JP2019180244A - Plant culture medium using paper making residue - Google Patents

Abstract

To solve problems in paper making residue, reuse of the paper making residue as a plant culture medium is considered, however, paper making sludge is formed of cellulose fiber mainly, so that, as it is, generation of bacteria cannot be suppressed, and for plant, the medium is in a nitrogen starvation state, on the other hand, for complete carbonization, much energy is required and actual use is inhibited in aspect of cost.SOLUTION: The medium for plant culture comprises paper making residue and charcoal, and is formed into a pellet form, and inside of the medium for plant culture is a rice hull charcoal, in the medium for plant culture, charcoal included therein generates heat by self-heating, so that, inside of the medium for plant culture is made into a rice hull charcoal with low heat quantity, and bacteria are less likely to be generated inside.SELECTED DRAWING: None

Description

  The present invention relates to a plant cultivation medium using a papermaking residue (sludge).

  A papermaking residue is an aggregate of extremely short fibers, and as such has very good water retention. Moreover, it is a problem for papermaking related companies to treat papermaking residues as industrial waste. Therefore, the utilization method has been examined as a culture medium for plant cultivation (Patent Document 1). However, when a plant is grown using the material as a culture medium, the papermaking residue itself rots. Eventually, a large amount of mold, yeast, bacteria, etc. are generated in the medium, and the fertilizer elements added for the purpose of plant fertilizer are utilized for these microorganisms that grow quickly. Therefore, it becomes a nitrogen starvation state for the plant, and the growth of the plant is inhibited.

  In order to solve the problem, as a prior art, a paper was obtained by dehydrating and pulverizing a papermaking residue into a granular papermaking residue and further carbonizing only the surface of these grains (Patent Document 2).

JP-A-9-28178 JP 52-20374 A

  However, since the following problems have not been solved in the medium prepared by the above method, it has not been put into practical use. The first reason is that the surface of the carbonized granular papermaking residue becomes hydrophobic, so that it repels water and the water absorption decreases. The second reason is that the surface carbonization can suppress the growth of mold and microorganisms in the case of short-term use (for example, sowing culture medium), but long-term use (for example, bonsai culture medium). Cellulose inside the non-carbonized particles is spoiled by microorganisms. This leads to nitrogen starvation of the plant.

  Complete carbonization of papermaking residues was also investigated. Like rice husk charcoal medium. However, carbonization of papermaking residue cannot be a suitable medium for plant growth. The reason is as follows. The first reason is that, by carbonizing the papermaking residue, the aggregate that has lost the hydroxy group, which is a hydrophilic functional group, has a significantly reduced water absorption. The second reason is that the papermaking residue is an aggregate of extremely short fibers, and once water is absorbed, the water retention is too strong and the air permeability is hindered.

  The present invention has been conceived in view of the above problems, and provides a plant cultivation medium that is formed into pellets and carbonized to the inside using papermaking residues.

More specifically, the plant cultivation medium according to the present invention comprises:
It contains papermaking residue and activated carbon, and is charred to the inside.

  Furthermore, the activated carbon to be mixed is characterized in that it contains a certain amount of nitrogen and minerals necessary for plant growth, specifically phosphorus, calcium, magnesium, potassium, molybdenum and the like.

  By mixing the activated carbon, the set temperature of carbonization of the particles can be suppressed to 200 to 300 ° C., and the required time is reduced to half or less. The reason is considered to be due to the far-infrared effect of activated carbon.

  By mixing the activated carbon, it became possible to decompose the organic matter not only on the surface of the particles but also inside to convert it into a substance with many carbon components by heating at 200 to 300 ° C. in an oxygen-free state. In addition, the pores inherent to the activated carbon are maintained, and water retention and air permeability are improved by carbonization.

  Moreover, since the fertilizer component contained in charcoal is confined in pores and fine structures such as carbon, it is expected to gradually elute. Therefore, it can also be used as seed sowing culture soil containing a slow-acting fertilizer.

  In addition, the carbonized pellets mainly composed of papermaking residues can be incinerated when discarded. In addition, overseas exports of Japanese bonsai have increased rapidly in recent years, but there are many countries where quarantine restrictions are imposed on imports of plants with soil culture media. However, it is expected that the hurdles of quarantine at the time of export will be lowered by bonsai cultivation using a charcoal carbonized PS pellet medium instead of soil.

  The plant cultivation medium according to the present invention will be described below with reference to examples. The following description shows one embodiment of the present invention, and the present invention is not limited to the following description. The following description can be modified without departing from the spirit of the present invention.

The papermaking machine had a water content of 10 to 50 as a base material, and 5 to 40 parts by mass of charcoal were mixed with 100 parts by mass of the papermaking machine.
Furthermore, the mixture was pelletized.
The pellet was carbonized at 250 ° C. in an oxygen-free state.
The produced char carbonized PS pellet was used as a plant cultivation medium.
As a cultivation experiment, cultivation of vitamin vegetables was carried out from sowing.

  The seeds of vitamin vegetables are relatively small, 1-2 mm. However, since the diameter of the carbonized PS pellet is as large as 7 mm, the gap between the pellets is considerably larger than the seed. Therefore, seeds sown on the surface of the medium fall into the gaps in the medium. For this reason, seeds that have fallen into the deep part of the medium are likely to fail to germinate. Moreover, it cannot be said that a medium having a large gap is suitable as a base material for supporting freshly rooted roots.

  Therefore, a base material for filling between the pellets of the medium was prepared. It was broken by applying pressure and impact to the carbonized PS pellets to make small pieces. The collapsed pellets were sieved with a wire mesh (mesh 2.5 mm), and small pieces were collected. This small piece was mixed with semi-carbonized pellets (small piece: pellet = 1: 5, volume ratio) to obtain a medium.

  Powder having a mesh size of 1.5 mm or less is not used as a medium because it may cause clogging of the medium.

  Even in this fragmentation process, the present invention can be performed simply by applying an impact. The reason for this is considered to be that the inside of the pellet is sufficiently carbonized and the cellulose fiber is not left so that it is brittle against impact. In addition, the surface and the inside of the small piece have innumerable pores due to the mixture of charcoal. Therefore, even if a small piece fills the gap between the pellets, drainage and air permeability are maintained.

  As a result of the vitamin vegetable cultivation experiment, “seedling culture soil” was used as the target section. The results are shown in Table 1. In Table 1, “carp carbonized PS pellet medium” is a culture medium for cultivation according to the present invention.

  In the carbonized PS pellet medium, rooting and germination were slightly delayed compared to the sowing medium, and the leaf width and plant height were both small. The reason is considered to be that the surface near the surface of the carbonized PS pellet is easy to dry. As a countermeasure, it is improved by covering with wet newspaper immediately after sowing until germination and rooting. Alternatively, it can be overcome by soaking the seed overnight in water. Furthermore, after germination and rooting, it was found that it grows in no way inferior to seed sowing medium. It has been confirmed that it is also effective as a bonsai cultivation area for pine, southern sky, ten thousand cars, firewood, etc.

  The culture medium for plant cultivation according to the present invention can be used not only for plant cultivation but also effectively as a temporary medium for plant export.

Claims (1)

  A plant cultivation medium that is formed into pellets containing papermaking residue and charcoal, and is carbonized inside.