Method for afforestation in desert area
By using modified sand particles, combined with specific watering amounts and tree pit densities, the problem of low plant survival rates caused by water scarcity in desert areas has been solved, achieving the effect of improving survival rates and water retention capacity while reducing water consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-12
- Publication Date
- 2026-04-10
AI Technical Summary
The scarcity of water resources in desert areas leads to low plant survival rates. Existing methods, while improving survival rates, consume large amounts of water, making them difficult to solve effectively.
Modified sand particles, including a combination of sand particles, biomass pellets, peat, and modified cellulose, are used. The modified cellulose consists of polylactic acid and a cellulose core and a chitosan shell. It is prepared by coaxial electrospinning. Combined with specific watering amounts and tree pit density, a wind erosion resistant consolidation system is formed, which improves water retention capacity and plant survival rate.
While reducing water consumption, it significantly improves plant survival rate and the water retention capacity of sand, creating a stable growth environment and promoting root development.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of desert management, in particular to a method for afforestation in desert areas. BACKGROUND
[0002] As an important part of human ecological protection, desert management is of great significance for the long-term protection of the ecological system. The harsh natural conditions of desert areas, such as water scarcity, soil barrenness, and large temperature difference, are one of the key obstacles to desert greening, among which the limitation of water resources is the most significant.
[0003] In view of the limitation of plant growth caused by water scarcity in desert areas, the skilled person has developed some methods to improve the water environment faced by plant growth. For example, by slowly releasing water through water-retaining agents, reducing the frequency and amount of irrigation, and by drip irrigation to provide water resources more accurately to plants.
[0004] Although the above methods solve the problem of water scarcity to some extent, the above methods more or less cause the survival rate of plants to decrease. Therefore, how to reduce the amount of water used while maintaining the survival rate of plants is one of the key problems in the field. SUMMARY
[0005] Therefore, the present application provides a method for afforestation in desert areas, which can effectively improve the survival rate of plants and has strong water retention capacity and low water consumption.
[0006] The present application provides a method for afforestation in desert areas, comprising the following steps: (1) digging a tree pit with a depth of 0.5-0.8 m and a diameter of 0.8-1.1 m in the target area, the density of the tree pit is not higher than 80000 / km 2 , and then watering the tree pit (referred to as first watering); (2) fixing the root of the seedling at the center of the tree pit; (3) filling the modified sand particles in the tree pit and watering; the modified sand particles comprise the following components by mass fraction: sand particles 100 parts, biomass particles 10-20 parts, peat 10-15 parts, and modified cellulose 30-50 parts; the modified cellulose comprises a core, a shell coated on the surface of the core, and methyl cellulose modified on the surface of the shell; the core comprises polylactic acid and cellulose; the shell comprises chitosan.
[0007] Preferably, the single tree pit watering amount of the first watering is 50-500 L.
[0008] Preferably, the filling amount of the modified sand particles is 4-6 cm in the final depth of the tree pit.
[0009] Preferably, the second watering amount of the single-tree pit is 10-100 L.
[0010] Preferably, in the core, the mass ratio of polylactic acid and cellulose is 20-30:25-35.
[0011] Preferably, the thickness of the shell is 1-5 microns; the diameter of the shell is 10-30 microns.
[0012] Preferably, the mass percentage of methyl cellulose in the modified cellulose is 1-2 wt%.
[0013] Preferably, the preparation method of the modified cellulose comprises the following steps: mixing polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide (DMF) to obtain a core solution; mixing chitosan and acetic acid solution to obtain a shell solution; performing coaxial electrospinning using the core solution and the shell solution to obtain core-shell particles; and immersing the core-shell particles in a methyl cellulose aqueous solution to obtain the modified cellulose.
[0014] Preferably, the working conditions of the coaxial electrospinning include: positive voltage of 14-15 kV, negative voltage of -2 to -2.5 kV, core layer flow rate of 0.1-0.14 mm / min, shell layer flow rate of 0.15-0.2 mm / min, receiving distance of 20-25 cm, translation speed of 280-300 mm / min, temperature of 25-26 °C, and relative humidity of 40-43%.
[0015] Preferably, the temperature of the immersion is 20-25 °C, and the immersion time is 10-15 min; the concentration of the methyl cellulose aqueous solution is 1-2 wt%.
[0016] The present application provides a method for afforestation in desert area. The present application endows sand particles with good water retention and stable water content by using modified cellulose with specific structure. The present application adds polylactic acid, which will gradually and partially degrade during work, so as to offset the tendency of water release caused by the decrease of water content in modified cellulose, and improve the relative stability of water release during the whole work process. The present application uses methyl cellulose to improve the water retention capacity of modified cellulose, and to improve the binding capacity of modified cellulose to water and the acting capacity of modified cellulose to sand particles by using the moisture retention and adhesion of methyl cellulose. Further, the present application enhances the interaction between modified sand particles by the combined effect of modified cellulose, biomass particles and peat, so as to change the loose state of modified sand particles into modified sand particles with water and fertilizer retention capacity. The modified sand particles in the present application form a wind erosion resistant consolidation system around the tree seedlings, realize rapid water locking, enhance the water retention capacity of modified sand particles, and significantly reduce the water consumption during the plant growth period; on the other hand, the present application can ensure the stability of the water content of modified sand particles for a long time, promote the root development of plants and the stability of the growth environment, and improve the survival rate of plants. DETAILED DESCRIPTION
[0017] The present application provides a method for afforestation in desert area, comprising the following steps: (1) digging tree pits with a depth of 0.5-0.8 m and a diameter of 0.8-1.1 m in the target area, the density of the tree pits is not higher than 80000 per / km 2 and then watering the tree pits; (2) fixing the root of the tree seedling at the center of the tree pit; (3) filling modified sand particles into the tree pit and then watering; the modified sand particles comprise the following components in mass fraction: sand particles 100 parts, biomass particles 10-20 parts, peat 10-15 parts and modified cellulose 30-50 parts; the modified cellulose comprises a core, a shell coated on the surface of the core and methyl cellulose modified on the surface of the shell; the core comprises polylactic acid and cellulose; the shell comprises chitosan.
[0018] The present application digs tree pits with a depth of 0.5-0.8 m and a diameter of 0.8-1.1 m in the target area, the density of the tree pits is not higher than 80000 per / km 2 and then watering the tree pits (marked as the first watering).
[0019] In the present application, the diameter of the tree pit is preferably 0.9-1 m, and the depth is preferably 0.6-0.7 m.
[0020] In the present application, the density of the tree pit is preferably not higher than 75000 per / km 2 , more preferably not higher than 60000 per / km.2 .
[0021] In the present application, the single-tree pit watering amount of the first watering is preferably 50-500L, more preferably 200-300L.
[0022] After the first watering, the present application fixes the root of the sapling at the center of the tree pit.
[0023] In the present application, the sapling preferably includes one or more of Inner Mongolia Salix, Hippophae, Salix and Caragana. The present application can also use arbor, shrub and grass to form a multi-layer protection system, which is more conducive to plant growth. For example, the common one is: the outer layer uses sand shrubs and sand-fixing herbaceous plants to block sand and wind, the middle layer uses drought-resistant economic fruit trees, and the inner layer uses mixed conifer forest belts.
[0024] In the present application, the center of the tree pit refers to the center of the tree pit in the horizontal direction, and the vertical direction is preferably determined according to the size of the sapling and the volume of the root, so that the depth of the root does not affect the growth of the sapling.
[0025] After the root of the sapling is fixed, the present application fills the modified sand particles into the tree pit and then waters (referred to as the second watering); the modified sand particles include the following components in mass fraction: 100 parts of sand particles, 10-20 parts of biomass particles, 10-15 parts of peat, and 30-50 parts of modified cellulose; the modified cellulose includes a core, a shell coated on the surface of the core, and methyl cellulose modified on the surface of the shell; the core includes polylactic acid and cellulose; and the shell includes chitosan.
[0026] In the present application, the filling amount of the modified sand particles is preferably 4-6cm in the final depth of the tree pit. The present application uses the above filling amount, which on the one hand can ensure that the root of the sapling is in full contact with the modified sand particles, and on the other hand facilitates the subsequent watering step, ensures that the water content of the modified sand particles reaches the ideal state after watering, and at the same time avoids water resource waste caused by excessive watering.
[0027] In the present application, the single-tree pit watering amount of the second watering is preferably 10-100L, more preferably 20-50L.
[0028] In the present application, the sand particles preferably use sand particles in the target desert area for afforestation.
[0029] In the present application, the modified sand particles preferably include 10-20 parts of biomass particles in mass fraction, more preferably 14-17 parts, and further preferably 15 parts.
[0030] In the present application, the biomass particles preferably include one or more of rice husk powder and corn stalk powder.
[0031] In the present application, the modified sand particles preferably include peat 10-15 parts by mass, more preferably 11-14 parts, and further preferably 12-13 parts.
[0032] In the present application, the modified sand particles preferably include modified cellulose 30-50 parts by mass, more preferably 35-45 parts, and further preferably 40 parts.
[0033] In the present application, the modified cellulose includes a core, a shell coated on the surface of the core, and methyl cellulose modified on the surface of the shell; the core includes polylactic acid and cellulose; and the shell includes chitosan.
[0034] In the present application, the mass ratio of polylactic acid to cellulose in the core is preferably 20-30:25-35, more preferably 24-27:27-32, and further preferably 25:28-30.
[0035] In the present application, the thickness of the shell is preferably 1-5 microns, more preferably 2-4 microns, and further preferably 3 microns; and the diameter of the shell is preferably 10-30 microns, more preferably 15-25 microns, and further preferably 20 microns.
[0036] In the present application, the mass percentage of methyl cellulose in the modified cellulose is preferably 1-2 wt%, and more preferably 1.5 wt%.
[0037] In the present application, the preparation method of the modified cellulose preferably includes the following steps: mixing polylactic acid, cellulose, dimethyl sulfoxide, and dimethyl formamide (DMF) to obtain a core solution; mixing chitosan and an acetic acid solution to obtain a shell solution; performing coaxial electrospinning using the core solution and the shell solution to obtain core-shell particles; and immersing the core-shell particles in a methyl cellulose aqueous solution to obtain the modified cellulose.
[0038] In the present application, the mass concentration of polylactic acid in the core solution is preferably 10-14 wt%, and more preferably 12 wt%; and the volume ratio of dimethyl sulfoxide to DMF is preferably 10:10-20, and more preferably 10:18.
[0039] In the present application, the concentration of the acetic acid solution is preferably 1 wt%; and the mass concentration of chitosan in the shell solution is preferably 1.7-2 wt%, and more preferably 1.8 wt%.
[0040] In the present application, the working conditions of the coaxial electrospinning preferably include: positive voltage of 14-15 kV, negative voltage of -2--2.5 kV, core layer flow rate of 0.1-0.14 mm / min, shell layer flow rate of 0.15-0.2 mm / min, receiving distance of 20-25 cm, translation speed of 280-300 mm / min, temperature of 25-26℃, and relative humidity of 40-43%.
[0041] In the present application, the temperature of the impregnation is preferably 20-25℃, and the time of the impregnation is preferably 10-15 min, more preferably 10-12 min.
[0042] In the present application, the concentration of the methyl cellulose aqueous solution is preferably 1-2 wt%, more preferably 1.5 wt%.
[0043] The method provided by the present application can also be used together with grass square sand barriers to reduce wind power and further reduce water evaporation and improve the water retention capacity of the modified sand particles.
[0044] In order to further illustrate the present application, the technical solutions in the present application will be described clearly and completely below in combination with the embodiments in the present application.
[0045] Embodiment 1 The modified cellulose in the present embodiment includes a polylactic acid and cellulose core (the mass ratio of polylactic acid and cellulose is 20:25), a chitosan (diameter of 30 microns and thickness of 4.5 microns) coated on the surface of the core, and a methyl cellulose modified on the surface of the shell, the mass percentage of the methyl cellulose in the modified cellulose being 1 wt%.
[0046] The preparation method of the modified cellulose in the present embodiment includes the following specific steps: The polylactic acid, the cellulose, the dimethyl sulfoxide and the dimethyl formamide are mixed to obtain a core solution, and the volume ratio of the dimethyl sulfoxide and the DMF is 10:20, and the concentration of the polylactic acid is 14 wt%.
[0047] The chitosan and the acetic acid solution (concentration of 1 wt%) are mixed to obtain a shell solution, and the concentration of the chitosan is 1.8 wt%.
[0048] The core solution and the shell solution are used for coaxial electrospinning, and the working conditions of the coaxial electrospinning are as follows: positive voltage of 14 kV, negative voltage of -2.5 kV, core layer flow rate of 0.14 mm / min, shell layer flow rate of 0.2 mm / min, receiving distance of 25 cm, translation speed of 300 mm / min, temperature of 25℃, and relative humidity of 40%, to obtain the core-shell particles.
[0049] The core-shell particles are immersed in a methyl cellulose aqueous solution (1wt%) at 25 degrees Celsius for 10 minutes, and then taken out and dried to obtain modified cellulose.
[0050] The modified sand particles in this embodiment include the following components: 2000 kg of sand particles, 400 kg of rice husk powder biomass particles, 300 kg of peat, and 700 kg of modified cellulose.
[0051] The preparation method of the modified sand particles in this embodiment is as follows: The sand particles, biomass particles, peat, and modified cellulose are stirred and mixed at a speed of 50 rpm for 4 minutes to obtain modified sand particles.
[0052] This embodiment provides a method for afforestation in desert areas, and the specific steps are as follows: (1) Dig tree holes with a depth of 0.7 m and a diameter of 1 m in the target area, and the density of the tree holes is 75,000 per km 2 Then water the tree holes, and the water volume of a single tree hole is controlled at 300 L.
[0053] (2) Fix the roots of the Inner Mongolia Salix trees at the center of the tree holes.
[0054] (3) Fill the tree holes with modified sand particles, and use feet to tamp them to make the final depth of the tree holes in the range of 4-6 cm, and then water them, and the water volume of a single tree hole is 50 L.
[0055] Example 2 The modified cellulose in this embodiment includes polylactic acid and a cellulose core (the mass ratio of polylactic acid to cellulose is 30:35), chitosan (30 microns in diameter and 5 microns in thickness) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, and the mass percentage of methyl cellulose in the modified cellulose is 1wt%.
[0056] The preparation method of the modified cellulose in this embodiment is as follows: Mix polylactic acid, cellulose, dimethyl sulfoxide, and dimethyl formamide, and the volume ratio of dimethyl sulfoxide to DMF is 10:18 to obtain a core solution, and the concentration of polylactic acid is 13wt%.
[0057] Mix chitosan and acetic acid solution (1wt%) to obtain a shell solution, and the concentration of chitosan is 1.8wt%.
[0058] The coaxial electrospinning is performed by using the core solution and the shell solution, and the working conditions of the coaxial electrospinning are as follows: the positive voltage is 15 kV, the negative voltage is -2 kV, the flow rate of the core layer is 0.14 mm / min, the flow rate of the shell layer is 0.2 mm / min, the receiving distance is 25 cm, the translation speed is 300 mm / min, the temperature is 25℃, and the relative humidity is 40%, so that the core-shell particles are obtained.
[0059] The core-shell particles are immersed in a methyl cellulose aqueous solution (the concentration is 2 wt%) at 25℃ for 15 min, and then taken out and dried, so that the modified cellulose is obtained.
[0060] The modified sand particles in this embodiment include the following components: 2000 kg of sand particles, 200 kg of rice husk powder biomass particles, 300 kg of peat, and 800 kg of modified cellulose.
[0061] The preparation method of the modified sand particles in this embodiment is specifically as follows: The sand particles, the biomass particles, the peat, and the modified cellulose are stirred and mixed at a rotation speed of 60 rpm for 3 min, so that the modified sand particles are obtained.
[0062] The embodiment provides a method for afforesting in a desert area, and the specific steps are as follows: (1) A tree pit with a depth of 0.8 m and a diameter of 1.1 m is dug in a target area, and the density of the tree pit is 75000 per km 2 Then, water is poured into the tree pit, and the water pouring amount of a single tree pit is controlled to be 300 L.
[0063] (2) The root of a Salix mongolica seedling in Inner Mongolia is fixed at the center of the tree pit.
[0064] (3) The modified sand particles are filled into the tree pit, the modified sand particles are tamped with feet, so that the final depth of the tree pit is in a range of 4-6 cm, and then water is poured, and the water pouring amount of a single tree pit is 80 L.
[0065] Embodiment 3 The modified cellulose in this embodiment includes polylactic acid and a cellulose core (the mass ratio of polylactic acid to cellulose is 22:27), chitosan (the diameter is 20 microns, and the thickness is 3.5 microns) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, and the mass percentage of the methyl cellulose in the modified cellulose is 1.5 wt%.
[0066] The preparation method of the modified cellulose in this embodiment is specifically as follows: The polylactic acid, the cellulose, dimethyl sulfoxide, and dimethyl formamide are mixed, the volume ratio of the dimethyl sulfoxide to the DMF is 10:16, so that the core solution is obtained, and the concentration of the polylactic acid is 12 wt%.
[0067] The chitosan and acetic acid solution (concentration of 1wt%) are mixed to obtain a shell solution, and the concentration of the chitosan is 1.8wt%.
[0068] The coaxial electrospinning is performed by using the core solution and the shell solution, and the working conditions of the coaxial electrospinning are as follows: positive voltage of 15kV, negative voltage of -2kV, core layer flow rate of 0.14mm / min, shell layer flow rate of 0.2mm / min, receiving distance of 25cm, translation speed of 300mm / min, temperature of 25℃, and relative humidity of 40%, so as to obtain the core-shell particles.
[0069] The core-shell particles are immersed in the methyl cellulose aqueous solution (concentration of 1wt%) at 25℃ for 12min, and then taken out and dried to obtain the modified cellulose.
[0070] The modified sand particles in the embodiment include the following components: 2000kg of sand particles, 400kg of corn stalk powder biomass particles, 300kg of peat, and 900kg of modified cellulose.
[0071] The preparation method of the modified sand particles in the embodiment is specifically as follows: The sand particles, the biomass particles, the peat, and the modified cellulose are stirred and mixed at a rotation speed of 40rpm for 5min to obtain the modified sand particles.
[0072] The embodiment provides a method for afforestation in a desert area, and the specific steps are as follows: (1) A tree pit with a depth of 0.5m and a diameter of 0.8m is dug in a target area, and the density of the tree pit is 75000 per km 2 Then, water is poured into the tree pit, and the water pouring amount of a single tree pit is controlled to be 300L.
[0073] (2) The root of the Inner Mongolia Salix mongolica seedling is fixed at the center of the tree pit.
[0074] (3) The modified sand particles are filled into the tree pit, the modified sand particles are tamped with feet, so that the final depth of the tree pit is in the range of 4-6cm, and then water is poured, and the water pouring amount of a single tree pit is 50L.
[0075] Embodiment 4 The modified cellulose in the embodiment includes polylactic acid and a cellulose core (the mass ratio of polylactic acid and cellulose is 25:29), chitosan (diameter of 20 microns and thickness of 2.5 microns) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, and the mass percentage of the methyl cellulose in the modified cellulose is 1.5wt%.
[0076] The preparation method of the modified cellulose in the embodiment is specifically as follows: Mix polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide, the volume ratio of dimethyl sulfoxide and DMF is 10:15, to obtain a core solution, the concentration of polylactic acid is 11wt%.
[0077] Mix chitosan and acetic acid solution (the concentration is 1wt%) to obtain a shell solution, the concentration of chitosan is 1.8wt%.
[0078] Carry out coaxial electrospinning by using the core solution and the shell solution, the working conditions of the coaxial electrospinning are as follows: positive voltage is 14kV, negative voltage is -2.5kV, core layer flow rate is 0.1mm / min, shell layer flow rate is 0.15mm / min, receiving distance is 25cm, translation speed is 300mm / min, temperature is 25℃, relative humidity is 40%, to obtain core-shell particles.
[0079] Soak the core-shell particles in methyl cellulose aqueous solution (the concentration is 2wt%) for 10min at 25℃, take out and dry, to obtain modified cellulose.
[0080] The modified sand particles in this embodiment include the following components: sand particles 2000kg, corn stalk powder biomass particles 400kg, peat 300kg and modified cellulose 700kg.
[0081] The preparation method of the modified sand particles in this embodiment, the specific steps are as follows: Mix the sand particles, biomass particles, peat and modified cellulose at a stirring speed of 60rpm for 3min, to obtain modified sand particles.
[0082] This embodiment provides a method for afforestation in desert areas, the specific steps are as follows: (1) Dig tree holes with a depth of 0.5m and a diameter of 1.1m in the target area, the density of the tree holes is 75000 per km 2 Then water the tree holes, and the water amount of a single tree hole is controlled to be 300L.
[0083] (2) Fix the root of the Inner Mongolia Salix mongolica seedling at the center of the tree hole.
[0084] (3) Fill the modified sand particles into the tree hole, and step on it to make it compact, so that the final depth of the tree hole is in the range of 4~6cm, then water, and the water amount of a single tree hole is 60L.
[0085] Example 5 The modified cellulose in this embodiment includes polylactic acid and cellulose core (the mass ratio of polylactic acid and cellulose is 30:33), chitosan (the diameter is 20 microns and the thickness is 3 microns) coated on the surface of the core, methyl cellulose modified on the surface of the shell, and the mass percentage of the methyl cellulose in the modified cellulose is 1.5wt%.
[0086] The preparation method of the modified cellulose in this embodiment is as follows: The polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide are mixed to obtain a core solution, and the volume ratio of the dimethyl sulfoxide and the DMF is 10:20, and the concentration of the polylactic acid is 14 wt%.
[0087] The chitosan and the acetic acid solution (the concentration is 1 wt%) are mixed to obtain a shell solution, and the concentration of the chitosan is 1.8 wt%.
[0088] The coaxial electrospinning is performed by using the core solution and the shell solution, and the working conditions of the coaxial electrospinning are as follows: the positive voltage is 15 kV, the negative voltage is -2 kV, the core layer flow rate is 0.14 mm / min, the shell layer flow rate is 0.2 mm / min, the receiving distance is 25 cm, the translation speed is 300 mm / min, the temperature is 25°C, and the relative humidity is 40%, so as to obtain the core-shell particles.
[0089] The core-shell particles are immersed in the methyl cellulose aqueous solution (the concentration is 2 wt%) at 25°C for 10 min, and then taken out and dried to obtain the modified cellulose.
[0090] The modified sand particles in this embodiment include the following components: 2000 kg of sand particles, 300 kg of corn stalk powder biomass particles, 300 kg of peat and 800 kg of modified cellulose.
[0091] The preparation method of the modified sand particles in this embodiment is as follows: The sand particles, the biomass particles, the peat and the modified cellulose are stirred and mixed at a rotation speed of 60 rpm for 4 min to obtain the modified sand particles.
[0092] The embodiment provides a method for afforestation in a desert area, and the specific steps are as follows: (1) A tree pit with a depth of 0.8 m and a diameter of 1.1 m is dug in a target area, and the density of the tree pit is 65000 pieces / km 2 Then, the tree pit is watered, and the watering amount of a single tree pit is controlled to be 400 L.
[0093] (2) The root of the Inner Mongolia Salix mongolica seedling is fixed at the center of the tree pit.
[0094] (3) The modified sand particles are filled into the tree pit, the modified sand particles are tamped with feet, so that the final depth of the tree pit is in the range of 4-6 cm, and then the tree pit is watered, and the watering amount of a single tree pit is 40 L.
[0095] Embodiment 6 The modified cellulose in the embodiment includes polylactic acid and a cellulose core (the mass ratio of polylactic acid and cellulose is 28:35), chitosan (15 microns in diameter and 1.5 microns in thickness) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, the mass percentage of the methyl cellulose in the modified cellulose being 1.6 wt%.
[0096] The preparation method of the modified cellulose in the embodiment is as follows: The polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide are mixed to obtain a core solution, the volume ratio of the dimethyl sulfoxide and the DMF being 10:10, and the concentration of the polylactic acid being 10 wt%.
[0097] The chitosan and the acetic acid solution (1 wt% in concentration) are mixed to obtain a shell solution, the concentration of the chitosan being 1.8 wt%.
[0098] The core solution and the shell solution are used for coaxial electrospinning, the working conditions of the coaxial electrospinning being as follows: the positive voltage is 15 kV, the negative voltage is -2 kV, the core layer flow rate is 0.14 mm / min, the shell layer flow rate is 0.2 mm / min, the receiving distance is 25 cm, the translation speed is 300 mm / min, the temperature is 25°C, and the relative humidity is 40%, to obtain the core-shell particles.
[0099] The core-shell particles are immersed in the methyl cellulose aqueous solution (2 wt% in concentration) at 25°C for 10 min, and then taken out and dried to obtain the modified cellulose.
[0100] The modified sand particles in the embodiment include the following components: 2000 kg of sand particles, 200 kg of corn stalk powder biomass particles, 200 kg of peat, and 1000 kg of modified cellulose.
[0101] The preparation method of the modified sand particles in the embodiment is as follows: The sand particles, the biomass particles, the peat and the modified cellulose are stirred and mixed at a rotation speed of 60 rpm for 3 min to obtain the modified sand particles.
[0102] The embodiment provides a method for afforestation in a desert area, and the specific steps are as follows: (1) A tree pit with a depth of 0.6 m and a diameter of 1 m is dug in a target area, and the density of the tree pit is 60000 per km 2 Then, the tree pit is watered, and the watering amount of a single tree pit is controlled to be 240 L.
[0103] (2) The root of the Inner Mongolia Salix mongolica seedling is fixed at the center of the tree pit.
[0104] (3) Fill the tree hole with modified sand particles, and tamp with feet to make the final depth of the tree hole in the range of 4-6 cm, then water, the water volume of a single tree hole is 50 L.
[0105] Example 7 The modified cellulose in this example includes polylactic acid and a cellulose core (the mass ratio of polylactic acid and cellulose is 20:27), chitosan (the diameter is 13 microns and the thickness is 1.5 microns) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, the mass percentage of methyl cellulose in the modified cellulose is 1.8wt%.
[0106] The preparation method of the modified cellulose in this example is as follows: Mix polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide, the volume ratio of dimethyl sulfoxide and DMF is 10:20, to obtain a core solution, the concentration of polylactic acid is 14wt%.
[0107] Mix chitosan and acetic acid solution (the concentration is 1wt%) to obtain a shell solution, the concentration of chitosan is 1.8wt%.
[0108] Use the core solution and the shell solution to perform coaxial electrospinning, the working conditions of the coaxial electrospinning are as follows: positive voltage is 14kV, negative voltage is -2.5kV, core layer flow rate is 0.14mm / min, shell layer flow rate is 0.2mm / min, receiving distance is 25cm, translation speed is 300mm / min, temperature is 25℃, and relative humidity is 40%, to obtain core-shell particles.
[0109] Soak the core-shell particles in methyl cellulose aqueous solution (the concentration is 2wt%) at 25℃ for 15min, take out and dry, to obtain modified cellulose.
[0110] The modified sand particles in this example include the following components: 2000kg of sand particles, 400kg of rice husk powder biomass particles, 300kg of peat, and 600kg of modified cellulose.
[0111] The preparation method of the modified sand particles in this example is as follows: Mix the sand particles, biomass particles, peat and modified cellulose at a stirring speed of 50rpm for 4min to obtain modified sand particles.
[0112] The example provides a method for afforestation in desert areas, and the specific steps are as follows: (1) Dig a tree hole with a depth of 0.8m and a diameter of 1.1m in the target area, the density of the tree hole is 75000 per km 2 Then water the tree hole, the water volume of a single tree hole is controlled at 300L.
[0113] (2) Fix the root of the Inner Mongolia Salix seedling at the center of the tree hole.
[0114] (3) Fill the tree hole with modified sand particles, and use feet to tamp, so that the final depth of the tree hole is in the range of 4-6 cm, then water, the water amount of a single tree hole is 50 L.
[0115] Example 8 The modified cellulose in this example includes polylactic acid and cellulose core (the mass ratio of polylactic acid and cellulose is 25:35), chitosan (10 microns in diameter and 1 micron in thickness) coated on the surface of the core, and methyl cellulose modified on the surface of the shell, the mass percentage of methyl cellulose in the modified cellulose is 2wt%.
[0116] The preparation method of the modified cellulose in this example is as follows: Mix polylactic acid, cellulose, dimethyl sulfoxide and dimethyl formamide, the volume ratio of dimethyl sulfoxide and DMF is 10:10, to obtain a core solution, the concentration of polylactic acid is 14wt%.
[0117] Mix chitosan and acetic acid solution (concentration is 1wt%) to obtain a shell solution, the concentration of chitosan is 1.8wt%.
[0118] Use the core solution and the shell solution to perform coaxial electrospinning, the working conditions of the coaxial electrospinning are as follows: positive voltage is 15kV, negative voltage is -2kV, core layer flow rate is 0.14mm / min, shell layer flow rate is 0.2mm / min, receiving distance is 25cm, translation speed is 300mm / min, temperature is 25℃, and relative humidity is 40%, to obtain core-shell particles.
[0119] Soak the core-shell particles in methyl cellulose aqueous solution (concentration is 2wt%) at 25℃ for 15min, take out and dry, to obtain modified cellulose.
[0120] The modified sand particles in this example include the following components: 2000kg of sand particles, 400kg of corn stalk powder biomass particles, 200kg of peat, and 1000kg of modified cellulose.
[0121] The preparation method of the modified sand particles in this example is as follows: Mix the sand particles, biomass particles, peat and modified cellulose at a stirring speed of 50rpm for 4min to obtain modified sand particles.
[0122] The example provides a method for afforestation in desert areas, and the specific steps are as follows: (1) Dig a tree hole with a depth of 0.5m and a diameter of 0.8m in the target area, the density of the tree hole is 80000 per km2 Then, water is poured into the tree hole, and the amount of water poured into a single tree hole is controlled to be 200L.
[0123] (2) The root of the Inner Mongolia Salix tree seedling is fixed at the center of the tree hole.
[0124] (3) The modified sand particles are filled into the tree hole, and the tree hole is tamped with feet to make the final depth of the tree hole in the range of 4-6cm, and then water is poured, and the amount of water poured into a single tree hole is 20L.
[0125] Comparative Example 1 The preparation method of the present comparative example is the same as that of Example 1, except that the core-shell particles are not immersed in the methyl cellulose aqueous solution.
[0126] Comparative Example 2 The preparation method of the present comparative example is the same as that of Example 1, except that the polylactic acid is replaced by an equal amount of cellulose.
[0127] Comparative Example 3 The preparation method of the present comparative example is the same as that of Example 1, except that no biomass particles are added.
[0128] Comparative Example 4 The preparation method of the present comparative example is the same as that of Example 1, except that no modified cellulose is added.
[0129] Comparative Example 5 The preparation method of the present comparative example is the same as that of Example 1, except that the modified sand particles are replaced by ordinary sand particles (sand particles without modification).
[0130] Test Example 1 The afforestation effects of Examples 1-8 and Comparative Examples 1-5 are statistically analyzed, and the statistical items include the survival rate of tree seedlings and the water retention capacity of sand particles (the calculation of water retention rate: first calculate the weight difference of Comparative Example 5 on the first day and the last day, denoted as M, and the weight loss of other examples and comparative examples accounts for the proportion of M, which is the water retention rate), and the results are accurate to the integer (rounded), and the specific results are shown in Tables 1-2.
[0131] Table 1 Survival rate of tree seedlings in Test Example 1
[0132] Table 2 Water retention capacity of sand particles in Test Example 1
[0133] According to Tables 1-2, it can be seen that the method provided by the present application can effectively improve the survival rate of tree seedlings and the water retention capacity of sand particles, and achieve the goal of reducing water consumption under the premise of ensuring the survival rate of tree seedlings.
[0134] The above describes embodiments of the present application, but these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present application. Based on the above embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the present application.
Claims
1. A method for afforestation in desert areas, characterized in that, Includes the following steps: (1) Excavate tree pits with a depth of 0.5~0.8m and a diameter of 0.8~1.1m in the target area, wherein the density of the tree pits is not higher than 80,000 / km. 2 Then water the tree pit; (2) Fix the roots of the sapling to the center of the tree pit; (3) After filling the tree pit with modified sand, water is poured in; the modified sand comprises the following components in parts by mass: 100 parts sand, 10-20 parts biomass pellets, 10-15 parts peat and 30-50 parts modified cellulose; the modified cellulose comprises a core, an outer shell covering the surface of the core and methylcellulose modified on the surface of the outer shell; the core comprises polylactic acid and cellulose; the outer shell comprises chitosan.
2. The method according to claim 1, characterized in that, In step (1), the amount of water poured into a single tree pit is 50~500L.
3. The method according to claim 1, characterized in that, The amount of modified sand used to fill the pit should be based on a final depth of 4-6 cm.
4. The method according to claim 1, characterized in that, In step (3), the amount of water poured into a single tree pit is 10~100L.
5. The method according to claim 1, characterized in that, In the core, the mass ratio of polylactic acid to cellulose is 20~30:25~35.
6. The method according to claim 1, characterized in that, The thickness of the outer shell is 1 to 5 micrometers; the diameter of the outer shell is 10 to 30 micrometers.
7. The method according to claim 1, characterized in that, The methylcellulose accounts for 1-2 wt% of the modified cellulose.
8. The method according to claim 1, characterized in that, The method for preparing the modified cellulose includes the following steps: mixing polylactic acid, cellulose, dimethyl sulfoxide and dimethylformamide to obtain a core solution; mixing chitosan and acetic acid solutions to obtain a shell solution; performing coaxial electrospinning using the core solution and shell solution to obtain core-shell particles; and immersing the core-shell particles in an aqueous solution of methylcellulose to obtain the modified cellulose.
9. The method according to claim 8, characterized in that, The working conditions for coaxial electrospinning include: positive voltage of 14~15kV, negative voltage of -2~-2.5kV, core flow rate of 0.1~0.14mm / min, shell flow rate of 0.15~0.2mm / min, receiving distance of 20~25cm, translation speed of 280~300mm / min, temperature of 25~26℃, and relative humidity of 40~43%.
10. The method according to claim 8, characterized in that, The impregnation temperature is 20-25 degrees Celsius, and the impregnation time is 10-15 minutes; the concentration of the methylcellulose aqueous solution is 1-2 wt%.