JP3903272B2

JP3903272B2 - Seedling method

Info

Publication number: JP3903272B2
Application number: JP36227297A
Authority: JP
Inventors: 藤芳廣斎
Original assignee: Hokuetsu Paper Mills Ltd
Current assignee: Hokuetsu Paper Mills Ltd
Priority date: 1997-12-12
Filing date: 1997-12-12
Publication date: 2007-04-11
Anticipated expiration: 2017-12-12
Also published as: JPH11168987A

Description

【０００１】
【発明の属する技術分野】
本発明は、育苗方法に関し、さらに詳しくは、優れた植物育成適性と良好な育苗作業性を確保しつつ、本田に移植後の追肥作業を省略あるいは軽減でき、育苗から収穫に至るまでの一連の作業の効率化を図ることのできる合理的かつ効率的な育苗方法に関する。
【０００２】
【従来の技術】
現在、水稲の育苗方法は、育苗箱に培土を床土として入れ、灌水した後に播種し、覆土し、出芽、緑化し、稚苗段階で田植機によって本田に移植するのが一般的な方法であるが、一部に、本田移植後の追肥作業の軽減を目的に、育苗時に育苗期間に必要となる量の肥料のみならず、本田移植から収穫までに必要となる量の全部または大部分の肥料分を緩効性肥料などを用いて配合しておく方法が行われている。なお、以下においてかかる育苗時に育苗期間に必要となる量の肥料のみならず、本田移植から収穫までに必要となる量の全部または大部分の肥料分を配合しておく方法のことを育苗箱多量施肥育苗法と言うことがある。
【０００３】
【発明が解決しようとする課題】
しかし、育苗箱多量施肥育苗法においては、育苗箱への肥料配合量が多量となるため、配合し得る正味の培土分が少なくなり、根張りが不十分となりやすく、マット形成が悪化しやすくなる。マット形成が不良となると、マットを育苗箱から取り上げ田植機に装着する際にマットが形くずれしたりばらけたりして作業が困難となる。こういった問題があるために、育苗箱多量施肥育苗法の普及率はまだきわめて低くごく限られた地域でしか実施されていないのが現状である。よって、育苗箱多量施肥育苗法でのマット形成不良による田植機への装着時の支障等を解決できるような育苗方法の出現が強く求められていた。
【０００４】
本発明者は、育苗箱多量施肥育苗法を実施するに際して、何らかの補強シートを下敷きすることにより上記課題を解決できないものかと検討した。かかる目的の補強シートとして参考になりそうなものとして、近年、繊維素系あるいは無機繊維系の各種合成培地マットが開発されているが、かかる合成培地マットは根の食い込みを良くし根上りを防止するために、ごく少量のバインダーによる乾式法により製造されるものがほとんどであり、低密度で、かつ強度も著しく弱く、マット補強という機能を十分に発現できるものは見あたらない。
【０００５】
一方、湿式抄造によるものは、一般に繊維間結合が強くなりやすく、根の貫通できるようなマットを得ることは困難なためほとんどなかったが、先般、本発明者は特定の高吸水性樹脂を繊維間隙に均一に散在せしめ、吸水時に該高吸水性樹脂が吸水膨張して繊維間結合を破断または弛緩するようにすることにより根の貫通適性を確保できることを提案した。
【０００６】
しかし、吸水膨張した状態の高吸水性樹脂を含有する原料スラリーによる抄造は、抄造網に吸水膨張状態の高吸水性樹脂が付着しやすいなど製造工程上の問題が発生することがあるとともに、吸水時のシートはきわめて弱くなり、場合によってはマット補強力が不足することもある。
このように、現状では、目的に合致する補強シートとして使用できるもの、あるいは、それを示唆するようなものは見出せない。
【０００７】
そこで、本発明者は、育苗箱多量施肥育苗法でのマット形成不良による田植機への装着時の支障等を防止するのに効果的な補強シートを得るべく、熟慮のすえ、特にバインダーを使わずとも繊維間結合（水素結合）という結合力によりシート形成できるセルロース系繊維による湿式抄造の利点を活かしつつ、根が貫通できるように、その繊維間結合を可能な限り弱めるにはどうすればよいかという観点から、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維の検討を進めた。
【０００８】
かかるセルロース系繊維はほとんど繊維間結合力を有さないか有しても非常に繊維間結合力が弱いものであるため、抄造性が悪く通常それ単体で抄造できるものではなく、薬品処理による解質あるいは叩解等を施して、ある程度の繊維間結合力を付与せしめてからでないと抄造には適用されないものである。
【０００９】
しかして、本発明者は、あえて、かかる抄造には不向きな素材をできるだけそのままの形態で用いて抄造する技術を指向して検討を重ねた結果、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を高含有するシートを形成せしめ、厚さ及び密度を所定範囲とし、さらに親水化処理を施し、所定の湿潤条件下の湿潤引張強度と湿潤裂断長を特定範囲とすることにより、育苗箱多量施肥育苗法に際し、下敷きとして利用した場合に、根の貫通適性とマット補強という相反する機能を両立できること、すなわち、かかる方法で育苗すれば、根の貫通性が良好であると同時に、田植機への装着時に、たとえ根張りが少なくマット形成が不良でも下敷シートの補強効果によって支障なく作業できること等をつきとめ本発明を完成した。
【００１０】
本発明の目的は、優れた植物育成適性と良好な育苗作業性を確保しつつ、本田移植後の追肥作業を省略あるいは軽減でき、育苗から収穫までの一連の作業の効率化を図ることのできる合理的かつ効率的な育苗方法を提供することにある。
【００１１】
【課題を解決するための手段】
本発明の育苗方法は、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース繊維を５０〜９０重量％含有する親水化処理シートであって、該シートの厚さが０．８〜５ｍｍ、密度が０．１〜０．５ｇ／ｃｍ³ であり、かつ２０℃の蒸留水に５分間浸漬後の該シートの繊維配向方向及びこれと直角をなす方向について測定して両者の平均を求めた湿潤引張強度（ＪＩＳＰ−８１１３に基づく測定）及び湿潤裂断長（ＪＩＳＰ−８１１３に基づく測定）のそれぞれは該湿潤引張強度が０．２〜１．０ｋｇ／１５ｍｍ幅で、該湿潤裂断長が０．０２〜０．１ｋｍからなる補強シートを作成し、該補強シートを育苗箱に敷き、該補強シートの上に、少なくとも育苗期間に必要となる量の肥料及び本田に移植してから収穫までに必要となる量の全部または大部分の肥料分を供給せしめるようにした後に播種して苗を育成するようにしたものである。
【００１２】
また請求項１記載の育苗方法にあっては、前記補強シートの上には育苗期間に必要となる量の肥料及び本田に移植してから収穫までに必要となる量の全部または大部分の肥料分を供給せしめるにあたり、培土あるいは合成培地とともに供給せしめるようにしてもよい。
さらに請求項１記載の育苗方法は播種後の苗が乳苗段階あるいは稚苗段階において本田に移植するようにしてもよい。
【００１３】
本発明の育苗方法は、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース繊維を５０〜９０重量％含有する親水化処理シートであって、該シートの厚さが０．８〜５ｍｍ、密度が０．１〜０．５ｇ／ｃｍ³ であり、かつ２０℃の蒸留水に５分間浸漬後の該シートの繊維配向方向及びこれと直角をなす方向について測定して両者の平均を求めた湿潤引張強度（ＪＩＳＰ−８１１３に基づく測定）及び湿潤裂断長（ＪＩＳＰ−８１１３に基づく測定）のそれぞれは該湿潤引張強度が０．２〜１．０ｋｇ／１５ｍｍ幅で、該湿潤裂断長が０．０２〜０．１ｋｍからなる補強シートを作成し、該補強シートを育苗箱に敷き、該補強シートの上に、培土あるいは合成培地とともに、育苗期間に必要となる量の肥料のみならず、本田に移植してから収穫までに必要となる量の全部または大部分の肥料分を供給せしめてから、灌水した後に播種し、覆土し、出芽し、緑化し、乳苗段階あるいは稚苗段階において本田に移植するようにしたものである。
【００１４】
本発明の育苗方法に用いる補強シートは、化学処理を受けておらず、実質的にフィブリル化されていないセルロース系繊維を５０〜９０重量％、好ましくは６０〜８０重量％含有しなければならない。該含有率が５０重量％未満では根の貫通に支障が出て、根上りを発生しやすくなる。反対に９０重量％を超えた場合は、抄造性が悪化するとともに、得られるシートの強度が弱すぎ十分なマット補強効果を得ることができない。
化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維としては、木材粉砕物、木質系繊維化物等の各種木材繊維あるいは機械パルプのごとき化学処理を受けていない木材パルプ等を使用できる。
【００１５】
また、本発明の育苗方法に用いる補強シートにおいては、所定のシート強度を得るために、上記した化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維以外のセルロース系繊維を併用するのが望ましい。かかるセルロース系繊維としては、針葉樹系あるいは広葉樹系の化学パルプ、セミケミカルパルプ等の木材パルプあるいは各種古紙、バガス、ワラ、リンターなどの中から選ばれる１種類もしくは２種類以上を併用して使用することができる。かかるセルロース系繊維の本発明に係る育苗シート中における含有率は５〜４０重量％とするのが好ましい。該含有率が５重量％未満では所定のシート強度が得られないことがあり得る。反対に４０重量％を超えた場合は、シート強度が強くなり過ぎ、根の貫通性に支障が出て根上りを生ずることがあり得る。
【００１６】
本発明の育苗方法に用いる補強シートの厚さは、０．８〜５ｍｍ、好ましくは１．５〜３ｍｍでなければならない。該厚さが０．８ｍｍ未満では強度が不足し、十分なマット補強効果を得ることができない。反対に５ｍｍを超えた場合は、根の貫通性に支障が出て根上りを生じやすくなる。
本発明の育苗方法に用いる補強シートの密度は、０．１〜０．５ｇ／ｃｍ³ 、好ましくは０．１５〜０．４ｇ／ｃｍ³ でなければならない。該密度が０．１ｇ／ｃｍ³ 未満ではシート強度が弱すぎ十分なマット補強効果が得られない。反対に０．５ｇ／ｃｍ³ を超えた場合は、根の食い込みが悪化し、根上りを生じやすくなる。
【００１７】
本発明の育苗方法に用いる補強シートは親水化処理を施さなければならない。該補強シートは化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を高含有しているため、親水化処理を施さないと補強シートとして必要な吸水性を確保することができない。
親水化処理は特に限定するものではなく、スルホン酸型、カルボン酸型、りん酸エステル型、硫酸エステル型、第四級アンモニウム塩型等の各種界面活性剤あるいは高級アルコール類、多価アルコール類、シリコン系親水化剤、ＰＶＡ系親水化剤などの親水性付与剤を内添したり含浸もしくは塗布するなどすればよい。また、かかる親水性付与剤の添加量は特に限定されるものではないが、重要なことはシートの湿潤引張強度と湿潤裂断長が本発明で特定する範囲内となるような添加量とする必要がある。
【００１８】
本発明の育苗方法に用いる補強シートを２０℃の蒸留水中に５分間浸漬した後に、ＪＩＳＰ−８１１３に基づいて測定した湿潤引張強度は、繊維配向方向と直角をなす方向の平均で０．２〜１．０ｋｇ／１５ｍｍ幅、好ましくは０．３〜０．７ｋｇ／１５ｍｍ幅でなければならない。また、該湿潤引張強度から求めた湿潤裂断長は０．０２〜０．１ｋｍ、好ましくは０．０３〜０．０７ｋｍでなければならない。前記した湿潤引張強度が０．２ｋｇ／１５ｍｍ幅未満もしくは前記した湿潤裂断長が０．０２ｋｍ未満のときは、十分なマット補強効果が得られず、根張りの少ないときにマットを取り上げる際に補強シートが破断するなどの支障を来しやすい。反対に前記した湿潤引張強度が１．０ｋｇ／１５ｍｍ幅を超える、もしくは前記した湿潤裂断長が０．１ｋｍを超える場合は、根の食い込みが悪化し、根上りを生じやすくなる。
【００１９】
本発明の育苗方法に用いる補強シートは、上述したように化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を高含有せしめ、親水化処理を施し、かつ厚さ、密度、湿潤引張強度及び湿潤裂断長をそれぞれ所定範囲とすることにより、根の貫通適性とマット補強力を併せ持たせたものであるが、クレー、タルクなどの無機填料あるいはロックウール繊維、ガラス繊維、セラミック繊維などの無機繊維を配合することにより、さらに繊維間結合を弱めて根の貫通性を向上せしめることができる。
【００２０】
また、必要に応じて各種合成樹脂ラテックス等のバインダーの類を配合してもよいが、この場合、根の貫通性等を阻害しないように、その添加量をごく少量に抑えるべきことは当然である。
さらに、必要に応じて、硫安、塩安、尿素等の窒素系肥料、あるいは硫酸カリ、塩化カリ等のカリ系肥料もしくは過リン酸石灰、リン安等のリン酸系肥料などを配合したり、硫酸、クエン酸、フミン酸、ニトロフミン酸、ピートモス等のＰＨ調整剤及び防カビ剤等を配合してもよい。
なお、湿式抄造で内添により肥料を配合する場合、水に溶けにくい粉体状の緩効性肥料を用いるのがより効果的である。
【００２１】
本発明の育苗方法に用いる補強シートを製造するには、乾式成形によってもよいが、湿式抄造によるのがより好ましい。乾式成形の場合、十分なマット補強効果を発現するに足るシート強度を得るには、各種合成樹脂ラテックス等のバインダーの類を相応量配合することが不可欠となり、根の貫通適性とマット補強力とを両立させることがかなり難しくなる場合があり得る。これに対し、湿式抄造の場合、必ずしも前記したバインダーの類を使わなくとも、抄造過程で成生するセルロース系繊維同志の水素結合による繊維間結合でもって、十分なマット補強効果を発現するに足るシート強度を得ることができるので、根の貫通適性とマット補強力とを両立させることができる。
【００２２】
ここでは、湿式抄造により本発明の育苗方法に用いる補強シートを製造する場合について、さらに説明する。
すなわち、本発明の育苗シートを湿式抄造で製造するには、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を所定量含有する原料スラリーを調成し、通常の抄造法により抄造すればよい。そして、前記した各種親水性付与剤を原料スラリー中に内添するか、シートを形成せしめてから含浸もしくは塗布するなどして親水化処理を施せばよい。
【００２３】
また、必要に応じて叩解処理を施してもよいが、原料スラリー中の化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維をかかる状態に維持し、繊維間結合力を発現しにくい状態を保たねばならない。従って、実質的にフィブリル化の起こらないごく弱い条件で叩解するか、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維の処理を別経路とし、かかるセルロース系繊維は叩解しないで使用する等の工夫が必要である。抄造については、通常の長網、円網あるいは傾斜網等の抄造網上に原料スラリーを供給し、濾過、脱水した後、圧搾・乾燥すればよい。また、必要に応じて各種コンビネーション網や多槽円網あるいは各種ラミネーターなどにより、紙層を２層以上重ね合わせてもよい。なお、圧搾条件はできるだけ弱くして、紙層を極力かさ高にした方が本発明の育苗方法に用いる補強シートとしては好適なものを得やすい。
【００２４】
つぎに本発明の育苗方法に用いる培土あるいは肥料について説明する。
培土としては、市販の土壌系資材あるいは、減菌した土壌に肥料を配合し、ＰＨ調整して農家が自前で調整した培土材等の通常の育苗で使用される培土資材を使用することができる。培土は必要に応じて使用することができる。また培土に代えて合成培地を使用することもできる。
肥料としては、育苗期間中に効果を発現する速効性肥料と本田移植後に効果を発現する緩効性肥料を併用する。
速効性の肥料の運用については、従来慣用の乳苗育苗あるいは、稚苗育苗の場合のそれに従えばよい。すなわち、必要に応じて、硫安、塩安、尿素等の窒素系肥料、あるいは硫酸カリ、塩化カリ等のカリ系肥料、もしくは過リン酸石灰、リン安等のリン酸系肥料などの所定量を培土あるいは補強シートに配合せしめればよい。
【００２５】
前記した緩効性肥料としては、硫安、塩安、硝安、尿素、硝酸カルシウム等の窒素系肥料、あるいは硫酸カリ、塩化カリ、硝酸カリ等のカリ系肥料、もしくは過リン酸石灰、リン安、リン酸カルシウム等のリン酸系肥料等の群から選ばれた１種類または２種類以上の肥料からなる粒状物を被膜で被覆し、物理的に成分溶出速度が調節された被覆緩効性肥料、またはこれらの混合物、あるいはイソブチルアルデヒド加工尿素肥料、アセトアルデヒド加工尿素肥料、ホルムアルデヒド加工尿素肥料、硫酸グアニル尿素、オキサミド等の化学合成緩効性肥料の粒状物からなる群より選ばれた１種類または２種類以上の肥料またはこれらを被覆した肥料もしくはそれらの肥料の混合物を用いることができる。
特に、窒素系肥料の育苗箱多量施肥育苗法には、シグモイドタイプの被覆緩効性肥料が好適である。
【００２６】
施肥量は、肥料の種類により異なるが、たとえば窒素系肥料の育苗箱多量施肥の場合、窒素分で育苗箱当り２００〜２４０ｇ程度、すなわち、一般的な窒素含有率約４０重量％のシグモイドタイプの被覆緩効性肥料で育苗箱当り５００〜６００ｇ程度となる。ただし、目的とする本田移植後の追肥作業の省略あるいは軽減の程度によって施肥量を加減すればよいのは当然である。
【００２７】
本発明の育苗方法における本田移植後に効果を発現する緩効性肥料の育苗箱への施肥方法は、培土と該緩効性肥料を混合してから施肥する方法と培土と該緩効性肥料をそれぞれ層状に施肥する方法のいずれでもよいが、層状施肥の方が育苗準備作業の一連の工程に施肥作業を１工程導入するだけでよく、かつ、培土との混合に労力をかける必要もないことからより効果的である。また、層状施肥の場合、種子が前記した緩効性肥料と接触するように播種することにより、根が該緩効性肥料を捕捉しやすく、本田移植時に、より多くの緩効性肥料が本田に持ち込まれることになるとともに持ち込まれた緩効性肥料は根の近傍に位置することになるので一段と施肥効率が高まる。
【００２８】
灌水は下敷きした育苗シートが十分に湿潤するよう十分に（育苗箱当り約１リットル）与えるのが望ましい。
播種量は育苗箱当り、稚苗育苗の場合１６０〜１８０ｇ（乾籾）、乳苗育苗の場合２００〜２５０ｇ（乾籾）とするのが望ましい。
覆土、出芽、緑化は常法によればよく、乳苗育苗の場合は５〜７日の育苗期間で、また、稚苗育苗の場合は約３週間の育苗期間で本田への移植ができる。
本田への移植も常法に従えばよい。
【００２９】
【作用】
本発明の育苗方法の特徴は、根の貫通適性と田植機装着時のマット補強という今まで両立が困難であった機能を併せ持たせた補強シートを用いることにより、育苗箱多量施肥育苗法でのマット形成不良による田植機への装着時の支障等を解決できた点にある。
本発明の育苗方法に用いる補強シートの、根の貫通適性とマット補強力の発現機構の詳細については未だ不明であるが、以下において、本発明者が考察している内容を記す。
【００３０】
まず、根の貫通適性の発現について考察する。本発明の育苗方法に用いる補強シートは、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を高含有しているので、シートを構成する繊維同志の繊維間結合はかなり弱い。加えて、本発明の育苗方法に用いる補強シートは密度が０．１〜０．５ｇ／ｃｍ³ と非常にかさ高で、かつ親水化処理が施されている。
従って、育苗箱に本発明に係る補強シートを敷き、該補強シートの上に育苗期間に必要となる量の肥料のみならず、本田移植から収穫までに必要となる量の全部または大部分の肥料分を含有するように調整した培土を入れた後に十分に灌水した場合、この灌水は前記した培土を通過して補強シートに到達すると速やかに補強シートに吸収される。
その結果、補強シートは十分に湿潤し、保水するとともにその強度は一段と低下する。
【００３１】
本発明の育苗方法に用いる補強シートの湿潤裂断長は０．０２〜０．１ｋｍであり、これは通常の木材パルプによるシートの最も弱いレベルのものと比べてもさらにその数分の１から１／１０程度ときわめて弱い強度である。このように、湿潤時にきわめて強度が低下する。すなわち、繊維間結合がきわめて弱くなるため、前記した培土からなる層を進んできた根は０．８〜５ｍｍ厚の本発明の育苗方法に用いる補強シート中の繊維間結合を押し分けて食い込み、貫通することができる。
【００３２】
つぎに、マット補強力の発現について考察する。
上述したように、本発明の育苗方法に用いる補強シートの湿潤裂断長はきわめて弱く、このために根が貫通できるのであるが、本発明の育苗方法に用いる補強シートは０．８〜５ｍｍの厚さを有するのでシートの湿潤引張強度は０．２〜１．０ｋｇ／１５ｍｍ幅である。この０．２〜１．０ｋｇ／１５ｍｍ幅という湿潤引張強度について考察する。比較のために、ここで市販の床土の下敷用育苗シートと床土代替用合成培地マットの強度について述べる。後述するように（比較例７）、たとえば、市販の床土の下敷用の高吸水性樹脂担持パルプ系育苗シートについて見ると、常態での引張強度は０．４４４ｋｇ／１５ｍｍ幅であり、２０℃蒸留水５分浸漬時の引張強度はシートがくずれてしまって測定不能であり事実上強度なしである。
【００３３】
従って、実際に前記した培土の下敷きとして使用し、通常の育苗条件で湿潤している状態ではシート強度がほとんどなくなりマット補強力はないものと考えられる。また、市販の厚さ１８ｍｍの無機繊維系合成培地マットについて同様にシート強度を測定すると、常態での引張強度は０．２０４ｋｇ／１５ｍｍ幅であり、２０℃蒸留水５分浸漬後の引張強度は０．０８８ｋｇ／１５ｍｍ幅である。
従って、本発明の育苗方法に用いる補強シートの２０℃蒸留水５分浸漬後の引張強度０．２〜１．０ｋｇ／１５ｍｍ幅は、厚さ１８ｍｍもある無機繊維系合成培地マットのそれの２．３〜１１．４倍も強いのである。
よって、この優れた湿潤引張強度により、本発明の育苗方法に用いる補強シートに固有なマット補強力が発現し、たとえ根張りが少なく、マット形成が不良でも、かかる補強シートが下支えになってマットを補強するため、支障なく田植機に装着できるというきわめて有益な特性が発現するのである。
【００３４】
【実施例】
次に、本発明を以下の実施例に基づいてさらに具体的に説明する。
本実施例中各項目の測定は次の方法によった。
▲１▼ シートの厚さ：ＪＩＳＰ−８１１８
▲２▼ シートの密度：ＪＩＳＰ−８１１８
▲３▼ シートの引張強度：ＪＩＳＰ−８１１３（ただし、繊維配向方向とこれと直角をなす方向について測定し、両者の平均を求めた。）
▲４▼ シートの裂断長：上記▲１▼シートの厚さ、▲２▼シートの密度及び▲３▼シートの引張強度より

より求めた。
▲５▼ シートの湿潤引張強度：２０℃蒸留水５分浸漬後にＪＩＳＰ−８１１３によって測定した（ただし、繊維配向方向及びこれと直角をなす方向について測定し、両者の平均を求めた。）。
【００３５】
▲６▼ シートの湿潤裂断長：上記▲１▼シートの厚さ、▲２▼シートの密度及び▲５▼シートの湿潤引張強度より

より求めた。
▲７▼ 根の貫通性１、稚苗時マットの田植機装着作業性１、水稲用育苗箱の中に２５ｃｍ×２０ｃｍの面積となるように木枠で囲いを設け、該囲いの中にシートを敷き、該シートの上に市販の培土を床土として入れ、その上にシグモイドタイプの被覆緩効性肥料（窒素含有率４０重量％、溶出抑制期間３０日、全溶出期間１００日である。以下において同じ。）１７５ｇを施肥し、十分に灌水した後、水稲催芽籾６５ｇを播種し、次いで約３００ｇの覆土を行い、常法に順じて出芽、緑化し、根上りの発生状況を観察するとともに、シート裏面からの根の貫通状況を観察した。また、稚苗まで成育した時点で枠よりマットを取り上げ田植機への装着作業性を調べた。
▲８▼ 根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、田植適性：５７ｃｍ×２７．５ｃｍに断裁したシートを水稲用育苗箱に敷き、該シートの上に市販の培土を床土として入れ、その上にシグモイドタイプの被覆緩効性肥料５５０ｇを施肥し、十分に灌水した後、水稲催芽籾２００ｇを播種し、次いで約１０００ｇの覆土を行い、常法により出芽、緑化し、根上りの発生状況を観察するとともに、シート裏面からの根の貫通状況を観察した。また、稚苗まで成育した時点でマット強度及び育苗箱からマットを取り上げ田植機に装着する際の装着作業性を調べるとともに、通常の田植機により本田への移植を行い、田植適性を評価した。
【００３６】
なお、根の貫通性１、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性１、稚苗時マットの田植機装着作業性２及び田植適性の評価は次に示す評価基準に基づいて行った。
（ア）根の貫通性１、根の貫通性２
◎ ：ほとんど根上りの発生がなく、かつ局所的な根上りも見られない。（平均的根上り発生率≒０％）
○〜◎：ほとんど根上りの発生がないが、わずかに局所的な根上りが見られる。（平均的根上り発生率５％未満）
○ ：ほとんど根上りの発生がないが、局所的な根上りがある。（平均的根上り発生率５％以上１０％未満）
× ：部分的に根の食い込みが認められるが、全体に根上りが多発し不可。
（イ）稚苗時マットのマット強度
稚苗時マットの２７．５ｃｍ長の端部から幅１００ｍｍの帯状試験体を切り取り、台の上に乗せ、一端を固定しもう一端をバネ計りで引張り、破断時の荷重を測定した。
【００３７】
（ウ）稚苗時マットの田植機装着作業性１、稚苗時マットの田植機装着作業性２
◎ ：下敷シートの支えにより、しっかりしたマットが形成されており、図１のようにマットを片手で持ち上げても破断や形くずれを生じない。従ってきわめて効率的にかつ安心して田植機への装着等の作業を行うことができる。
○ ：下敷シートの支えにより、かなりしっかりしたマットが形成されており、図１のようにマットを片手で持ち上げてもほとんど破断や形くずれを生じない。従って、効率的に、かつ安心して田植機への装着等の作業を行うことができる。
△ ：マットの保形性がある程度はあるものの、ていねいに扱わないと破断したり形くずれすることがあり、田植機への装着作業は、慎重に行わねばならない。
× ：下敷シートによる補強がないか、あっても不十分で、破断あるいは形くずれしやすく、下敷シートそのものも破断しやすいため、田植機への装着作業は、熟練者が苗取り板を使用して慎重に行わねばならない。
【００３８】
（エ）田植適性
◎ ：欠株の発生はほとんどなく田植機上でのマットの滑り性も良好で問題なく田植作業を進めることができる。また、根のブロック形成も良好で、該ブロックによる緩効性肥料の捕捉状態も良好。
○ ：欠株の発生は少なく田植機上でのマットの滑り性も良好で、概ね問題なく田植作業を進めることができる。また、根のブロック形成もほぼ良好で、該ブロックによる緩効性肥料の捕捉も概ね良好。
× ：マット形成が不十分で破断したり形くずれしやすいため、田植機装着に際しては、苗取り板を使用しなければならなかった。欠株の発生が比較的多く、また、根のブロック形成が不良で良好なブロックになっていないため、該ブロックによる緩効性肥料の捕捉状態も悪い。
【００３９】
実施例１
化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙を離解機にて混合離解して得た重量比で該木材繊維：新聞古紙＝７０：３０のセルロース系繊維分散液の所定量を取り、これにスルホン酸変性ポリビニルアルコール系親水化剤をセルロース系繊維重量に対して固形分で２．５重量％、シリコン系親水化剤をセルロース系繊維重量に対して固形分で０．５重量％添加し、撹拌機にて十分に分散混合して親水化処理した後、角型手抄機にて手抄を行いシートＡを得た。
シートＡについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。なお床土量は４００ｇとした。
【００４０】
実施例２
実施例１において、スルホン酸変性ポリビニルアルコール系親水化剤の添加量をセルロース系繊維重量に対し固形分で１．０重量％、シリコン系親水化剤の添加量をセルロース系繊維重量に対し固形分で０．２重量％とした以外は実施例１と同様にしてシートＢを得た。
シートＢについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４１】
実施例３
実施例１において、スルホン酸変性ポリビニルアルコール系親水化剤の添加量をセルロース系繊維重量に対し固形分で０．５重量％、シリコン系親水化剤の添加量をセルロース系繊維重量に対し固形分で０．１重量％とした以外は実施例１と同様にしてシートＣを得た。
シートＣについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４２】
実施例４
実施例１において、セルロース系繊維分散液中の化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙の比率を重量比で該木材繊維：新聞古紙＝８５：１５とした以外は実施例１と同様にしてシートＤを得た。
シートＤについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。ただし床土量は３２０ｇとした。
【００４３】
実施例５
実施例２において、セルロース系繊維分散液中の化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙の比率を重量比で該木材繊維：新聞古紙＝６０：４０とした以外は実施例２と同様にしてシートＥを得た。
シートＥについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４４】
実施例６
実施例１において、親水化処理後に、さらに環状窒素化合物系防カビ剤をセルロース系繊維重量に対し固形分で６０ｐｐｍ、水に難溶性で粉体状の緩効性肥料（窒素含有率３０重量％である。以下において同じ。）をセルロース系繊維重量に対し固形分で２．０重量％添加し、十分に撹拌混合した以外は実施例１と同様にしてシートＦを得た。
シートＦについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４５】
比較例１
実施例１において、スルホン酸変性ポリビニルアルコール系親水化剤とシリコン系親水化剤を添加しない以外は実施例１と同様にしてシートＧを得た。
シートＧについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４６】
比較例２
実施例１において、セルロース系繊維分散液中の化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙の比率を重量比で該木材繊維：新聞古紙＝４０：６０とした以外は実施例１と同様にしてシートＨを得た。
シートＨについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４７】
比較例３
実施例１において、シート厚さを厚くし本発明の範囲外とした以外は実施例１と同様にしてシートＩを得た。
シートＩについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。ただし床土量は３２０ｇとした。
【００４８】
比較例４
実施例１において、シート厚さを薄くし本発明の範囲外とした以外は実施例１と同様にしてシートＪを得た。
シートＪについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性１、及び稚苗時マットの田植機装着作業性１をそれぞれ測定し、その結果を表１に示した。
【００４９】
実施例７
化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙をパルパーにて混合離解し、重量比で該木材繊維：新聞古紙＝７０：３０のセルロース系繊維分散原料を得、次いで、スルホン酸変性ポリビニルアルコール系親水化剤をセルロース系繊維重量に対し固形分で２．５％、シリコン系親水化剤をセルロース系繊維重量に対し固形分で０．５重量％添加し、十分に撹拌混合して親水化処理した後、長網抄造網上に供給し紙層形成せしめ、ワインドアップロールにて所定厚さになるまで巻き付けた後、切断し、圧搾、乾燥しシートＫを得た。
シートＫについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は、１２５０ｇとした。
【００５０】
実施例８
実施例７において、セルロース系繊維分散原料中の化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙の重量比を該木材繊維：新聞古紙＝８０：２０とした以外は実施例７と同様にしてシートＬを得た。
シートＬについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は、１０００ｇとした。
【００５１】
実施例９
実施例７において、セルロース系繊維分散原料中の化学処理を受けておらず、かつ実質的にフィブリル化されていない木材繊維と新聞古紙の重量比を該木材繊維：新聞古紙＝６０：４０とした以外は実施例７と同様にしてシートＭを得た。
シートＭについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、及び田植適性をそれぞれ測定し、その結果を表２に示した。
【００５２】
実施例１０
実施例７において、スルホン酸変性ポリビニルアルコール系親水化剤の添加量をセルロース系繊維重量に対し１．０重量％、シリコン系親水化剤の添加量をセルロース系繊維重量に対し０．２重量％とし、親水化処理後に、さらに環状窒素化合物系カビ剤をセルロース系繊維重量に対し固形分で６０ｐｐｍ、水に難溶性で粉体状の緩効性肥料をセルロース系繊維重量に対し固形分で２．０重量％添加し、十分に撹拌混合した以外は実施例７と同様にしてシートＮを得た。
シートＮについて、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、及び田植適性をそれぞれ測定し、その結果を表２に示した。
【００５３】
比較例５
通常の培土のみを用い、補強シートを使わなかった場合の、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２、及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は１２５０ｇとした。
【００５４】
比較例６
新聞紙について、厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は１２５０ｇとした。
【００５５】
比較例７
市販の床土の下敷用の高吸水性樹脂担持パルプ系育苗シートについて厚さ、密度、引張強度、裂断長、湿潤引張強度、湿潤裂断長、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は１２５０ｇとした。
【００５６】
比較例８
通常の培土のみを用い、新聞紙を下敷きにして、かつ、シグモイドタイブの被覆緩効性肥料を施肥せずに通常の稚苗育苗を実施した場合について、根の貫通性２、稚苗時マットのマット強度、稚苗時マットの田植機装着作業性２及び田植適性をそれぞれ測定し、その結果を表２に示した。なお、床土量は１８００ｇとした。
【００５７】
【発明の効果】
本発明の育苗方法によれば、上記した実施例１〜１０、比較例１〜８、表１及び表２からわかるように、化学処理を受けておらず、かつ実質的にフィブリル化されていないセルロース系繊維を高含有せしめ、厚さ及び密度を所定範囲とし、さらに親水化処理を施し、所定の湿潤条件時の湿潤引張強度と湿潤裂断長を特定範囲とした補強シートを用いて育苗箱多量施肥育苗法を実施することとした結果、優れた植物育成適性と良好な育苗作業性を確保しつつ、本田移植後の追肥作業を省略あるいは軽減でき、育苗から収穫に至るまでの一連の作業性改善及び効率向上を図ることができる。
【００５８】
本発明の育苗方法の特に優れている点は、根の貫通適性と田植機装着作業時のマット補強という今まで両立が困難であった機能を兼備した補強シートを用いることにより、育苗箱多量施肥育苗法でのマット形成不良による田植機への装着作業時の支障等を解決できた点である。
すなわち、本発明の育苗方法によれば、田植機への装着時に、育苗箱多量施肥育苗法のため正味の培土量が少なくマット形成が不良となっても、補強シートのマット補強効果により支障なく作業を行うことができる。
【００５９】
かかる補強シートによるマット補強効果についてさらに説明する。
本発明の育苗方法を適用した育苗箱多量施肥育苗法による稚苗時マット（実施例７〜１０）のマット強度は従来の育苗箱多量施肥育苗法（床土の下に何も敷かない（比較例５）か、新聞紙を敷く（比較例６）か、従来の床土の下敷用育苗シートを敷いた（比較例７）場合）に比べ、２．２〜２．５倍も強く、さらに育苗箱多量施肥を行わない一般的稚苗育苗（比較例８（床土の下に新聞紙を敷いた。））に、比べても１．４〜１．５倍も強くきわめて、顕著なマット補強効果が発現していることがわかる。
【００６０】
また、従来の育苗箱多量施肥育苗法では稚苗段階でもマット形成が不良となりやすく、まして乳苗段階での田植機装着は全く不可能であったが、本発明の育苗方法によれば、上述したように育苗箱多量施肥育苗法による稚苗時マットのマット強度が育苗箱多量施肥を行わない一般的稚苗育苗に比べてもかなり強く、従って、マットの根ばりがもっと少なくなって、マット強度がもう少し弱くなった場合においてもまだ十分に、田植機装着が可能であることから、補強シートの強度及び育苗時期等の条件の選択によっては乳苗育苗においても育苗箱多量施肥育苗法を適用できるものと考えられる。
さらに、本発明の育苗方法に用いる補強シートは床土の代替機能も有するため、該補強シートの厚さ、育苗箱への施肥量、育苗時期及び育苗期間等の条件の選択によっては、床土としての培土あるいは合成培地を全く使用しないやり方も考えられる。
【００６１】
このように、今までの育苗箱多量施肥育苗法が、本田移植後の追肥作業の省略あるいは軽減等の優れた効果がありながら、マット形成が不良となりやすいために普及率がきわめて低く、ごく限られた地域でしか実施されていないのに対し、本発明の育苗方法によれば、マット形成が不良となる心配をせずに育苗箱多量施肥育苗法を実施できる。
従って、本発明の育苗方法は育苗箱多量施肥育苗法を広く一般的に普及せしめ得る育苗方法である。
【００６２】
加えて、本発明の育苗方法によれば、根が補強シートに多数貫通することにより、根と該補強シートが一体となってブロックを形成するため、育苗箱多量施肥育苗法での根による緩効性肥料の捕捉がきわめて良好となり、本田移植時により多くの緩効性肥料が根の近傍に施肥されることになるので施肥効率が一段と高まることとなる。
その結果、育苗箱多量施肥育苗法による
▲１▼本田移植後の追肥作業を省略あるいは軽減できる。
▲２▼根に捕捉された緩効性肥料が本田移植時に根の近傍に施肥されるため、肥料効果の発現の効率及び有効性が向上するとともに良好な活着が得られる（本田移植後に追肥する場合に比べ、施肥量は３０〜４０％少なくてすむ。）。
▲３▼育苗箱に多量施肥する分培土量が３０〜４０％少なくてすむ。
▲４▼育苗期間中においても、床土中の肥料濃度が障害が出ない程度の高水準に常時保たれるので苗の成育が良好となる。
などの利点をあますところなく享受できる。
【図面の簡単な説明】
【図１】本発明の育苗方法により得たマットをを片手で持ち上げた状態を示す描写図である。
【符号の説明】
１補強シート
２床土あるいは合成培地マット
３緩効性肥料
４苗
【表１】

【表２】

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for raising seedlings, and more specifically, while ensuring excellent plant growth aptitude and good seedling workability, additional fertilization work after transplanting to Honda can be omitted or reduced, and a series of processes from raising seedlings to harvesting The present invention relates to a rational and efficient seedling raising method capable of improving work efficiency.
[0002]
[Prior art]
Currently, paddy rice seedling is usually put in a seedling box as soil, and after irrigation, seeding, covering, budding, greening, and transplanting to Honda at the seedling stage with rice transplanter. However, in part, not only the amount of fertilizer required during the seedling raising period, but also all or most of the amount required from the time of transplanting to the harvest, for the purpose of reducing the additional fertilization work after transplanting Honda. A method of blending the fertilizer with a slow-release fertilizer or the like has been performed. In addition, in the following, not only the amount of fertilizer required during the seedling period at the time of such seedling, but also the method of blending all or most of the fertilizer required from transplanting to harvesting in the seedling box Sometimes called fertilizer seedling raising method.
[0003]
[Problems to be solved by the invention]
However, in the seedling box mass fertilization method, the amount of fertilizer added to the seedling box is large, so the net soil content that can be blended decreases, the rooting tends to be insufficient, and the mat formation tends to deteriorate. . When the mat formation is poor, the mat is deformed or scattered when the mat is taken out from the nursery box and mounted on the rice transplanter, and the work becomes difficult. Due to these problems, the prevalence rate of the seedling box mass fertilization method is still very low and is only being implemented in a very limited area. Accordingly, there has been a strong demand for the emergence of a seedling method that can solve the troubles and the like when mounted on a rice transplanter due to poor mat formation in the seedling box mass fertilization method.
[0004]
The present inventor examined whether the above-mentioned problem could be solved by laying some reinforcing sheet when carrying out the seedling box mass fertilization raising seedling method. In recent years, various fiber-based or inorganic fiber-based synthetic medium mats have been developed as reference sheets for reinforcing sheets for such purposes. Such synthetic medium mats improve root bite and prevent root-up. For this reason, most of them are manufactured by a dry method using a very small amount of binder, and there is no low density and extremely low strength, and there is no material that can fully exhibit the function of mat reinforcement.
[0005]
On the other hand, in the case of wet papermaking, generally, the bond between fibers is likely to be strong and it is hardly possible to obtain a mat that can penetrate the roots. It has been proposed that the penetration ability of the roots can be ensured by dispersing the superabsorbent resin evenly in the gaps so that the highly water-absorbent resin absorbs and expands during water absorption and breaks or relaxes the bond between fibers.
[0006]
However, papermaking with a raw material slurry containing a highly water-absorbing resin in a water-absorbed and expanded state may cause problems in the manufacturing process, such as the water-absorbing and highly water-absorbing resin easily adhering to the papermaking net. The sheet at the time becomes very weak, and in some cases the mat reinforcement is insufficient.
Thus, at present, there is no sheet that can be used as a reinforcing sheet that matches the purpose, or that suggests it.
[0007]
In view of this, the present inventor has used careful consideration, in particular, a binder, in order to obtain a reinforcing sheet that is effective in preventing troubles when attached to a rice transplanter due to poor mat formation in the seedling box mass fertilization raising seedling method. What should be done to weaken the bond between fibers as much as possible so that the root can penetrate while taking advantage of the wet papermaking with cellulosic fiber that can form a sheet by the bond strength between fibers (hydrogen bond) at least? From the point of view, we proceeded to study cellulosic fibers that had not undergone chemical treatment and were not substantially fibrillated.
[0008]
Such cellulosic fibers have little or no fiber-to-fiber bond strength, and are very weak in fiber-to-fiber bond strength. It must be applied to the papermaking after the quality or beating is applied to give a certain degree of interfiber bonding force.
[0009]
As a result, the present inventor has deliberately studied a technique for making paper using materials that are unsuitable for such paper making as much as possible. A sheet containing a high amount of non-fibrillated cellulosic fibers is formed, the thickness and density are set within the specified ranges, and the surface is further hydrophilized, and the wet tensile strength and wet tear length under the specified wet conditions are within the specified ranges. Therefore, when used as an underlay in the seedling box mass fertilizer raising seedling method, it is possible to achieve both the ability to penetrate the root and the contradictory functions of mat reinforcement, that is, if the seedling is grown by such a method, the penetration of the root is good At the same time, when installing on a rice transplanter, it is possible to work without trouble by the reinforcement effect of the underlay sheet even if there is little rooting and the mat formation is poor. It was completed a light.
[0010]
The object of the present invention is to ensure excellent plant growth aptitude and good seedling workability, while omitting or reducing the post-fertilization work after transplanting Honda, and improving the efficiency of a series of operations from seedling to harvesting. It is to provide a rational and efficient seedling raising method.
[0011]
[Means for Solving the Problems]
The seedling raising method of the present invention is a hydrophilized sheet containing 50 to 90% by weight of cellulose fiber that has not undergone chemical treatment and is not substantially fibrillated, and the thickness of the sheet is 0.00. 8-5mm, density 0.1-0.5g / cm ^Three The wet tensile strength obtained by measuring the fiber orientation direction of the sheet after being immersed in distilled water at 20 ° C. for 5 minutes and the direction perpendicular to the fiber orientation (measurement based on JIS P-8113) And the wet tear length (measured based on JIS P-8113) are reinforcements having the wet tensile strength of 0.2 to 1.0 kg / 15 mm width and the wet tear length of 0.02 to 0.1 km. A sheet is prepared, the reinforcing sheet is laid on a seedling box, and on the reinforcing sheet, at least the amount of fertilizer necessary for the seedling growing period and all or most of the amount necessary for harvesting after transplanting to Honda The seedlings are cultivated by sowing after the fertilizer is supplied.
[0012]
Further, in the seedling raising method according to claim 1, on the reinforcing sheet, an amount of fertilizer required for the seedling period and all or most of the fertilizer required for harvesting after transplanting to Honda. When supplying the fraction, it may be supplied together with the soil or the synthetic medium.
Further, in the seedling raising method according to the first aspect, the seedling after sowing may be transplanted to Honda at the stage of nurturing or seedling.
[0013]
The seedling raising method of the present invention is a hydrophilized sheet containing 50 to 90% by weight of cellulose fiber that has not undergone chemical treatment and is not substantially fibrillated, and the thickness of the sheet is 0.00. 8-5mm, density 0.1-0.5g / cm ^Three The wet tensile strength obtained by measuring the fiber orientation direction of the sheet after being immersed in distilled water at 20 ° C. for 5 minutes and the direction perpendicular to the fiber orientation (measurement based on JIS P-8113) And the wet tear length (measured based on JIS P-8113) are reinforcements having the wet tensile strength of 0.2 to 1.0 kg / 15 mm width and the wet tear length of 0.02 to 0.1 km. Create a sheet, lay the reinforcing sheet on the seedling box, and on the reinforcing sheet, together with the soil or synthetic medium, not only the amount of fertilizer required for the seedling period, but also the transplanting to Honda, it is necessary before harvesting After supplying all or most of the amount of fertilizer to be irrigated, seeding, covering, budding, greening, and transplanting to Honda at the seedling stage or seedling stage .
[0014]
The reinforcing sheet used in the seedling raising method of the present invention must contain 50 to 90% by weight, preferably 60 to 80% by weight, of a cellulose fiber that has not undergone chemical treatment and is not substantially fibrillated. If the content is less than 50% by weight, the penetration of the roots is hindered, and the roots are easily generated. On the other hand, when it exceeds 90% by weight, the papermaking property is deteriorated and the strength of the obtained sheet is too weak to obtain a sufficient mat reinforcing effect.
Cellulose fibers that have not undergone chemical treatment and are not substantially fibrillated include various types of wood fibers such as pulverized wood and wood fiber, or wood pulp that has not undergone chemical treatment such as mechanical pulp. Can be used.
[0015]
Further, in the reinforcing sheet used in the seedling raising method of the present invention, in order to obtain a predetermined sheet strength, cellulose-based fibers other than the cellulose-based fibers not subjected to the above-described chemical treatment and substantially not fibrillated are used. It is desirable to use together. As the cellulose fiber, one or two or more kinds selected from wood pulp such as coniferous or hardwood chemical pulp, semi-chemical pulp, various waste paper, bagasse, straw, linter, etc. are used in combination. be able to. The content of such cellulosic fibers in the seedling sheet according to the present invention is preferably 5 to 40% by weight. If the content is less than 5% by weight, a predetermined sheet strength may not be obtained. On the other hand, if it exceeds 40% by weight, the sheet strength becomes too strong, and root penetration may be hindered and root up may occur.
[0016]
The thickness of the reinforcing sheet used in the seedling raising method of the present invention should be 0.8 to 5 mm, preferably 1.5 to 3 mm. If the thickness is less than 0.8 mm, the strength is insufficient and a sufficient mat reinforcing effect cannot be obtained. On the other hand, when it exceeds 5 mm, the penetrability of the roots is hindered and the roots are likely to rise.
The density of the reinforcing sheet used in the seedling raising method of the present invention is 0.1 to 0.5 g / cm. ^Three , Preferably 0.15 to 0.4 g / cm ^Three Must. The density is 0.1 g / cm ^Three If it is less than 1, the sheet strength is too weak to obtain a sufficient mat reinforcing effect. Conversely, 0.5 g / cm ^Three If it exceeds, the root bite deteriorates, and it tends to cause uprooting.
[0017]
The reinforcing sheet used in the seedling raising method of the present invention must be hydrophilized. Since the reinforcing sheet has not been subjected to chemical treatment and contains a high amount of cellulose fibers that are not substantially fibrillated, the water absorption necessary for the reinforcing sheet can be ensured unless the hydrophilic treatment is performed. I can't.
Hydrophilization treatment is not particularly limited, and various surfactants such as sulfonic acid type, carboxylic acid type, phosphoric ester type, sulfuric acid ester type, quaternary ammonium salt type or higher alcohols, polyhydric alcohols, A hydrophilicity imparting agent such as a silicon hydrophilizing agent or a PVA hydrophilizing agent may be internally added, impregnated or coated. Further, the amount of the hydrophilicity-imparting agent is not particularly limited, but it is important that the amount is such that the wet tensile strength and the wet tear length of the sheet are within the ranges specified in the present invention. There is a need.
[0018]
The wet tensile strength measured according to JIS P-8113 after dipping the reinforcing sheet used in the seedling raising method of the present invention for 5 minutes in distilled water at 20 ° C. is 0.2 on the average in the direction perpendicular to the fiber orientation direction. It should be -1.0 kg / 15 mm wide, preferably 0.3-0.7 kg / 15 mm wide. The wet tear length determined from the wet tensile strength should be 0.02 to 0.1 km, preferably 0.03 to 0.07 km. When the above-mentioned wet tensile strength is less than 0.2 kg / 15 mm width or the above-mentioned wet tearing length is less than 0.02 km, sufficient mat reinforcing effect cannot be obtained, and when taking up the mat when there is little rooting It is easy to cause troubles such as breakage of the reinforcing sheet. On the other hand, when the above-described wet tensile strength exceeds 1.0 kg / 15 mm width, or the above-mentioned wet tearing length exceeds 0.1 km, root biting deteriorates and root upping is likely to occur.
[0019]
The reinforcing sheet used in the seedling raising method of the present invention has not been subjected to chemical treatment as described above, and has a high content of cellulosic fibers that are not substantially fibrillated, subjected to hydrophilic treatment, and has a thickness, The density, wet tensile strength, and wet tearing length are within the prescribed ranges, so that both the ability to penetrate the root and the mat reinforcing force are combined. However, inorganic fillers such as clay and talc or rock wool fibers, glass By blending inorganic fibers such as fibers and ceramic fibers, it is possible to further weaken the bond between fibers and improve the penetration of the roots.
[0020]
Also, if necessary, binders such as various synthetic resin latices may be blended, but in this case, it is natural that the amount added should be kept to a very small amount so as not to inhibit root penetration. is there.
Furthermore, if necessary, nitrogen-based fertilizers such as ammonium sulfate, ammonium chloride, and urea, or potassium-based fertilizers such as potassium sulfate and potassium chloride or phosphate-based fertilizers such as superphosphate lime and ammonium phosphate, PH adjusting agents such as sulfuric acid, citric acid, humic acid, nitrohumic acid, peat moss and fungicides may be blended.
In addition, when blending fertilizer by internal addition in wet papermaking, it is more effective to use a powdery slow-acting fertilizer that is difficult to dissolve in water.
[0021]
In order to manufacture the reinforcing sheet used in the seedling raising method of the present invention, dry molding may be used, but wet papermaking is more preferable. In the case of dry molding, in order to obtain a sheet strength sufficient to exhibit a sufficient mat reinforcing effect, it is indispensable to add an appropriate amount of various types of binders such as various synthetic resin latexes. It may be quite difficult to achieve both. On the other hand, in the case of wet papermaking, it is sufficient to exhibit a sufficient mat reinforcing effect by inter-fiber bonding by hydrogen bonding between cellulosic fibers formed in the papermaking process without necessarily using the above-mentioned binders. Since the sheet strength can be obtained, both the ability to penetrate the root and the mat reinforcing force can be achieved.
[0022]
Here, the case where the reinforcement sheet | seat used for the seedling raising method of this invention by wet papermaking is further demonstrated.
That is, in order to produce the seedling sheet of the present invention by wet papermaking, a raw material slurry containing a predetermined amount of a cellulose-based fiber that has not been subjected to chemical treatment and is not substantially fibrillated is prepared. What is necessary is just to make a paper by the paper making method. Then, the above-described various hydrophilicity imparting agents may be internally added to the raw material slurry, or may be subjected to a hydrophilization treatment by impregnation or coating after forming a sheet.
[0023]
In addition, beating treatment may be performed as necessary, but the cellulosic fibers that have not undergone chemical treatment in the raw slurry and are not substantially fibrillated are maintained in this state, and the interfiber bonding force Must be kept in a state where it is difficult to express. Therefore, the cellulosic fibers are beaten under very weak conditions that do not substantially cause fibrillation, or are not subjected to chemical treatment, and treatment of cellulosic fibers that are not substantially fibrillated is another route. It is necessary to devise such as using without beating. For papermaking, the raw material slurry may be supplied onto a papermaking net such as a normal long net, circular net or inclined net, filtered and dehydrated, and then compressed and dried. If necessary, two or more paper layers may be overlapped by various combination nets, multi-tank circular nets, or various laminators. In addition, it is easy to obtain a suitable reinforcing sheet for use in the seedling raising method of the present invention by reducing the pressing conditions as much as possible and making the paper layer as bulky as possible.
[0024]
Next, the soil or fertilizer used in the seedling raising method of the present invention will be described.
As soil for cultivation, commercially available soil-based materials or soil-cultivated materials that are used for normal seedlings such as soil-grown materials prepared by the farmer by adjusting the pH and adjusting the pH can be used. . The soil can be used as needed. A synthetic medium can also be used instead of the soil.
As the fertilizer, a fast-acting fertilizer that produces an effect during the seedling period and a slow-acting fertilizer that produces an effect after transplanting Honda are used in combination.
About the operation of a fast-acting fertilizer, what is necessary is just to follow that in the case of conventionally used nursery seedling raising seedlings or young seedling raising seedlings. That is, if necessary, a predetermined amount of nitrogenous fertilizers such as ammonium sulfate, ammonium sulfate and urea, potassium fertilizers such as potassium sulfate and potassium chloride, or phosphate fertilizers such as superphosphate lime and phosphate. What is necessary is just to mix | blend with culture soil or a reinforcement sheet | seat.
[0025]
As the above-mentioned slow release fertilizer, ammonium fertilizer such as ammonium sulfate, ammonium sulfate, ammonium nitrate, urea, calcium nitrate, or potassium fertilizer such as potassium sulfate, potassium chloride, potassium nitrate, or lime superphosphate, ammonium phosphate, Coated slow-release fertilizer in which granular materials composed of one or more fertilizers selected from the group of phosphate fertilizers such as calcium phosphate are coated with a coating, and the component elution rate is physically adjusted, or these Or one or more kinds selected from the group consisting of granules of chemically synthesized slow-release fertilizers such as isobutyraldehyde processed urea fertilizer, acetaldehyde processed urea fertilizer, formaldehyde processed urea fertilizer, guanyl urea sulfate, oxamide Fertilizers, fertilizers coated with these, or mixtures of these fertilizers can be used.
In particular, a sigmoid type coated slow-acting fertilizer is suitable for a large-scale fertilizer raising method of a nitrogen-based fertilizer.
[0026]
The amount of fertilization varies depending on the type of fertilizer. For example, in the case of large-scale fertilization of a nitrogen-based fertilizer in a seedling box, the nitrogen content is about 200 to 240 g per seedling box, that is, a sigmoid type having a general nitrogen content of about 40% by weight. It becomes about 500-600g per seedling box with a covering slow-release fertilizer. However, it is natural that the amount of fertilization should be adjusted according to the degree of omission or reduction of the additional fertilization work after the target Honda transplantation.
[0027]
The fertilizer application method to the seedling box of the slow-acting fertilizer that expresses the effect after Honda transplantation in the seedling-raising method of the present invention is the method of fertilizing after mixing the soil and the slow-acting fertilizer, the culture soil and the slow-acting fertilizer. Any of the methods of applying fertilization in layers may be used, but layered fertilization requires only one step of fertilization work in the series of seedling preparation work, and does not require effort to mix with soil Is more effective. In the case of layered fertilization, seeds are sown so that they come into contact with the above-mentioned slow-release fertilizer, so that the roots can easily capture the slow-release fertilizer, and more slow-release fertilizer is added to Honda at the time of Honda transplantation. Since the slow-release fertilizer brought in is located in the vicinity of the roots, the fertilization efficiency is further increased.
[0028]
It is desirable that irrigation is given sufficiently (about 1 liter per nursery box) so that the underlaying seedling sheet is sufficiently wetted.
The seeding amount per seedling box is preferably 160 to 180 g (dry pods) for young seedlings and 200 to 250 g (dry pods) for nurturing seedlings.
Covering, budding, and greening may be carried out according to conventional methods. In the case of nurturing seedlings, transplanting to Honda can be performed in a seedling period of 5 to 7 days, and in the case of young seedlings, it can be transplanted in about 3 weeks.
Transplanting into Honda can be done according to conventional methods.
[0029]
[Action]
The feature of the seedling raising method of the present invention is that it is a seedling box mass fertilization raising seedling method by using a reinforcing sheet having a function that has been difficult to achieve both of the ability to penetrate the root and mat reinforcement at the time of rice transplanter installation. The problem is that it was possible to solve the troubles when mounting to rice transplanters due to poor mat formation.
The details of the root penetration suitability and the expression mechanism of the mat reinforcing force of the reinforcing sheet used in the seedling raising method of the present invention are still unclear, but the contents considered by the present inventors will be described below.
[0030]
First, the expression of root penetration suitability will be considered. The reinforcing sheet used in the seedling raising method of the present invention is not subjected to chemical treatment and contains a high content of cellulose fibers that are not substantially fibrillated. Pretty weak. In addition, the reinforcing sheet used in the seedling raising method of the present invention has a density of 0.1 to 0.5 g / cm. ^Three It is very bulky and has been hydrophilized.
Accordingly, the reinforcing sheet according to the present invention is laid on the seedling box, and not only the amount of fertilizer required during the seedling period on the reinforcing sheet, but also all or most of the amount of fertilizer required from the transplanting to harvesting In the case where water is sufficiently irrigated after adding the soil adjusted so as to contain the water, the water is quickly absorbed by the reinforcing sheet when it reaches the reinforcing sheet through the above-mentioned soil.
As a result, the reinforcing sheet becomes sufficiently wet and retains water, and the strength further decreases.
[0031]
The wet tear length of the reinforcing sheet used in the seedling raising method of the present invention is 0.02 to 0.1 km, which is a fraction of that of the weakest level of a sheet made of ordinary wood pulp. The strength is very weak, about 1/10. Thus, the strength is extremely reduced when wet. That is, since the fiber-to-fiber bond becomes extremely weak, the roots that have advanced through the layer made of the above-mentioned soil dig into and penetrate through the fiber-to-fiber bond in the reinforcing sheet used in the seedling method of the present invention having a thickness of 0.8 to 5 mm. can do.
[0032]
Next, the expression of the mat reinforcing force will be considered.
As described above, the wet tear length of the reinforcing sheet used in the seedling raising method of the present invention is very weak, and thus the root can penetrate, but the reinforcing sheet used in the seedling raising method of the present invention is 0.8 to 5 mm. Since it has a thickness, the wet tensile strength of the sheet is 0.2 to 1.0 kg / 15 mm width. Consider the wet tensile strength of 0.2 to 1.0 kg / 15 mm width. For comparison, the strength of a commercial seedling sheet for underlaying and a synthetic medium mat for substituting floor soil will be described here. As will be described later (Comparative Example 7), for example, when viewing a commercially available superabsorbent resin-supported pulp-based seedling sheet for underlaying, the tensile strength in a normal state is 0.444 kg / 15 mm width and 20 ° C. The tensile strength when immersed in distilled water for 5 minutes is unmeasurable because the sheet is broken and cannot be measured.
[0033]
Accordingly, it is considered that the sheet strength is almost lost and there is no mat reinforcing force when it is actually used as an underlay for the above-mentioned cultivated soil and is moistened under normal seedling raising conditions. In addition, when the sheet strength is measured in the same manner for a commercially available inorganic fiber synthetic medium mat having a thickness of 18 mm, the tensile strength in a normal state is 0.204 kg / 15 mm width, and the tensile strength after immersion for 5 minutes at 20 ° C. in distilled water is The width is 0.088 kg / 15 mm.
Therefore, the tensile strength 0.2-1.0 kg / 15 mm width after immersion of 20 ° C. distilled water for 5 minutes of the reinforcing sheet used in the seedling raising method of the present invention is 2 of that of the inorganic fiber synthetic medium mat having a thickness of 18 mm. It is 3 to 11.4 times stronger.
Therefore, this excellent wet tensile strength develops a mat reinforcing force unique to the reinforcing sheet used in the seedling raising method of the present invention, and even if there is little rooting and the mat is poorly formed, the reinforcing sheet serves as a support for the mat. This is a very useful property that can be attached to rice transplanters without any problems.
[0034]
【Example】
Next, the present invention will be described more specifically based on the following examples.
The measurement of each item in this example was performed according to the following method.
(1) Sheet thickness: JIS P-8118
(2) Sheet density: JIS P-8118
{Circle around (3)} Tensile strength of sheet: JIS P-8113 (however, the fiber orientation direction and the direction perpendicular thereto were measured, and the average of both was determined.)
(4) Sheet tear length: From the above (1) sheet thickness, (2) sheet density, and (3) sheet tensile strength

I asked more.
(5) Wet tensile strength of sheet: Measured according to JIS P-8113 after immersion in distilled water at 20 ° C. for 5 minutes (however, the fiber orientation direction and the direction perpendicular thereto were measured to determine the average of both).
[0035]
(6) Wet tear length of sheet: From the above (1) sheet thickness, (2) sheet density, and (5) sheet wet tensile strength

I asked more.
▲ 7 ▼ Root penetration, 1 seedling matting planter installation workability, 1 paddy rice seedling box with a wooden frame so that it has an area of 25cm x 20cm, and a sheet in the enclosure A commercially available soil is placed on the sheet as a floor soil, and a sigmoid type coated slow-release fertilizer (nitrogen content 40% by weight, elution suppression period 30 days, total elution period 100 days). The same applies in the following.) After fertilizing 175 g and sufficiently irrigating, 65 g of paddy rice sprouting rice seeds are sown, and then about 300 g of soil is covered, and budding and greening is observed in accordance with the usual method, and the occurrence of uprooting is observed. At the same time, the state of root penetration from the back of the sheet was observed. In addition, when the seedlings were grown up, the mats were taken out of the frame and the workability on the rice transplanter was examined.
▲ 8 ▼ Root penetration 2, Mat strength of seedling mat, Rice transplanter installation workability 2 of mating seedling, Suitability for rice transplanting: Place the sheet cut to 57cm x 27.5cm in a seedling box for paddy rice, Put commercially available soil as a floor soil on the sheet, apply 550g of sigmoid-type coated slow-release fertilizer on it, and after thoroughly irrigating, seed 200g of paddy rice germination bud, then cover about 1000g of soil. Then, budding and greening was observed by a conventional method, and the occurrence of roots was observed, and the penetration of roots from the back of the sheet was observed. In addition, when the seedlings were grown up, the mat strength and the mounting workability when the mats were picked up from the seedling box and mounted on the rice transplanter were examined, and transplanted to Honda using a normal rice transplanter, and the rice transplanting suitability was evaluated.
[0036]
Root penetrability 1, root penetrability 2, mat strength of seedling mat, rice transplanter attachment workability 1 of seedling mat, rice transplanter attachment workability 2 of seedling mat and evaluation of rice planting suitability Was performed based on the following evaluation criteria.
(A) Root penetration 1 and root penetration 2
A: Almost no uprooting occurs and no local uprooting is observed. (Average uprooting rate ≒ 0%)
○ to ◎: There is almost no occurrence of rooting, but a slight local rooting is observed. (Average uptake rate of less than 5%)
○: Almost no uprooting occurs, but there is local uprooting. (Average uptake rate of 5% or more and less than 10%)
×: Root biting is partially observed, but the entire roots are frequent and cannot be used.
(I) Mat strength of mat for seedlings
A strip-shaped test specimen having a width of 100 mm was cut from a 27.5 cm long end of the mat for seedlings, placed on a table, one end was fixed and the other end was pulled with a spring gauge, and the load at the time of breaking was measured.
[0037]
(C) Rice transplanter mounting workability 1 for seedling mats, rice transplanter mounting workability 2 for seedling mats
A: A solid mat is formed by the support of the underlay sheet, and even if the mat is lifted with one hand as shown in FIG. 1, it does not break or deform. Accordingly, it is possible to perform operations such as mounting on a rice transplanter extremely efficiently and with peace of mind.
○: A fairly firm mat is formed by the support of the underlay sheet, and even if the mat is lifted with one hand as shown in FIG. 1, it is hardly broken or deformed. Accordingly, it is possible to efficiently and safely perform operations such as mounting on a rice transplanter.
Δ: Although there is a certain degree of shape retention of the mat, it may break or lose shape if not handled carefully, and the mounting work on the rice transplanter must be done carefully.
×: There is no reinforcement by the underlay sheet, even if it is insufficient, it is easy to break or deform, and the underlay sheet itself is easy to break. Must be done carefully.
[0038]
(D) Rice transplanting aptitude
◎: There is almost no stock loss and the slipperiness of the mat on the rice transplanter is good, so that rice transplanting can be carried out without any problem. In addition, the formation of root blocks is good, and the slow-release fertilizer is well captured by the blocks.
○: There are few outbreaks and the slipperiness of the mat on the rice transplanter is good. In addition, the formation of the root block is almost good, and the slow-release fertilizer is generally well captured by the block.
X: The mat formation was insufficient, and it was easy to break or lose shape. Therefore, when the rice transplanter was installed, a seedling collecting plate had to be used. Since there are relatively many outbreaks and the formation of the root block is not good and the block is not good, the trapped state of slow-release fertilizer by the block is also poor.
[0039]
Example 1
Cellulosic fiber of wood fiber: newspaper waste paper = 70: 30 in a weight ratio obtained by mixing and disaggregating wood fiber that has not undergone chemical treatment and is not substantially fibrillated and wastepaper wastepaper by a disaggregator A predetermined amount of the dispersion is taken, and the sulfonic acid-modified polyvinyl alcohol-based hydrophilizing agent is 2.5% by weight in solid content with respect to the cellulosic fiber weight, and the silicon-based hydrophilizing agent is solid with respect to the cellulosic fiber weight. After adding 0.5% by weight in minutes, the mixture was sufficiently dispersed and mixed with a stirrer to make it hydrophilic, and then hand-drawn with a square-type hand machine to obtain Sheet A.
For sheet A, the thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 1 and seedling mater attachment workability 1 were measured. Is shown in Table 1. The amount of floor soil was 400 g.
[0040]
Example 2
In Example 1, the addition amount of the sulfonic acid-modified polyvinyl alcohol hydrophilizing agent is 1.0% by weight in solid content with respect to the weight of the cellulosic fiber, and the addition amount of the silicon hydrophilizing agent is solid content with respect to the weight of the cellulosic fiber. A sheet B was obtained in the same manner as in Example 1 except that the content was 0.2 wt%.
For sheet B, the thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 1 and seedling mater mounting workability 1 for seedlings were measured, respectively. Is shown in Table 1.
[0041]
Example 3
In Example 1, the addition amount of the sulfonic acid-modified polyvinyl alcohol hydrophilizing agent is 0.5% by weight in solid content with respect to the weight of the cellulose fiber, and the addition amount of the silicon hydrophilizing agent is solid content with respect to the weight of the cellulose fiber. A sheet C was obtained in the same manner as in Example 1 except that the content was 0.1 wt%.
For sheet C, the thickness, density, tensile strength, breaking length, wet tensile strength, wet breaking length, root penetration 1 and seedling mater attachment workability 1 were measured, respectively. Is shown in Table 1.
[0042]
Example 4
In Example 1, the weight ratio of wood fiber to newspaper waste paper not subjected to chemical treatment in the cellulosic fiber dispersion and substantially fibrillated was: wood fiber: new waste paper = 85: 15 A sheet D was obtained in the same manner as in Example 1 except that.
For sheet D, the thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 1 and mater attachment workability 1 for seedling mats were measured respectively. Is shown in Table 1. However, the floor soil amount was 320 g.
[0043]
Example 5
In Example 2, the wood fiber: newspaper waste paper = 60: 40 in terms of weight ratio of wood fibers not subjected to chemical treatment in the cellulose fiber dispersion and not substantially fibrillated to wastepaper wastepaper. A sheet E was obtained in the same manner as in Example 2 except that.
For sheet E, the thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 1 and seedling mater mounting workability 1 for seedlings were measured respectively. Is shown in Table 1.
[0044]
Example 6
In Example 1, after the hydrophilization treatment, a cyclic nitrogen compound-based fungicide was further added to the cellulose fiber weight in a solid content of 60 ppm, a water-soluble and powdery slow-release fertilizer (nitrogen content 30% by weight) In the following, sheet F was obtained in the same manner as in Example 1 except that 2.0% by weight of the solid content with respect to the weight of the cellulosic fiber was added and the mixture was sufficiently stirred and mixed.
For sheet F, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 1 and seedling mater attachment workability 1 were measured, respectively. Is shown in Table 1.
[0045]
Comparative Example 1
In Example 1, a sheet G was obtained in the same manner as in Example 1 except that the sulfonic acid-modified polyvinyl alcohol hydrophilizing agent and the silicon hydrophilizing agent were not added.
For sheet G, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 1 and seedling mater attachment workability 1 were measured, respectively. Is shown in Table 1.
[0046]
Comparative Example 2
In Example 1, the weight ratio of wood fiber to newspaper waste paper not subjected to chemical treatment in the cellulose-based fiber dispersion and not substantially fibrillated was 40:60. A sheet H was obtained in the same manner as in Example 1 except that.
For sheet H, the thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 1 and seedling mater attachment workability 1 were measured. Is shown in Table 1.
[0047]
Comparative Example 3
In Example 1, Sheet I was obtained in the same manner as in Example 1 except that the sheet thickness was increased to be outside the scope of the present invention.
For sheet I, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 1 and mater attachment workability 1 for seedlings were measured, respectively. Is shown in Table 1. However, the floor soil amount was 320 g.
[0048]
Comparative Example 4
In Example 1, a sheet J was obtained in the same manner as in Example 1 except that the sheet thickness was reduced to be outside the scope of the present invention.
For sheet J, the thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 1 and seedling mater mounting workability 1 for seedlings were measured, respectively. Is shown in Table 1.
[0049]
Example 7
Wood fiber that has not been subjected to chemical treatment and is not substantially fibrillated and waste paper are mixed and disaggregated by a pulper, and the weight ratio of the wood fiber: new waste paper = 70: 30 cellulosic fiber-dispersed raw material. Then, a sulfonic acid-modified polyvinyl alcohol-based hydrophilizing agent is added in a solid content of 2.5% based on the weight of the cellulose-based fiber, and a silicon-based hydrophilizing agent is added in a solid content of 0.5% by weight based on the weight of the cellulose-based fiber. Then, after sufficiently mixing and agitating and hydrophilizing, it is fed onto a long net-making net to form a paper layer, wound with a windup roll until it reaches a predetermined thickness, then cut, squeezed and dried, sheet K Got.
For sheet K, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 2, mat strength at seedling mat, rice transplanter installation workability 2 at seedling mat , And rice transplantability were measured, respectively, and the results are shown in Table 2. The floor soil amount was 1250 g.
[0050]
Example 8
In Example 7, the weight ratio of wood fibers not subjected to chemical treatment in the cellulose-based fiber-dispersed raw material and not substantially fibrillated to waste newspaper was set to 80:20. Except for this, a sheet L was obtained in the same manner as in Example 7.
For sheet L, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 2, mat strength at seedling mat, rice transplanter installation workability 2 at seedling mat , And rice transplantability were measured, respectively, and the results are shown in Table 2. The floor soil amount was 1000 g.
[0051]
Example 9
In Example 7, the weight ratio of wood fibers not subjected to chemical treatment in the cellulose-based fiber-dispersed raw material and not substantially fibrillated to waste newspaper was set to 60:40. A sheet M was obtained in the same manner as Example 7 except for the above.
For sheet M, thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 2, mat strength at seedling mat, rice transplanter installation workability 2 at seedling mat , And rice transplantability were measured, respectively, and the results are shown in Table 2.
[0052]
Example 10
In Example 7, the addition amount of the sulfonic acid-modified polyvinyl alcohol hydrophilizing agent is 1.0% by weight with respect to the weight of the cellulose fiber, and the addition amount of the silicon hydrophilizing agent is 0.2% by weight with respect to the weight of the cellulose fiber. In addition, after the hydrophilization treatment, the cyclic nitrogen compound mold agent is 60 ppm in solid content with respect to the weight of the cellulosic fiber, and the powdery slow-release fertilizer is slightly soluble in water and 2 in solid content with respect to the cellulosic fiber weight. A sheet N was obtained in the same manner as in Example 7 except that 0.0% by weight was added and the mixture was sufficiently stirred and mixed.
For sheet N, thickness, density, tensile strength, tear length, wet tensile strength, wet tear length, root penetration 2, mat strength at seedling mat, rice transplanter installation workability 2 at seedling mat , And rice transplantability were measured, respectively, and the results are shown in Table 2.
[0053]
Comparative Example 5
Measure root penetration 2, mat strength at the time of seedling, rice planter installation workability 2 at the time of seedling, and rice planting aptitude when using only normal cultivated soil and no reinforcing sheet, The results are shown in Table 2. The floor soil amount was 1250 g.
[0054]
Comparative Example 6
For newspapers, thickness, density, tensile strength, tearing length, wet tensile strength, wet tearing length, root penetration 2, mat strength of seedling mat, rice transplanter installation workability 2 of seedling mat and The rice planting aptitude was measured and the results are shown in Table 2. The floor soil amount was 1250 g.
[0055]
Comparative Example 7
Pulp seedling sheet carrying super absorbent polymer for underlay of commercial floor soil Thickness, density, tensile strength, breaking length, wet tensile strength, wet breaking length, root penetration 2, root mat The mat strength, the rice transplanter mounting workability 2 and the rice planting suitability of the mat at the time of seedling were measured, and the results are shown in Table 2. The floor soil amount was 1250 g.
[0056]
Comparative Example 8
About normal seedling raising using only normal soil, newspaper underlay and without applying sigmoidal tie-coated slow-release fertilizer, root penetration 2 and seedling mat The mat strength, the rice transplanter mounting workability 2 and the rice planting suitability of the mat at the time of seedling were measured, and the results are shown in Table 2. The floor soil amount was 1800 g.
[0057]
【The invention's effect】
According to the seedling raising method of the present invention, as can be seen from the above-described Examples 1 to 10, Comparative Examples 1 to 8, Tables 1 and 2, it has not undergone chemical treatment and is not substantially fibrillated. A seedling box using a reinforcing sheet with a high content of cellulosic fibers, a thickness and density within a predetermined range, a hydrophilic treatment, and a specific range of wet tensile strength and wet tear length under predetermined wet conditions As a result of implementing the mass fertilization and raising seedling method, it is possible to omit or reduce the additional fertilization work after transplanting Honda while ensuring excellent plant growth aptitude and good seedling workability, and a series of work from raising seedling to harvesting Improvement in efficiency and efficiency can be achieved.
[0058]
The particularly excellent point of the seedling raising method of the present invention is that a large amount of seedling box fertilization is achieved by using a reinforcing sheet having a function that has been difficult to achieve both of the ability to penetrate the root and the mat reinforcement at the time of attaching the rice transplanter It was the point that the trouble at the time of the installation work to the rice transplanter due to the poor mat formation by the seedling raising method could be solved.
That is, according to the seedling raising method of the present invention, when mounted on a rice transplanter, there is no problem due to the mat reinforcing effect of the reinforcing sheet even if the net soil volume is small and the mat formation is poor due to the seedling box mass fertilization method. Work can be done.
[0059]
The mat reinforcing effect by the reinforcing sheet will be further described.
The mat strength of the seedling mats (Examples 7 to 10) by the seedling box mass fertilization breeding seedling method to which the seedling raising method of the present invention is applied is compared with the conventional seedling box mass fertilization breeding seedling method (nothing under the floor soil (comparison) Compared to Example 5), newspaper (Comparative Example 6), or a conventional seedling sheet for underlaying (Comparative Example 7)), it is 2.2 to 2.5 times stronger, and raising seedlings. It is 1.4 to 1.5 times stronger than general young seedling raising seedlings (Comparative Example 8 (newspaper laid under the floor soil)) that does not perform large-volume fertilization of boxes, and a remarkable mat reinforcing effect It can be seen that is expressed.
[0060]
Further, in the conventional seedling box mass fertilization raising seedling method, mat formation is likely to be poor even at the seedling stage, and it was impossible to attach a rice transplanter at the seedling stage at all, but according to the seedling method of the present invention, Thus, the mat strength of the mat at the time of seedling by the seedling box mass fertilization raising seedling method is considerably stronger than the general seedling raising seedling that does not perform mass fertilization of the seedling box, so the mat has less root and the mat Even if the strength is a little weaker, it is still possible to attach a rice transplanter, so depending on the choice of conditions such as the strength of the reinforcing sheet and the time of seedling, the seedling box mass fertilization raising seedling method can be applied. It is considered possible.
Furthermore, since the reinforcing sheet used in the seedling raising method of the present invention also has an alternative function of floor soil, depending on the selection of conditions such as the thickness of the reinforcing sheet, the amount of fertilizer applied to the seedling box, the seedling time and the seedling period, etc. It is also conceivable to use no soil or synthetic medium.
[0061]
As described above, the conventional method of mass-seeding seedling box mass fertilization has excellent effects such as omission or reduction of additional fertilizer work after Honda transplantation, but the mat formation tends to be poor, so the diffusion rate is extremely low, and it is extremely limited. However, according to the seedling raising method of the present invention, the seedling box mass fertilization raising seedling method can be carried out without worrying that the mat formation will be poor.
Therefore, the seedling raising method of the present invention is a seedling raising method that can spread the seedling box mass fertilization raising seedling method widely and generally.
[0062]
In addition, according to the seedling raising method of the present invention, the root penetrates the reinforcing sheet so that the root and the reinforcing sheet are integrated to form a block. Effective fertilizer capture becomes very good, and more slow-release fertilizer is fertilized near the roots at the time of Honda transplantation, so the fertilization efficiency is further increased.
As a result, according to the seedling box mass fertilization raising seedling method
(1) Additional fertilization work after Honda transplanting can be omitted or reduced.
(2) Since the slow-acting fertilizer trapped in the root is fertilized near the root at the time of Honda transplantation, the efficiency and effectiveness of the fertilizer effect is improved and good survival is obtained (additional fertilization after Honda transplantation) Compared to the case, the amount of fertilization can be reduced by 30-40%.)
(3) The amount of cultivated soil to be fertilized in large quantities in the seedling box can be reduced by 30-40%.
(4) Even during the seedling period, the fertilizer concentration in the floor soil is always kept at a high level that does not cause damage, so that seedling growth is good.
You can enjoy all the benefits such as.
[Brief description of the drawings]
FIG. 1 is a depiction diagram showing a state where a mat obtained by the seedling raising method of the present invention is lifted with one hand.
[Explanation of symbols]
1 Reinforcement sheet
2 floor soil or synthetic medium mat
3 slow release fertilizer
4 seedlings
[Table 1]

[Table 2]

Claims

A hydrophilized sheet containing 50 to 90% by weight of cellulose fiber that has not been subjected to chemical treatment and is not substantially fibrillated, wherein the sheet has a thickness of 0.8 to 5 mm and a density of 0. 0.1 to 0.5 g / cm ³ , and the wet tensile strength obtained by measuring the fiber orientation direction and the direction perpendicular to the fiber orientation of the sheet after being immersed in distilled water at 20 ° C. for 5 minutes. (Measurement based on JIS P-8113) and wet tear length (measurement based on JIS P-8113) each have a wet tensile strength of 0.2 to 1.0 kg / 15 mm width, and the wet tear length is 0. A reinforcing sheet composed of 0.02 to 0.1 km is prepared, and the reinforcing sheet is laid on a seedling box, and on the reinforcing sheet, it is transplanted to at least the amount of fertilizer and Honda necessary for the seedling raising period and before harvesting. All of the required amount A seedling raising method characterized in that seedlings are grown by seeding after supplying most of the fertilizer.

On the reinforcing sheet, in order to supply the fertilizer of the amount necessary for the seedling period and all or most of the fertilizer necessary for the harvesting after transplanting to Honda, the fertilizer is supplied together with the soil or the synthetic medium. The seedling raising method according to claim 1, wherein the seedling raising method is performed.

The seedling method according to claim 1 or 2, wherein the seedling after sowing according to claim 1 is transplanted to Honda at the stage of seedling or young seedling.

A hydrophilized sheet containing 50 to 90% by weight of cellulose fiber that has not been subjected to chemical treatment and is not substantially fibrillated, wherein the sheet has a thickness of 0.8 to 5 mm and a density of 0. 0.1 to 0.5 g / cm ³ , and the wet tensile strength obtained by measuring the fiber orientation direction and the direction perpendicular to the fiber orientation of the sheet after being immersed in distilled water at 20 ° C. for 5 minutes. (Measurement based on JIS P-8113) and wet tear length (measurement based on JIS P-8113) each have a wet tensile strength of 0.2 to 1.0 kg / 15 mm width, and the wet tear length is 0. A reinforcing sheet composed of 0.02 to 0.1 km is prepared, the reinforcing sheet is laid on a seedling box, and on the reinforcing sheet, not only the amount of fertilizer required for the seedling period, but also the soil or the synthetic medium, Honda After transplanting to After supplying all or most of the fertilizer required for harvesting, irrigating, sowing, covering, budding, greening, and transplanting to Honda at the seedling or seedling stage The seedling raising method characterized.

The seedling raising method according to claim 1, wherein the cellulose fiber is a wood fiber.

The seedling raising method according to claim 1, wherein the hydrophilized sheet is a papermaking sheet.

The fertilizer supplied as all or most of the fertilizer necessary for the harvest after transplanting to Honda is a coated slow-release fertilizer. Seedling raising method.