Study on a new type of environment-friendly polymer and its preliminary application as soil consolidation agent during tree transplanting

Abstract

Transplanting trees with rhizospheric soil is an important way to facilitate tree survival in the process of landscaping and reforestation. Traditional way to prevent looseness of rhizospheric soil is forming soil balls around the roots with bags, boxes or rope wrapping, which is cumbersome, laborious and easy to break. This study is aimed to develop a new type of degradable environment-friendly polymer as soil consolidation agent to facilitate tree transplanting. In this paper, the KGM/CA/PVA ternary blending soil consolidation agent was prepared by using Konjac glucomannan (KGM), chitosan (CA) and polyvinyl alcohol (PVA) as raw materials. Through the verification and evaluation, the clay and sandy soil can be consolidated and formed into soil balls by the ternary blend adhesive, which was convenient for transportation. The preliminary application of the ternary blend adhesive in the transplanting process of sierra salvia, Japanese Spindle (Euonymus japonicus) and Juniperus sabina ‘Tamaricifolia’ confirmed that the application of soil consolidation agent can effectively solve the problem that the root ball of seedling is easily broken in the process of transplant. And the application of soil consolidation agent has no adverse effect on the growth of transplanted seedlings. The research and development of ternary blending soil consolidation agent and its preliminary application in seedling transplanting will provide a new solution to solve the problem of soil ball breakage in the process of seedling transplanting. This is an important stage in the development of new seedling transplanting technology. Therefore, the research and development of soil consolidation agent is of great significance.

Method for Simulating the Anti-Damage Performance of Consolidation Soil Balls at the Roots of Seedlings during Transportation Using Consolidated Soil Columns

“…The diameter and height of the soil ball at the root of the transplanted seedlings are proportional to the diameter at breast height (DBH) of the transplanted seedlings [11]. Generally, the thicker the DBH of transplanted seedlings, the larger the soil ball requirement at the root of the seedlings [12][13][14]. Due to the loose soil in the nursery, the soil ball has a low degree of consolidation.…”

“…Due to the loose soil in the nursery, the soil ball has a low degree of consolidation. After successfully raising seedlings from the nursery, the soil balls at the roots of the seedlings are easily broken during transportation due to squeezing, bumping, and mutual impact [13][14][15]. In order to ensure the integrity of the soil ball at the root of seedlings, commonly employed methods currently include wrapping, binding, or wooden crate packaging, among others.…”

“…The key is that it is difficult to ensure the integrity of soil balls in the end, especially during the loading, unloading, and transportation of seedlings, where the mother soil ball is often damaged. Among the causes of death of transplanted seedlings, soil ball breakage is the main cause [8,12,13,16].…”

“…Based on this, in response to the demand for the integrity of the mother soil ball during seedling transplantation, our research team prepared environmentally friendly and degradable polymer-based soil consolidation agents using biodegradable and environmentally friendly materials such as konjac glucomannan (KGM) [25][26][27][28][29][30], chitosan (CA) [31][32][33][34], and polyvinyl alcohol (PVA) [35,36] as the main raw materials in the previous research work [13][14][15][16]. The prepared KGM/CA/PVA soil consolidation agent was uniformly sprayed to the surface of the soil ball at the root of the transplanted seedlings.…”

“…Once this consolidating agent had dried, it formed a rigid, net-like film together with the soil on the surface of the root ball. We have observed that after completing the transplanting task, the KGM/CA/PVA net-like gel film formed on the surface of the root ball of transplanted seedlings gradually degraded [13][14][15]. Furthermore, the degradation products were non-polluting to groundwater and soil, and they did not adversely affect the growth of the seedlings [13][14][15]20].…”