Short-duration hydrothermal fermentation of food waste: preparation of soil conditioner for amending organic-matter-impoverished arable soils

Abstract

Soil conditioners can be used to compensate for the insufficient soil nutrition and organic matter (OM) of arable soils. However, the traditional preparation method for soil conditioners is lengthy and requires facilities that occupy large tracts of land. In this study, a short-duration hydrothermal fermentation (SHF) method was developed for the preparation of soil conditioners from food waste. The SHF method required only 18 h to produce soil conditioners with physicochemical characteristics that were similar to those of soil conditioners obtained through traditional fermentation (TF), which takes 20 days to complete. Inoculation and dynamic SHF significantly affected the distribution of different molecular weight fractions in the prepared soil conditioners. The results of spectral analysis revealed that a large amount of soluble microbial byproducts and carbohydrate C formed in the SHF soil conditioner. This effect indicated that the SHF soil conditioner supplied not only immediately available nutrients, which can stimulate the growth of soil microbial communities, but also provided sustained-release nutrients for the long-term cultivation of crops on OM-impoverished soils. Cyanobacteria were present in the SHF soil conditioner at a relative abundance of 6.29%, which was 28.6 and 314.5 times those in the raw material and TF soil conditioner, respectively. Amending OM-impoverished soil with the SHF soil conditioner enhanced the carbon pool management index of the resulting SHF soil by 1.50 and 1.12 times those of unfertilized soil and TF soil, respectively. These results indicated that the SHF soil exhibited a high capacity to supply nutrients for crop growth.

Exploring the nitrogen reservoir of biodegradable household garbage and its potential in replacing synthetic nitrogen fertilizers in China

“…Aerobic composting is a relatively environmentally friend technology for food waste treatment, as foods contain high concentrations of easily degradable organic substances and nutrients which are easily to be decomposed ( Hou et al, 2017 ). Studies have found that food waste composted with Chinese medicinal herbal residues ( Zhou, Selvam & Wong, 2018 ), green waste ( Williams et al, 2019 ), sugarcane leaves ( Shan et al, 2019 ), cattle manure ( Xing et al, 2019 ), pig manure ( Dennehy et al, 2017 ; Jiang et al, 2018 ), chicken manure ( Saad, Rahman & Yusoff, 2019 ) could be processed to form biological fertilizers, which would increase organic matters in the soil and improve the soil structure ( Wang & Zeng, 2018 ).…”

“…Therefore, this article did not consider them as organic fertilizers. During fermentation process, various components in food waste are converted into stable humus-like substances and rapidly available nutrients, which can be quickly hydrolyzed ( Bi et al, 2019 ), or directly absorbed by plants ( Hou et al, 2017 ). Those materials could also improve nutrition levels of the soil ( Du et al, 2018 ) and could be generally beneficial to soil microbial communities ( Liu et al, 2020 ) which are closely related to soil fertility.…”

Exploring the Nitrogen Reservoir of Biodegradable Household Garbage and its Potential in Replacing Chemical Fertilizers in China

“…Aerobic composting is currently a relatively environmentally friend technology for food waste treatment, as it contains high concentrations of easily degradable organic substances and nutrients which are easily to be decomposed (Hou et al 2017 (Saad et al 2019) to form biological fertilizer, could increase organic matters in the soil and improve the soil structure (Wang and Zeng 2018). Therefore, the degradable food waste, especially rural food waste could be used on-site as fertilizers for organic crop production, reducing transportation costs and increasing farmers' income.…”

“…Therefore, this article did not consider treating them as organic fertilizers. During fermentation process, various components in food waste are converted into stable humus-like substances and rapidly available nutrients, which can be quickly hydrolyzed (Bi et al 2019), or directly absorbed by plants (Hou et al 2017). Those materials could also improve nutrition levels of the soils (Du et al 2018).…”

An innovative solution for rural food waste treatment: From waste to organic grains

“…For instance, it is suitable to be processed into a stable and nutrient-rich biological fertilizer (Haddad and Batarseh 2019;Waqas et al 2019). Studies have demonstrated that food waste could be fermented to prepare soil conditioners, which might decrease carbon emission and improve land use e ciency (Hou et al 2017). Some found that long-term application of food waste could increase total organic carbon content in orchard soils and improve soil fertility (Jia et al 2019).…”