Sediment matrix vegetation concrete for Aegiceras corniculatum seed seedling raising and application method thereof

Abstract

The invention discloses sediment matrix vegetation concrete for Aegiceras corniculatum seed seedling raising and an application method thereof.The sediment matrix vegetation concrete is prepared by evenly stirring and mixing sediment soil, cement, seawater and fertilizer, the sediment matrix vegetation concrete is poured into a seedling raising pipe, Aegiceras corniculatum seeds are implanted, and the concrete seedling raising pipe of an integrated structure can be formed; the Aegiceras corniculatum seedling culture medium can be directly planted on a field mud flat wetland for seed seedling culture of Aegiceras corniculatum, so that seed germination, seedling breeding and field planting application can be realized. According to the method, the concrete seedling raising pipe of an integrated structure is constructed by utilizing the sediment matrix vegetation concrete, the concrete seedling raising pipe has proper strength, porosity and density, the specific growth rate and the survival rate of aegiceras corniculatum seedlings can be increased, and the cultivation process of aegiceras corniculatum seeds is greatly simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of marine engineering materials, and particularly relates to a sediment matrix vegetation concrete for growing Paulownia truncatum seeds and an application method thereof. Background Art

[0002] Mangroves are one of the most productive marine ecosystems in the tropical and subtropical coastal zones, playing an extremely important role in purifying seawater, preventing wind and waves, maintaining biodiversity, and fixing and storing carbon. 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.

[0003] 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 has problems such as slow seedling development and low seedling survival rate. Artificial container seedling afforestation has problems such as seedling transplanting process is very easy to damage the root system, resulting in low planting survival rate and low forest retention rate. The current situation of low survival rate of mangrove seedling cultivation and afforestation has hindered the ecological restoration and recovery of mangroves, and to a certain extent has led to a series of ecological dilemmas and economic problems such as the decline in the yield of economic organisms on tidal flats, continuous outbreaks of diseases in artificial breeding on tidal flats, serious red tide disasters, a surge in typhoon losses, and a reduction in tourism resources. Therefore, it is particularly necessary to develop new models of mangrove seed germination, seedling rapid propagation and planting.

[0004] Tung tree is an evergreen shrub or small tree of the genus Tung tree in the Myrsinaceae family. It is the second largest mangrove species in China, second only to Avicennia marina. Tung tree can be found in silt, muddy and sandy beaches. It is a mid-to-early succession tree species and is mostly distributed on the outer edge of mangroves. In tropical areas, it can reach a maximum height of 4-5 m. The Luoyang River estuary in Quanzhou City, Fujian Province is the northernmost edge of the natural community of Tung tree in the world. Tung tree likes light, is resistant to low temperatures and seawater inundation, has strong salt tolerance, and has good wind and wave protection. It is currently the main excellent afforestation tree species for coastal shelterbelts. The bark and leaves of Tung tree can be used as medicine, which can be used to assist in the treatment of asthma, diabetes, inflammation, rheumatism and other diseases. Tung tree is a cryptoviviparous mangrove plant that reproduces sexually by seeds. The flowering period is from December to April of the following year, and the fruit ripening period is from August to November. The cryptic capsule is cylindrical, curved like a crescent, with a gradually pointed top and a length of 5 to 10 cm. The hypocotyl never breaks through the pericarp during the development process. After maturity and shedding, it will float with the water. The seeds are the same shape as the fruit and weigh about 0.5 to 1.5 g. Since the natural seeds of Tung Blossom Tree have no hypocotyl and the viviparous seedlings are too small, they are not suitable for afforestation with natural seed hypocotyls or viviparous seedlings. Traditionally, artificial container seedlings are used for afforestation: Tung Blossom Tree seeds are first used as seedbeds for seedling cultivation, then transplanted into nutrient bags for cultivation, and then transplanted and planted in coastal wetland tidal flats after being planted in nurseries to qualified seedlings. However, the roots of artificial container seedlings of Tung Blossom Tree are easily damaged during the transplanting and planting process, which will lead to low survival rate and retention rate of seedlings. Preliminary experiments have found that muddy soil is suitable for the cultivation of artificial container seedlings of Tung Blossom Tree seeds. Therefore, it is particularly necessary to develop new models for seed germination, seedling rapid propagation and planting of Tung Blossom Tree seeds. Summary of the invention

[0005] The purpose of the present invention is to provide a silt matrix vegetation concrete for raising tung tree seeds and seedlings and an application method thereof, which is a new model for tung tree seed germination, seedling rapid propagation and planting application. The concrete seedling tube with integrated structure and stable performance is prepared by using commonly available raw materials. The seedling tube can be directly inserted into the wild tidal flat wetland for raising tung tree seeds and seedlings, thereby realizing the integrated functions of seed germination, seedling propagation and planting application, and can significantly improve the rate and survival rate of tung tree seedling cultivation.

[0006] To achieve the above object, the present invention adopts the following technical solution: A silt matrix vegetation concrete for raising tung tree seeds and seedlings, which is composed of silty soil, cement, seawater, and fertilizer; wherein, based on the mass of the silty soil, the cement content in the vegetation concrete is 4.4-9.2%, the water-cement ratio is 2.52-5.10, and the fertilizer content is 0.5‰. Preferably, by mass, the amount of silty soil is 1017-1400 parts, the amount of cement is 56.5-118 parts, the amount of seawater is 181-378 parts, and the amount of fertilizer is 0.53-0.68 parts.

[0007] Specifically, when the cement content is 6.8%, the sand content is 25-80%, and the water-cement ratio is 2.52-5.10, the compressive strength of the obtained sediment matrix vegetation concrete is 1.267-2.001 MPa, the porosity is 22.11-32.98%, and the density is 1345-1635 kg / m 3 When the sand content is 66.6%, the water-binder ratio is 3.2, and the cement content is 4.4-9.2%, the compressive strength of the obtained sediment matrix vegetation concrete is 0.680-2.572 MPa, the porosity is 27.79-31.44%, and the density is 1543-1635 kg / m 3 .

[0008] Furthermore, the silty soil is made by mixing sea mud and sea sand, and its sand content is 25-80%. Preferably, by weight, the amount of sea mud in the silty soil is 280-763 parts, the amount of sea sand is 254-1120 parts, and its sand content is 66.6%.

[0009] Furthermore, the particle sizes of the sea mud and sea sand are both 0.5-1.0 mm.

[0010] Furthermore, the total nutrient content of the fertilizer is 24%, wherein the ratio of N, P2O5, and K2O is 16:5:3%.

[0011] The method for raising tung tree seeds by using the silt matrix vegetation concrete comprises the following steps: mixing silt soil, cement, seawater and fertilizer in proportion and pouring the mixture into a seedling tube, pre-growing the mixture for one day to obtain the silt matrix vegetation concrete, then implanting a tung tree seed in the seedling tube at a distance of 3 to 5 cm from the concrete surface, and directly inserting the formed integrated structure concrete seedling tube into a tidal flat wetland after curing for 7 days to achieve germination of tung tree seeds, seedling breeding and planting application.

[0012] Furthermore, the seedling tube is a bamboo tube, a plastic tube, a ceramic tube or a metal tube with openings at both ends, an inner tube diameter of 7 to 9 cm and a length of 25 to 30 cm.

[0013] The silt matrix vegetation concrete of the present invention has suitable strength and density, which can not only help the fixation and lodging resistance of seeds and seedlings, but also prevent the loss of seedling matrix, seeds and seedlings; its suitable porosity can also effectively improve the water permeability and air permeability of the matrix during seed germination, seedling breeding and planting applications; the addition of fertilizers can make up for the deficiency of nitrogen, phosphorus and potassium in silty soil raw materials, and improve the specific growth rate and survival rate of seedlings; the integrated structure constructed by using concrete and seedling tubes can also play a role in slowing down the scouring of sea waves and tides, and the present invention 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 adjusts the sand content of the silty soil raw material so that the soil raw material has the advantages of both sandy soil and silty soil, thereby improving the water permeability and air permeability of the matrix soil. In addition, through soil testing and fertilization, fertilizers are added to the vegetation concrete according to the nutritional needs of the Tung tree seedling cultivation to make up for the deficiency of nitrogen, phosphorus and potassium in the silty soil raw material, improve the nutritional structure of the matrix soil, and provide the Tung tree with a good habitat.

[0015] 2. The concrete nursery tube with integrated structure and stable performance formed by solidifying the muddy soil of the present invention can effectively improve the retention rate of Tung trees and protect the Tung trees planted on the tidal flats of coastal wetlands from being scoured by waves and eaten by aquatic animals. Its high strength and large density can play a role in slowing down the scouring by waves and tides.

[0016] 3. The sandy soil of the present invention can be solidified to obtain suitable strength and density of vegetation concrete, which can effectively improve the fixation of seedling cultivation matrix, not only can help the fixation and lodging resistance of seeds and seedlings, but also can prevent the loss of seedling cultivation matrix, seeds and seedlings, and avoid the tiny Paulownia seeds and seedlings being washed away by waves due to periodic tidal scouring.

[0017] 4. The vegetation concrete prepared from the solidified silty soil 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 death of seedlings due to lack of oxygen due to the burial of aerial roots and the decrease of water permeability and air permeability, which makes it difficult to retain the Paulownia tree seedlings.

[0018] 5. The present invention is a new afforestation model integrating natural seed germination, container seedling rapid propagation and field transplant-free planting. The present invention can realize the three functions of seed germination, seedling propagation and planting application by using the same seedling raising tube, which not only overcomes the defect that natural seeds and seedlings of Paulownia tree are too small to withstand the impact of waves and are damaged, but also avoids the problem of low seedling planting survival rate and low retention rate due to root damage when the container seedlings of Paulownia tree are transplanted to the tidal flats of coastal wetlands, and can significantly improve the rate and survival rate of Paulownia tree seedling cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a real picture of the tung tree seeds.

[0020] Figure 2 This is a real picture of the Tung tree seedlings. DETAILED DESCRIPTION

[0021] A method for raising tung tree seeds by using the silt matrix vegetation concrete comprises the following steps: mixing silt soil and cement for 1 minute, then successively adding fertilizer and seawater and stirring until uniform to prepare concrete slurry, then pouring the slurry into a seedling tube with openings at both ends, an inner diameter of 7-9 cm and a length of 25-30 cm, pre-growing the tube for 1 day to prepare silt matrix vegetation concrete, then implanting a tung tree seed in the seedling tube at a distance of 3-5 cm from the concrete surface, and continuing to maintain for 7 days to form a concrete seedling tube with an integrated structure and stable performance, and the concrete seedling tube can be directly inserted into a wild tidal flat wetland to raise tung tree seeds, thereby realizing the three functions of seed germination, seedling breeding and planting application.

[0022] Among them, based on the quality of silty soil, the cement content in the concrete slurry is 4.4~9.2%, the water-cement ratio is 2.52~5.10, and the fertilizer content is 0.5‰.

[0023] The silty soil is made of a mixture of sea mud and sea sand, and the sand content is 25-80%. The particle sizes of the sea mud and sea sand are both 0.5-1.0 mm.

[0024] The total nutrient content of the fertilizer is 24%, wherein the ratio of N, P2O5 and K2O is 16:5:3%; the fertilizer can be added directly or prepared into an aqueous solution for use.

[0025] The seedling tube can be one of a bamboo tube, a plastic tube, a ceramic tube or a metal 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: The Tung tree seeds used weighed about 0.5-1.5 g, were 3.5-4.5 cm long, and about 0.5 cm in diameter.

[0028] The cement used was PS 32.5 and PS 32.5 slag Portland cement; The seawater comes from the natural seawater (salinity 20~33‰) at the estuary of Jinjing Creek, Jinjiang Campus of Fuzhou University; The sandy soil is prepared according to the sand content index requirements with sea mud and sea sand as raw materials in different proportions; the sea mud used is excavated from the muddy mud under the natural mangrove community in Quanzhou Bay, Fujian, and is water-milled and screened to particle sizes of 0.25~0.5mm, 0.5~1.0 mm, 1.0~1.5mm and 1.5~2.0 mm, and then drained for use; the sea sand used is natural sea sand that has been water-milled and screened to particle sizes of 0.35~0.45 mm, 0.5~1.0 mm, 1.0~1.5mm and 1.5~2.0 mm, and then drained for use; The total nutrient content of the fertilizer is 24%, and it is compounded according to the ratio of N:P2O5:K2O of 16:5:3%. The fertilizer dosage is 0.5‰ of the dosage for sandy soil. It 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 number of valid tested 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). Example

[0032] 1. Influence of sea mud particle size on concrete performance 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. After pre-growing the blanks under normal temperature and pressure for 1 day, mud vegetation concrete was obtained, which was demolded after 28 days of standard curing for performance testing.

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

[0034] As can be seen from Table 1, when the water-binder ratio is 4.6 and the cement content is 7.5%, as the particle size of the sea mud increases, the porosity of the concrete increases, and the compressive strength and density decrease. When the particle size of the sea mud is 0.5-1.0 mm, the porosity of the concrete is 28.76% and the compressive strength is 1.039 MPa. Its comprehensive performance can initially meet the needs of Paulownia seed seedling cultivation.

[0035] 2. Effect of sea sand particle size on concrete performance According to the formula in Table 2, sea sand of 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 the seedling tube. After pre-growing the blanks under normal temperature and pressure for 1 day, the sandy vegetation concrete was obtained, which was demolded after 28 days of standard curing for performance testing.

[0036] Table 2 Effect of sea sand particle size on concrete performance

[0037] It can be seen from Table 2 that when the water-binder ratio is 3.5 and the cement content is 6.25%, as the sea sand particle size increases, the porosity of the concrete increases, and the compressive strength and density decrease. When the sea sand particle size is 0.5-1.0 mm, the porosity of the concrete is 33.46% and the compressive strength is 1.209 MPa. Its comprehensive performance can initially meet the needs of Paulownia seed seedling cultivation.

[0038] 3. Effect of sand content and water-cement ratio on concrete performance According to the formula in Table 3, different proportions of silty soil 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. After pre-growing the blanks under normal temperature and pressure conditions for 1 day, silt matrix vegetation concrete was obtained, which was demolded after 28 days of standard curing for performance testing.

[0039] Table 3 Effect of sand content and water-cement ratio on concrete performance

[0040] As can be seen from Table 3, compared with the lower porosity and compressive strength of the sandy soil in the control example, the porosity and compressive strength of the concrete solidified by cement are significantly improved. When the cement content is fixed at 6.8%, when the water-cement ratio is 2.52 and the matrix sand content is 80%, the compressive strength and density of the ecological concrete are the largest and the porosity is the smallest; when the water-cement ratio is 5.10 and the matrix sand content is 25%, the compressive strength and density of the ecological concrete are the smallest and the porosity is the largest.

[0041] 4. Effect of cement content on concrete performance According to the formula in Table 4, the silty soil 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 the seedling tube. After pre-growing the blanks under normal temperature and pressure for 1 day, the silt matrix vegetation concrete was obtained. After standard curing for 28 days, the concrete was demolded and the performance was tested.

[0042] Table 4 Effect of cement content on concrete performance

[0043] As can be seen from Table 4, compared with the lower porosity and compressive strength of the sandy soil in the control example, with the increase of cement content, the porosity, compressive strength and density of the cement-cured concrete are significantly improved. When the matrix sand content is 66.6%, the water-cement ratio is 3.2, and the cement content is 4.4-9.2%, the mathematical expressions of the correlation between the porosity, compressive strength, density and cement content of the concrete are as follows: The relationship between porosity Y and cement content X: Y=-0.7775X+34.917, R²=0.9976; The relationship between compressive strength Y and cement content X: Y=0.3973X-1.0171, R²=0.9939; Relationship between density Y and cement content X: Y=0.3968X 2 +13.77X+1474.9, R²=0.9997.

[0044] In summary, silty soil 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, solidification with cement, a cementitious material, can greatly improve its compressive strength, and the poured 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 Tung trees under different tidal conditions.

[0045] Application Example: Application of concrete seedling tube According to the formulas in Tables 5 and 6, the silty soil and cement were stirred for 1 minute respectively, and then fertilizers and seawater were added successively and stirred until uniform to make concrete slurry, which was then poured into a plastic nursery tube with an inner diameter of 7-9 cm and a length of 25-30 cm and opened at both ends. After pre-growing the blanks under normal temperature and pressure for 1 day, the silt matrix vegetation concrete was obtained. After that, the Tung tree seeds were implanted in the nursery tube at a distance of 3-5 cm from the concrete surface. After continuing conventional maintenance for 7 days, a concrete nursery tube with 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 Tung tree.

[0046] Table 5 Effect of water-cement ratio in concrete on specific growth rate and survival rate of Paulownia ovata seedlings

[0047] As shown in Table 5, when the muddy soil is not solidified with cement, the specific growth rate and survival rate of the Paulownia truncatum seedlings are low; adding fertilizers can make up for the lack of nitrogen, phosphorus and potassium in the muddy soil raw materials and improve the specific growth rate and survival rate of the seedlings. This may be because the compressive strength and porosity of the muddy soil are low when it is not solidified with cement, making it difficult to provide a water-permeable and air-permeable matrix environment, and the planting matrix is ​​easy to lose, making it difficult for the Paulownia truncatum seedlings to grow stably under the scouring of waves and tides.

[0048] At the same time, it can be seen from the table that when the cement content is fixed at 6.8% and the fertilizer content is 0.5‰, the specific growth rate of the tung tree seedlings increases first and then decreases with the decrease of the water-binder ratio. When the water-binder ratio is 3.2, the specific growth rate of the tung tree seedlings can reach 0.225 cm / d, and the survival rate can reach 100%, which is the best effect. When the cement content is 6.8%, the fertilizer content is 0.5‰, and the water-binder ratio is 2.8~4.7, the mathematical expression of the correlation between the specific growth rate of the tung tree seedlings and the water-binder ratio of the ecological concrete is as follows: Relationship between specific growth rate Y and water-binder ratio X: Y=-0.0352X 2 +0.2415X-0.1936, R²= 0.9624.

[0049] Table 6 Effect of cement content in concrete on specific growth rate and survival rate of Paulownia truncatula seedlings

[0050] As can be seen from Table 6, when the water-cement ratio is 3.2 and the fertilizer content is 0.5‰, the specific growth rate shows a trend of first increasing and then decreasing with the increase of cement content. This is because the cement content of 9.2% will increase the pH value of the concrete, which cannot guarantee the normal environmental requirements for the germination of Tung tree seeds and the breeding of seedlings. When the water-cement ratio is 3.2, the fertilizer content is 0.5‰, and the cement content is 4.4-9.2%, the mathematical expression of the correlation between the specific growth rate of Tung tree seedlings and the cement content of ecological concrete is as follows: Relationship between specific growth rate Y and cement content X: Y=-0.013X 2 +0.1606X-0.2697, R²= 0.9938.

[0051] In addition, the seeds of the Paulownia truncatum in the muddy soil seedling tube of the control example 2 began to germinate on the 17th day after implantation, and the germination rate was 85% on the 25th day. It was also found that 60% of the Paulownia truncatum seeds were lost due to the scouring of the sea waves and tides. However, the seeds of the Paulownia truncatum in the concrete seedling tube of the application example 2 were not found to be lost, and they began to germinate on the 13th day after implantation, and the germination rate was 100% on the 19th day.

[0052] 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 silt matrix vegetation concrete for raising Paulownia truncatum seeds and seedlings, characterized in that: The vegetation concrete is composed of silty soil, cement, seawater and fertilizer; wherein, based on the quality of the silty soil, the cement content in the vegetation concrete is 4.4-9.2%, the water-cement ratio is 2.52-5.10, and the fertilizer content is 0.5‰; the silty soil is made by mixing sea mud and sea sand, and its sand content is 25-80%.

2. The sediment matrix vegetation concrete according to claim 1, characterized in that: The total nutrient content of the fertilizer is 24%, wherein the ratio of N, P2O5, and K2O is 16:5:3%.

3. The sediment matrix vegetation concrete according to claim 1, characterized in that: The particle sizes of the sea mud and sea sand are both 0.5-1.0 mm.

4. A method for growing Paulownia truncatum seeds using the sediment matrix vegetation concrete according to claim 1, characterized in that: Silt soil, cement, seawater and fertilizer are mixed in proportion and poured into seedling tubes. The mixture is pre-grown for one day to prepare silt matrix vegetation concrete. Then, Tung tree seeds are planted in the seedling tubes 3 to 5 cm away from the concrete surface. After curing and maintenance for 7 days, the integrated structural concrete seedling tubes are directly inserted into the tidal flat wetlands to achieve seed germination, seedling breeding and planting applications of Tung tree.

5. The method according to claim 4, characterized in that: The seedling raising tube is a bamboo tube, a plastic tube, a ceramic tube or a metal tube with openings at both ends, an inner tube diameter of 7 to 9 cm and a length of 25 to 30 cm.

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