The High Cost of the Low-Cost Polybag System: A Review of Nursery Seedling Production Systems

Abstract

An important strategy for meeting global landscape restoration goals is nursery production of high-quality seedlings. Growing seedlings with attributes that promote post-planting survival and growth can be dramatically influenced by the nursery container system. In many countries, nurseries produce seedlings in polybags filled with excavated soil. These seedlings often develop deformed roots with limited fibrosity which can lead to poor survival and growth after outplanting. Polybags are initially inexpensive but using these single-use plastic containers accrues expenses that are often untracked. Comparisons among nursery production systems must account for factors such as container longevity, labor efficiency, and seedling field performance. A more holistic approach to account for environmental, economic, social, logistic, and cultural elements in the cost–benefit equation that influences nursery production systems is needed. Converting to a modern container system requires concomitant adjustments in nursery scheduling and culturing matched to the new stock type. Doing so provides an opportunity to align nursery production techniques and resulting seedling attributes with anticipated field conditions. This article describes and discusses the advantages and disadvantages of nursery production systems and provides recommendations and case studies to aid nurseries in improving seedling quality toward meeting restoration goals in a cost-effective and timely manner.

Quality of African mahogany seedlings in substrates with soils from the Cerrado biome

“…The substrate density is influenced, by soil texture, nature and amount of organic matter, particle size and arrangements, bulk density of the materials used, total porosity and its distribution, packaging and the pressure applied when filling the containers (Othman et al, 2019; Haase et al, 2021). The addition of CRH, which has great lightness and volume, promoted a decrease in density and an increase in porosity in the substrates evaluated in this study.…”

“…A quality seedling should have characteristics that provide a high chance of survival and rapid initial growth in the field (Auca et al, 2018). The production of seedlings considered to be of good quality depends on several factors, including the composition of the substrates (Araújo et al, 2020;Haase et al, 2021), substrate humidity, substrate porosity, temperature, recipient volume, irrigation, fertilization, and the seedlings management in the forest nursery (Costa et al, 2015;Marques et al, 2018). Root initiation and rooting, biomass accumulation and quality indicators are directly related to the chemical, physical and biological characteristics of the substrate (Delarmelina et al, 2014;Othman et al, 2019;Araújo et al, 2020;Haase et al, 2021).…”

“…In visits carried out by the authors to foresters in western Maranhão, it was found that commercial substrates for the nursery phase available on the market have a high cost, which has led forest seedling producers to use soil and organic materials available locally. Typically, land for nursery production has high density values, poor drainage and low fertility, as they are extracted from the B horizon of weathered soils (Haase et al, 2021). For this reason, there is a need to generate results that demonstrate the technical efficiency of mixtures of organic materials with representative soils in the region.…”

Accounting for seedling performance from nursery to outplanting when reforesting degraded tropical peatlands

“…Furthermore, despite the higher cost, bakuls have the advantage of potential provision of alternative income benefits (e.g. USD 800 income across two groups involving 19 local women, from producing 3,000 bakul for Borneo Nature Foundation‐related planting in 2019: BNF, unpublished data), plus avoiding the plastic waste costs associated with polybags (Haase et al 2021).…”

Water Relations, Gas Exchange, Chlorophyll Fluorescence and Electrolyte Leakage of Ectomycorrhizal Pinus halepensis Seedlings in Response to Multi-Heavy Metal Stresses (Pb, Zn, Cd)

“…To improve the survival, growth and physiological processes of tree seedlings that are intended for reforestation and mine site restoration programs, the use of seedlings with high morphophysiological quality that are produced in modern forest nurseries is necessary [8,9,36]. In addition to the choice of local forest species that are already adapted to the interactions of different environmental stresses, improving the root system using compatible host-ectomycorrhizal fungi that are resistant to environmental stresses would improve the survival, growth and physiology of the seedlings after their installation in mining and reforestation sites.…”