JP2004229637A - Method for cultivating plant and substrate for cultivating the plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cultivating a plant, by using polyurethane foam chips as a clean substrate for cultivating the plant, without using soil, and to provide the substrate for cultivating the plant, capable of being used for a long period, regardless of whether a seedling, etc., is cultivated therein in a short period or not. <P>SOLUTION: The method for cultivating the plant comprises cultivating it by using the substrate comprising the open-cell polyurethane foam chips of which the main part has a particle diameter of 0.2-25.0 mm, wherein the substrate is controlled to have a water-holding capacity of 0.4-0.7 g/cm<SP>3</SP>. The substrate for cultivating the plant is chipped out of open-cell hydrophilic polyurethane foam so as to have the particle diameter of 0.2-25.0 mm, wherein the polyurethane foam has a density of 10-100 kg/m<SP>3</SP>, an elongation percentage of ≤ 130%, an air permeability of 5-400 cc/cm<SP>2</SP>/sec, a compression strength at 50% of 0.8-20.0 N/cm<SP>2</SP>, a water-suction height of ≥3 mm, and a water absorption speed of ≤10 sec as physical characteristics. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

また栽培容器が大型で重量を計れない場合、あるいは広い平地でポリウレタンフォームチップを植物栽培基体として使用する場合には、例えば散水後１時間以上放置した後、薄い肉厚のステンレス製の直径１０ｃｍ×高さ３０ｃｍの筒を該フォームチップ栽培基体に挿し込んでこぼれないように一定体積取り出し、重量（Ｇ２）を測定する。次いで取り出したフォームチップを完全に乾燥させた後、フォームチップ重量（Ｇ１）を測定し上記計算式に準じて算出すればよい。
但し本測定方式に限定されたものではなく、要は１時間以上放置後の保水量が測定されれば良い。
また栽培途中での保水量については前述の方法に準じて算出し、あくまでも測定時点の体積と含水フォーム重量より算出するものとする。
【００１４】
さらに、本願第２の発明は植物栽培基体が後述の物性条件を満たす連続気泡性親水ポリウレタンからチップ化された粒径が０．２ｍｍ〜２５．０ｍｍの植物栽培基体である。
１） 密度：１０ｋｇ／ｍ^３〜１００ｋｇ／ｍ^３
２） 伸び：１３０％以下
３） 通気度：４ｃｃ／ｃｍ^２／ｓｅｃ〜４００ｃｃ／ｃｍ^２／ｓｅｃ
４） 圧縮強度：０．８Ｎ／ｃｍ^２〜２０Ｎ／ｃｍ^２
５） 水吸上げ高さ：３ｍｍ以上
【００１５】
なお、本発明に於いて各物性は次のようにして算出した。
密度、伸び、通気度はＪＩＳＫ６４００に準じて測定し、特に通気度については１０ｍｍ厚さで測定した。
また圧縮強度はＪＩＳＫ６４００の硬さ測定に用いる試験機を使用して直径２０ｃｍの円盤で縦７５ｍｍ、横７５ｍｍ、高さ５０ｍｍのサンプルを高さ方向に５０％圧縮した時点の応力として測定した。
水吸上げ高さは縦２０ｍｍ、横２０ｍｍ、高さ６０ｍｍのサンプルを縦４５０ｍｍ、横３５０ｍｍ、深さ２０ｍｍのステンレス製バットの中に置き、バット底面から１０ｍｍの高さまで蒸留水を注ぎ入れ、１時間放置後の水面より上の水の吸上げ高さとして測定した。
吸水時間とは縦３０ｍｍ、横３０ｍｍ、高さ１０ｍｍのサンプル上表面に針規格２２Ｇ×１^１／４″（ニップル社製）注射器で蒸留水一滴を滴下したとき、支持体中に完全に吸水されるまでに要した時間をいう（水滴滴下法）。
【００１６】
見掛け密度が１０ｋｇ／ｍ^３に満たない連続気泡性親水ポリウレタンフォームでは苗を保持する支持力に欠け、１００ｋｇ／ｍ^３より大きな支持体では根が生長するにつれ過密となって酸素の供給が不十分となり、生育が遅れる。植物の支持力、酸素の供給からみて見掛け密度は１０ｋｇ／ｍ^３〜１００ｋｇ／ｍ^３の支持力が好ましい。
伸びが１３０％より大きい支持体では例えフォームチップを圧縮して使用しても植物を保持する支持力に欠け植物が傾いたりして十分に固定することができないため本願の要求を満たさない。また植物の支持力からみて伸びは３０％以下の支持体がより好ましい。
通気度が４ｃｃ／ｃｍ^２／ｓｅｃより低い支持体では酸素の供給が不足して根の生長を阻害すると共に水または液肥を散水する時に連続気泡性親水ポリウレタンフォームへの浸透が遅れ供給時間を要し好ましくない。
また４００ｃｃ／ｃｍ^２／ｓｅｃよりも大きい場合には、水を保持する保水力に欠け、水の供給が不足しがちとなるため本願の要求を満たさない。
保水力、酸素の供給のバランスからみて通気度は５ｃｃ／ｃｍ^２／ｓｅｃ〜３００ｃｃ／ｃｍ^２／ｓｅｃの連続気泡性親水ポリウレタンフォームがより好ましく、更に好ましくは１０ｃｃ／ｃｍ^２／ｓｅｃ〜２００ｃｃ／ｃｍ^２／ｓｅｃが良い。
【００１７】
本発明の連続気泡性親水ポリウレタンフォームの５０％圧縮強度は０．８Ｎ／ｃｍ^２〜２０．０Ｎ／ｃｍ^２の範囲であるが０．８Ｎ／ｃｍ^２以下では植物の支持力に欠け、２０．０Ｎ／ｃｍ^２を越えると、フォームをチップ化するのが困難であるばかりか、例えチップ化されても本来の気泡体構造が壊れて粉末状となり、保水性が低下するなどの問題点がある。
５０％圧縮硬さが２０．０Ｎ／ｃｍ^２以上となると植物の根は連続気泡性親水ポリウレタンフォーム気泡中をほとんど貫通せずフォームチップとフォームチップとの隙間で根が生長するため生育が遅くなる。
水吸上げ高さが３ｍｍ以下では毛細管作用が十分に働かず、フォームチップとフォームチップとの間で水または液肥の伝達が不十分になって長時間に渡り根に均一に供給することができない。
水の吸水速度が１０秒以上では親水性が劣り、ポリウレタンフォームへの水または液肥の供給並びに保持が容易にできない。
【００１８】
本発明の連続気泡性親水ポリウレタンフォームチップの粒径は０．２ｍｍ〜２５．０ｍｍの範囲である。０．２ｍｍ以下では、気泡サイズより小さいため発泡体とは云えず、発泡体のような気泡部あるいはフォームチップとフォームチップとの隙間の空気層をほとんど作ることができないため植物の栽培に適さない。また粒径が２５．０ｍｍ以上となるとフォームチップとフォームチップとの隙間が大きくなって単位体積当たりの保水量が低下して植物の栽培に適さない。
前述のような特定の物性を有する親水ポリウレタンフォームから作られた特定粒径を有するフォームチップは通気性並びに保水性に優れ、植物の種類を問わず、また特定な管理をも必要としない植物栽培基体として最適である。
【００１９】
なお、同一の連続気泡性ポリウレタンフォームであっても定形品とフォームチップ品との保水性能は全く異なる。これは連続気泡性親水ポリウレタンフォームでも同様で、定形品として使用する場合、保水性能は定形品の大きさにより変化せず一定である。これに対してフォームチップの場合には同一の連続気泡性ポリウレタンフォームであっても保水性能即ち保水量を自由に変えることができる。具体的にはフォームチップの粒径、形状並びに気泡の壊れ具合により保水量を大幅に変えることができる。
一般に粒径が小さくなるとフォームチップとフォームチップとの隙間が小さくなって一定容量当たりのフォーム重量が大きくなる（嵩密度が上昇する）ため保水量は増大し、逆に粒径が大きくなると空間部が多くなって一定容積当たりのフォーム重量が小さくなる（嵩密度が低下する）ため保水量は低下する。
また、フォームチップ形状により嵩密度が変化するために保水量も変化する。気泡の壊れ具合については一般に気泡が壊れれば嵩密度が上昇して、保水量も上昇する。
即ち、同一の連続気泡性ポリウレタンフォームブロックあるいは連続気泡性親水ポリウレタンフォームブロックでも、フォームチップ種類、例えば粒径、形状等変えることによって保水量の異なるさまざまなフォームチップを作ることができ、また複数の粒径あるいは形状等の異なる種類のフォームチップを混合使用することにより更に保水量を変えることができる。このことにより植物の種類に適合した保水量に自由に対応することができる。
【００２０】
ここに、ある一種類の連続気泡性親水フォームを用いて各種フォームチップを作成して保水量を測定した具体例を示す。
チップ化する前の連続気泡性親水フォームの物性を表１に、各種フォームチップの保水量を表２に示す。
【００２１】

１、体積Ｖを測定した後２５℃の蒸留水中に浮かべ、５分後に引き上げ５メッシュの金網の上に１時間放置した後、重量Ｍ２を測定する。

【００２２】

ここで、チップ１はカッターナイフにてサイコロ状に作成した。チップ２はロータリークラッシャー（美善社製タイプＰＫ−７）にて作成した。表２から分かるように同一の連続気泡性親水ポリウレタンフォームでも保水量が大幅に変わる。従って実際の栽培に於いては例えば栽培植物の保水量が０．５ｇ／ｃｍ^３〜０．７ｇ／ｃｍ^３が最適保水量の場合チップ２を使用すればいくら水を多く与えても保水量は０．７ｇ／ｃｍ^３以上になることがなく、保水量が０．５ｇ／ｃｍ^３に低下したら水を与えるように栽培すればよい。
【００２３】
本発明において、前述連続気泡性親水ポリウレタンフォームチップを栽培容器にいれて植物を栽培するに当たっては、その栽培容器として底面吸水式になっている鉢またはプランターを好適に使用することができる。
底面吸水式にも各種タイプがあり、下側に直接水分を補給するタイプあるいは上面より補給して底面に流れて溜まるタイプ等がある。
下側の底の水が布等を介して、あるいは直接該フォームチップそのものを水輸送体として、毛細管作用により上側のポリウレタンフォームチップに水分を移行させることにより湿分を好む植物に対して良好な生育が得られる。
一般の鉢またはプランターにするか、あるいは底面吸水式の鉢またはプランターにするかは植物の種類により適宜選択すれば良い。
【００２４】
また、本発明の前述連続気泡性ポリウレタンフォームチップを用いた特定保水量で生育させる栽培方法並びに特定の物性を有する連続気泡性親水ポリウレタンフォームからチップ化された植物栽培基体を用いて、観葉植物、特にミニ観葉植物を好適に、特別の管理なしに栽培することができる。
これら観葉植物としては例えばドラセナ類、ポトス類、ピレア類、アイビー類等がある。
【００２５】
本発明の前述連続気泡性ポリウレタンフォームチップ、および連続気泡性親水ポリウレタンフォームチップからなる植物の栽培基体は単独でも使用することができるが、他の植物の栽培基体等を混合して使用することもできる。
前述他の植物の栽培基体としては天然土壌、繊維質材料あるいはＳｉＯ_２系発泡体等を挙げられる。天然土壌としては土、砂、礫、バーミーキュライト等があり、繊維質材料としては、やしがら等のバーク、ピートモス、腐葉土、パルプがあり、またＳｉＯ_２系発泡体としてはパーライト、イソライト、シラスバルーン等があるがこれらに限定されない。
特に親水性が劣る連続気泡性ポリウレタンフォームチップについては前述他の植物栽培基体を混合して栽培するのが好ましい。また逆の親水性が大きすぎる連続気泡性ポリウレタンフォームチップに於いても前述他の植物栽培基体を混合して栽培するのが良い。
これら連続気泡性ポリウレタンフォームに他の植物の栽培基体を混合するのも本発明の範囲に含まれる。
【００２６】
本発明の植物の栽培基体を構成する連続気泡性親水ポリウレタンフォームを製造する方法としては従来公知の製造方法を用いることができる。
なお、連続気泡性親水ポリウレタンフォームには主にイソシアネートインデックスが１．０以下の低インデックスで発泡させるポリウレタンフォーム、イソシアネートインデックスが１．０〜１．１の通常インデックスで発泡させるポリウレタンフォーム、イソシアネートインデックスが１．０より大きいイソシアヌレート結合を含むポリウレタンフォーム等がある。
前者は特開昭４６−７４１，特開昭４８−２５０９８，特開昭４９−９７８９７，特開平２−１４２０９，特開平９−３２８５３１において詳細に説明されている。具体的には、ポリオールとして、主にオキシエチレン含有ポリオキシアルキレンエーテルポリオールを使用してポリウレタンフォームを製造するのであるが、イソシアネートインデックスを例えば０．５〜０．９としてポリウレタンフォーム中にポリオール中のＯＨ基を残存させて親水化並びに連続気泡化したポリウレタンフォームを製造する方法である。
ここで、イソシアネートインデックスとは、ポリウレタンフォーム中の末端水酸基（−ＯＨ）の当量とイソシアネート中のイソシアネート基（−ＮＣＯ）の当量とから求められるＮＣＯ／ＯＨの比率である。
【００２７】
イソシアネートインデックスが１．０〜１．１の特許としては特開昭５０−１５１６４６，特開昭５４−１０１０８などがある。
また、イソシアネートインデックスが１．０より大きいイソシアヌレート結合を含むポリウレタンフォームとしては、特開平１１−１９３３２０において詳細に説明されている。具体的には、ポリオールとして主に高オキシエチレン含有ポリオキシアルキレンエーテルポリオールを使用し、イソシアネートインデックスを１．０より大きく設定するとともに例えばポリオキシアルキレングリコール末端ＯＨ基を活性水素を有さない化合物でキャップした親水性可塑剤を併用する方法であり、親水化並びに連続気泡化したイソシアヌレート結合を含むポリウレタンフォームを製造する方法である。
チップ化前のポリウレタンフォームは一般のポリウレタンフォームブロック製造機あるいはポリウレタンフォームモールド製造機等従来公知の製造装置を用いて製造することができる。
【００２８】
本発明に於いては連続気泡性ポリウレタンフォームおよび連続気泡性親水ポリウレタンフォームブロックを製造した後、チップ化製造機を用いて粒状化するが、チップ化製造機としては数多くの種類の機械を用いることができる。例えばロータリーカッター方式、イックスツルーダー方式等がある。一般の軟質ポリウレタンフォームをチップ化する各種設備も使用することができる。
【００２９】
次に本発明の栽培形態について具体的に図をもって説明する。
図１は本発明の連続気泡性親水ポリウレタンフォームチップからなる本発明の植物栽培基体２を用いて苗３を鉢１に植えた状態を示す断面図である。まず本発明の植物栽培基体２を鉢１に１／３容量程度いれ、次に苗３を立てた状態で鉢１に入れ、更に本発明の植物栽培基体２を鉢１に追加する。この状態で上面より水道水を約１０分間散水すると本発明の植物栽培基体２の高さが低下する。更に本発明の植物栽培基体２を追加して、散水し鉢１の８分目程度になるまでくりかえす。この間苗３を少々上に持ち上げるようにして苗の根４が本発明の植物栽培基体２中に広がるようにする。その後２〜３日に一度の割合で上面より散水して保水量が常に０．４〜０．７ｇ／ｃｍ^３を保つようにして栽培を行なう。
ここで、連続気泡性ポリウレタンフォームチップを用いる場合は、散水回数を増やしたり、あるいは保水性の大きいピートモスをブレンドしたりして２〜３日に一度の割合の散水で保水量が常に０．４〜０．７ｇ／ｃｍ^３を保たれるようにして栽培を行なってもよい。
【００３０】
また、図２は底面吸水式鉢５に本発明の連続気泡性親水ポリウレタンフォームチップからなる植物栽培基体２を用いて苗３を植えた状態を示す断面図である。本発明の植物栽培基体２を用いて苗３を植える方法については図１と同一である。本鉢５では水並びに液肥の供給は下段底５１部位に供給され、下段底５１に保持水あるいは液肥６として保持され、布７を通して毛細管作用により本発明の植物栽培基体２に伝えられ苗の根４を通して苗本体に伝えられる。
【００３１】
【実施例】
以下ポリウレタンフォームの作成並びに実施例を挙げて更に説明する。
連続気泡性親水ポリウレタンフォームブロック−１の作成
グリセリンにエチレンオキサイドとプロピレンオキサイドとを重量比で８０／２０の割合でランダム重合させた分子量３４００のポリエーテルポリオール１００重量部，水７．５重量部、トリス（ジメチルアミノプロピル）ヘキサヒドロＳ−トリアジン２．０部、ポリシロキサン−ポリオキシアルキレン共重合体（ジメチルシロキサン単位２０，オキシアルキレン付加メチルシロキサン単位１．１、ポリオキシアルキレン鎖中のオキシエチレンとオキシプロピレンの重量割合は８０／２０、ポリオキシアルキレン末端基はメトキシ、ポリオキシアルキレンの分子量１３００）６部、ノニオン界面活性剤イオネットＤＯ−６００（三洋化成工業社製）８５重量部、アニオン界面活性剤ニューコール２７１Ｓ（日本乳化剤社製）１６重量部、炭酸カルシウム２０重量部を十分に撹拌混合した後、クルードＭＤＩを３７０部加えて更に撹拌してポリイソシアヌレート基を含むポリウレタンフォームを得た。
フォーム物性を表３に示す。
【００３２】
連続気泡性親水ポリウレタンフォーム−２の作成
グリセリンにエチレンオキサイドとプロピレンオキサイドを９３／７重量割合で付加した分子量３０００のポリオール１００に対してトリレンジイソシアネート（Ｔ−８０）を加えて末端ＮＣＯ基を有するプレポリマーを合成した本プレポリマーのＮＣＯ％は６．９％であった。本プレポリマー１１８ｇに対して炭酸カルシウム８０ｇ、水６０ｇを加え撹拌混合して発泡体を得た。
本発泡体の物性を表３に示す。
【００３３】
連続気泡性汎用ポリウレタンフォームの作成
グリセリンにエチレンオキサイド／プロピレンオキサイドを８／９２の重量割合で付加重合させた分子量３０００のポリオールとトリレンジイソシアネート（２．４体／２．６体比８０／２０）から汎用軟質ポリウレタンフォームを得た。本ポリウレタンフォームの物性を表３に示す。
【００３４】

【００３５】
以下実施例並びに比較例を挙げて本発明を更に具体的に説明する。
【実施例１】
表３に示した連続気泡性親水ポリウレタンフォーム−１をロータリークラッシャー（美善社製タイプＰＫＳ−７）にかけてチップ長さ２０ｍｍ以下の不定形チップを作成した。このフォームチップの保水量は０．６５ｇ／ｃｍ^３であった。本フォームチップを図１に示した鉢に入れ図１の方法でシンゴニウムを植え付け上面より１０分間水道水を散水した。上面に固形肥料を置き、上面より水を与え、２ヶ月間栽培したところ良好の生長をみた。植物の植え付け１時間後の保水量は鉢の体積並びに使用した連続気泡性親水ポリウレタンフォーム−１の重量より計算して約０．６０ｇ／ｃｍ^３であった。以後３日に一度の割合で上面より散水して１時間以上経過後の保水量を常に０．４２ｇ／ｃｍ^３〜０．６７ｇ／ｃｍ^３に保ったところ、良好な生長を示した。また散水量を多くしても保水量は０．６７ｇ／ｃｍ^３以上にはならなかった。
【００３６】
【実施例２】
表３の連続気泡性親水ポリウレタンフォーム−２をウレタンチップ製造機（岩本綿機社製ＳＫ−３００）にかけてチップ長さ２０ｍｍ以下の不定形チップを作成した。このフォームチップの保水量は約０．５８ｇ／ｃｍ^３であった。
本フォームチップを図２に示した鉢に入れ図２の方法にてアビスを植え付け、下面より水並びに液肥を与えた。
栽培したところ良好であった。
実施例１と同様にして植物の植え付け１時間後の保水量を調べたところ約０．５５ｇ／ｃｍ^３であり、常に保水量が０．４５ｇ／ｃｍ^３〜０．６６ｇ／ｃｍ^３の範囲に安定していた。
【００３７】
【比較例１】
表３に示した汎用ポリウレタンフォームチップを実施例１に示した鉢に入れ、図１の方法でシンゴニウムを植える方式をした。しかしながらポリウレタンフォームが水を容易に吸水しないため、やむを得ず別容器にポリウレタンフォームチップを入れ、強制的に手でポリウレタンチップを圧縮／開放を繰り返して吸水させ、本吸水したポリウレタンフォームを用いて図１の方法でシンゴニウムを植えた。
ポリウレタンフォームが圧縮硬さが小さく、伸びが大きいため、支持力が小さく、垂直に植えるのが困難であった。
植物の植え付け１時間後の保水量は０．２８ｇ／ｃｍ^３であった。以後１日に１回の割合で上面より散水したが、保水量は次第に減水して６日後には０．２２ｇ／ｃｍ^３、１２日後には０．１８ｇ／ｃｍ^３，１８日後には０．１６ｇ／ｃｍ^３，２４日後には０．１５ｇ／ｃｍ^３，３０日後には０．１４ｇ／ｃｍ^３となった。このことから１日ごとの散水はフォームにはほとんど吸水並びに保水されず、初期の強制的保水だけが植物に吸収されていたものと考えられる。
定植したシンゴニウムは全く生長せず、１ヶ月後には枯死寸前であった。
【００３８】
【比較例２】
実施例１と全く同一条件にてシンゴニウムを定植させた。
その後散水を２週間行わず保水量を０．３７ｇ／ｃｍ^３まで低下させ、以後１ヶ月間に保水量０．２５ｇ／ｃｍ^３〜０．３８ｇ／ｃｍ^３に保ちながら２ヶ月間栽培させたところ生長は全くなく、いくらかシンゴニウムがやや株が小さくなった。
【００３９】
【発明の効果】
本発明の粒径が主に０．２ｍｍ〜２５．０ｍｍの連続気泡性ポリウレタンフォームチップからなる植物栽培基体を用いて植物を栽培するに当たり、該連続気泡性ポリウレタンフォームチップからなる植物栽培基体の保水量を０．４〜０．７ｇ／ｃｍ^３になるようにした植物の栽培方法を用いることにより、一般の土壌と同様に幅広い種類の植物を栽培することができると共に、土壌からくる病虫害がなく、しかも連作が可能である。
また、本発明の特定の物性を有する連続気泡性親水ポリウレタンフォームからチップ化された特定の粒径の植物栽培基体を用いることにより、特別な管理なしで保水量を０．４〜０．７ｇ／ｃｍ^３になるように調整することができる。
これらのことにより工業的に管理された水耕栽培や苗等の工業的管理による栽培に限定されず、一般家庭等においても播種から枯れるまでの長期に渡り使用可能な植物の栽培に適したポリウレタンフォーム並びにポリウレタンフォームチップを用いた栽培方法を提供することができる。
また、軽さを必要とする屋上緑化用植物栽培基体としても使用することができるし、産業廃棄物処理の必要なロックウールに代替してハウス用植物栽培基体、などとしても使用することができるし、一般家庭等においても播種から枯れるまでの室内観賞用植物栽培基体としても使用できる。
特に観賞用として室内で使用する場合、土を全く使用しないため清潔に栽培することができる。
【図面の簡単な説明】
【図１】本発明の連続気泡性親水ポリウレタンフォームチップからなる植物栽培基体を用いて鉢に植物を定植した状態を示す断面図
【図２】本発明の連続気泡性親水ポリウレタンフォームチップからなる植物栽培基体を用いて底面吸水式鉢に植物を定植した状態を示す断面図
【記号の説明】
１． 鉢
２． 植物栽培基体
３． 苗
４． 苗の根
５． 底面吸水式鉢
５１．下段底
６． 保持水または液肥
７． 布[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plant cultivation method, a plant cultivation substrate, and a plant cultivation method using the plant cultivation substrate.
More particularly, the present invention relates to a method for cultivating a plant using an open-celled polyurethane foam chip, a plant cultivation substrate produced from an open-celled hydrophilic polyurethane foam having specific physical properties, and a method for cultivating a plant using the plant-cultivated substrate. Things.
[0002]
[Prior art]
Polyurethane foam is (1) flammable and (2) does not generate formaldehyde like phenol foam. (3) It is easy to biodegrade. (4) Continuous cropping is possible. (5) Over-humidity like rock wool. There are many advantages such as (6) the specific gravity is light, which does not cause a condition or illness. As a few practical examples of using polyurethane foam as a plant cultivation base, hydroponic cultivation of leek and the like, hydroponic cultivation such as Japanese radish, rice using a regular form of tens of cm square with a cut in several cm square, rice Seedling cultivation and cutting seedling cultivation such as poinsettia, and are used in the form of fixed products. Here, the fixed product refers to a cut foam product of a fixed shape and a fixed size, for example, a rectangular parallelepiped having a width of 30 cm x a length of 60 cm x a height of 5 cm, or a length of 10 cm x a width of 10 cm x a height of 10 cm, or a depth of them It means a cross cut of about 3 cm.
Also, the cultivation of plants using polyurethane foam chips is old, and Japanese Patent Application Laid-Open Nos. 48-67018, 52-47149, 53-39938, 56-15619, and 56-15619, and newly, Japanese Patent Application Laid-Open No. 7-327483. It is described in JP-A-9-168341 and the like and is well known.
Specific usage methods include a method of using a polyurethane foam chip alone, a method of using a polyurethane foam chip solidified with an adhesive or the like, and integrating the solidified polyurethane foam chip with another sheet-like polyurethane foam or cloth. Or a mixture of a natural plant cultivation medium such as peat moss and the like with a polyurethane foam chip has been proposed, but there are few practical examples.
[0003]
This is because the bottom, side, and top of the general-purpose flexible polyurethane foam block used for cushions, etc. other than the non-defective parts were pulverized (commonly known as soft urethane chips) and used as a plant cultivation base as it was to retain water. Is small and could not be adapted to plant cultivation. It is also considered that at the same time, chipping technology suitable for plant cultivation was not developed, and at the same time, a cultivation method suitable for plant cultivation was not developed.
Utilizing the advantages of polyurethane foam, and even using polyurethane foam alone, it is not limited to industrially managed hydroponics or cultivation of seedlings, etc. It has been desired to develop a polyurethane foam suitable for cultivation of a possible plant and a cultivation method using a polyurethane foam chip.
[0004]
[Patent Document 1]
JP-A-48-67018 (page 2, upper right column, line 4 to page 3, upper right column, line 20)
[0005]
[Patent Document 2]
52-49149 (2 lines, upper line of page 2 to 16 lines of upper line, page 2)
[0006]
[Patent Document 3]
53-9738 (2 lines, upper line, 16 lines-2 pages, upper line, 20 lines)
[0007]
[Patent Document 4]
JP-A-56-15619 (page 2, upper left column, line 12 to page 2, upper right column, line 7)
[0008]
[Patent Document 5]
JP-A-7-327483 (paragraph
[0007]
[0008]
[0009]
[Patent Document 6]
JP-A-9-168341 (paragraph
[0011] ~
[0014]
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems, and without losing the advantages of polyurethane foam chips, is not limited to specific hydroponic cultivation, and can be cultivated in general households and the like, similar to general soil. The present invention provides a cultivation method capable of cultivating plants for a wide variety of plants for a long period of time and a plant cultivation substrate chipped from open-cell hydrophilic polyurethane foam having specific physical properties.
[0011]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, to cultivate a wide variety of plants for a long period of time in the same manner as general soil without industrial management such as hydroponic cultivation, the conventional Open-cell hydrophilic with specific physical properties that can be achieved by cultivating it under specific water retention conditions (water retention amount) using polyurethane foam chips instead of the fixed product The present inventors have found a plant cultivation substrate chipped from polyurethane foam and completed the present invention.
The first invention of the present application relates to a method for culturing a plant using a plant cultivation substrate comprising an open-celled polyurethane foam chip having a particle size of 0.2 mm to 25.0 mm, wherein a polyurethane foam is supplied in a state where water is supplied to the plant cultivation substrate. Chip water retention 0.4g / cm³~ 0.7g / cm₃Is to cultivate the plant so as to fall within the range. The object can be achieved by specifying the water retention amount of the above-mentioned plant cultivation substrate using the plant cultivation substrate.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The first invention of the present application uses a foam chip made of an open-cell polyurethane foam having a specific particle size as a plant cultivation substrate, and further cultivates the foam chip while maintaining a specific water retention amount using the foam chip. The present inventors have found that the present invention shows better growth than cultivation of plants using conventional fixed-form products, and have completed the present invention.
Although the reason is not clear, it is considered as follows.
In the case of open-celled polyurethane foam fixed-form products, if the emphasis is placed on the water retention performance, the air supply performance (air permeability) will decrease. Conversely, if the air supply performance is increased, the water retention performance will decrease. In the case of a foam chip, the air supply performance can be increased as well as the water retention performance. This is because even if the foam has a large water retention performance, it is possible to sufficiently form an air space in the gap between the foam chips by forming the chip into chips. As a result, plant growth may be caused by the fact that there is a part where the root is in contact with or penetrates the water-containing foam chip and a part that is not completely in contact with water, such as a gap between the foam chip and the foam chip. It is also thought to be related to.
The particle size of the open cell polyurethane foam chips of the present invention ranges from 0.2 mm to 25.0 mm. If it is 0.2 mm or less, it cannot be called a foam because it is smaller than the cell size, and it is not suitable for plant cultivation because it is almost impossible to form an air layer in a bubble portion such as a foam or a gap between foam chips. . On the other hand, if the particle size is 25.0 mm or more, the gap between the foam chips becomes large, and the water holding capacity per unit volume decreases, which is not suitable for plant cultivation.
Here, the open-celled polyurethane foam refers to a non-hydrophilized flexible polyurethane foam used for general-purpose mattresses or the like, or a hydrophilized soft polyurethane foam, a non-hydrophilized rigid foam used for a general-purpose heat insulating material, or the like. Insert all open cell polyurethane foam.
Using a foam chip made from the open-celled polyurethane foam having the specific particle size described above as a plant cultivation substrate, the water retention amount is 0.4 to 0.7 g / cm.³By setting to, it is not limited to industrially managed hydroponic cultivation method or simply seedling cultivation, it is possible to cultivate for a long time from sowing to withering with simple management like general soil .
[0013]
The water retention of the open-cell polyurethane foam chip (hereinafter sometimes referred to as a polyurethane foam chip or simply a foam chip) in the present application is measured as follows.
When the cultivation container is a pot or a planter, a polyurethane foam chip is put in the cultivation container, and the weight (G1) is measured. The cultivation container containing the polyurethane foam chip, which has been sprinkled with tap water from the upper surface for at least a sufficient amount of time and allowed to absorb water, is allowed to stand for 1 hour or more, and is allowed to water naturally, and the weight (G2) and height are measured. When water is released, the gap between the open-cell polyurethane foam chip and the foam chip becomes small and dense, and if the height decreases, the open-cell polyurethane foam from the reduced height after water release, not from the volume before watering Calculate the tip volume (V).
The water retention of the open-cell polyurethane foam chip is determined by the following equation.

When the cultivation container is large and cannot be weighed, or when the polyurethane foam chip is used as a plant cultivation base on a wide flat ground, for example, after watering, leave it for one hour or more, and then make a thin stainless steel 10 cm diameter. A tube having a height of 30 cm is inserted into the foam chip cultivation base, and a certain volume is taken out so as not to be spilled, and the weight (G2) is measured. Next, after completely removing the taken out foam chips, the weight (G1) of the foam chips may be measured and calculated according to the above formula.
However, the present invention is not limited to this measuring method, and the point is that the amount of water retained after being left for one hour or more may be measured.
The water retention during cultivation is calculated according to the method described above, and is calculated from the volume at the time of measurement and the weight of the hydrated foam.
[0014]
Furthermore, the second invention of the present application is a plant cultivation substrate having a particle size of 0.2 mm to 25.0 mm, in which the plant cultivation substrate is chipped from open-cell hydrophilic polyurethane satisfying the physical property conditions described below.
1) Density: 10kg / m³~ 100kg / m³
2) Elongation: 130% or less
3) Air permeability: 4cc / cm²/ Sec-400cc / cm²/ Sec
4) Compressive strength: 0.8 N / cm²~ 20N / cm²
5) Water suction height: 3 mm or more
[0015]
In the present invention, each physical property was calculated as follows.
The density, elongation, and air permeability were measured according to JIS K6400, and particularly the air permeability was measured at a thickness of 10 mm.
The compressive strength was measured as the stress when a sample having a length of 75 mm, a width of 75 mm and a height of 50 mm was compressed 50% in the height direction with a disk having a diameter of 20 cm using a testing machine used for measuring hardness according to JIS K6400.
The water suction height was set at a height of 20 mm, a width of 20 mm, and a height of 60 mm in a stainless steel vat having a length of 450 mm, a width of 350 mm and a depth of 20 mm, and distilled water was poured from the bottom of the vat to a height of 10 mm. It was measured as the water suction height above the water surface after standing for a period of time.
The water absorption time is 30 mm long, 30 mm wide, and 10 mm high on the surface of the sample.^1/4"The time required for a drop of distilled water to be completely absorbed into the support when a drop of distilled water was dropped with a syringe (manufactured by Nipple) (water drop method).
[0016]
Apparent density is 10kg / m³The open-celled hydrophilic polyurethane foam less than 10 kg lacks the supporting force to hold the seedlings, and 100 kg / m³Larger supports become overcrowded as the roots grow, resulting in an inadequate supply of oxygen and delayed growth. The apparent density is 10 kg / m in view of plant support and oxygen supply.³~ 100kg / m³Is preferred.
A support having an elongation of more than 130% does not satisfy the requirements of the present application because even if the foam chip is compressed and used, the plant has a lack of supportive force for holding the plant and cannot be fixed sufficiently due to slanting of the plant. In addition, a support having an elongation of 30% or less is more preferable from the viewpoint of plant support.
Air permeability is 4cc / cm²If the support is lower than / sec, the supply of oxygen is insufficient to inhibit the root growth, and when water or liquid fertilizer is sprinkled, the permeation into the open-celled hydrophilic polyurethane foam is delayed, which is not preferable.
Also 400cc / cm²When it is larger than / sec, the water holding capacity for holding water is lacking, and the supply of water tends to be insufficient.
The air permeability is 5 cc / cm, considering the balance between water retention and oxygen supply.²/ Sec-300cc / cm²/ Sec open cell hydrophilic polyurethane foam is more preferable, and more preferably 10 cc / cm.²/ Sec-200cc / cm²/ Sec is good.
[0017]
The 50% compressive strength of the open-cell hydrophilic polyurethane foam of the present invention is 0.8 N / cm.²~ 20.0N / cm²0.8 N / cm²In the following, lack of plant support is 20.0 N / cm²When it exceeds, not only is it difficult to form the foam into chips, but even if the foam is formed into chips, there are problems such as the original foam structure being broken and becoming powdery, resulting in reduced water retention.
50% compression hardness is 20.0 N / cm²In this case, the root of the plant hardly penetrates the cells of the open-celled hydrophilic polyurethane foam, and the root grows in the gap between the foam chips, so that the growth is slowed.
When the water suction height is 3 mm or less, the capillary action does not work sufficiently, and the water or liquid fertilizer is not sufficiently transmitted between the foam chips and the root cannot be uniformly supplied to the roots for a long time. .
If the water absorption rate is 10 seconds or more, the hydrophilicity is poor, and it is not easy to supply and hold water or liquid fertilizer to the polyurethane foam.
[0018]
The particle size of the open-cell hydrophilic polyurethane foam chips of the present invention is in the range of 0.2 mm to 25.0 mm. If it is 0.2 mm or less, it cannot be called a foam because it is smaller than the cell size, and it is not suitable for plant cultivation because it is almost impossible to form an air layer in a bubble portion such as a foam or a gap between foam chips. . On the other hand, if the particle size is 25.0 mm or more, the gap between the foam chips becomes large, and the water holding capacity per unit volume decreases, which is not suitable for plant cultivation.
Foam chips having a specific particle size made of hydrophilic polyurethane foam having the above-mentioned specific physical properties have excellent air permeability and water retention, and are suitable for plant cultivation regardless of the type of plant and without requiring special management. Most suitable as a substrate.
[0019]
In addition, even if it is the same open-cell polyurethane foam, the water retention performance of a regular-shaped product and a foam chip product is completely different. The same applies to the open-cell hydrophilic polyurethane foam. When used as a fixed product, the water retention performance is constant without being changed by the size of the fixed product. On the other hand, in the case of a foam chip, even with the same open-cell polyurethane foam, the water retention performance, that is, the water retention can be freely changed. Specifically, the water retention amount can be significantly changed depending on the particle size and shape of the foam chip and the degree of breakage of the bubbles.
In general, when the particle size is reduced, the gap between the foam chips becomes smaller and the foam weight per fixed volume increases (the bulk density increases), so that the water retention increases. Conversely, when the particle size increases, the space becomes smaller. And the weight of the foam per fixed volume decreases (the bulk density decreases), so that the water retention capacity decreases.
Further, since the bulk density changes depending on the shape of the foam chip, the amount of water retention also changes. Regarding the degree of breakage of air bubbles, generally, the breakage of air bubbles increases the bulk density and the water retention.
That is, even with the same open-celled polyurethane foam block or open-celled hydrophilic polyurethane foam block, various foam chips having different water retention amounts can be produced by changing the type of foam chip, for example, particle size, shape, etc. The amount of water retention can be further changed by mixing and using different types of foam chips having different particle sizes or shapes. This makes it possible to freely cope with the amount of water retention suitable for the type of plant.
[0020]
Here, specific examples in which various types of foam chips were prepared using a certain kind of open-cell hydrophilic foam and the water retention was measured.
Table 1 shows the physical properties of the open-cell hydrophilic foam before chipping, and Table 2 shows the water retention of various foam chips.
[0021]

1. After measuring the volume V, float it in distilled water at 25 ° C., pull it up 5 minutes later, leave it on a 5-mesh wire net for 1 hour, and measure the weight M2.

[0022]

Here, the chip 1 was formed in a dice shape with a cutter knife. The tip 2 was made with a rotary crusher (type PK-7 manufactured by Bizen Co., Ltd.). As can be seen from Table 2, even with the same open-cell hydrophilic polyurethane foam, the water retention varies greatly. Therefore, in actual cultivation, for example, the water holding capacity of the cultivated plant is 0.5 g / cm.³~ 0.7g / cm³If the water retention amount is optimal, the water retention amount is 0.7 g / cm no matter how much water is given if chip 2 is used.³Water content is 0.5 g / cm³If it is lowered, it can be cultivated so that water is given.
[0023]
In the present invention, when cultivating a plant by putting the open-cell hydrophilic polyurethane foam chip in a cultivation container, a pot or a planter having a bottom-absorbing type can be suitably used as the cultivation container.
There are also various types of bottom water absorption type, such as a type that supplies water directly to the lower side or a type that supplies water from the top and flows to the bottom to accumulate.
The lower bottom water is good for plants that prefer moisture by transferring water to the upper polyurethane foam chip by capillary action, using the foam chip itself as a water transporter through a cloth or the like. Growth is obtained.
Whether to use a common pot or planter or a bottom-absorbing pot or planter may be appropriately selected depending on the type of plant.
[0024]
In addition, using a cultivation method to grow at a specific water retention amount using the open-cell polyurethane foam chip of the present invention and a plant cultivation substrate chipped from open-cell hydrophilic polyurethane foam having specific physical properties, houseplants, In particular, mini houseplants can be suitably cultivated without special management.
These houseplants include, for example, dracaenas, pothos, pyreas, ivy and the like.
[0025]
The above-described open-cell polyurethane foam chip of the present invention, and a plant cultivation substrate comprising the open-cell hydrophilic polyurethane foam chip can be used alone, but also a mixture of other plant cultivation substrates and the like can be used. it can.
The cultivation base for the other plant is natural soil, fibrous material or SiO.₂And the like. Natural soils include soil, sand, gravels, vermiculite, and the like. Fibrous materials include bark such as palms, peat moss, mulch, pulp, and SiO.₂Examples of the system foam include perlite, isolite, and shirasu balloon, but are not limited thereto.
In particular, open-cell polyurethane foam chips having poor hydrophilicity are preferably cultivated by mixing the above-mentioned other plant cultivation substrates. In the case of open-celled polyurethane foam chips having too high hydrophilicity, it is preferable to mix the above-mentioned other plant cultivation bases for cultivation.
It is also within the scope of the present invention to mix these open-celled polyurethane foams with cultivation substrates of other plants.
[0026]
As a method for producing the open-cell hydrophilic polyurethane foam constituting the plant cultivation substrate of the present invention, a conventionally known production method can be used.
The open-celled hydrophilic polyurethane foam mainly includes a polyurethane foam foamed at a low index of 1.0 or less, a polyurethane foam foamed at a normal index of 1.0 to 1.1, and an isocyanate index of 1.0 to 1.1. Examples include polyurethane foams containing isocyanurate linkages greater than 1.0.
The former is described in detail in JP-A-46-741, JP-A-48-25098, JP-A-49-97897, JP-A-2-14209, and JP-A-9-32853. Specifically, a polyurethane foam is produced by mainly using an oxyethylene-containing polyoxyalkylene ether polyol as the polyol. This is a method for producing a polyurethane foam that has been hydrophilized and made into open cells by leaving OH groups.
Here, the isocyanate index is a ratio of NCO / OH determined from the equivalent of the terminal hydroxyl group (-OH) in the polyurethane foam and the equivalent of the isocyanate group (-NCO) in the isocyanate.
[0027]
Patents having an isocyanate index of 1.0 to 1.1 include JP-A-50-151466 and JP-A-54-10108.
The polyurethane foam having an isocyanurate bond having an isocyanate index larger than 1.0 is described in detail in JP-A-11-193320. Specifically, a high oxyethylene-containing polyoxyalkylene ether polyol is mainly used as the polyol, and the isocyanate index is set to be larger than 1.0 and, for example, the polyoxyalkylene glycol terminal OH group is a compound having no active hydrogen. This is a method in which a capped hydrophilic plasticizer is used in combination, and is a method for producing a polyurethane foam containing an isocyanurate bond that has been hydrophilized and is open-celled.
The polyurethane foam before chipping can be manufactured using a conventionally known manufacturing apparatus such as a general polyurethane foam block manufacturing machine or a polyurethane foam mold manufacturing machine.
[0028]
In the present invention, after the open-cell polyurethane foam and the open-cell hydrophilic polyurethane foam block are manufactured, they are granulated by using a chipping machine, but many types of machines are used as the chipping machine. Can be. For example, there are a rotary cutter method and an extruder method. Various facilities for chipping general flexible polyurethane foam can also be used.
[0029]
Next, the cultivation mode of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a sectional view showing a state where a seedling 3 is planted in a pot 1 using a plant cultivation substrate 2 of the present invention comprising an open-cell hydrophilic polyurethane foam chip of the present invention. First, the plant cultivation base 2 of the present invention is put into the pot 1 in about 1/3 volume, and then the seedling 3 is put in the pot 1 in a standing state, and the plant cultivation base 2 of the present invention is further added to the pot 1. When tap water is sprinkled from the upper surface for about 10 minutes in this state, the height of the plant cultivation substrate 2 of the present invention decreases. Further, the plant cultivation substrate 2 of the present invention is added, and watering is repeated until the pot 1 reaches about 8 minutes. During this time, the seedlings 3 are slightly lifted so that the roots 4 of the seedlings spread in the plant cultivation substrate 2 of the present invention. After that, water is sprayed from the top surface once every two to three days, and the water retention amount is always 0.4 to 0.7 g / cm.³Cultivation is carried out so as to maintain
Here, when the open-cell polyurethane foam chip is used, the number of times of watering is increased, or peat moss having a large water-holding property is blended, and the water-holding amount is always 0.4 to 2 times every three days. ~ 0.7g / cm³The cultivation may be carried out in such a way as to keep
[0030]
FIG. 2 is a sectional view showing a state in which seedlings 3 are planted in a bottom water-absorbing pot 5 using a plant cultivation substrate 2 made of the open-cell hydrophilic polyurethane foam chip of the present invention. The method of planting a seedling 3 using the plant cultivation substrate 2 of the present invention is the same as that of FIG. In the pot 5, the supply of water and liquid fertilizer is supplied to the lower bottom portion 51, the water or liquid fertilizer 6 is held in the lower bottom 51, and is transmitted to the plant cultivation substrate 2 of the present invention by the capillary action through the cloth 7 and the roots of the seedlings. It is transmitted to the seedling body through 4.
[0031]
【Example】
Hereinafter, the production of the polyurethane foam and examples will be further described.
Preparation of open-cell hydrophilic polyurethane foam block-1
100 parts by weight of a polyether polyol having a molecular weight of 3400 obtained by randomly polymerizing glycerin with ethylene oxide and propylene oxide at a weight ratio of 80/20, 7.5 parts by weight of water, tris (dimethylaminopropyl) hexahydro S-triazine 2 0.0 parts, a polysiloxane-polyoxyalkylene copolymer (dimethylsiloxane unit 20, oxyalkylene-added methylsiloxane unit 1.1, the weight ratio of oxyethylene and oxypropylene in the polyoxyalkylene chain was 80/20, The alkylene terminal group has a methoxy or polyoxyalkylene molecular weight of 1300) 6 parts, the nonionic surfactant ionet DO-600 (manufactured by Sanyo Chemical Industries) 85 parts by weight, and the anionic surfactant Newcol 271S (manufactured by Nippon Emulsifier) 16 parts by weight. Part, carbonated After calcium thoroughly stirred and mixed to 20 parts by weight, to obtain a polyurethane foam containing polyisocyanurate groups further added and stirred 370 parts of crude MDI.
Table 3 shows the physical properties of the foam.
[0032]
Preparation of open-cell hydrophilic polyurethane foam-2
The NCO of the prepolymer was prepared by adding tolylene diisocyanate (T-80) to polyol 100 having a molecular weight of 3,000 in which ethylene oxide and propylene oxide were added to glycerin in a 93/7 weight ratio to synthesize a prepolymer having a terminal NCO group. % Was 6.9%. 80 g of calcium carbonate and 60 g of water were added to 118 g of the prepolymer, followed by stirring and mixing to obtain a foam.
Table 3 shows the physical properties of the foam.
[0033]
Preparation of open-cell general-purpose polyurethane foam
A general-purpose flexible polyurethane foam was obtained from a polyol having a molecular weight of 3,000 obtained by addition polymerization of glycerin with ethylene oxide / propylene oxide at a weight ratio of 8/92 and tolylene diisocyanate (ratio of 2.4 / 2.6 is 80/20). . Table 3 shows the physical properties of the polyurethane foam.
[0034]

[0035]
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
Embodiment 1
The open-cell hydrophilic polyurethane foam-1 shown in Table 3 was applied to a rotary crusher (type PKS-7 manufactured by Bizen Co., Ltd.) to produce an irregular shaped chip having a chip length of 20 mm or less. The water retention of this foam chip is 0.65 g / cm³Met. This foam chip was put in the pot shown in FIG. 1, and planted with symnium by the method shown in FIG. 1, and sprinkled with tap water from the upper surface for 10 minutes. When solid fertilizer was placed on the upper surface, water was supplied from the upper surface, and cultivation was performed for 2 months, favorable growth was observed. The amount of water retained 1 hour after planting was about 0.60 g / cm, calculated from the volume of the pot and the weight of the open-cell hydrophilic polyurethane foam-1 used.³Met. After that, once every 3 days, water is sprayed from the upper surface and the water retention after 1 hour or more has passed is always 0.42 g / cm.³~ 0.67g / cm³, Showed good growth. Even if the amount of watering is increased, the water retention is 0.67 g / cm.³It didn't go any further.
[0036]
Embodiment 2
The open-cell hydrophilic polyurethane foam-2 shown in Table 3 was applied to a urethane chip manufacturing machine (SK-300 manufactured by Iwamoto Cotton Machine Co., Ltd.) to produce irregular shaped chips having a chip length of 20 mm or less. The water retention of this foam chip is about 0.58 g / cm³Met.
The foam chip was placed in the pot shown in FIG. 2 and Abyss was planted by the method shown in FIG. 2, and water and liquid fertilizer were applied from the lower surface.
It was good when cultivated.
When the amount of water retention one hour after planting was examined in the same manner as in Example 1, the water retention was about 0.55 g / cm.³And the water retention is always 0.45 g / cm³~ 0.66 g / cm³The range was stable.
[0037]
[Comparative Example 1]
The general-purpose polyurethane foam chips shown in Table 3 were placed in the pots shown in Example 1, and a method of planting a symgonium by the method of FIG. However, since the polyurethane foam does not readily absorb water, the polyurethane foam chip is unavoidably placed in another container, and the polyurethane chip is forcibly repeatedly compressed / released by hand to absorb water. Planted Singonium by the method.
Due to the low compression hardness and high elongation of the polyurethane foam, the supporting force was low and it was difficult to plant vertically.
Water holding capacity 1 hour after planting is 0.28 g / cm³Met. Thereafter, water was sprinkled from the upper surface once a day, but the water retention gradually decreased to 0.22 g / cm after 6 days.³0.18 g / cm after 12 days³0.16g / cm after 18 days³0.15g / cm after 24 days³0.14g / cm after 30 days³It became. From this, it is considered that watering every day hardly absorbed or retained water in the foam, and only forced initial water retention was absorbed by the plants.
The planted Singonium did not grow at all and was almost dead after one month.
[0038]
[Comparative Example 2]
Singonium was planted under exactly the same conditions as in Example 1.
After that, without watering for 2 weeks, the water retention was 0.37 g / cm.³To 0.25 g / cm for one month³~ 0.38g / cm³After cultivation for 2 months with no growth, there was no growth at all and some strains of Symgonium were slightly smaller.
[0039]
【The invention's effect】
When cultivating a plant using the plant cultivation base composed of open-cell polyurethane foam chips having a particle diameter of 0.2 mm to 25.0 mm according to the present invention, the plant cultivation base composed of the open-cell polyurethane foam chips is maintained. 0.4 to 0.7 g / cm of water³By using the plant cultivation method, the wide variety of plants can be cultivated in the same manner as general soil, and there is no disease and insect damage from the soil, and continuous cropping is possible.
Further, by using a plant cultivation substrate having a specific particle size chipped from the open-celled hydrophilic polyurethane foam having the specific physical properties of the present invention, the water retention can be increased to 0.4 to 0.7 g / without any special management. cm³Can be adjusted to
Polyurethane suitable for cultivation of plants that can be used for a long period from seeding to withering even in general households and the like is not limited to industrially managed hydroponics or cultivation by industrial management such as seedlings. A cultivation method using a foam and a polyurethane foam chip can be provided.
In addition, it can be used as a plant cultivation base for rooftop greening that requires lightness, and can be used as a plant cultivation base for house, etc., instead of rock wool that requires industrial waste treatment. It can also be used as an indoor ornamental plant cultivation base from sowing to withering in ordinary households.
In particular, when used indoors for ornamental use, no soil is used, so that it can be cultivated cleanly.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a plant is planted in a pot using a plant cultivation base comprising an open-cell hydrophilic polyurethane foam chip of the present invention.
FIG. 2 is a cross-sectional view showing a state in which a plant is planted in a bottom water-absorbing pot using a plant cultivation base comprising the open-cell hydrophilic polyurethane foam chip of the present invention.
[Explanation of symbols]
1. Bowl
2. Plant cultivation substrate
3. Seedling
4. Seedling root
5. Bottom water absorption bowl
51. Bottom bottom
6. Retain water or liquid fertilizer
7. cloth

Claims (6)

When cultivating a plant using a plant cultivation substrate composed of open-celled polyurethane foam chips having a particle size of mainly 0.2 mm to 25.0 mm, the water retention of the plant cultivation substrate composed of the open-celled polyurethane foam chips is set to 0. A plant cultivation method characterized by cultivating the plant so as to have a concentration of 4 to 0.7 g / cm ³ . As physical properties of the polyurethane foam, density of ^{10kg / m 3 ~100kg / m 3} , 130% elongation or less, air permeability ^{4cc / cm 2 / sec~400cc / cm} 2 / sec, compression strength 0.8N ^/ cm 2 ~20N / Cm ² , a water suction height of 3 mm or more, and a water absorption rate of 10 seconds or less Open-cell hydrophilic polyurethane foam chipped from an open-cell hydrophilic polyurethane foam having a particle size of about 0.2 mm to 25.0 mm Polyurethane foam chip plant cultivation substrate. When cultivating a plant by putting the open-cell hydrophilic polyurethane foam chip plant cultivation base in a cultivation container, the cultivation container is a bottom-absorbing pot or planter, and a water component is put into a lower bottom to perform a capillary action. Cultivating a plant by transferring a water component to the upper open-cell hydrophilic polyurethane foam chip by using the above, so that the water holding capacity of the plant cultivation substrate becomes 0.4 to 0.7 g / cm ^3. The method for cultivating a plant according to claim 1. The method for cultivating a plant according to any one of claims 1 or 3, wherein the plant is a houseplant in cultivating the plant. The method for cultivating a plant according to claim 1, wherein the open-cell hydrophilic polyurethane foam chip according to claim 2 is used as a plant cultivation substrate comprising the open-cell polyurethane foam chip. The method for cultivating a plant according to claim 4, wherein the open-cell hydrophilic polyurethane foam chip according to claim 2 is used as a plant cultivation substrate when cultivating the houseplant.

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