JPH0123253Y2

JPH0123253Y2 -

Info

Publication number: JPH0123253Y2
Application number: JP1982046414U
Authority: JP
Priority date: 1982-03-31
Filing date: 1982-03-31
Publication date: 1989-07-18
Also published as: JPS58150944U

Description

[Detailed explanation of the idea]

本考案は育苗用下敷きシートに関する。ここに
おいて「育苗用下敷きシート」とは、育苗箱にお
いて水稲、その他の植物を育苗する際育苗箱の底
に敷きその上に培土を盛るようにして用いるシー
トをいう。育苗箱には、主に透水の目的から底に通常５mm
径以上の穴が設けられている。そのため培土を盛
りそこに潅水をすると土が徐々に流失してしまう
という問題があつた。このような土の流失を防止
するために従来より育苗箱の底に新聞紙などを敷
くことが行なわれていた。ここにおいて、本考案者らは新聞紙に代えて適
切量の高吸水性樹脂を配合して作られたシートを
用いてみたところ、このものは流失を防ぐ作用を
するだけに止まらず、後述せる育苗試験の結果よ
り明らかな如く培土に施された過剰水分を吸収し
かつ水分不足の状況に際してはそこから水分を放
出する作用も行いうることを見い出した。この発
見は、高吸水性樹脂の吸水は物理的な吸水とは異
なり化学的なものであつて、一旦吸水したのちは
圧力をかけても離水は少ないといわれていること
からして驚くべきことであつた。よつて、本考案はこのような知見に基いて従来
にない新規な育苗用下敷きシートを提供すること
を目的とする。本考案者らの鋭意研究の結果完成された本考案
は、パルプと高吸水性樹脂とからなる吸収層と、
その両面に設けられた薄葉紙層とからなるシート
からなり、上記パルプ、高吸水性樹脂および薄葉
紙の含有量がそれぞれ65〜260ｇ／m²、25〜60
ｇ／m²および10〜30ｇ／m²であること、並びに上
記シートが一体的に型押し加工されたものである
ことを特徴とする、育苗用下敷きシートを提供す
るものである。本考案の育苗用下敷きシートをなすところの、
パルプと高吸水性樹脂とからなる吸収層とその両
面に設けられた薄葉紙層とからなるシート（以
下、単にシートと称すこともある）は、上記した
構成成分の含有量から明らかな如く、100〜350
ｇ／m²の坪量を有するものである。この範囲外の
坪量を有するシートでは適切な過剰水分の吸収−
不足水分の放出のサイクルが行なわれ難くなるた
めか望ましい育苗は期待し難いからである。シートの吸収層をなす高吸水性樹脂とパルプの
含有量は、シートの形成上および適切な過剰水分
の吸収−不足水分の放出サイクルの形成上などか
ら上記範囲であるべきである。尚、ここにおいて
高吸水性樹脂とは、例えばデンプン・グラフト
系、アクリル・グラフト系、セルロース・グラフ
ト系などの樹脂であつて自重の数百倍もの水を吸
収しうるものを意味し、特に制限を課すものでは
ないが、本考案においては自重の150〜300倍の水
を吸収しうるものが好ましい。具体的には、例え
ば、デンプン−ポリアクリル酸ナトリウムグラフ
ト系樹脂（「サンウエツトIM−300」）、糊化デン
プン−ポリアクリロニトリルグラフト系樹脂
（「Ｈ−SPAN」）、メタクリル酸メチル−酢酸ビニ
ル共重合体の加水分解物、カルボキシメチル化セ
ルロースの架橋物などを挙げることができる。上記の吸収層を両面から支えるべく設けられた
薄葉紙層はその手旨からして上記した範囲内の含
有量が必要にして充分なる量といえる。本考案の育苗用下敷きシートは、上記したよう
な吸収層と薄葉紙層とが一体的にシート加工され
ているシート、好ましくは一体的に型押し加工さ
れているシートからなり、かつこのものが一定形
状、例えば市販の育苗機器用に約280×580mmの大
きさ、に裁断されているものである。特に一体的
に型押し加工されているシートからなるものが好
ましいのは、表面積が大きいほど過剰水分の吸収
−不足水分の放出サイクルが効果的になされうる
からである。本考案の育苗用下敷きシートの好ましい具体例
を第１図に示す。図中、１は吸収層、２および
２′は薄葉層、および３はシボを意味する。第２
図は第１図のＡ−Ａ切断面である。このような本考案の育苗用下敷きシートは、実
際の使用に際して従来の新聞紙等に代えて育苗箱
の底に敷くだけでよく、他の使用の態様は従来の
ものと何ら異るものではない。次に、本考案の育苗用下敷きシートを実際に水
稲の育苗に際して使用し、それが健苗を得るのに
いかに効果的であるかを試験例１および２の結果
でもつて明らかにする。試験例１本考案の育苗用下敷きシートＡ、対照の育苗用
下敷きシートＢおよび新聞紙を、準備した別個の
育苗箱の底にそれぞれ一枚ずつ敷き、その上にマ
サ土を盛り、次いで常法に準じて水稲の苗を育て
た。尚、用いた本考案のシートＡは坪量が171ｇ／
m²で、パルプ：サンウエツトIM−300（デンプン
−ポリアクリル酸ナトリウムグラフト系高吸水性
樹脂）：薄葉紙の割合がそれぞれ124：30：17
（ｇ／m²）のもので、対照のシートＢは上記のシ
ートと同一の配合組成比を有するが坪量が56ｇ／
m²のものであつた。播種時（昭和57年１月９日）から10日目までの
苗の生育状況は以下の第１表の通りであつた。 The present invention relates to an underlay sheet for raising seedlings. The term "underlay sheet for seedling raising" as used herein refers to a sheet that is used when raising seedlings of paddy rice or other plants in a seedling raising box by laying it on the bottom of the seedling raising box and mounding soil on top of it. The bottom of the seedling box is usually 5mm, mainly for water permeability.
A hole larger than the diameter is provided. As a result, there was a problem in that when soil was filled up and watered, the soil would gradually wash away. In order to prevent soil from being washed away, newspapers or the like have traditionally been placed at the bottom of seedling boxes. In this case, the present inventors tried using a sheet made by blending an appropriate amount of superabsorbent resin instead of newspaper, and found that this sheet not only works to prevent washing away, but also has the effect of raising seedlings, which will be described later. As is clear from the test results, it has been found that it can absorb excess water applied to the soil and also release water from it in the event of water shortage. This discovery is surprising since it is said that the water absorption of superabsorbent resins is chemical, unlike physical water absorption, and that once water has been absorbed, there is little syneresis even when pressure is applied. It was hot. Therefore, an object of the present invention is to provide a novel underlay sheet for raising seedlings that has not been seen before based on such knowledge. The present invention, which was completed as a result of intensive research by the inventors, consists of an absorbent layer made of pulp and super absorbent resin,
It consists of a sheet consisting of a thin paper layer provided on both sides, and the contents of the pulp, super absorbent resin, and thin paper are 65 to 260 g/m 2 and 25 to 60 g/m ² , respectively.
g/m ² and 10 to 30 g/m ² , and the sheet is integrally embossed. The underlay sheet for seedling raising of this invention is made of
A sheet (hereinafter sometimes simply referred to as a sheet) consisting of an absorbent layer made of pulp and a superabsorbent resin and thin paper layers provided on both sides of the absorbent layer has a 100% ~350
It has a basis weight of g/m ² . Adequate excess moisture absorption for sheets with basis weights outside this range
This is because it is difficult to expect desired seedling growth, probably because the cycle of releasing insufficient water becomes difficult to perform. The contents of the superabsorbent resin and pulp constituting the absorbent layer of the sheet should be within the above range from the viewpoint of forming the sheet and forming an appropriate excess moisture absorption-deficiency moisture release cycle. The term superabsorbent resin as used herein refers to resins such as starch graft, acrylic graft, and cellulose graft resins that can absorb several hundred times their own weight in water, and there are no particular restrictions. However, in the present invention, it is preferable to use a material that can absorb 150 to 300 times its own weight of water. Specifically, for example, starch-sodium polyacrylate graft resin ("SUNWETT IM-300"), gelatinized starch-polyacrylonitrile graft resin ("H-SPAN"), methyl methacrylate-vinyl acetate copolymer Examples include a hydrolyzate of a combination, a crosslinked product of carboxymethylated cellulose, and the like. Considering the purpose of the thin paper layer provided to support the above-mentioned absorbent layer from both sides, it can be said that the content within the above-mentioned range is necessary and sufficient. The underlay sheet for seedling raising of the present invention consists of a sheet in which the above-mentioned absorbent layer and thin paper layer are integrally processed, preferably integrally embossed, and this is The shape is, for example, cut into a size of about 280 x 580 mm for commercially available seedling raising equipment. In particular, a sheet made of an integrally embossed sheet is preferred because the larger the surface area, the more effective the cycle of absorbing excess moisture and releasing insufficient moisture. A preferred example of the underlay sheet for raising seedlings of the present invention is shown in FIG. In the figure, 1 means an absorbent layer, 2 and 2' a thin layer, and 3 a grain. Second
The figure is a cross section taken along the line AA in FIG. When actually using the underlay sheet for seedling raising of the present invention, it is sufficient to simply place it on the bottom of a seedling raising box in place of conventional newspapers, etc., and the other modes of use are no different from conventional ones. Next, the underlay sheet for raising seedlings of the present invention was actually used for raising paddy rice seedlings, and the results of Test Examples 1 and 2 were used to demonstrate how effective it is in obtaining healthy seedlings. Test Example 1 One sheet each of the seedling-raising underlay sheet A of the present invention, the seedling-raising underlay sheet B of the present invention, and newspaper was placed at the bottom of a separate prepared seedling-raising box, and masa soil was piled up on top of it, followed by a conventional method. Paddy rice seedlings were grown accordingly. In addition, the sheet A of the present invention used has a basis weight of 171g/
^m2 , the ratio of pulp: Sunwet IM-300 (starch-sodium polyacrylate grafted super absorbent resin): tissue paper is 124:30:17, respectively.
(g/m ² ), and the control sheet B has the same composition ratio as the above sheet, but has a basis weight of 56 g/m 2
It was ² m2. The growth status of the seedlings from the time of sowing (January 9, 1981) to the 10th day was as shown in Table 1 below.

【表】第１表の結果より、本考案のシートＡを用いた
場合は草丈、第２葉身長との他のものを用いた場
合に比べて長くて苗の生育が進んでいることがわ
かる。また、第１葉鞘長は良苗の特長通りに短か
く、更に根長は他のものに比べてやや短かいとは
いえ、根数は多くなつており、これはとりもなお
さず強固な苗マツトが形成されたことを意味し、
よつて、マサ土のような粘質土の少ない土壌には
マツト形成上非常に効果的であることが理解され
る。本考案の育苗用下敷きシートによるこのような
効果は、理論上限定されるものではないが多分、
潅水の際過剰の水分を吸収してそれを保持し、床
土が一旦水分不足の状態になつた際には保持して
いた水分を適切に放出し、よつて苗の育成を助成
するように作用する結果もたらされるのではない
かと推定される。試験例２下記の条件の下で稲の育苗を行なつた。 (イ) シートの種類：上記試験例１で用いた本考案の育苗用下敷きシ
ートおよび新聞紙 (ロ) 育苗器： KSA220C、積重ね方式（オートアクアヒータ
ーＨ−95AA）。30℃で出芽させる (ハ) シートの配置位置：上段−下から26段目の箱に本考案のシート下から27段目の箱に新聞紙中段−下から14段目の箱に本考案のシート下から15段目の箱に新聞紙尚、シートは各箱の底に一枚ずつ敷く (ニ) 床土：クボタ春風床土（NO8ｇ、P₂O₅1.8ｇ、K₂O1.5
ｇ／箱） (ホ) 播種量：催芽籾１箱当り200ｇ (ヘ) 播種期：昭和57年２月23日 (ト) 水分調査：土壌水分は容水量／最大容水量×100（％）で示す。
尚、床土の最大容水量は47.2％であつた（Hilgard法）。生育、光合成には50〜80％の
土壌水分が好適であるとされている。播種時および出芽終了時の土壌水分は下記の第
２表の通りであつた。[Table] From the results in Table 1, it can be seen that when sheet A of the present invention is used, the plant height and second leaf height are longer than when other sheets are used, and seedling growth is progressing. . In addition, the length of the first leaf sheath is short, which is the characteristic of good seedlings, and although the root length is a little shorter than other types, the number of roots is large, which is a characteristic of strong seedlings. It means that a pine tree has been formed,
Therefore, it is understood that it is very effective in forming pine trees in soils with little clay, such as masa soil. Although the effects of the underlay sheet for seedling raising of the present invention are not limited in theory, it is likely that
It absorbs excess moisture during irrigation and retains it, and when the bed soil becomes dehydrated, it releases the retained moisture appropriately, thereby supporting the growth of seedlings. It is presumed that this is brought about as a result of the action. Test Example 2 Rice seedlings were raised under the following conditions. (a) Type of sheet: Underlay sheet and newspaper for raising seedlings of the present invention used in Test Example 1 above (b) Seedling raiser: KSA220C, stacking method (auto aqua heater H-95AA). Germination at 30℃ (c) Placement of sheets: Top row - 26th box from the bottom is the sheet of the invention Newspaper is in the 27th box from the bottom - Middle row - The 14th box from the bottom is the sheet of the invention Newspaper in the 15th box from the bottom. Also, place one sheet at the bottom of each box (d) Soil: Kubota Harufaze Soil (NO8g, P ₂ O ₅ 1.8g, K ₂ O 1.5
(g/box) (E) Seed amount: 200g per box of germinated paddy (F) Sowing date: February 23, 1980 (G) Moisture survey: Soil moisture is calculated as water capacity/maximum water capacity x 100 (%) show.
The maximum water capacity of the bed soil was 47.2% (Hilgard method). A soil moisture content of 50 to 80% is considered suitable for growth and photosynthesis. Soil moisture at the time of sowing and at the end of germination was as shown in Table 2 below.

【表】第２表より、本考案のシートは過剰水分を吸収
し、また土壌水分の減水量が少ないことからよく
保水することが認められる。出芽終了時（２月27日）の苗の生育状況は以下
の第３表の通りであつた。[Table] From Table 2, it is recognized that the sheet of the present invention absorbs excess water and retains water well because the amount of water loss in the soil is small. The growth status of the seedlings at the end of germination (February 27th) was as shown in Table 3 below.

【表】第３表より、本考案のシートを用いた場合の方
が芽長は長く、また１個体当りの根数も多いこと
が認められ、しかも種子根の根毛の観察によれば
根毛の発達がより良好であることが認められた。
このことは本考案のシートを用いた場合の方が保
水量上より適切であつたことがわかる。出芽直後から無潅水の条件下で３月４日まで育
苗を続け、無潅水５日目の土壌中の残存水分量を
測定した。（尚、この際育苗箱は育苗器からハウ
ス内に移し、昼間は20〜25℃、夜間は15〜18℃の
条件下で成育を続けた。）結果は第４表の通りで
あつた。[Table] From Table 3, it is recognized that when the sheet of the present invention is used, the bud length is longer and the number of roots per individual is larger. Better development was observed.
This indicates that the use of the sheet of the present invention was more appropriate in terms of water retention. Seedlings were raised immediately after emergence until March 4th without watering, and the residual water content in the soil was measured on the 5th day without watering. (At this time, the seedling growing box was moved from the seedling grower to the greenhouse, and growth was continued under conditions of 20 to 25°C during the day and 15 to 18°C at night.) The results are shown in Table 4.

【表】第４表より、本考案のシートを用いた場合の方
が土壌中の減水量が少なく、これによつて、本考
案のシートに保持されていた水分が放出されたと
いうことが推定される。上記の３月４日における苗の生育状況は以下の
第５表の通りであつた。[Table] From Table 4, the amount of water loss in the soil was smaller when the sheet of the present invention was used, and it is presumed that the water retained in the sheet of the present invention was released. be done. The growth status of the seedlings on March 4th was as shown in Table 5 below.

【表】第５表より、本考案のシートを用いた場合の方
が草丈が長く、根長は短かくても根数が多くて生
育は良好であることが認められる。このことは、
本考案のシートに保持されていた水分がこのシー
トから土壌へと毛管水のようにして苗に供給さ
れ、延いては水分吸収を通して供給される養分量
が多く、よつて苗の生育が良好になつたものと推
定される。３月４日に各試験箱に1000ml、３月７日に1000
ml、３月９日に500mlずつそれぞれ潅水し、３月
11日目に生育状況を観察した。結果は下記の第６
表の通りであつた。[Table] From Table 5, it can be seen that when the sheet of the present invention is used, the plant height is longer, and even though the root length is short, the number of roots is large and the growth is good. This means that
The water retained in the sheet of the present invention is supplied to the seedlings from this sheet into the soil like capillary water, and as a result, a large amount of nutrients are supplied through water absorption, resulting in good growth of the seedlings. It is presumed to have been lost. 1000ml in each test box on March 4th, 1000ml on March 7th
ml, watered 500ml each on March 9th, and in March
The growth status was observed on the 11th day. The results are shown in section 6 below.
It was as shown in the table.

【表】第６表より、本考案のシートを用いた場合の方
が草丈は長く、１個体当りの根数が多く、また莖
が太くてかなり苗質が優れていることが認められ
る。[Table] From Table 6, it can be seen that when the sheet of the present invention was used, the plant height was longer, the number of roots per individual was larger, the pods were thicker, and the quality of the seedlings was considerably better.

[Brief explanation of the drawing]

第１図は本考案の育苗用下敷きシートの一具体
例を示す図である。第２図は第１図のＡ−Ａ切断
面である。図中、１は吸収層、２および２′は薄葉層、お
よび３および３′はシボを示す。 FIG. 1 is a diagram showing a specific example of an underlay sheet for raising seedlings according to the present invention. FIG. 2 is a cross section taken along the line AA in FIG. 1. In the figure, 1 is an absorbent layer, 2 and 2' are thin layers, and 3 and 3' are grains.

Claims

[Scope of utility model registration request]

It consists of a sheet consisting of an absorbent layer made of pulp and super absorbent resin, and a thin paper layer provided on both sides of the absorbent layer, and the contents of the pulp, super absorbent resin, and thin paper are 65 to 260 g/m ² and 25, respectively. ~60g/
m ² and 10 to 30 g/m ² , and the sheet is integrally embossed.