Reuse of Wasted Bread as Soil Amendment: Bioprocessing, Effects on Alkaline Soil and Escarole (Cichorium endivia) Production

: In an era characterized by land degradation, climate change, and a growing population, ensuring high-yield productions with limited resources is of utmost importance. In this context, the use of novel soil amendments and the exploitation of plant growth-promoting microorganisms potential are considered promising tools for developing a more sustainable primary production. This study aimed at investigating the potential of bread, which represents a large portion of the global food waste, to be used as an organic soil amendment. A bioprocessed wasted bread, obtained by an enzymatic treatment coupled with fermentation, together with unprocessed wasted bread were used as amendments in a pot trial. An integrated analytical plan aimed at assessing i) the modification of the physicochemical properties of a typical Mediterranean alkaline agricultural soil, and ii) the plant growth-promoting effect on escarole (Cichorium endivia var. Cuartana), used as indicator crop, was carried out. Compared to the unamended soils, the use of biomasses raised the soil organic content (up to 37%) and total nitrogen content (up to 40%). Moreover, the lower pH and the higher organic acid content, especially in bioprocessed wasted bread, determined a major availability of Mn, Fe, and Cu in amended soils. The escaroles from pots amended with raw and bioprocessed bread had a number of leaves, 1.7- and 1.4-fold higher than plants cultivated on unamended pots, respectively, showing no apparent phytotoxicity and thus confirming the possible re-utilization of such residual biomasses as agriculture amendments.

Investigating potential hydrological ecosystem services in urban gardens through soil amendment experiments and hydrologic models

Among the ecosystem services provided by urban greenspace are the retention and infiltration of stormwater, which decreases urban flooding, and enhanced evapotranspiration, which helps mitigate urban heat island effects. Some types of urban greenspace, such as rain gardens and green roofs, are intentionally designed to enhance these hydrologic functions. Urban gardens, while primarily designed for food production and aesthetic benefits, may have similar hydrologic function, due to high levels of soil organic matter that promote infiltration and water holding capacity. We quantified leachate and soil moisture from experimental urban garden plots receiving various soil amendments (high and low levels of manure and municipal compost, synthetic fertilizer, and no inputs) over three years. Soil moisture varied across treatments, with highest mean levels observed in plots receiving manure compost, and lowest in plots receiving synthetic fertilizer. Soil amendment treatments explained little of the variation in weekly leachate volume, but among treatments, high municipal compost and synthetic fertilizer had lowest leachate volumes, and high and low manure compost had slightly higher mean leachate volumes. We used these data to parameterize a simple mass balance hydrologic model, focusing on high input municipal compost and no compost garden plots, as well as reference turfgrass plots. We ran the model for three growing seasons under ambient precipitation and three elevated precipitation scenarios. Garden plots received 12–16% greater total water inputs compared to turfgrass plots because of irrigation, but leachate totals were 20–30% lower for garden plots across climate scenarios, due to elevated evapotranspiration, which was 50–60% higher in garden plots. Within each climate scenario, difference between garden plots which received high levels of municipal compost and garden plots which received no additional compost were small relative to differences between garden plots and turfgrass. Taken together, these results indicate that garden soil amendments can influence water retention, and the high-water retention, infiltration, and evapotranspiration potential of garden soils relative to turfgrass indicates that hydrologic ecosystem services may be an underappreciated benefit of urban gardens.

The Potential of Paper Industry Sludge Potency as Organic Soil Amandment

Sludge from the paper industry can affect soil fertility due to its organic content. However, sludge as waste has a contamination risk of polluting the soil. This research focused on the chemical properties content of sludge from the paper industry (pH, organic C, macro and micronutrients, heavy metals) and contaminant microbes (E. coli and Salmonella sp.) in order to evaluate to the potency of sludge to be soil amendment. Sludge sample was taken in 0-20 cm depth from Sumengko Village, Wringinanom, Gresik. The chemical properties were measured in Soil Chemistry Laboratory in Soil Science Department, and the biological properties were measured in Pest and Disease Laboratory in the Agricultural Faculty of Brawijaya University. The chemical and biological properties of sludge were compared to quality standards according to Keputusan Menteri Pertanian No. 261/2019 (Kepmentan No. 261/2019) from the Ministry of Agriculture, Indonesia. Sludge from the paper industry has the potency to be soil amendment because it meets the requirement from Kepmentan No. 261/2019. Its pH was neutral (6.9), the macro and micronutrients contents fit the requirement, and it had no microbial contaminant content. However, the organic C was under expectation, and it has over Hg content.

The Importance of Proper Dam Maintenance Due to the Increase of Torrential Floods in the Face of Climate Change

In this chapter, the author discusses the importance of mitigation and adaptation actions needed to be taken from an environmental and engineering standpoint in regards to dams, reservoirs they form, the river basins they serve, and how this can benefit these systems in the future. One of the main problems identified for the mid-21st century will be the availability of fresh water. Currently, appx. 20% of the world's freshwater is stored in manmade reservoirs. However, these reservoirs sediment over time. This “sediment phenomena'' adversely affects the water volume in reservoirs and their sustainable maintenance, potentially jeopardizing water supply and lives. To answer the “sediment phenomena,'' this chapter will explore a new approach to a no less devastating problem of land degradation, developed at the Technical University of Vienna. In the Balkan region, sediments are mostly composed of alluvial soil, decomposing organic matter, and sands, making them indeed a perfect soil amendment for degraded lands and barren topsoil terrains destroyed during torrential floods and landslides.