Pineapple planting soil improvement method and special modifier thereof

Abstract

The invention relates to the technical field of soil improvement, in particular to a pineapple planting soil improvement method and a special modifier thereof. According to the pineapple planting soil improvement method, the special improver for the pineapple planting soil is applied to the soil before planting, the application amount is 15-25 kg / mu, and shallow turning is conducted after application; the special modifier for the pineapple planting soil is prepared from the following raw materials in percentage by mass: 35 to 65 percent of activated carbon or loaded activated carbon, 30 to 60 percent of cake fertilizer containing nematode inhibiting substances, 0.5 to 5 percent of loaded pomegranate peel ethanol extract and the balance of adhesive. The cake fertilizer (such as cottonseed meal and tea seed meal) containing the nematode inhibiting substance is an agricultural by-product, the raw materials are easy to obtain, and the cost is low; the activated carbon can be prepared from agricultural and forestry wastes (such as coconut shell charcoal), and accords with circular economy. Meanwhile, the environment-friendly and environment-friendly pesticide is eco-friendly, biodegradable, free of chemical residues and capable of killing insects and inhibiting bacteria at the same time.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a method for improving soil for pineapple cultivation and a special soil improver thereof. Background Technology

[0002] Pineapple (scientific name: Ananas comosus Pineapple (L.) Merr. is a tropical fruit. Its edible part mainly consists of a fleshy, enlarged inflorescence axis and spirally arranged flowers on the outer periphery. The flowers are usually non-fertile; the persistent perianth lobes form a cavity containing withered stamens and a style. The leaves have very strong fibers that can be used for weaving, rope making, net making, and papermaking. When eaten fresh, pineapple has golden-yellow flesh, a rich aroma, a sweet and sour taste, and is crisp and juicy.

[0003] However, the indiscriminate use of chemical fertilizers often leads to increasingly serious soil degradation problems in pineapple cultivation. Therefore, the research and application of soil conditioners are of great significance in preventing soil degradation. Existing soil conditioners on the market can be divided into four main categories: natural conditioners, synthetic conditioners, natural-synthetic copolymer conditioners, and biological conditioners. However, what farmers actually accept are mostly new, multifunctional soil conditioners developed using natural materials. These conditioners are characterized by their low price, wide availability of raw materials, and ability to provide a significant amount of organic matter. They are effective in solving soil compaction, mitigating soil salinity, regulating soil pH balance, and enhancing soil fertility and water retention. However, pineapples cannot effectively absorb organic matter and trace elements from the soil, preventing the conditioners from providing immediate results.

[0004] Meanwhile, root-knot nematodes also exist in the soil where pineapples are grown. These nematodes damage the vascular bundles of the roots, leading to stunted pineapple plants and reduced fruit yield. Their larvae can survive in the soil for 2-3 years and easily develop resistance to conventional nematicides (such as thiazophos). Current control methods rely on chemical drenching, which carries the risk of soil residue and cannot restore the soil microecology after nematode infestation, causing significant damage to the pineapple industry.

[0005] There is a need for a soil improvement method for pineapple cultivation that can both improve soil structure and provide long-lasting, slow-release control of pineapple root-knot nematodes. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for improving soil conditions for pineapple cultivation and a specific soil conditioner thereof.

[0007] A method for improving soil for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 15-25 kg / mu, followed by shallow tilling. The raw materials of the special soil conditioner for pineapple cultivation, by weight percentage, include: 35-65% activated carbon or activated carbon-loaded, 30-60% cake fertilizer containing nematode-inhibiting substances, 0.5-5% pomegranate peel ethanol extract-loaded, and the remainder being a binder.

[0008] Preferably, the loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 1-10:1:2-4.

[0009] Pomegranate peel ethanol extract can be freely purchased from the market or made at home (after drying and crushing the pomegranate peel, soak it in anhydrous ethanol overnight, extract it by shaking on a shaker for 12 hours, filter it, concentrate the filtrate to near dryness using a rotary evaporator, and store it in a refrigerator at 4°C for later use).

[0010] Preferably, the oilseed cake containing nematode-inhibiting substances is at least one of cottonseed meal, tea seed meal, and tung seed meal.

[0011] Preferably, the oilseed cake containing nematode-inhibiting substances has a mesh size of 80-100 mesh.

[0012] Preferably, the binder is humic acid and / or diatomaceous earth.

[0013] Preferably, the supported activated carbon is prepared by the following steps: adding activated carbon powder and dispersant to an alkaline aqueous solution with pH=8-9 and stirring for 5-15 minutes, adding dopamine hydrochloride and continuing to stir for 2-6 hours, filtering, washing, and vacuum drying.

[0014] More preferably, the dispersant is polyvinylpyrrolidone and / or sodium dodecylbenzenesulfonate.

[0015] More preferably, the mass ratio of activated carbon, dispersant, and dopamine hydrochloride is 20-40:1:2-10.

[0016] More preferably, the activated carbon powder has a mesh size of 100 mesh.

[0017] More preferably, the alkaline aqueous solution is a sodium hydroxide solution.

[0018] A soil conditioner specifically for pineapple cultivation, which is the soil conditioner specifically for pineapple cultivation used in the above-mentioned soil improvement method for pineapple cultivation.

[0019] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix activated carbon or activated carbon loaded with cake fertilizer containing nematode-inhibiting substances, and dry it until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to an ethanol aqueous solution and stir for 10-30 min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto the mixing matrix, seal and stir at 60-70℃ for 10-30 min, and vacuum dry. Then add a binder, mix, and granulate.

[0020] Beneficial effects: 1. The oilseed cake containing nematode-inhibiting substances (such as cottonseed meal, tea seed meal, and tung seed meal) used in the improved method of this invention is an agricultural by-product, with readily available and low-cost raw materials; while the activated carbon can be prepared from agricultural and forestry waste (such as coconut shell charcoal), conforming to the circular economy. Furthermore, this invention is environmentally friendly, biodegradable, and leaves no chemical residues; the oilseed cake containing nematode-inhibiting substances releases nitrogen, phosphorus, and potassium after decomposition, increasing soil organic matter content and providing soil improvement functions.

[0021] 2. The improver obtained in this invention uses cake fertilizer containing nematode-inhibiting substances and activated carbon or loaded activated carbon as a mixed matrix. The cake fertilizer containing nematode-inhibiting substances can provide organic matter to promote the proliferation of beneficial bacteria in the soil and improve soil structure. On the other hand, it is rich in plant-derived toxic substances such as gossypol and tea saponin, which can effectively inhibit the hatching of nematode eggs. Activated carbon, as a slow-release carrier, prolongs the release time of nutrients and can adsorb soil toxins to improve the microenvironment. At the same time, it can prolong the inhibitory effect on nematodes (lasting for more than 90 days) and enhance the insecticidal effect.

[0022] 3. This invention uses pomegranate peel ethanol extract, triptolide, and terminal carboxyl polyamide amine to construct a loaded pomegranate peel ethanol extract. Tripterygium wilfordii, a diterpenoid compound extracted from Tripterygium wilfordii, has insecticidal activity, exhibiting antifeedant, stomach poison, and contact toxicity. Pomegranate peel ethanol extract has highly efficient contact toxicity. Terminal carboxyl polyamide amine, as a dendritic macromolecule, is loaded into a mixed matrix in this invention, effectively enhancing the loading stability of pomegranate peel ethanol extract and triptolide in the mixed matrix, and enhancing their toxicity against root-knot nematodes. This invention utilizes activated carbon or activated carbon-loaded with activated carbon, cake fertilizer containing nematode-inhibiting substances, and loaded pomegranate peel ethanol extract in combination, achieving synergistic effects through a three-pronged mechanism of slow release → toxicity → toxicity improvement.

[0023] 4. This invention utilizes the oxidative self-polymerization of dopamine hydrochloride to form a three-dimensional network structure in the pore structure of activated carbon, thereby improving the adsorption and loading capacity of the supported activated carbon for pomegranate peel ethanol extract and triptolide, effectively reducing the loss of pomegranate peel ethanol extract and triptolide during application; and the terminal carboxyl polyamide amine can also combine with polydopamine in the supported activated carbon, further enhancing the loading stability of pomegranate peel ethanol extract and triptolide in the mixed matrix, with a lower degradation rate at room temperature (degradation rate ≤2% after 6 months).

[0024] 5. This invention utilizes a combination of pomegranate peel ethanol extract and activated carbon powder, which significantly prolongs the efficacy and extends the retention time in the soil. Field experiments have confirmed that it can reduce nematode density by 95% and achieve a control effect of over 90%. Attached Figure Description

[0025] Figure 1 Soil pH values ​​of Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3 and the control group, and a comparison chart of soil organic matter growth rates of Example 3, Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0026] Figure 2 The soil porosity of Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 3 and the control group are shown in the comparison chart of soil bulk density change rate of Example 3, Example 4, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0027] Figure 3 The graph shows a comparison of the growth rate of soluble sugar content and yield of pineapples in Example 3, Example 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0028] Figure 4 The graph shows a comparison of the nematode density reduction rate and control effect among Example 3, Example 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3. Detailed Implementation

[0029] The present invention will be further explained below with reference to specific embodiments.

[0030] The coconut shell activated carbon used below has a mesh size of 100 and an average specific surface area of ​​857±43 m². 2 / g. The gossypol content in the cottonseed meal used below is 1.037 g / kg. The tea saponin content in the tea seed meal used below is 17.62%.

[0031] Example 1 A method for improving soil for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 15 kg / mu, followed by shallow tilling.

[0032] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 35% coconut shell activated carbon, 60% 80-mesh tea seed meal, 0.5% pomegranate peel ethanol extract, and the remainder is humic acid.

[0033] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and 2.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 1:1:2.

[0034] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix coconut shell activated carbon with tea seed meal and dry at 60℃ until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 5% (w / w) ethanol aqueous solution and stir for 10 min at a stirring speed of 100 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 60℃ for 10 min, and vacuum dry at 60℃. Then add humic acid and mix, and form particles with a particle size of 1-3 mm using an extrusion granulator.

[0035] Example 2 A method for improving soil for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 25 kg / mu, followed by shallow tilling.

[0036] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 63% coconut shell activated carbon, 30% 90-mesh cottonseed meal, 4% pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0037] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and 2.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 10:1:4.

[0038] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix coconut shell activated carbon with cottonseed meal and dry at 60°C until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 7.5% (w / w) ethanol aqueous solution and stir for 30 min at a stirring speed of 500 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 70℃ for 30 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm by extrusion granulation.

[0039] Example 3 A method for improving soil conditions for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 20 kg / mu, followed by shallow tilling.

[0040] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 55% coconut shell activated carbon, 40% 100-mesh tea seed meal, 3% pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0041] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and 3.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 6:1:3.

[0042] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix coconut shell activated carbon with tea seed meal and dry at 60℃ until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 10% (w / w) ethanol aqueous solution and stir for 20 min at a stirring speed of 300 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 65℃ for 20 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm using an extrusion granulator.

[0043] Example 4 A method for improving soil conditions for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 20 kg / mu, followed by shallow tilling.

[0044] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 55% loaded activated carbon, 40% 100-mesh tea seed meal, 3% loaded pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0045] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and 3.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 6:1:3.

[0046] The loaded activated carbon was prepared by the following steps: 7.5 kg of coconut shell activated carbon and 0.25 kg of PVP-K30 were added to 50 kg of sodium hydroxide solution with pH=8.5 and stirred for 10 min at a stirring speed of 1000 r / min. 1.5 kg of dopamine hydrochloride was added and stirring was continued for 4 h. The mixture was then filtered, washed, and vacuum dried.

[0047] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix the loaded activated carbon with tea seed meal and dry it at 60°C until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 10% (w / w) ethanol aqueous solution and stir for 20 min at a stirring speed of 300 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 65℃ for 20 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm using an extrusion granulator.

[0048] Comparative Example 1 A method for improving soil conditions for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 20 kg / mu, followed by shallow tilling.

[0049] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 55% loaded activated carbon, 40% 100-mesh tea seed meal, 3% loaded pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0050] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract, triptolide, and 3.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 6:1:3.

[0051] The loaded activated carbon was prepared by the following steps: 1.5 kg of dopamine hydrochloride was added to 50 kg of sodium hydroxide solution with pH=8.5 and stirred for 4 hours at a stirring speed of 1000 r / min. 7.5 kg of coconut shell activated carbon was added and mixed evenly. The mixture was then filtered, washed, and vacuum dried.

[0052] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix the loaded activated carbon with tea seed meal and dry it at 60°C until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 10% (w / w) ethanol aqueous solution and stir for 20 min at a stirring speed of 300 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 65℃ for 20 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm using an extrusion granulator.

[0053] Comparative Example 2 A method for improving soil conditions for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 20 kg / mu, followed by shallow tilling.

[0054] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 55% loaded activated carbon, 40% 100-mesh tea seed meal, 3% loaded pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0055] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract and 3.0 generation carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, tripterygium lactone and carboxyl-terminated polyamide amine is 2:1.

[0056] The loaded activated carbon was prepared by the following steps: 7.5 kg of coconut shell activated carbon and 0.25 kg of PVP-K30 were added to 50 kg of sodium hydroxide solution with pH=8.5 and stirred for 10 min at a stirring speed of 1000 r / min. 1.5 kg of dopamine hydrochloride was added and stirring was continued for 4 h. The mixture was then filtered, washed, and vacuum dried.

[0057] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix the loaded activated carbon with tea seed meal and dry it at 60°C until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to a 10% (w / w) ethanol aqueous solution and stir for 20 min at a stirring speed of 300 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 65℃ for 20 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm using an extrusion granulator.

[0058] Comparative Example 3 A method for improving soil conditions for pineapple cultivation involves applying a special soil conditioner for pineapple cultivation to the soil before planting at a rate of 20 kg / mu, followed by shallow tilling.

[0059] The above-mentioned soil conditioner for pineapple cultivation contains the following raw materials by weight percentage: 55% loaded activated carbon, 40% 100-mesh tea seed meal, 3% loaded pomegranate peel ethanol extract, and the remainder is diatomaceous earth.

[0060] The loaded pomegranate peel ethanol extract comprises: pomegranate peel ethanol extract and triptolide; the mass ratio of pomegranate peel ethanol extract to triptolide is 6:1.

[0061] The loaded activated carbon was prepared by the following steps: 7.5 kg of coconut shell activated carbon and 0.25 kg of PVP-K30 were added to 50 kg of sodium hydroxide solution with pH=8.5 and stirred for 10 min at a stirring speed of 1000 r / min. 1.5 kg of dopamine hydrochloride was added and stirring was continued for 4 h. The mixture was then filtered, washed, and vacuum dried.

[0062] The above-mentioned method for preparing a soil conditioner specifically for pineapple cultivation includes the following steps: S1. Mix the loaded activated carbon with tea seed meal and dry it at 60°C until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract and tripterygium lactone to a 10% (w / w) ethanol aqueous solution and stir for 20 min at a stirring speed of 300 r / min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto a mixing matrix, seal and stir at 65℃ for 20 min, and vacuum dry at 60℃. Then add diatomaceous earth and mix, and form particles with a particle size of 1-3 mm by extrusion granulation.

[0063] The improved methods of Examples 3, 4, 1, 2, and 3 were used to conduct field trials in a nematode test area of ​​an ecological agricultural pineapple planting base in Sanya, Hainan. The incidence of root-knot nematodes in this plot was 100%, and the previous crop was pineapple.

[0064] The area has a tropical maritime monsoon climate, with an average annual soil temperature of 22-25℃ and an average annual rainfall of 1500-2200mm. The basic physical and chemical properties of the soil are as follows: pH value 4.37, organic matter 6.82g / kg, available nitrogen 253.48mg / kg, available phosphorus 141.95mg / kg, and available potassium 29.03mg / kg.

[0065] This study continued with the cultivation of pineapple (Tainong 17), with six groups. Example 3, Example 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3 employed the improved methods of Example 3, Example 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively. The control group received a mixture of coconut shell activated carbon, rapeseed meal, and diatomaceous earth (in a mass ratio of 55:40:2) applied to the soil before planting. The application rate for each group was 20 kg / mu. After application, the soil in each group was lightly tilled. Each group had five replicates, with no adjacent replicates. Planting management for each group was the same as general production (each group used independent agricultural tools, which were not shared).

[0066] After the pineapple harvest, the soil in the 0-20cm depth of each group was sampled using a five-point sampling method. The pH value, soil porosity, organic matter content and bulk density were then measured, and the organic matter growth rate and soil bulk density change rate of each group were calculated.

[0067] Organic matter growth rate = (soil organic matter content in the treatment group - soil organic matter content in the control group) ÷ soil organic matter content in the control group × 100%.

[0068] Soil bulk density change rate = (control group soil bulk density - treatment group soil bulk density) ÷ control group soil bulk density × 100%.

[0069] like Figure 1 As shown, the soil pH value of the control group was lower than that of the soil before planting, indicating that conventional fertilization lowers the soil pH value for pineapple cultivation, leading to soil acidification. However, the soil pH values ​​of all treatment groups were higher than those of the soil before planting and the control group, indicating that the soil conditioner obtained in this invention can regulate the soil pH value for pineapple cultivation and effectively alleviate further soil acidification caused by conventional fertilization. However, there was no significant difference between the treatment groups. Meanwhile, although the organic matter growth rate of the Example 3 group was the lowest, its organic matter growth rate exceeded 20%, demonstrating a good improvement effect on soil fertility. The organic matter growth rate of the Example 4 group was the highest, superior to the other groups (P < 0.05).

[0070] like Figure 2 As shown, the soil porosity of each treatment group was higher than that of the control group, indicating that the soil conditioner obtained by this invention enhances soil permeability. The soil porosity of the Example 4 group was the highest, which was better than the other groups (P < 0.05). At the same time, although the soil bulk density change rate of the Example 3 group was the lowest, its soil bulk density change rate reached 4.8%, showing a good soil improvement effect; while the soil bulk density change rate of the Example 4 group was the highest, which was better than the other groups (P < 0.05).

[0071] The yield of pineapples harvested in each group was counted, and the soluble sugar content of the pineapples was measured. The growth rate of soluble sugar content and the increase in pineapple yield were calculated.

[0072] The growth rate of soluble sugar content = (soluble sugar content of pineapple in the treatment group - soluble sugar content of pineapple in the control group) ÷ soluble sugar content of pineapple in the control group × 100%.

[0073] Pineapple yield increase rate = (Pineapple yield in treatment group - Pineapple yield in control group) ÷ Pineapple yield in control group × 100%.

[0074] like Figure 3 As shown, although the growth rate of soluble sugar content and the yield of pineapple in Example 3 were the lowest, the growth rate of soluble sugar content exceeded 7% and the yield of pineapple exceeded 20%, showing a good effect on improving the quality of pineapple and promoting the yield of pineapple; while the growth rate of soluble sugar content and the yield of pineapple in Example 4 were the highest, which were better than the other groups (P<0.05).

[0075] Simultaneously, after the pineapple harvest period, the nematode density and root knot number of each group were measured. Based on the control group, the nematode density reduction rate and control effect of Example 3 group, Example 4 group, Comparative Example 1 group, and Comparative Example 2 group were calculated.

[0076] Nematode density reduction rate = (control group nematode density - treatment group nematode density) ÷ control group nematode density × 100%.

[0077] Control effect = (Number of root knots in control group - Number of root knots in treatment group) ÷ Number of root knots in control group × 100%.

[0078] like Figure 4 As shown, although the nematode density reduction rate and control effect of the 3rd group were the lowest, its nematode density reduction rate exceeded 92% and its control effect exceeded 85%, which showed that it had an excellent control effect on root-knot nematodes in the soil; while the nematode density reduction rate and control effect of the 4th group were the highest, which were better than the other groups (P<0.05).

[0079] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for improving soil for pineapple cultivation, characterized in that, Before planting, apply a pineapple-specific soil conditioner to the soil at a rate of 15-25 kg / acre, and then lightly till the soil. The raw materials of the pineapple planting soil conditioner include, by weight percentage: 35-65% activated carbon or loaded activated carbon, 30-60% cake fertilizer containing nematode-inhibiting substances, 0.5-5% loaded pomegranate peel ethanol extract, and the remainder is a binder. The oilseed cake containing nematode-inhibiting substances is at least one of cottonseed meal, tea seed meal, and tung seed meal; The loaded pomegranate peel ethanol extract includes: pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine; the mass ratio of pomegranate peel ethanol extract, triptolide, and carboxyl-terminated polyamide amine is 1-10:1:2-4.

2. The method for improving soil for pineapple cultivation according to claim 1, characterized in that, The mesh size of cake fertilizer containing nematode-inhibiting substances is 80-100 mesh.

3. The method for improving soil for pineapple cultivation according to claim 1, characterized in that, The binder is humic acid and / or diatomaceous earth.

4. The method for improving soil for pineapple cultivation according to claim 1, characterized in that, The supported activated carbon is prepared by the following steps: add activated carbon powder and dispersant to an alkaline aqueous solution with pH=8-9 and stir for 5-15 minutes, add dopamine hydrochloride and continue stirring for 2-6 hours, filter, wash, and vacuum dry.

5. The method for improving soil for pineapple cultivation according to claim 4, characterized in that, The dispersant is polyvinylpyrrolidone and / or sodium dodecylbenzenesulfonate.

6. The method for improving soil for pineapple cultivation according to claim 4, characterized in that, The mass ratio of activated carbon, dispersant, and dopamine hydrochloride is 20-40:1:2-10.

7. The method for improving soil for pineapple cultivation according to claim 4, characterized in that, The activated carbon powder has a mesh size of 100, and the alkaline aqueous solution is a sodium hydroxide solution.

8. A soil conditioner specifically for pineapple cultivation, characterized in that, The pineapple-specific soil conditioner used in the pineapple planting soil improvement method according to any one of claims 1-7.

9. A method for preparing a soil conditioner specifically for pineapple cultivation as described in claim 8, characterized in that, Includes the following steps: S1. Mix activated carbon or activated carbon loaded with cake fertilizer containing nematode-inhibiting substances, and dry it until the moisture content is ≤5% to obtain a mixed matrix; S2. Add pomegranate peel ethanol extract, tripterygium lactone, and carboxyl-terminated polyamide amine to an ethanol aqueous solution and stir for 10-30 min to obtain a mixture containing pomegranate peel ethanol extract. Spray the mixture containing pomegranate peel ethanol extract onto the mixing matrix, seal and stir at 60-70℃ for 10-30 min, and vacuum dry. Then add a binder, mix, and granulate.

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