201121425 六、發明說明 【發明所屬之技術領域】 本發明係有關挺水植物、浮葉植物 於淡水水域底泥中之水生植物的發芽防 物的防止發芽方法。 【先前技術】 已知於河川及湖泊等淡水水域中， 中或底泥中吸收磷及氮等營養鹽類後生 發生藻華（water bloom)之效果。 然而，當水生植物生長異常茂盛時 成惡臭（對生活的不良影響）、船舶航； (漁場環境惡化）、湖底環境惡化（泥化’ 系產生不良影響的各式問題。 去除茂盛生長於淡水水域之水生植 生植物割除之方法。但該方法需要極大 必須處理割除的水生植物之問題。 專利文件1記載作爲防止地面上的 係使地面硬化之方法。該專利文件1所 之方法，係供給地面含氧化鎂之雜草繁 草繁殖防止材與土壤攪拌及混合後，澆 壤混合之氧化鎂與水產生反應而硬化之 [先前技術文件] [專利文件] 及沉水植物等生根 止劑，以及水生植 由於水生植物自水 長茂盛，具有抑制 ，會發生因腐敗造 Ϊ障礙、漁業障礙 缺氧化）等對生態 物的方法，有將水 的勞動力，且存在 雜草繁殖之方法， 記載之使地面硬化 殖防止材，且將雜 水於土壤，使與土 方法。 -5- 201121425 [專利文件1]特開2003-47388號公報 【發明內容】 [發明欲解決之課題] 前述專利文件1中所記載之使地面硬化的方法，對防 止地面的雜草繁殖極爲有效，但由於淡水水域的底泥棲息 著許多種生物’使淡水水域的底泥硬化，恐將對淡水水域 的生態係造成不良影響。 因此’本發明之目的係提供不會使淡水水域之底泥硬 化’且可防止水生植物發芽之方法，以及適用於防止該水 生植物發芽之水生植物的發芽防止劑。 [解決課題之手段] 本發明團隊發現於淡水水域之底泥上散佈粒徑爲 1 mm以下之氧化鎂粉末，可不使底泥硬化，且可防止水 生植物發芽。 因此，本發明係一種根系生根於淡水水域底泥中之水 生植物的發芽防止劑，其係含有粒徑爲1 m m以下之氧化 鎂粉末。 適合本發明之水生植物的發芽防止劑的實施方式係如 下所述。 (1) 氧化鎂粉末係含有80質量％以上之粒徑爲1mm 以下之粒子。 (2) 氧化錶粉末係含有80質量％以上之粒徑爲 -6- 201121425 0.75mm以下之粒子。 (3 )氧化鎂粉末係顯示2.1 0g/cm3以上之表觀密度。 (4) 氧化鎂粉末係燒硬氧化鎂粉末或電熔氧化鎂粉 末。 (5) 水生植物係菱科[Hydrocaryaceae family(亦稱 Trapaceae family)]植物。 本發明進而係於淡水水域之底泥上散佈前述本發明之 水生植物的發芽防止劑，防止挺水植物、浮葉植物及沉水 植物等生根於淡水水域底泥中之水生植物發芽之方法。 [發明的效果] 藉由將本發明之水生植物的發芽防止劑散佈於淡水水 域之底泥上，可效率良好地防止特別爲菱科植物的發芽。 [實施發明之最佳型態] 本發明之發芽防止劑係含有粒徑爲1 m m以下較細微 的氧化鎂粉末。氧化鎂粉末之平均粒徑以0.75mm以下爲 佳，0.03〜0.5mm之範圍更佳。氧化鎂粉末之表觀密度 (或體密度）以2.10 g/cm3以上爲佳，3.10〜3.56 g/cm3之 範圍更佳’ 3.10〜3.50 g/cm3之範圍亦佳，3.15〜3.30 g/cm3之範圍特佳。氧化鎂粉末之表觀密度可以阿基米得 原理爲基礎之氣相取代法進行測定。 本發明之發芽防止劑所使用之氧化鎂粉末，亦可含有 較粒徑爲1 mm大的粗顆粒。但氧化鎂粉末以含有go質量 201121425 %以上之粒徑1 mm以下之細微粒子爲佳，含有90質量％ 以上特佳。進而氧化鎂粉末以含有80質量％以上之粒徑 爲0.7 5mm以下之粒子爲佳，含有90質量％以上特佳。另 外，以含有80質量％以上之粒徑較0.005mm爲大之粒子 爲佳，含有90質量％以上特佳。 本發明之發芽防止劑所使用之氧化鎂粉末，以燒硬氧 化鎂粉末及電熔氧化鎂粉末爲佳。 本發明中燒硬氧化鎂粉末，可藉由將氫氧化鎂及碳酸 鎂等鎂化合物以900°C以上，更佳以1 600°C以上之溫度， 特佳以1700〜210(TC之溫度，進行燒成後所得之氧化鎂 燒成物，直接使用或使其經破碎處理後，以篩子等一般分 級的方法調整粒度之方法製造。 本發明中電熔氧化鎂粉末，可藉由將氧化鎂或氫氧化 鎂及碳酸鎂等鎂化合物，進行電熔後所得之氧化鎂溶融固 化物，直接使用或使其經破碎處理後，以篩子等一般分級 的方法調整粒度之方法製造。 使用爲燒硬氧化鎂粉末及電熔氧化鎂粉末之製造原料 的氫氧化鎂，可舉出例如藉由將熟石灰加入海水、或含鎂 鹽的鹽滷及鹽水中後，使析出之氫氧化鎂乾燥而獲得氫氧 化鎂粉末。碳酸鎂可舉出例如天然的菱鎂礦。使用爲電熔 氧化鎂粉末之製造原料的氧化鎂，可舉出例如燒輕氧化鎂 粉末、燒硬氧化鎂粉末以及燒結氧化鎂。 氧化鎂燒成物以及氧化鎂溶融固化物其體密度以2.1 0 g/cm3以上爲佳，3.10〜3.50 g/cm3之範圍更佳，3.10〜 -8- 201121425 3.3 0 g/cm3之範圍特佳。且氧化鎂燒成物以及氧化鎂溶融 固化物之體密度，可使用媒介爲煤油並利用阿基米得法進 行測定。 藉由將本發明之發芽防止劑散佈於淡水水域之底泥 上，可防止挺水植物（例如蘆葦、香蒲、蓮花、茭白筍、 水蔥、萍蓬草）、浮葉植物（例如菱角，大王蓮、睡蓮、眼 子菜）、以及沉水植物（例如水蘭、水蘊草、聚藻、馬藻、 輪藻）等根系生根於淡水水域底泥中之水生植物發芽。 發芽防止劑之散佈量係相對於面積1 m2之底泥，以 0.1〜10 kg之範圍爲佳，〇.5〜5kg之範圍特佳。發芽防止 劑之散佈時期，以水生植物開始發芽期的1週〜3個月前 爲佳。 並未特別限制發芽防止劑之散佈方法。例如可將發芽 防止劑以粉末狀態散佈於淡水水域的水面，或可將使發芽 防止劑分散於水中後，以分散液的狀態注入淡水水域的水 中。 被散佈於淡水水域之發芽防止劑，會沉降至淡水水域 中而快速到達底泥的表面。由於到達底泥表面的發芽防止 劑（氧化鎂粉末）屬於微小粉末，迅速溶解於水使周圍的底 泥變質爲弱鹼性的同時，溶解的鎂離子會與底泥周圍的磷 化物產生反應，形成難溶性的磷酸鎂。藉由使底泥變質爲 弱鹼性，進而使底泥周圍的磷化物成爲難溶於水的磷酸鎂 加以固定，可有效地抑制水生植物的發芽。 -9 - 201121425 【實施方式】 [實施例] [實施例1] 採取湖中菱角茂盛生長的底泥與湖水，使 (長 18 cm X 寬 30 cm X 高 23 cm)中，底 3cm，湖水深度爲約9cm。其次將54g(底泥每 量爲lkg)之燒硬氧化鎂粉末（粒徑：〇.75mm以 度：3.23 g/cm3)，以均勻堆積於底泥全體上之 佈，並靜置。圖1係顯示經3週後自透明塑膠 行攝影之相片。如圖1所示，即使經過.3星期 生長。另外，以玻璃棒穿刺經過3星期後之底 底泥有硬化現象。 [比較例1 ] 除未散佈氧化鎂粉末之外，進行與實施例 驗，將底泥與湖水置入透明塑膠箱後並靜置。 經3週後自透明塑膠箱的上方進行攝影之相片 示，經過3星期後菱角生長茂盛。 【圖式簡單說明】 [圖1]自實施例1透明塑膠箱的上方進 片。 [圖2]自比較例1透明塑膠箱的上方進 片。 透明塑膠箱 泥深度爲約 lm2面積之 下，表觀密 方式進行散 箱的上方進 亦未有菱角 泥，未發現 1相同之實 圖2係顯示 。如圖2所 行攝影之相 行攝影之相 -10-201121425 VI. Description of the Invention [Technical Field] The present invention relates to a method for preventing germination of germination inhibitors of aquatic plants in the sediment of freshwater waters of emergent plants and floating plants. [Prior Art] It is known that in freshwater waters such as rivers and lakes, the effect of water bloom occurs after absorbing nutrients such as phosphorus and nitrogen in the middle or sediment. However, when the aquatic plants grow abnormally, they become stinking (bad effects on life), ship navigation; (the fishery environment deteriorates), and the lake bottom environment deteriorates (muddy' system has various problems of adverse effects. Removal of lush growth in freshwater waters The method of cutting aquatic plants, but this method requires a great deal of the problem of cutting the aquatic plants. Patent Document 1 describes a method for preventing the ground from hardening on the ground. The method of Patent Document 1 is for supplying the ground. The weeds of magnesium oxide are propagated to prevent the soil and the soil from being stirred and mixed, and the mixed magnesium oxide reacts with water to harden it [previous technical documents] [patent documents] and rooting agents such as submerged plants, and aquatic Because of the growth of aquatic plants due to the prosperous waters, there are methods for inhibiting ecological diseases such as osmotic barriers due to corruption and lack of oxidation in fisheries, and there is a method of reproducing the labor of weeds and weeds. Ground hardening prevents the material, and will mix the water into the soil to make the soil method. [Patent Document 1] JP-A-2003-47388 SUMMARY OF INVENTION [Problem to be Solved by the Invention] The method of hardening the ground described in the above Patent Document 1 is extremely effective for preventing weed propagation on the ground. However, because the sediments of freshwater waters are inhabited by many kinds of organisms', the sediments in freshwater waters are hardened, which may adversely affect the ecosystems of freshwater waters. Therefore, the object of the present invention is to provide a method for preventing the germination of aquatic plants without hardening the sediment of fresh water, and a germination preventing agent for aquatic plants suitable for preventing the germination of the aquatic plants. [Means for Solving the Problem] The present inventors have found that magnesium oxide powder having a particle diameter of 1 mm or less is dispersed on the bottom mud of fresh water, so that the sediment can be hardened and the aquatic plants can be prevented from germinating. Accordingly, the present invention is a germination preventing agent for root plants rooted in the sediment of freshwater water, which contains magnesium oxide powder having a particle diameter of 1 m or less. Embodiments of the germination preventing agent suitable for the aquatic plant of the present invention are as follows. (1) The magnesium oxide powder contains 80% by mass or more of particles having a particle diameter of 1 mm or less. (2) The oxidation table powder contains 80% by mass or more of particles having a particle diameter of -6-201121425 0.75 mm or less. (3) The magnesium oxide powder showed an apparent density of 2.10 g/cm3 or more. (4) Magnesium oxide powder is burnt hard magnesium oxide powder or fused magnesium oxide powder. (5) Hydrocaryaceae family (also known as Trapaceae family) plants. Further, the present invention is a method for dispersing the above-mentioned germination preventing agent for aquatic plants of the present invention on the sediment of fresh water, and preventing the germination of aquatic plants rooted in the sediment of freshwater water, such as emergent plants, floating leaf plants and submerged plants. [Effects of the Invention] By displacing the germination preventing agent of the aquatic plant of the present invention on the sediment of the freshwater water region, germination particularly in the Lingaceae plant can be effectively prevented. [Best Mode of Carrying Out the Invention] The germination preventing agent of the present invention contains finely divided magnesium oxide powder having a particle diameter of 1 m or less. The average particle diameter of the magnesium oxide powder is preferably 0.75 mm or less, and more preferably in the range of 0.03 to 0.5 mm. The apparent density (or bulk density) of the magnesium oxide powder is preferably 2.10 g/cm 3 or more, and the range of 3.10 to 3.56 g/cm 3 is more preferable. The range of 3.10 to 3.50 g/cm 3 is also preferably 3.15 to 3.30 g/cm 3 . The range is excellent. The apparent density of the magnesium oxide powder can be measured by a gas phase substitution method based on the principle of Archimedes. The magnesium oxide powder used in the germination preventing agent of the present invention may contain coarse particles having a larger particle diameter of 1 mm. However, the magnesium oxide powder preferably contains fine particles having a particle diameter of 1, 2011,225,5% or more and a particle diameter of 1 mm or less, and is preferably 90% by mass or more. Further, the magnesium oxide powder is preferably a particle having a particle diameter of 80% by mass or more and 0.75 mm or less, and more preferably 90% by mass or more. Further, it is preferable that the particles having a particle diameter of 80% by mass or more are larger than 0.005 mm, and more preferably 90% by mass or more. The magnesium oxide powder used in the germination preventing agent of the present invention is preferably a calcined magnesia powder or an fused magnesia powder. The burnt hard magnesium oxide powder in the present invention may be a temperature of 900 ° C or higher, more preferably 1 600 ° C or higher, and particularly preferably 1700 to 210 (TC temperature), by using a magnesium compound such as magnesium hydroxide or magnesium carbonate. The calcined magnesia obtained after calcination is used as it is, or is subjected to crushing treatment, and then produced by a method of adjusting the particle size by a general classification method such as a sieve. In the present invention, the fused magnesia powder can be obtained by using magnesium oxide. Or a magnesium compound such as magnesium hydroxide or magnesium carbonate, which is obtained by directly melting or crushing the magnesium oxide melted product obtained by electrofusion, and then is manufactured by a method of adjusting the particle size by a general classification method such as a sieve. The magnesium hydroxide of the raw material of the magnesium oxide powder and the fused magnesia powder can be obtained by, for example, adding slaked lime to seawater or a salt of a magnesium salt and brine, and drying the precipitated magnesium hydroxide to obtain a hydroxide. Magnesium powder, for example, natural magnesite, and magnesium oxide used as a raw material for producing fused magnesium oxide powder, for example, calcined light magnesium oxide powder or burnt hard magnesium oxide powder Sintered magnesia. Magnesium oxide calcined product and magnesia molten solidified body preferably have a bulk density of 2.10 g/cm3 or more, and a range of 3.10 to 3.50 g/cm3 is more preferable, 3.10~-8-201121425 3.3 0 g/cm3 The range of the magnesium oxide burned material and the magnesia molten solidified body can be measured by using the medium as kerosene and using the Archimedes method. The germination preventive agent of the present invention is dispersed in the bottom of fresh water. On the mud, it can prevent emergent plants (such as reeds, cattails, lotus, white bamboo shoots, scallions, scallops), floating leaf plants (such as water chestnuts, big lotus, water lily, eye vegetables), and submerged plants (such as water) Roots such as orchid, water-grass, poly-algae, equine, and spirulina are rooted in aquatic plants in the sediment of freshwater water. The amount of germination inhibitor is 0.1 to 10 kg relative to the sediment of 1 m2. The range of 5 to 5 kg is particularly preferable. The dispersion period of the germination inhibitor is preferably from 1 week to 3 months before the germination period of the aquatic plant begins. The method for dispersing the germination inhibitor is not particularly limited. For example, a germinating agent can be used The powder state is dispersed in the water surface of the freshwater water, or the germination inhibitor can be dispersed in the water and then injected into the freshwater water in the state of the dispersion. The germination inhibitor dispersed in the freshwater water will settle into the freshwater water and quickly Reach the surface of the sediment. Since the germination inhibitor (magnesium oxide powder) reaching the surface of the sediment is a tiny powder, it dissolves rapidly in the water to deteriorate the surrounding sediment to a weak alkalinity, and the dissolved magnesium ions will surround the sediment. The phosphide reacts to form a poorly soluble magnesium phosphate, which is effective in inhibiting aquatic plants by degrading the sediment to a weakly alkaline state, thereby making the phosphide around the sediment a magnesium phosphate which is poorly soluble in water. [Embodiment] [Embodiment] [Example 1] The bottom sediment and the lake water which are lush in the water in the lake are made so that (length 18 cm X width 30 cm X height 23 cm), bottom 3 cm, The depth of the lake is about 9cm. Next, 54 g (the amount of the sludge per lkg) of the calcined magnesium oxide powder (particle diameter: 75.75 mm in degrees: 3.23 g/cm3) was uniformly deposited on the entire sediment and allowed to stand. Figure 1 shows a photograph taken from a transparent plastic after 3 weeks. As shown in Figure 1, it grew even after .3 weeks. In addition, the bottom mud was hardened after 3 weeks of puncture with a glass rod. [Comparative Example 1] Except that the magnesium oxide powder was not dispersed, the sediment and the lake water were placed in a transparent plastic case and allowed to stand. Photographs taken from above the transparent plastic box after 3 weeks showed that the water chestnuts flourished after 3 weeks. [Simplified description of the drawings] [Fig. 1] The film was fed from the top of the transparent plastic case of Example 1. [Fig. 2] The film was fed from the upper side of the transparent plastic case of Comparative Example 1. The transparent plastic box has a mud depth of about lm2, and the apparently dense method does not have a water chestnut on the top of the bulk box. No identical 1 is shown in Fig. 2. As shown in Figure 2, the phase of photography is -10-