CN107258520A - Plant strain body is locally kept the skin wet or nutrient cultivation material - Google Patents

Plant strain body is locally kept the skin wet or nutrient cultivation material Download PDF

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Publication number
CN107258520A
CN107258520A CN201610216782.1A CN201610216782A CN107258520A CN 107258520 A CN107258520 A CN 107258520A CN 201610216782 A CN201610216782 A CN 201610216782A CN 107258520 A CN107258520 A CN 107258520A
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CN
China
Prior art keywords
cultivation
plant strain
strain body
nutrient
bag
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Pending
Application number
CN201610216782.1A
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Chinese (zh)
Inventor
李萧池
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Individual
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Individual
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Priority to CN201610216782.1A priority Critical patent/CN107258520A/en
Publication of CN107258520A publication Critical patent/CN107258520A/en
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Classifications

    • AHUMAN NECESSITIES
    • A01AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01GHORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G31/00Soilless cultivation, e.g. hydroponics
    • A01G31/02Special apparatus therefor
    • AHUMAN NECESSITIES
    • A01AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01GHORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G7/00Botany in general
    • A01G7/06Treatment of growing trees or plants, e.g. for preventing decay of wood, for tingeing flowers or wood, for prolonging the life of plants
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P60/00Technologies relating to agriculture, livestock or agroalimentary industries
    • Y02P60/20Reduction of greenhouse gas [GHG] emissions in agriculture, e.g. CO2
    • Y02P60/21Dinitrogen oxide [N2O], e.g. using aquaponics, hydroponics or efficiency measures

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  • Life Sciences & Earth Sciences (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Ecology (AREA)
  • Forests & Forestry (AREA)
  • Environmental Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Botany (AREA)
  • Cultivation Receptacles Or Flower-Pots, Or Pots For Seedlings (AREA)

Abstract

It is a kind of plant strain body is locally kept the skin wet or nutrient cultivation material, the cultivation timber-used in cultivation medium cultivated plant strain body, its can be formed top have opening cultivation bag.The cultivation bag is used to store at the girding of cultivation medium and plant strain body, cultivation medium is set to coat at the girding of plant strain body, plant strain body is set to absorb moisture or nutrient from the cultivation medium at girding, and spontaneous differentiation, breeding, germination or long root, with contribute to plant strain body to bloom or result increment.It is described to be open whether sufficient for observing the moisture or nutrient of cultivation medium inside cultivating bag body, and it is able to keep the skin wet to the cultivation medium inside cultivating bag body or nutrient in good time.

Description

Plant strain body is locally kept the skin wet or nutrient cultivation material
Technical field
The present invention relates to a kind of plant culture material, in particular it relates to which a kind of plant can utilize the office of itself strain body The cultivation material that portion is cultivated in cultivation medium.
Background technology
The strain body of most plants is local all to have differentiation, the ability of regeneration and breeding, thus plant is available The part of itself strain body is cultivated.However, current gardening circle has no useful instrument and come to plant strain body Local cultivation is carried out, this turns into problem urgently to be resolved hurrily at present.
The content of the invention
In view of the shortcoming of above-mentioned prior art, present invention offer is a kind of locally to keep the skin wet or supports to plant strain body The cultivation material divided, the cultivation timber-used is in the cultivated plant strain body in cultivation medium.The cultivation material of the present invention includes Sheet noumenon, upper limb strengthening section, side joint portion, root edge joint portion and location division.Sheet noumenon has a left side Side, right edge, left root edge and right root edge.Upper limb strengthening section is located at the upper limb of sheet noumenon.Side is combined Portion is used to combine left side and right edge.Root edge joint portion is used to combine left root edge and right root edge.Sheet noumenon Cultivation bag is formed behind the combination by side joint portion and root edge joint portion.Cultivating bag has storage empty Between, upper shed and under shed, accommodation space be used to storing cultivation medium with the girding of plant strain body, Cultivation medium is coated at the girding of plant strain body, make plant strain body from the cultivation medium at girding Moisture or nutrient are absorbed, with spontaneous differentiation, breeding, germination or long root, and contributes to plant strain body to bloom Or the increment of result.Upper shed is formed by upper limb strengthening section, and location division, which is used to position by plant strain body, to plant Bag is trained, plant strain body extends into accommodation space via under shed, and is extended storage by upper shed Space, plant strain body substantially closes under shed, and the aperture area of upper shed is more than the section of plant strain body Area, is kept the skin wet or nutrient with providing space to cultivation medium, or observes the moisture or nutrient of cultivation medium It is whether enough.
In one embodiment of the invention, the intermediate region of sheet noumenon is provided with the first broken line, for sheet Body doubling makes left and right sides coincide, and two root edges of left and right is coincided.The upper edge region of sheet noumenon is provided with Second broken line, so that the upper edge region of sheet noumenon is folded down and forms upper limb strengthening section.
Optionally, upper limb strengthening section extends from the upper limb of sheet noumenon to the inside of accommodation space.Upper limb Strengthening section has raised strip shape body.Side joint portion extends from the left side or right edge of sheet noumenon.Bottom Edge joint portion extends from the left root edge or right root edge of sheet noumenon.
Optionally, location division can be through cultivation bag and penetrate the nail of plant strain body.
Optionally, location division is the snap engagement part of internal flexible crimp body, and snap engagement part leads to Elastic compression joint body, crimping cultivation bag and plant strain body are crossed, and cultivation bag is positioned on plant strain body.
Optionally, location division is C-shaped elastic clamping pieces, to clamp plant strain body so that bag will be cultivated Positioning.
Optionally, the width dimensions of accommodation space between six times of plant strain body diameter dimension to it is octuple it Between;The length dimension of accommodation space is between 17 times to 19 times of plant strain body diameter dimension.
Compared with prior art, the present invention provide it is a kind of plant strain body is locally kept the skin wet or nutrient cultivation Material, the cultivation timber-used makes plant strain body from ring in cultivation medium is coated at the girding of plant strain body Cultivation medium absorption moisture or nutrient at shape peeling, and spontaneous differentiation, breeding, germination or long root, with Help plant strain body bloom or result increment.The cultivation material of the present invention, which can form top, has the cultivation of opening Aperture area above bag, cultivation bag is more than the area of section of plant strain body, thus can be from cultivation bag Top cultivation medium is kept the skin wet or nutrient, can also be from the top of cultivation bag in cultivation medium Moisture or nutrient it is whether enough.
Brief description of the drawings
Fig. 1, be the present invention plant strain body is locally kept the skin wet or nutrient cultivation material expanded schematic diagram.
Fig. 2, be plant strain body is locally kept the skin wet shown in Fig. 1 or nutrient cultivation material the first use state Figure.
Fig. 3, be plant strain body is locally kept the skin wet shown in Fig. 1 or nutrient cultivation material the second use state Figure.
Fig. 4, is that the present invention locally keeps the skin wet to plant strain body or the first implementation state of cultivation material of nutrient is shown It is intended to.
Fig. 5, is that the present invention locally keeps the skin wet to plant strain body or the second implementation state of cultivation material of nutrient is shown It is intended to.
Fig. 6, is that the present invention locally keeps the skin wet to plant strain body or the first embodiment for cultivating material of nutrient is illustrated Figure.
Fig. 7, be plant strain body is locally kept the skin wet shown in Fig. 6 or nutrient cultivation material use state figure.
Fig. 8, is plant strain body locally to be kept the skin wet shown in Fig. 6 or the cultivation material of nutrient is splitted along AA line segments Profile.
Fig. 9, is that the present invention locally keeps the skin wet to plant strain body or the second embodiment for cultivating material of nutrient is illustrated Figure.
Figure 10, is that the present invention locally keeps the skin wet to plant strain body or the 3rd embodiment of cultivation material of nutrient is shown It is intended to.
Embodiment
Herein below will illustrate the technology contents of the present invention by particular specific embodiment with reference to accompanying drawing, ripe The further advantage and work(of the present invention can be understood easily by content disclosed in the present specification by knowing the personage of this technology Effect.The present invention also can be implemented or applied by other different specific embodiments.It is each in this specification Details may be based on different viewpoints and application, under the spirit without departing substantially from the present invention, carry out various modifications with Change.Especially, the proportionate relationship and relative position of each component only have exemplary use in accompanying drawing, not Represent the actual state that the present invention is implemented.
In addition, identical or approximation function structure or component will be entered using identical symbol in following embodiment Row explanation, and the description of identical or impartial technical characteristic is omitted, so that the content disclosed is more succinct and easy Understand.
The present invention provide it is a kind of plant strain body is locally kept the skin wet or nutrient cultivation material, the cultivation material utilize The strain body of plant itself is cultivated in cultivation medium, to pass through cultivation medium by the girding of plant strain body Cladding, makes plant strain body absorb moisture or nutrient from the cultivation medium at girding, and spontaneous differentiation, Breeding, germination or long root, contribute to plant strain body bloom or result increment, be also provided with opening, to sentence Whether the moisture or nutrient of disconnected cultivation medium are sufficient, and are able to keep the skin wet to cultivation medium or nutrient in good time.
On the explanation of the technology of the present invention content, please also refer to Fig. 1 to Figure 10.
As shown in Figure 1 to Figure 3, cultivation material 1 of the invention include sheet noumenon 11, upper limb strengthening section 12, Side joint portion 13, root edge joint portion 14 and location division 15.Sheet noumenon 11 have left side 111, Right edge 112, left root edge 113 and right root edge 114.Upper limb strengthening section 12 is located at the upper limb of sheet noumenon 11, Be folded down by the upper edge region 117 of sheet noumenon 11 by the second broken line 118 in Fig. 2 directions for being denoted as B and Formed, selectively, upper limb strengthening section 12 has raised strip shape body 121, uses reinforced structure intensity. Side joint portion 13 be, for example, extend from the left side 111 of sheet noumenon 11 or the gluing body of right edge 112 or Felt button.Root edge joint portion 14 is, for example, the left root edge 113 or right root edge 114 for extending from sheet noumenon 11 Gluing body or felt button.But all materials that can be used for combining sheet noumenon of the present invention are should be noted that, all Side joint portion of the invention and root edge joint portion can be used as, i.e. side joint portion of the invention and root edge Joint portion is non-to be limited with above-mentioned gluing body or felt button.
In addition, the intermediate region of sheet noumenon 11 is provided with the first broken line 116, for being denoted as A's in Fig. 2 Direction doubling sheet noumenon 11, makes left and right sides 111,112 coincide, to make side joint portion 13 such as Fig. 3 Shown combination left and right sides 111,112, and two root edges 113,114 of left and right is coincided, to make root edge combine Portion 14 combines two root edges 113,114 of left and right as shown in Figure 3.Sheet noumenon 11 is passing through side joint portion 13 And after the combination of root edge joint portion 14, cultivation bag 115 as shown in Figure 3 is formed, cultivation bag 115 has There are accommodation space 1151, upper shed 1152 and under shed 1153, plant can be positioned at by location division 15 On strain body 2.
In the present invention, location division 15 may be selected it is any can will cultivation bag 115 be positioned on plant strain body 2 Structure.As seen in the embodiment shown in fig. 10, location division 15 can be through cultivation bag 115 and penetrate plant strain The nail of body 2, but be not limited, as shown in Fig. 6 to Fig. 8 embodiment, location division 15 has to be internal The snap engagement part 151 of flexible crimp body 1511, the elastic compression joint body 1511 of snap engagement part 151 is in figure C side shown in 7 is rotated up, and until crimping cultivation bag 115 and plant strain body 2, and will cultivate bag 115 It is positioned on plant strain body 2.It should be noted that the meeting when being crimped onto plant strain body 2 of elastic compression joint body 1511 Elastic deformation is to avoid weighing wounded plant strain body 2.Shown in embodiment as shown in Figure 9, location division 15 is C-shaped Elastic clamping pieces, are positioned cultivation bag 115 with clamping plant strain body 2.
The accommodation space 1151 is used to store cultivation medium 3 and at the girding of plant strain body 2 21, makes Cultivation medium 3 is coated 21 at the girding of plant strain body 2 as shown in Figure 4, makes the ring-type of plant strain body 2 21 spontaneous differentiations, breeding or germination as shown in Figure 5 at peeling, to absorb moisture from cultivation medium 3 or support Point, in this way, can help to plant strain body 2 bloom or result increment.Optionally, accommodation space 1151 Width dimensions (being labeled as W in Fig. 4) between plant strain body 2 diameter dimension (being labeled as D in Fig. 4) Six times between octuple, and accommodation space 1151 length dimension (being labeled as L in Fig. 4) between plant Between 17 times to 19 times of the diameter dimension (being labeled as D in Fig. 4) of strain body 2, in this way, storing empty Between 1151 enough space can be provided store cultivation medium 3 and at the girding of plant strain body 2 21.But, The size relationship of accommodation space 1151 and plant strain body 2 can be changed according to plant characteristic, not with above-mentioned interior Appearance is limited.
Upper shed 1152 is strengthened from the upper limb extended from the upper limb of sheet noumenon 11 to the inside of accommodation space 1151 Portion 12 is formed.Under shed 1153 is located at the lower section of accommodation space 1151, and plant strain body 2 is via under shed 1153 extend into accommodation space 1151, and are extended accommodation space 1151 by upper shed 1152. In the present invention, plant strain body 2 can substantially close under shed 1153, with reduce in cultivation medium 3 moisture or The loss of nutrient.The aperture area of upper shed 1152 is more than the area of section of plant strain body 2, to provide to planting Training medium 3 keep the skin wet or nutrient space, even, can also through upper shed 1152 watch cultivation medium 3 situation, uses and judges whether the moisture of cultivation medium 3 or nutrient are sufficient.
In summary, the top for the cultivation bag that present invention cultivation material is formed has opening, can be from top to down Whether the moisture or nutrient for observing cultivation medium inside cultivating bag body are sufficient, with to the cultivation inside cultivating bag body Medium keeps the skin wet or nutrient in good time, plant strain body is absorbed moisture or nutrient from cultivation medium, and utilizes and plant Thing itself strain body spontaneous differentiation, breeding, germination or long root, may help to plant strain body bloom or result increasing Amount.
The principle and effect of above-described embodiment only illustrative present invention, not for the limitation present invention.Appoint What person skilled in the art can enter under the spirit and scope without prejudice to the present invention to above-described embodiment Row modification is with changing.Therefore, the scope of the present invention, should be as listed by claims of the present invention.
Symbol description
1 cultivation material
11 sheet noumenons
111 left sides
112 right edges
113 left root edges
114 right root edges
115 cultivation bags
1151 accommodation spaces
1152 upper sheds
1153 under sheds
116 first broken lines
117 upper edge regions
118 second broken lines
12 upper limb strengthening sections
121 strip shape bodies
13 sides joint portion
14 root edge joint portions
15 location divisions
151 snap engagement parts
1511 elastic compression joint bodies
2 plant strain bodies
At 21 girdings
3 cultivation mediums

Claims (10)

1. it is a kind of plant strain body is locally kept the skin wet or nutrient cultivation material, the cultivation timber-used in cultivation Cultivated plant strain body in medium, it includes:
Sheet noumenon, with left side, right edge, left root edge and right root edge;
Upper limb strengthening section, positioned at the upper limb of the sheet noumenon;
Side joint portion, for combining the left side and the right edge;
Root edge joint portion, for combining the left root edge and the right root edge;And
Location division, wherein,
The sheet noumenon forms cultivation bag behind the combination by the side joint portion and the root edge joint portion, The cultivation bag has accommodation space, upper shed and under shed, and the accommodation space is used to store the cultivation medium At girding with the plant strain body, the cultivation medium is coated at the girding of the plant strain body, make The plant strain body absorbs moisture or nutrient from the cultivation medium at girding, with spontaneous differentiation, breeding, Germination or long root, and contribute to the plant strain body bloom or result increment;The upper shed is strengthened by the upper limb Portion is formed, and the location division is used to position the cultivation bag by the plant strain body, and the plant strain body is via this Under shed extends into the accommodation space, and is extended the accommodation space by the upper shed, the plant strain Body substantially closes the under shed, and the aperture area of the upper shed is more than the area of section of the plant strain body, The cultivation medium is kept the skin wet or nutrient with providing space, or observe the moisture or nutrient of the cultivation medium is It is no enough.
2. cultivation material according to claim 1, it is characterised in that the intermediate region of the sheet noumenon is set There is the first broken line, so that the sheet noumenon doubling makes the left and right sides coincide, and the root edge of left and right two is changed Close.
3. cultivation material according to claim 1, it is characterised in that the upper edge region of the sheet noumenon is set There is the second broken line, so that the upper edge region of the sheet noumenon is folded down and forms the upper limb strengthening section.
4. cultivation material according to claim 1, it is characterised in that the upper limb strengthening section is from the sheet sheet The upper limb of body extends to the inside of the accommodation space.
5. cultivation material according to claim 1, it is characterised in that the upper limb strengthening section has raised Strip shape body.
6. cultivation material according to claim 1, it is characterised in that the side joint portion extends from the piece The left side or right edge of shape body.
7. cultivation material according to claim 1, it is characterised in that the root edge joint portion extends from the piece The left root edge or right root edge of shape body.
8. cultivation material according to claim 1, it is characterised in that the location division is internal flexible The snap engagement part of crimp body, the snap engagement part crimps the cultivation bag with being somebody's turn to do by the elastic compression joint body Plant strain body, and the cultivation bag is positioned on the plant strain body.
9. cultivation material according to claim 1, it is characterised in that the location division system is through cultivating bag The cultivation bag is determined to clamp the plant strain body in body and the nail for penetrating plant strain body, or the location division The C-shaped elastic clamping pieces of position.
10. cultivation material according to claim 1, it is characterised in that the width dimensions of the accommodation space Between six times to eight times of the plant strain body diameter dimension;The length dimension of the accommodation space is between the plant Between 17 times to 19 times of thing strain body diameter dimension.
CN201610216782.1A 2016-04-08 2016-04-08 Plant strain body is locally kept the skin wet or nutrient cultivation material Pending CN107258520A (en)

Priority Applications (1)

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CN201610216782.1A CN107258520A (en) 2016-04-08 2016-04-08 Plant strain body is locally kept the skin wet or nutrient cultivation material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610216782.1A CN107258520A (en) 2016-04-08 2016-04-08 Plant strain body is locally kept the skin wet or nutrient cultivation material

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CN107258520A true CN107258520A (en) 2017-10-20

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101563985A (en) * 2009-05-18 2009-10-28 杭州蓝天园林建设集团有限公司余杭分公司 Technique for propagating bonsai seedling of sweet osmanthus through air layering
CN102273385A (en) * 2010-06-10 2011-12-14 李德伟 Plant layering device
CN202190588U (en) * 2011-08-25 2012-04-18 重庆丹海实业有限公司 Ecological nutrition bag
CN103477902A (en) * 2013-09-20 2014-01-01 汪盛明 Layering bag with pocket and method for manufacturing layering bag
CN103636390A (en) * 2013-12-13 2014-03-19 成都苗夫现代苗木科技有限公司 Air layering breeding method for chaenomeles speciosa
CN204426151U (en) * 2015-02-03 2015-07-01 广西南亚热带农业科学研究所 A kind of culture bag for overhead layering

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101563985A (en) * 2009-05-18 2009-10-28 杭州蓝天园林建设集团有限公司余杭分公司 Technique for propagating bonsai seedling of sweet osmanthus through air layering
CN102273385A (en) * 2010-06-10 2011-12-14 李德伟 Plant layering device
CN202190588U (en) * 2011-08-25 2012-04-18 重庆丹海实业有限公司 Ecological nutrition bag
CN103477902A (en) * 2013-09-20 2014-01-01 汪盛明 Layering bag with pocket and method for manufacturing layering bag
CN103636390A (en) * 2013-12-13 2014-03-19 成都苗夫现代苗木科技有限公司 Air layering breeding method for chaenomeles speciosa
CN204426151U (en) * 2015-02-03 2015-07-01 广西南亚热带农业科学研究所 A kind of culture bag for overhead layering

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
姜道滨: "《杜鹃》", 31 August 1982, 辽宁科学技术出版社 *
金银河: "《印后加工》", 30 September 2001, 化学工业出版社 *

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