Method for cultivating toona ciliata in stony desertification area

Abstract

The invention belongs to the technical field of planting, and discloses a method for cultivating toona ciliata in a stony desertification area. The method for cultivating toona ciliata in the stony desertification area comprises the following steps: (1) selecting a land parcel with sand and stones as bases, and digging holes for later use; (2) mixing a water-retaining agent, soil, a fertilizer and water to serve as a substrate; (3) farmyard manure and toona ciliata seedlings are sequentially put into the pits in the step (1), and then a matrix is added for landfill until the matrix is exposed out of the ground; the fertilizer comprises urea, sodium carboxymethyl cellulose, calcium alginate, potassium nitrate, magnesium chloride and crop straw powder. The water-retaining agent comprises composite acid, soybean meal, attapulgite, potassium persulfate, N, N '-methylene bisacrylamide and ferric salt, and the composite acid comprises acrylic acid, citric acid, 2-acrylamido-2-methylpropanesulfonic acid, polyaspartic acid, polyleucine and polyglutamic acid.By means of the toona ciliata cultivation method, the survival rate of toona ciliata can exceed 90%, for example, the survival rate reaches 94-98%.

Description

Technical Field

[0001] The invention belongs to the field of planting technology, and in particular relates to a toon cultivation method in rocky desertification areas. Background Art

[0002] Toona sinensis is a plant in the Meliaceae family with a wide range of applications. For example, the root bark of Toona sinensis has antibacterial and anti-inflammatory effects, astringent and antidiarrheal properties, insecticide and antipruritic properties, heat-clearing and detoxifying properties, and a diuretic and detumescent properties. Toona sinensis is rich in flavonoids and volatile oils, which have antibacterial and anti-inflammatory properties. Toona sinensis extract has inhibitory effects on a variety of bacteria and fungi and can be used to prevent and treat diseases such as food poisoning and skin infections. The volatile oils and alkaloids in Toona sinensis have the effect of clearing heat and detoxifying, can relieve the discomfort caused by internal heat, and can be used to treat symptoms such as dry mouth, bitter taste in the mouth, and sore throat caused by heat toxins.

[0003] Rocky desertification areas have more rocks than soil, resulting in a thinner soil layer and poor water retention. Conventional planting of toon trees has a low survival rate and slow growth. Rocky desertification areas are water-scarce, and because the soil layer has poor water retention, conventional fertilization methods and fertilizers lead to rapid fertilizer loss, resulting in a lack of nutrients and a low survival rate for toon trees.

[0004] The existing technology also uses a method of combining water-retaining agents and fertilizers to improve the survival rate of toon trees. However, the survival rate of toon trees planted using the existing method is generally still low, for example, less than 70%.

[0005] Therefore, there is an urgent need to provide a new method for planting toon, which has a high survival rate. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a method for cultivating toon in rocky desertification areas. The method of cultivating toon in the present invention can achieve a toon survival rate exceeding 90%, for example, reaching 94-98%.

[0007] The present invention uses a specific water-retaining agent and fertilizer to significantly improve the survival rate of toon after one year. In particular, the cultivation method of the present invention can significantly improve the survival rate of toon in desert areas due to the lack of water and fertilizer.

[0008] The uniqueness of the present invention lies in the use of a specific water-retaining agent to form a "micro-reservoir" to more effectively solve the problem of poor soil water retention capacity in rocky desertification areas.

[0009] The fertilizer used in the present invention can provide continuous nutrition for the growth of toon, thereby helping to improve the survival rate of toon.

[0010] A first aspect of the present invention provides a water-retaining agent.

[0011] Specifically, a water-retaining agent includes a composite acid, soybean meal, attapulgite, potassium persulfate, N,N'-methylenebisacrylamide, and iron salt;

[0012] The composite acid includes acrylic acid, citric acid, 2-acrylamido-2-methylpropanesulfonic acid, polyaspartic acid, polyleucine and polyglutamic acid.

[0013] Preferably, the composite acid, by weight, comprises 10 parts of acrylic acid, 0.5-2 parts of citric acid, 1-5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3-5 parts of polyaspartic acid, 1-5 parts of polyleucine and 1-3 parts of polyglutamic acid; further preferably, the composite acid, by weight, comprises 10 parts of acrylic acid, 0.5-1.5 parts of citric acid, 1.5-4 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3.5-4.5 parts of polyaspartic acid, 1.5-4.5 parts of polyleucine and 1.5-2.5 parts of polyglutamic acid.

[0014] Preferably, the water-retaining agent comprises, by weight, 41-48 parts of composite acid, 17-25 parts of soybean meal, 10-16 parts of attapulgite, 1-3 parts of potassium persulfate, 1-5 parts of N,N'-methylenebisacrylamide, and 6-10 parts of ferric chloride.

[0015] Further preferably, the water-retaining agent comprises, by weight, 44-46 parts of composite acid, 18-25 parts of soybean meal, 12-16 parts of attapulgite, 2-3 parts of potassium persulfate, 2-5 parts of N,N'-methylenebisacrylamide, and 6-10 parts of ferric chloride.

[0016] Preferably, the iron salt comprises ferric chloride.

[0017] Preferably, the water-retaining agent further comprises a neutral salt, which comprises sodium chloride or potassium chloride, preferably potassium chloride. The neutral salt is produced by the reaction of the added alkali solution and the acid adjusted to the acidic pH during the preparation of the water-retaining agent.

[0018] A second aspect of the present invention provides a method for preparing a water-retaining agent.

[0019] Specifically, a method for preparing a water-retaining agent comprises the following steps:

[0020] The soybean meal is mixed with alkali solution, heated, and then the pH is adjusted to acidic. Composite acid, attapulgite, and potassium persulfate are added and mixed. N,N'-methylenebisacrylamide and ferric chloride are then added, reacted, and dialyzed to obtain the water retaining agent.

[0021] Preferably, the alkali solution includes sodium hydroxide solution or potassium hydroxide solution, and further preferably, the alkali solution includes potassium hydroxide solution.

[0022] Preferably, the heating temperature is 50-70°C, and the corresponding holding time is 40-90 minutes. More preferably, the heating temperature is 60-70°C, and the corresponding holding time is 80-90 minutes.

[0023] Preferably, the mass volume ratio of the soybean meal to the alkali solution is 1 g: (10-40) mL, more preferably 1 g: (10-35) mL.

[0024] Preferably, the reaction temperature is 70-80° C., and the reaction time is 3-5 hours; further preferably, the reaction temperature is 75-80° C., and the reaction time is 3-5 hours.

[0025] Preferably, hydrochloric acid is used to adjust the pH to acidic.

[0026] Preferably, the acidity corresponds to a pH of 4-6.

[0027] Preferably, the dialysis is performed using a dialysis membrane with a pore size of 1-5 μm for 5-15 hours.

[0028] Preferably, after dialysis, the water-retaining agent is obtained by shredding and drying.

[0029] A third aspect of the present invention provides a method for cultivating toona sinensis in rocky desertification areas.

[0030] Specifically, a method for cultivating toon in rocky desertification areas comprises the following steps:

[0031] (1) In rocky desertified areas, dig pits and prepare:

[0032] (2) Mixing the above-mentioned water-retaining agent, soil and farmyard manure to form a matrix;

[0033] (3) placing the substrate into the pit of step (1), then covering the substrate with soil, placing the red toon seedlings, and then adding soil to fill the soil until the soil is exposed to the ground. When the red toon seedlings grow to the first month, apply fertilizer once. When the red toon seedlings grow to the seventh month, apply fertilizer once again. After one year, calculate the survival rate of the red toon;

[0034] The fertilizer comprises urea, sodium carboxymethyl cellulose, calcium alginate, potassium nitrate, magnesium chloride and crop straw powder.

[0035] Preferably, the fertilizer comprises, by weight, 70 parts of urea, 1-8 parts of sodium carboxymethyl cellulose, 5-15 parts of calcium alginate, 10-30 parts of potassium nitrate, 5-15 parts of magnesium chloride and 20-60 parts of crop straw powder.

[0036] Further preferably, the fertilizer comprises, by weight, 70 parts of urea, 1-5 parts of sodium carboxymethyl cellulose, 5-10 parts of calcium alginate, 20-30 parts of potassium nitrate, 8-10 parts of magnesium chloride and 30-50 parts of crop straw powder.

[0037] Preferably, the farmyard manure is farmyard manure that has been composted and naturally fermented for more than one month, for example, farmyard manure formed by composting and fermenting feces of various poultry and livestock under natural conditions for more than one month.

[0038] Preferably, the weight ratio of the water retaining agent, soil and farmyard manure is 1:(2-5):(1-3), more preferably 1:(2-3):(1-2).

[0039] Preferably, in step (3), the thickness of the soil covering the substrate is 4-6 cm, more preferably 4-5 cm.

[0040] Preferably, in step (3), the amount of fertilizer applied each time is 0.15-0.5 kg per toon seedling.

[0041] Preferably, the depth of the pit is 40-60 cm, more preferably 45-55 cm.

[0042] Preferably, the distance between the pits is 1-2.5 meters, more preferably 2-2.2 meters.

[0043] Preferably, the soil is derived from farmland or pond sludge or soil generated when digging a pit. More preferably, the soil is derived from farmland or pond sludge.

[0044] Preferably, the soil is exposed 5-15 cm above the ground, more preferably 8-10 cm.

[0045] Preferably, after the first month of growth of the toon seedlings, the virus and insect pest control process is also included. The virus and insect pest control methods are conventional methods.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The water-retaining agent of the present invention includes a composite acid, soybean meal, attapulgite, potassium persulfate, N,N'-methylenebisacrylamide, and iron salt; the composite acid includes acrylic acid, citric acid, 2-acrylamido-2-methylpropanesulfonic acid, polyaspartic acid, polyleucine, and polyglutamic acid. Through the cross-linking reaction between potassium persulfate, N,N'-methylenebisacrylamide, and ferric chloride and the composite acid components, as well as the interaction with the soybean meal and attapulgite, a stable three-dimensional network structure is formed, which effectively preserves and slowly releases water. Consequently, the survival rate of toon trees in rocky desert regions is significantly improved. Furthermore, when combined with the fertilizer of the present invention, the fertilizer provides toon trees with long-term, effective nutrients, ultimately increasing the survival rate of toon trees in rocky desert regions to 94-98%. DETAILED DESCRIPTION

[0048] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0049] Unless otherwise specified, the raw materials, reagents, or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0050] The farmyard manure used in the following examples is farmyard manure that has been composted and naturally fermented for more than one month, for example, farmyard manure formed by composting and fermenting feces of various poultry and livestock under natural conditions for more than one month.

[0051] The soil used in the following examples was derived from pond sludge.

[0052] The following red toon cultivation process is carried out in February of each year.

[0053] Example 1

[0054] A water-retaining agent, comprising, by weight, 45 parts of a composite acid, 20 parts of soybean meal, 12 parts of attapulgite, 2 parts of potassium persulfate, 2 parts of N,N'-methylenebisacrylamide, and 8 parts of ferric chloride;

[0055] The composite acid comprises, by weight, 10 parts of acrylic acid, 1 part of citric acid, 2 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4 parts of polyaspartic acid, 1 part of polyleucine and 2 parts of polyglutamic acid.

[0056] A method for preparing a water-retaining agent comprises the following steps:

[0057] The soybean meal is mixed with a potassium hydroxide solution (the concentration of the potassium hydroxide solution is 1 mol / L), the mass volume ratio of the soybean meal to the alkali solution is 1 g:30 mL, the temperature is raised to 60°C, and then the pH is adjusted to 5 with 0.5 mol / L hydrochloric acid, the composite acid, attapulgite, and potassium persulfate are added and mixed, and then N,N'-methylenebisacrylamide and ferric chloride are added and reacted at a temperature of 75°C and a reaction time of 4 hours. The dialysis is performed using a dialysis membrane with a pore size of 2 μm for 6 hours, and the water-retaining agent is obtained by cutting and drying.

[0058] A method for cultivating toon in rocky desertification areas comprises the following steps:

[0059] (1) Select a plot of land mainly composed of sand and stones (specific address: Dapingling, Zhoujiatang Village, Guanyin Village Committee, Guanyin Township, Gongcheng Yao Autonomous County, Guilin City), remove weeds, and dig pits with a depth of 50±5 cm and a distance of 2 meters between pits for standby use:

[0060] (2) mixing the water retaining agent, soil (the soil comes from farmland) and farmyard manure in a weight ratio of 1:2:2.5 as a matrix;

[0061] (3) Place the substrate in the pit of step (1), then cover the substrate with soil (the soil thickness is 5 cm), then place the red toon seedlings, and then add soil to fill until the soil is 8 cm above the ground, and lay a weed-proof cloth made of polypropylene material around the red toon seedlings. When the red toon seedlings grow to the first month, apply fertilizer once, and when the red toon seedlings grow to the seventh month, apply fertilizer once again. In step (3), the fertilizer amount of the fertilizer applied in the first month is 0.15 kg per red toon seedling, and the fertilizer amount of the fertilizer applied in the seventh month is 0.3 kg per red toon seedling. The survival rate of the red toon is calculated after one year;

[0062] The following treatments were carried out when the red toon seedlings were 3 months and 10 months old:

[0063] 1. Disease prevention and control

[0064] The main diseases of red toon include root rot, leaf rust, blight, and powdery mildew. For root rot, use mancozeb for root irrigation, Bordeaux mixture, or mancozeb for spraying the root base; use lime sulfur and triadimefon to control leaf rust; use thiophanate and zinc chloride glycerol to control blight; spray with 0.2Be lime sulfur mixture once every 15 days, using 100kg / mu of liquid for two consecutive sprays;

[0065] 2. Pest control

[0066] The main pests of red toon are the Chinese neem borer and the clouded longhorn beetle;

[0067] Neem borers bore into the tender stems of young trees, often causing the failure of red toon cultivation. You can use systemic insecticides such as thiamethoxam, imidacloprid or chlorfenapyr powder, 5g per plant, cover with thin soil, and prevent rainwater from washing away.

[0068] The clouded longhorn beetle is a toon borer pest. Use tweezers to stuff old cotton soaked in dimethoate or dichlorvos into the insect holes, and then plug the holes with yellow mud to kill the pests.

[0069] After one year, the survival rate of red toon trees was counted;

[0070] The fertilizer comprises, by weight, 70 parts of urea, 3 parts of sodium carboxymethyl cellulose, 6 parts of calcium alginate, 15 parts of potassium nitrate, 6 parts of magnesium chloride and 30 parts of corn straw powder.

[0071] Example 2

[0072] A water-retaining agent, comprising, by weight, 42 parts of a composite acid, 20 parts of soybean meal, 11 parts of attapulgite, 2 parts of potassium persulfate, 2 parts of N,N'-methylenebisacrylamide, and 6 parts of ferric chloride;

[0073] The composite acid comprises, by weight, 10 parts of acrylic acid, 1 part of citric acid, 2 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4.5 parts of polyaspartic acid, 1.5 parts of polyleucine and 2 parts of polyglutamic acid.

[0074] A method for preparing a water-retaining agent comprises the following steps:

[0075] The soybean meal is mixed with a potassium hydroxide solution (the concentration of the potassium hydroxide solution is 1 mol / L), the mass volume ratio of the soybean meal to the alkali solution is 1 g:30 mL, the temperature is raised to 60°C, and then the pH is adjusted to 5 with 0.5 mol / L hydrochloric acid, the composite acid, attapulgite, and potassium persulfate are added and mixed, and then N,N'-methylenebisacrylamide and ferric chloride are added and reacted at a temperature of 75°C and a reaction time of 4 hours. The dialysis is performed using a dialysis membrane with a pore size of 2 μm for 6 hours, and the water-retaining agent is obtained by cutting and drying.

[0076] A method for cultivating toon in rocky desertification areas comprises the following steps:

[0077] (1) Select a plot of land mainly composed of sand and stones (specific address: Dapingling, Zhoujiatang Village, Guanyin Village Committee, Guanyin Township, Gongcheng Yao Autonomous County, Guilin City), remove weeds, and dig pits with a depth of 50±5 cm and a distance of 2 meters between pits for standby use:

[0078] (2) mixing the water retaining agent, soil (the soil comes from farmland) and farmyard manure in a weight ratio of 1:2:2.4 as a matrix;

[0079] (3) Place the substrate in the pit of step (1), then cover the substrate with soil (the soil thickness is 5 cm), then place the red toon seedlings, and then add soil to fill until the soil is 9 cm above the ground, and lay a weed-proof cloth made of polypropylene material around the red toon seedlings. When the red toon seedlings grow to the first month, apply fertilizer once, and when the red toon seedlings grow to the seventh month, apply fertilizer once again. In step (3), the amount of fertilizer applied in the first month is 0.15 kg per red toon seedling, and the amount of fertilizer applied in the seventh month is 0.3 kg per red toon seedling. The survival rate of the red toon is calculated after one year;

[0080] The following treatments were carried out when the red toon seedlings were 3 months and 10 months old:

[0081] 1. Disease prevention and control

[0082] The main diseases of red toon include root rot, leaf rust, blight, and powdery mildew. For root rot, use mancozeb for root irrigation, Bordeaux mixture, or mancozeb for spraying the root base; use lime sulfur and triadimefon to control leaf rust; use thiophanate and zinc chloride glycerol to control blight; spray with 0.2Be lime sulfur mixture once every 15 days, using 100kg / mu of liquid for two consecutive sprays;

[0083] 2. Pest control

[0084] The main pests of red toon are the Chinese neem borer and the clouded longhorn beetle;

[0085] Neem borers bore into the tender stems of young trees, often causing the failure of red toon cultivation. You can use systemic insecticides such as thiamethoxam, imidacloprid or chlorfenapyr powder, 5g per plant, cover with thin soil, and prevent rainwater from washing away.

[0086] The clouded longhorn beetle is a toon borer pest. Use tweezers to stuff old cotton soaked in dimethoate or dichlorvos into the insect holes, and then plug the holes with yellow mud to kill the pests.

[0087] After one year, the survival rate of red toon trees was counted;

[0088] The fertilizer comprises, by weight, 70 parts of urea, 3.5 parts of sodium carboxymethyl cellulose, 5.5 parts of calcium alginate, 15.5 parts of potassium nitrate, 7 parts of magnesium chloride and 32 parts of corn straw powder.

[0089] Example 3

[0090] A water-retaining agent, comprising, by weight, 46 parts of a composite acid, 25 parts of soybean meal, 10 parts of attapulgite, 2 parts of potassium persulfate, 2.2 parts of N,N'-methylenebisacrylamide, and 5.8 parts of ferric chloride;

[0091] The composite acid comprises, by weight, 10 parts of acrylic acid, 1 part of citric acid, 2 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4.5 parts of polyaspartic acid, 1.5 parts of polyleucine and 2 parts of polyglutamic acid.

[0092] A method for preparing a water-retaining agent comprises the following steps:

[0093] The soybean meal is mixed with a potassium hydroxide solution (the concentration of the potassium hydroxide solution is 1 mol / L), the mass volume ratio of the soybean meal to the alkali solution is 1 g:30 mL, the temperature is raised to 60°C, and then the pH is adjusted to 5 with 0.5 mol / L hydrochloric acid, the composite acid, attapulgite, and potassium persulfate are added and mixed, and then N,N'-methylenebisacrylamide and ferric chloride are added and reacted at a temperature of 75°C and a reaction time of 4 hours. The dialysis is performed using a dialysis membrane with a pore size of 2 μm for 6 hours, and the water-retaining agent is obtained by cutting and drying.

[0094] A method for cultivating toon in rocky desertification areas comprises the following steps:

[0095] (1) Select a plot of land mainly composed of sand and stones (specific address: Dapingling, Zhoujiatang Village, Guanyin Village Committee, Guanyin Township, Gongcheng Yao Autonomous County, Guilin City), remove weeds, and dig pits with a depth of 50±5 cm and a distance of 2 meters between pits for standby use:

[0096] (2) mixing the water retaining agent, soil (the soil comes from farmland) and farmyard manure in a weight ratio of 1:2:2.5 as a matrix;

[0097] (3) Place the substrate in the pit of step (1), then cover the substrate with soil (the soil thickness is 5 cm), then place the red toon seedlings, and then add soil to fill until the soil is 8 cm above the ground, and lay a weed-proof cloth made of polypropylene material around the red toon seedlings. When the red toon seedlings grow to the first month, apply fertilizer once, and when the red toon seedlings grow to the seventh month, apply fertilizer once again. In step (3), the fertilizer amount of the fertilizer applied in the first month is 0.15 kg per red toon seedling, and the fertilizer amount of the fertilizer applied in the seventh month is 0.3 kg per red toon seedling. The survival rate of the red toon is calculated after one year;

[0098] The following treatments were carried out when the red toon seedlings were 3 months and 10 months old:

[0099] 1. Disease prevention and control

[0100] The main diseases of red toon include root rot, leaf rust, blight, and powdery mildew. For root rot, use mancozeb for root irrigation, Bordeaux mixture, or mancozeb for spraying the root base; use lime sulfur and triadimefon to control leaf rust; use thiophanate and zinc chloride glycerol to control blight; spray with 0.2Be lime sulfur mixture once every 15 days, using 100kg / mu of liquid for two consecutive sprays;

[0101] 2. Pest control

[0102] The main pests of red toon are the Chinese neem borer and the clouded longhorn beetle;

[0103] Neem borers bore into the tender stems of young trees, often causing the failure of red toon cultivation. You can use systemic insecticides such as thiamethoxam, imidacloprid or chlorfenapyr powder, 5g per plant, cover with thin soil, and prevent rainwater from washing away.

[0104] The clouded longhorn beetle is a toon borer pest. Use tweezers to stuff old cotton soaked in dimethoate or dichlorvos into the insect holes, and then plug the holes with yellow mud to kill the pests.

[0105] After one year, the survival rate of red toon trees was counted;

[0106] The fertilizer comprises, by weight, 70 parts of urea, 3.5 parts of sodium carboxymethyl cellulose, 6 parts of calcium alginate, 16 parts of potassium nitrate, 8 parts of magnesium chloride and 35 parts of crop straw powder (corn straw powder).

[0107] Comparative Example 1

[0108] Compared with Example 1, the only difference of Comparative Example 1 is that equal amounts of polyaspartic acid are used instead of polyleucine and polyglutamic acid, and the other processes are the same as those of Example 1.

[0109] Comparative Example 2

[0110] Compared with Example 1, the only difference in Comparative Example 2 is that an equal amount of polyaspartic acid is used instead of citric acid, and the other processes are the same as those in Example 1.

[0111] Comparative Example 3

[0112] Compared with Example 1, the only difference of Comparative Example 3 is that an equal amount of calcium chloride is used instead of calcium alginate, and the other processes are the same as those of Example 1.

[0113] Product effect testing

[0114] The number of toon seedlings planted in each embodiment and comparative example was 50. According to the methods of the above embodiments and comparative examples, the survival rates of the toon seedlings corresponding to embodiments 1-3 and comparative examples 1-3 were calculated one year later (survival rate = surviving toon seedlings after one year / toon seedlings at the time of planting * 100%). The results are shown in Table 1.

[0115] Table 1

[0116] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Survival rate (%) 96 98 94 88 90 86

[0117] As can be seen from Table 1, the method of the embodiment of the present invention can increase the survival rate of Toona crenata.

[0118] Compared with Example 1, changes in the compound acid type in Comparative Examples 1-2 and the fertilizer composition in Comparative Example 3 resulted in a significant decrease in the survival rate of toon. This is primarily due to the fact that changing the compound acid type can alter the three-dimensional network structure formed by the water-retaining agent, adversely affecting water retention. Changing the fertilizer composition can also weaken the slow-release effect of the fertilizer, thereby hindering the growth of toon.

Claims

1. A water-retaining agent, characterized in that: Including compound acid, soybean meal, attapulgite, potassium persulfate, N,N'-methylenebisacrylamide, iron salt; The composite acid includes acrylic acid, citric acid, 2-acrylamido-2-methylpropanesulfonic acid, polyaspartic acid, polyleucine and polyglutamic acid.

2. The water-retaining agent according to claim 1, characterized in that The composite acid comprises, by weight, 10 parts of acrylic acid, 0.5-2 parts of citric acid, 1-5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3-5 parts of polyaspartic acid, 1-5 parts of polyleucine and 1-3 parts of polyglutamic acid.

3. The water-retaining agent according to claim 1, characterized in that The water-retaining agent comprises, by weight, 41-48 parts of composite acid, 17-25 parts of soybean meal, 10-16 parts of attapulgite, 1-3 parts of potassium persulfate, 1-5 parts of N,N'-methylenebisacrylamide, and 6-10 parts of ferric chloride.

4. The water-retaining agent according to claim 1, characterized in that The water retaining agent further comprises a neutral salt; and / or the iron salt comprises ferric chloride.

5. The method for preparing the water-retaining agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: The soybean meal is mixed with alkali solution, heated, and then the pH is adjusted to acidic. Composite acid, attapulgite, and potassium persulfate are added and mixed. N,N'-methylenebisacrylamide and ferric chloride are then added, reacted, and dialyzed to obtain the water retaining agent.

6. The preparation method according to claim 5, characterized in that The alkali solution includes sodium hydroxide solution or potassium hydroxide solution; and / or, the mass volume ratio of the soybean meal to the alkali solution is 1g: (10-40)mL; and / or, the reaction temperature is 70-80°C, and the reaction time is 3-5 hours.

7. A method for cultivating toon in rocky desertification areas, characterized in that: The following steps are involved: (1) In rocky desertified areas, dig pits and prepare: (2) Mixing the above-mentioned water-retaining agent, soil and farmyard manure to form a matrix; (3) placing the substrate into the pit of step (1), then covering the substrate with soil, placing the red toon seedlings, and then adding soil to fill the soil until the soil is exposed to the ground. When the red toon seedlings grow to the first month, apply fertilizer once. When the red toon seedlings grow to the seventh month, apply fertilizer once again. After one year, calculate the survival rate of the red toon; The fertilizer comprises urea, sodium carboxymethyl cellulose, calcium alginate, potassium nitrate, magnesium chloride and crop straw powder.

8. The method for cultivating toon in rocky desertification areas according to claim 7, characterized in that: The fertilizer comprises, by weight, 70 parts of urea, 1-8 parts of sodium carboxymethyl cellulose, 5-15 parts of calcium alginate, 10-30 parts of potassium nitrate, 5-15 parts of magnesium chloride and 20-60 parts of crop straw powder.

9. The method for cultivating toon in rocky desertification areas according to claim 7, characterized in that: The weight ratio of water retaining agent, soil and farmyard manure is 1:(2-5):(1-3).

10. The method for cultivating toon in rocky desertification areas according to claim 7, characterized in that: The depth of the pit is 40-60 cm; and / or the distance between the pits is 1-2.5 meters; and / or the soil comes from farmland or pond sludge.