tube with openings at both ends, an inner diameter of 10-12 cm and a length of 32-36 cm, and after pre-growing into a blank for 1 day, implanting an Avicennia marina seed in the seedling tube at a distance of 1-2 cm from the soil surface, curing and curing for 7 days to form a structurally integrated vegetation concrete seedling system, and finally directly planting the system on a wild tidal flat wetland for seed seedling cultivation of Avicennia marina, and the same seedling tube can be used, thereby realizing seed germination, seedling breeding and planting application of Avicennia marina.

[0022] Among them, based on the quality of sea mud, the cement content in the vegetation concrete slurry is 3.0~9.0%, the water-cement ratio is 2.3~4.6, and the fertilizer content is 1‰.

[0023] The particle size of the sea mud is 0.5-1.0 mm.

[0024] The total nutrient content of the fertilizer is 35%, wherein the ratio of N, P2O5, and K2O is 16:10:9%.

[0025] The seedling tube can be one of a bamboo tube, a metal tube, a ceramic tube or a plastic tube.

[0026] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0027] Raw material selection: Avicennia marina seeds weigh about 3 g, are 2-3 cm long, 1.5-2.5 cm wide, and about 0.5 cm thick.

[0028] The cement used is PS 32.5 slag Portland cement; The seawater comes from the natural seawater in Weitou Bay, Jinjiang, Fujian (salinity 30~33‰); The sea mud was excavated from the muddy mud under the natural mangrove community in Quanzhou Bay, Fujian Province. It was water-milled and screened to particle sizes of 0.25-0.5 mm, 0.5-1.0 mm, 1.0-1.5 mm and 1.5-2.0 mm, and then drained for later use. The fertilizer is designed using soil testing and fertilization technology, and is compounded according to 35% total nutrients and a N:P2O5:K2O ratio of 16:10:9%. The fertilizer dosage is 1‰ of the sea mud dosage and can be added directly or prepared into an aqueous solution for use.

[0029] Unless otherwise specified, the test methods are conventional methods in the field, such as referring to "CECS 361-2003 Technical Specification for Application of Ecological Concrete" or "JGJ51-2002 Technical Specification for Lightweight Aggregate Concrete". During the performance test, the concrete is demoulded after 28 days of standard curing and made into standard test blocks with a specification of 100 mm×100 mm×100 mm for testing.

[0030] Germination rate (%): refers to the percentage of germinated seeds to the total number of valid test seeds, and the statistics begin when the seeds grow two cotyledons.

[0031] Specific growth rate (cm / d): Calculated from the time when two true leaves grow after germination, according to the following formula: , Where: V - specific growth rate (cm / d); h 1 - Initial plant height (cm); h 2 - Final plant height (cm); t 2 -t 1 - Plant growth time difference (d).

[0032] Example Preparation of Vegetated Concrete and Its Performance Influence According to the formula in Table 1, sea mud with different particle sizes and cement were stirred for 1 minute, and then seawater was added and stirred until uniform to form concrete slurry, which was then poured into seedling tubes. The slurry was pre-grown under normal temperature and pressure conditions for 1 day to obtain vegetation concrete, which was demolded after 28 days of standard curing for performance testing.

[0033] Table 1 Effect of sea mud particle size on the performance of vegetation concrete

[0034] It can be seen from Table 1 that when the water-binder ratio is 4.6 and the cement content is 7.5%, as the sea mud particle size increases, the porosity of the vegetation concrete increases, and the compressive strength and density decrease. When the sea mud particle size is 0.5-1.0 mm, the comprehensive performance of the vegetation concrete is the best, which can basically meet the needs of Avicennia marina seed seedling cultivation. Therefore, sea mud with a particle size of 0.5-1.0 mm was used for the following experiments.

[0035] Table 2 Effect of water-cement ratio on the performance of vegetation concrete

[0036] As can be seen from Table 2, compared with the control example, the porosity and compressive strength of the vegetation concrete slurry prepared with a cement content of 7.5% after curing are significantly improved, and the density does not change much. The compressive strength is the highest when the water-binder ratio is 2.3, and the porosity is the highest when the water-binder ratio is 4.6. When the cement content is 7.5% and the water-binder ratio is 2.3-4.6, there is a certain correlation between the porosity, compressive strength, density and water-binder ratio of the vegetation concrete, and the mathematical expressions are as follows: Relationship between porosity Y and water-cement ratio X: Y=-1.1568X 2 +11.199X+1.2047, R²=0.9649; The relationship between compressive strength Y and water-cement ratio X: Y=-0.226X+2.1223, R²=0.9595; The relationship between density Y and water-cement ratio X: Y=-114.79X+1790.5, R²=0.9931.

[0037] Table 3 Effect of cement content on the performance of vegetation concrete

[0038] As shown in Table 3, compared with the control example, when the water-binder ratio is 3.5, as the cement content increases, the strength of the solidified vegetation concrete increases significantly, the density increases slightly, and the porosity decreases slightly. When the water-binder ratio is 3.5 and the cement content is 3.0-9.0%, the mathematical expressions of the correlation between the porosity, compressive strength, density and cement content of the vegetation concrete are as follows: Relationship between porosity Y and cement content X: Y=-0.053X 2+0.1835X+27.248, R²=0.9785; Relationship between compressive strength Y and cement content X: Y=0.0151X 2 -0.0316X+0.745, R²=0.997; The relationship between density Y and cement content X: Y=6.8X+1329.6, R²=0.9973.

[0039] In summary, sea mud cannot withstand the erosion of waves and tides due to its low compressive strength, and its low porosity leads to insufficient water permeability and air permeability. However, the compressive strength of sea mud is greatly improved after solidification with cement, a cementitious material. The cast vegetation concrete can effectively resist the erosion of waves and tides. The appropriate porosity of the concrete can effectively improve the water permeability and air permeability of the matrix, meeting the needs of seed germination, seedling breeding and planting of Avicennia marina under different tidal conditions.

[0040] Application Examples According to the formula in Table 4, sea mud and cement were stirred for 1 minute, and then fertilizers and seawater were added successively and stirred until uniform to make concrete slurry, which was then poured into a galvanized seedling tube with openings at both ends, an inner diameter of 10-12 cm and a length of 32-36 cm, and pre-grown for 1 day under normal temperature and pressure conditions to make vegetation concrete. After that, a seed of Avicennia marina was implanted in the seedling tube at a distance of 1-2 cm from the soil surface. After conventional curing and maintenance for 7 days, a vegetation concrete seedling tube with an integrated structure and stable performance was formed, which was directly inserted into the tidal flat wetland at the estuary of Jinjing Creek in Jinjiang Campus of Fuzhou University for seed germination, seedling breeding and planting of Avicennia marina.

[0041] Table 4 Effects of vegetation concrete seedling tubes on the specific growth rate and survival rate of Avicennia marina seedlings

[0042] It can be seen from Table 4 that when the sea mud is not solidified with cement, the specific growth rate and survival rate of the Avicennia marina seedlings are low; adding fertilizers can make up for the deficiency of nitrogen, phosphorus and potassium in the sea mud raw materials, thereby improving the specific growth rate and survival rate of the seedlings, but the effect is not significant (Control Examples 1 and 2). This may be because the compressive strength and porosity of the sea mud are low when cement is not used for solidification, making it difficult to provide a water-permeable and breathable matrix environment, and the planting matrix is ​​easy to lose, making it difficult for the Avicennia marina seedlings to grow stably under the scouring of waves and tides.

[0043] At the same time, it can be seen from the table that when the cement content is 7.5% and the water-binder ratio is 2.5-4.6, the specific growth rate of Avicennia marina seedlings increases with the decrease of the water-binder ratio (Application Examples 1-4). Among them, the effect is best when the cement content is 4.5% and the water-binder ratio is 3.5. The specific growth rate of Avicennia marina seedlings can reach 0.189 cm / d and the survival rate can reach 100%. When the water-binder ratio is 2.5-4.6, the mathematical expression of the correlation between the specific growth rate of Avicennia marina seedlings and the water-binder ratio of green concrete is as follows: Relationship between specific growth rate Y and water-binder ratio X: Y=0.0195X 2 -0.1707X+0.5076, R²= 0.9926.

[0044] In addition, it can be seen from the table that when the water-cement ratio is 3.5 and the cement content is 4.5-9.0%, the specific growth rate of Avicennia marina seedlings decreases with the increase of cement content (Application Examples 5-8). This may be because the increase of cement content will lead to an increase in the pH value of concrete, which cannot guarantee the normal physiological needs of Avicennia marina seed germination and seedling breeding. When the cement content is 3.0-9.0%, the mathematical expression of the correlation between the specific growth rate of Avicennia marina seedlings and the cement content of green concrete is as follows: Relationship between specific growth rate Y and cement content X: Y=-0.007X 2 +0.073X-0.0101, R²= 0.9795.

[0045] In addition, the seeds of Avicennia marina in the seedling tube of Reference Example 2 began to germinate on the 16th day after implantation, and the germination rate was 80% on the 27th day. It was also found that 75% of the seeds of Avicennia marina were lost due to the scouring of waves and tides during statistics. The seeds of Avicennia marina in the concrete seedling tube of Application Example 3 were not found to be lost, and they began to germinate on the 12th day after implantation, and the germination rate was 100% on the 17th day. Therefore, the vegetation concrete seedling tube with a seamless structure and stable performance cast by cement solidification of sea mud can protect the Avicennia marina plants from being scoured by waves and gnawed by aquatic animals, and its higher strength and larger density can play a role in slowing down the scouring of waves and tides.

[0046] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for planting Avicennia marina using integrated vegetation concrete, characterized in that: Pour the vegetation concrete slurry into the seedling tube. After pre-growing into a blank for 1 day, plant the Avicennia marina seeds in the seedling tube 1-2 cm away from the soil surface. After curing and curing for 7 days, directly plant them in the tidal flat wetland to achieve the integrated planting of Avicennia marina seed germination, seedling breeding and planting application.

2. The method for planting Avicennia marina using integrated vegetation concrete according to claim 1, characterized in that: The vegetation concrete slurry is composed of sea mud, cement, seawater and fertilizer. Based on the mass of sea mud, the cement content in the vegetation concrete slurry is 3.0-9.0%, the water-cement ratio is 2.3-4.6, and the fertilizer content is 1‰.

3. The method for planting Avicennia marina using integrated vegetation concrete according to claim 2, characterized in that: The particle size of the sea mud is 0.5-1.0 mm.

4. The method for planting Avicennia marina using integrated vegetation concrete according to claim 2, characterized in that: The total nutrient content of the fertilizer is 35%, wherein the ratio of N, P2O5, and K2O is 16:10:9%.

5. The method for planting Avicennia marina using vegetation concrete integration according to claim 2, characterized in that: The seedling tube is a bamboo tube, a metal tube, a ceramic tube or a plastic tube with two ends open, an inner tube diameter of 10-12 cm and a length of 32-36 cm.

Images