Impact of Sugarcane Bagasse Ash as an Amendment on the Physical Properties, Nutrient Content and Seedling Growth of a Certified Organic Greenhouse Growing Media

Abstract

Sugarcane bagasse is the fibrous material remaining after removing the sucrose, water, and other impurities (filter mud) from the millable sugarcane. Louisiana sugarcane mills use a portion of the sugarcane bagasse to produce steam power to run equipment within the mill and/or as a boiler fuel for the clarification, evaporation, and crystallization processes. Sugarcane bagasse ash (SBA) is a by-product of the thermal conversion of the sugarcane bagasse. The purpose of this research was to investigate the use of SBA as an amendment to soilless planting media for the production of vegetable seedlings. The SBA was combined by volume with a commercial certified organic soilless growing media into 5 combinations (0%:100%, 25%:75%, 50%:50%, 75%:25%, and 100%:0%, SBA and growing media, respectively). Bean (Phaseolus vulgaris L.) var. 'Bowie' and Chinese kale (Brassica alboglabra) var. 'South Sea' were planted in each of the 5 different planting mixtures. As the percentage of SBA increased from 0% to 100%, the bulk densities increased, 0.118 to 0.712 g/cm 3 , while the porosity, water saturation percentage, and water at field capacity decreased. Increasing the SBA percentage significantly impacted total exchange capacity, pH, organic matter, estimated nitrogen release, and all other nutrients measured, except for sodium. The research indicates that the addition of SBA can enhance bean and Chinese kale seedling growth depending on the percentage of the ash added to the growth media. Bean and Chinese kale harvest parameters typically peaked at 25% SBA, and then decreased with increasing SBA %. Adding 25% SBA did benefit the seedling growth by providing additional nutrients for seedling growth, while reducing the cost of production by supplementing the more expensive greenhouse media by a readily available by-product of the sugarcane industry. Increasing the SBA % to 50% or greater is not recommend. Additional research is needed to determine the percentage above 25% and below 50% SBA that would still benefit seedling plant growth.

Sugarcane Biochar as an Amendment for Greenhouse Growing Media for the Production of Cucurbit Seedlings

“…The bulk densities then decreased from their highs at 25 and 50% levels as biochar content increased to 100%, 0.11 g cm -3 (SBB) and 0.11 g cm -3 (PBB) ( Table 3). These results are in contrast to similar research using the same mixture combinations with sugarcane bagasse ash instead of sugarcane biochar (Webber et al, 2017b). The bulk densities remained in an ideal range when the biochars were added, unlike earlier research where the addition of sugarcane bagasse ash increased bulk densities from 0.12 to 0.71 g cm -3 (Webber et al, 2017b).…”

“…These results are in contrast to similar research using the same mixture combinations with sugarcane bagasse ash instead of sugarcane biochar (Webber et al, 2017b). The bulk densities remained in an ideal range when the biochars were added, unlike earlier research where the addition of sugarcane bagasse ash increased bulk densities from 0.12 to 0.71 g cm -3 (Webber et al, 2017b). In contrast to Vaughn et al (2013) who used biochar wood (0.622 g cm -3…”

“…An increase in ash content typically will increase the biochar's bulk density and potential nutrient availability for seedling production (Table 1) (Webber et al, 2017b). The greater fixed carbon percentage increases the energy value (HHV and LHV) of the SBB compared to the PBB, and may influence the potential income streams for the two biochars (Table 1).…”

“…Investigating the use of sugarcane bagasse ash as an amendment to soilless greenhouse growing media, it was determined that the amended media functioned well in many respects for the seedling production for squash, cantaloupe, bean (Phaseolus vulgaris L.), and Chinese kale (Brassica alboglabra). Unfortunatly, as the percentage of bagasse ash increased from 0 to 100% ash, the bulk densities also increased (0.12 to 71 g cm -3 ), resulting in decrease in the physical growing media (Webber et al, 2016(Webber et al, , 2017b.…”

“…In contrast to sugarcane bagasse ash, adding biochar to a soilless growing media should provide a more ideal physical environment (Laird, 2008;Webber et al, 2016;2017b). Although, in general, biochars have many characteristics in common, the plant material source and the preparation methods employed can greatly influence the properties and effectiveness when used as an amendment in soilless growing media (Vaughn et al, 2013).…”