PLANT GROWTH PROMOTER

Abstract

The present invention is a plant growth promoter containing a lignocellulosic biomass, wherein the lignocellulosic biomass has a lignin content of 40% by mass or more and 60% by mass or less and a contact angle with water of 50° or less.

Claims

1-9. (canceled)

10. A method for growing a plant, the method comprising: cultivating the plant in a soil containing a plant growth promoter comprising a hydrophilized lignocellulosic biomass, and aggregating the soil to obtain a soil granulated material, wherein the hydrophilized lignocellulosic biomass has a lignin content of 40% by mass or more and 60% by mass or less and a contact angle with water of 50° or less.

11. The method for growing a plant according to claim 10, wherein the plant growth promoter is added to the soil before sowing.

12. The method for growing a plant according to claim 10, wherein the plant growth promoter is mixed into the soil or sprayed onto the soil.

13. The method for growing a plant according to claim 10, wherein the plant growth promoter is added, in terms of the hydrophilized lignocellulosic biomass, in an amount of 0.0001 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the soil for cultivating the plant.

14. The method for growing a plant according to claim 10, wherein the plant growth promoter is sprayed, in terms of the hydrophilized lignocellulosic biomass, in an amount of 0.2 kg or more and 20,000 kg or less per 10a of the soil for cultivating the plant.

15. The method for growing a plant according to claim 10, wherein the plant is an agricultural crop.

16. The method for growing a plant according to claim 10, wherein the plant is a plant selected from the group consisting of Cucurbitaceae, Solanaceae, Rosaceae, Malvaceae, Leguminosae, Gramineae, Brassicaceae, Alliaceae, Amaryllidaceae, Compositae, Amaranthaceae, Umbelliferae, Zingiberaceae, Lamiaceae, Araceae, Convolvulaceae, Dioscoreaceae, and Nelumbonaceae.

17. The method for growing a plant according to claim 10, wherein the plant is a plant selected from the group consisting of a fruit vegetable, a leaf vegetable, a root vegetable, rice, a wheat variety, and a flower.

18. The method for growing a plant according to claim 10, wherein the hydrophilized lignocellulosic biomass is a biomass from a Palmae plant.

19. The method for growing a plant according to claim 10, wherein the hydrophilized lignocellulosic biomass is a biomass from palm kernel shells.

20. The method for growing a plant according to claim 10, wherein the hydrophilized lignocellulosic biomass has an average particle size of 1,000 μm or less.

21. The method for growing a plant according to claim 10, wherein the hydrophilized lignocellulosic biomass is obtained by a method comprising subjecting a raw material lignocellulosic biomass to a hydrophilic treatment, wherein the hydrophilic treatment is at least one selected from the group consisting of: an alkali treatment, which includes contacting the raw material lignocellulosic biomass with an alkaline medium that has a pH of 10 or more and 14 or less and is at least one selected from the group consisting of an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous lithium hydroxide solution, an aqueous calcium hydroxide solution, an aqueous magnesium hydroxide solution, an aqueous sodium carbonate solution, an aqueous potassium carbonate solution, aqueous ammonia, and an aqueous tetramethylammonium hydroxide solution at a temperature of 25° C. or higher and 50° C. or lower for 0.1 hours or more and 7 days or less; a hot water treatment, which includes contacting the raw material lignocellulosic biomass with hot water at a temperature of 80° C. or higher and 200° C. or lower for 0.1 hours or more and 24 hours or less; an acid treatment, which includes contacting the raw material lignocellulosic biomass with an acidic medium having a pH of 1 or more and 5 or less at a temperature of 25° C. or higher and 200° C. or lower for 0.1 hours or more and 7 days or less; and an alkali hot water treatment, which includes contacting the raw material lignocellulosic biomass with an alkaline medium having a pH of 9 or more and 14 or less at a temperature of 50° C. or higher and 180° C. or lower for 0.5 hours or more and 24 hours or less.

Description

EXAMPLES

[0110] The plant growth promoter of the inventive product was produced as follows.

Production Example 1

[0111] Palm kernel shell (PKS) (palm kernel shell, Shodensya Co., Ltd.) that had been passed through a 1 mm diameter mold sieve in an amount of 30 g as a dry mass was placed in a glass bottle, and 0.8% by mass aqueous sodium hydroxide solution was added thereto so that the solid content was 40% by mass. The glass bottle was heated in an autoclave at 100° C. for 1 hour to obtain a reaction product. The resulting slurry was neutralized with 1 M aqueous sulfuric acid until a pH of 7, and then heat dried at 80° C. to obtain inventive product 1 of the plant growth promoter. In this example, the added amount of the 0.8% by mass aqueous sodium hydroxide solution was 150 parts by mass and the added amount of NaOH was 1.2 parts by mass with respect to 100 parts by mass of PKS as the raw material biomass.

Production Example 2

[0112] Inventive product 2 of the plant growth promoter was produced in the same manner as in Production Example 1, except that the raw material biomass was changed to coconut coir dust.

Production Example 3

[0113] Inventive product 3 of the plant growth promoter was produced by performing the same treatment as in Production Example 1, except that a 1.6% by mass aqueous sodium hydroxide solution was added so that the solid content of PKS as raw material biomass was 20% by mass.

Production Example 4

[0114] Palm kernel shell (PKS) (palm kernel shell, Shodensya Co., Ltd.) (water content 2.3%, lignin content 48.8% by mass) was placed into a mini-speed mill “MS-05” (manufactured by Labonect Co., Ltd.) and pulverized 5 times for 20 seconds. The obtained pulverized material was sieved, passed through a 500 μm diameter mold sieve, and the material that remained on the 355 μm diameter mold sieve was taken as inventive product 4 of the plant growth promoter.

Production Examples 5, 6, 7

[0115] Inventive products 5, 6, and 7 of the plant growth promoter were produced in the same manner as in Production Example 4, except that the raw material biomass was changed to peach seed shell, prune seed shell, or Japanese plum seed shell.

Production Examples 8 to 10

[0116] Inventive products 8 to 10 of the plant growth promoter were produced in the same manner as in Production Example 3, except that the raw material biomass was changed to Japanese apricot seed shell, peanut seed shell, or walnut seed shell.

[0117] As comparative plant growth promoter 1, calcium lignin sulfonate (Ligno Super D, manufactured by Kono New Material Development Co., Ltd.) was used as is.

[0118] Further, comparative plant growth promoters 2 and 3 were produced in the same manner as in Production Example 3, except that the type of raw material biomass and the treatment conditions were as shown in Table 1.

[0119] In addition, as comparative plant growth promoter 4, the coir dust of Production Example 2 was used as is.

[0120] Table 1 shows the lignin content in each raw material biomass, the treatment conditions, and the like for the inventive products and the comparative products of the plant growth promoter used in the following examples and comparative examples. The lignin content was determined by the Klason lignin method. Specifically, the total lignin content is calculated as the sum of the acid-insoluble lignin ratio and the acid-soluble lignin ratio, according to the TAPPI formula analysis method T222om-83.

[0121] Note that, in the conditions of the production examples and the comparative production examples, the lignin content in the raw material biomass hardly varies after the treatment, and therefore, for convenience, the lignin content in the raw material biomass is taken as the lignin content of a biomass after the treatment, that is, the lignin content in the biomass used as the plant growth promoter.

TABLE-US-00001 TABLE 1 plant yield enhancer raw material biomass treatment conditions pre- amount of post- lignin treatment aqueous NaOH amount of treatment content contact angle solution added NaOH added temperature treatment water contact symbol type (% by mass) with water (°) (parts by mass) (parts by mass) (° C.) time (h) angle (°) comparative calcium lignin 82.9 0.0 — — — — — product 1 sulfonate (no treatment) comparative bagasse 23.8 99.8 400 6.4 100 1 55.7 product 2 comparative Japanese 35.9 76.6 400 6.4 100 1 66.7 product 3 white birch comparative coconut coir 50.4 63.5 — — — — — product 4 dust (no treatment) inventive PKS 48.8 24.4 150 1.2 100 1 20.5 product 1 inventive coconut coir 50.4 63.5 150 1.2 100 1 43.8 product 2 dust inventive PKS 48.8 24.4 400 6.4 100 1 17.3 product 3 inventive PKS 48.8 24.4 — — — — — product 4 inventive peach seed 45.8 34.5 — — — — — product 5 shell inventive prune seed 45.4 29.4 — — — — — product 6 shell inventive Japanese plum 40.5 29.7 — — — — — product 7 seed shell inventive Japanese 42.2 56.3 400 6.4 100 1 26.3 product 8 apricot seed shell inventive peanut seed 42.0 77.3 400 6.4 100 1 29.7 product 9 shell inventive walnut seed 43.3 50.4 400 6.4 100 1 32.7 product 10 shell

[0122] In the table, the amount of the aqueous NaOH solution added and the amount of NaOH added in the treatment conditions are each represented as parts by mass with respect to 100 parts by mass of the raw material biomass.

<Evaluation>

(1) Water Resistance Evaluation of Soil Granulated Material

[0123] The water resistance of a mixed granulated material obtained by mixing a plant growth promoter and soil was evaluated.

[0124] As the soil, a sample of soil (alluvial soil) from Saga Prefecture that had been passed through a sieve having 2 mm openings to remove coarse particles, stones, and gravel was used.

[0125] The soil was placed in a 100 mL polycup, and the plant growth promoter was added so as to have the amount added shown in Table 2 with respect to 100 parts by mass of the soil. Further, water was added so as to be 30% by mass with respect to the soil, and after manually stirring for about 3 minutes, soil granulated material having a diameter of 1 to 3 mm was taken as a sample from the material obtained. The obtained soil granulated sample was placed in a disposable glass test tube (13 mm×100 mm, manufactured by IWAKI) filled with water to a height of 5 cm, and the time until the soil granulated material broke down was measured. Each test was repeated 5 times, and the average value is shown in Table 2. In addition, the amount of the plant growth promoter added in the table is represented as parts by mass with respect to 100 parts by mass of soil (the same applies hereinafter).

(2) Soybean Growth Test

[0126] The growth promotion effect on soybeans when the plant growth promoters were added to the soil and applied to soybeans was evaluated.

[0127] As the soil, Arakida soil (purchased from Kohnan Shoji Co., Ltd.) that had been passed through a sieve having 2 mm openings to remove coarse particles, stones, and gravel was used.

[0128] The soil was placed in an electric mixer (drum capacity 63L, “SS100-63” (Shinsei Co., Ltd.)), and a plant growth promoter was added so as to be 0.1 parts by mass with respect to 100 parts by mass of soil. Further, water was added so as to be 20 mass % with respect to the soil, and after stirring for about 5 minutes, the obtained mixture was taken as the soil sample. The soil sample was placed in a polyethylene pot for seedlings (diameter 12 cm), fertilized so that N/P/K=6 kg/6 kg/6 kg per 10 a, and soybeans grown separately until the cotyledon development stage (varieties: Fukuyutaka, IWAKURA SEED Co.) were replanted in the pot. About 3 weeks after the replanting, the soybean seedlings were taken out and washed with water, and the dry mass of the part below the ground was measured. The number of repetitions was 8, and the average value thereof was obtained. Each average value is shown in Table 3 as a relative value based on a control value of 100. The control was performed without using the plant growth promoter (Comparative Example 2-1 in Table 3). A large relative value in Table 3 means that viability until harvest is good, and an increase in crop yield is expected.

(3) Measurement of Soil Hardness

[0129] As the soil, Arakida soil (purchased from Kohnan Shoji Co., Ltd.) that had been passed through a sieve having 2 mm openings to remove coarse particles, stones, and gravel was used.

[0130] The soil was placed in an electric mixer (drum capacity 63L, “SS100-63” (Shinsei Co., Ltd.)), and a plant growth promoter was added so as to be 0.1 parts by mass with respect to 100 parts by mass of soil. Further, water was added so as to be 20 mass % with respect to the soil, and after stirring for about 5 minutes, the obtained mixture was taken as the soil sample.

[0131] A soil sample (900 g) was placed in a polyethylene pot for seedlings (diameter 12 cm). The pot was left outdoors, and 500 L/a of water was sprayed using natural water and a garden master sprayer (manufactured by KOSHIN) every two days. After 3 weeks, the hardness of the soil sample was measured. The hardness of the soil sample was measured using a Yamanaka-type soil hardness tester (Fujiwara Scientific Co., Ltd: standard soil hardness tester No. 351).

[0132] In accordance with the instruction manual of the soil hardness tester, the tip cone of the soil hardness tester was inserted until the surface of the soil sample contacted the brim, and then slowly pulled out. The reading of the scale (mm) at that time was read and calculated as a load bearing strength (kg/cm.sup.2) by the following formula. Table 3 shows the average value of 5 repetitions with the load bearing strength as soil hardness.

P=[100X]/[0.7952(40−X).sup.2] [0133] P: Load bearing strength (kg/cm.sup.2) [0134] X: Reading (mm)

TABLE-US-00002 TABLE 2 plant yield enhancer soil granulated contact angle amount added with material water lignin content with water respect to soil resistance symbol (% by mass) (°) (parts by mass) (second) Comparative 1-1 none — — — 27 Examples 1-2 comparative 82.9 0.0 0.1 11 product 1 1-3 comparative 23.8 55.7 0.1 36 product 2 1-4 comparative 35.9 66.7 0.1 32 product 3 1-5 comparative 50.4 63.5 0.1 71 product 4 Examples 1-1 inventive 48.8 20.5 0.1 168 product 1 1-2 inventive 50.4 43.8 0.1 100 product 2 1-3 inventive 48.8 17.3 0.1 288 product 3 1-4 inventive 48.8 20.5 0.075 186 product 1 1-5 inventive 48.8 20.5 0.05 114 product 1 1-6 inventive 48.8 24.4 0.1 168 product 4 1-7 inventive 45.8 34.5 0.1 104 product 5 1-8 inventive 45.4 29.4 0.1 133 product 6 1-9 inventive 40.5 29.7 0.1 116 product 7 1-10 inventive 42.2 26.3 0.1 132 product 8 1-11 inventive 42.0 29.7 0.1 112 product 9 1-12 inventive 43.3 32.7 0.1 117 product 10

TABLE-US-00003 TABLE 3 plant yield enhancer lignin contact amount added with mass of soybean soil content angle with respect to soil below ground hardness symbol (% by mass) water (°) (parts by mass) (relative value) (kg/cm.sup.2) Comparative 2-1 none — — — 100 1.25 Examples 2-2 comparative 82.9 27.9 0.1 105 0.73 product 1 2-3 comparative 23.8 99.8 0.1 99 0.72 product 2 Examples 2-1 inventive 48.8 20.5 0.1 112 0.40 product 1