Impact of brewery sludge application on heavy metal build-up, translocation, growth and yield of bread wheat (Triticum aestivum L.) crop in Northern Ethiopia.

In a field study, the impact of different levels of brewery sludge (BS) enrichment on Triticum aestivum L. (wheat plants) was examined in terms of growth, yield, heavy metal absorption, and potential health risks linked to plant consumption. Using a randomized complete block design with seven treatments and three blocks, the study showed that applying up to 12 t ha-1 brewery sludge significantly improved all agronomic parameters (except harvest index) compared to control and mineral-fertilized soil. Heavy metal translocation was generally low, except for Cu and Pb. The sequence of heavy metal translocation was Cu > Pb > Cd > Ni > Zn > Mn > Cr from soil to spikes and Cu > Zn > Mn > Pb > Ni > Cd > Cr from soil to grain. Heavy metal loads were mostly higher in roots than in the above-ground crop parts. The target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) within wheat grain remained within safe limits for all BS treatments. Consequently, consuming this wheat grain is considered safe regarding heavy metals. Thus, utilizing brewery sludge at 12 t ha-1 as a fertilizer for wheat production and as an alternative method for sludge disposal is plausible.

Effects of brewery sludge on soil chemical properties, trace metal availability in soil and uptake by wheat crop, and bioaccumulation factor.

Brewery sludge is the solid residue obtained from agro-industrial processing. It is possible to utilize the waste products in an environment friendly and economical way to replace mineral fertilizer due to its sufficient macronutrients and organic carbon content. However, its use is limited due to heavy metal concentration that may contaminate crops and then the food chain. The objective of this study was to assess the suitability of brewery sludge for using to grow bread wheat (Triticum aestivum L.) by determining the effect of brewery sludge (7 levels: 0, 3, 6, 9, 12 and 15 t ha-1, and 1 recommended rate of NPS only) on soil chemical properties, bioaccumulation factor, and heavy metal absorption in the soil and in the bread wheat grain using a Randomized Blocks Design field experiment conducted at two sites during the 2018 cropping season. Amendment of brewery sludge at a rate of 15 t ha-1 led to substantial variations in soil chemical properties except for Mg2+ content at both study sites. Concentrations of the studied heavy metals (except Zn in the soil) increased with increasing brewery sludge application rate in the soil and in the wheat grain. However, heavy metal uptake by wheat grain and heavy metal concentration in the soil were below the allowed limits. The bioaccumulation factor in the wheat grain was <1.0 for the studied heavy metals. The findings of the study suggest that brewery sludge at a rate of 15 t ha-1 could be recommended due to its high nourishing effect for soil and for promoting nutritional quality of wheat crop and is safe for human consumption. However, since sludge application may lead to increase in the amount of trace metals in the soil-plant system, a long-term study is recommended.

Assessment on post-harvest losses of tomato (Lycopersicon esculentem Mill.) in selected districts of East Shewa Zone of Ethiopia using a commodity system analysis methodology.

One of the main challenges facing Ethiopia today is to ensure food security for its rapidly growing population. Although Ethiopia's production is much lower than the national demand, there are high post-harvest food losses. In meeting a country's food demand, increasing production by itself is not enough unless what has been produced is properly managed. In line with this, extensive assessment of post-harvest losses of tomato along the supply chain and the associated factors were evaluated in four purposively selected districts of East Shewa Zone of Ethiopia. The assessment was made using Commodity System Assessment Methodology from "farm-to-fork" to investigate the status of post-harvest losses of tomato along the supply chain and the associated factors in the pursuit of recommending appropriate mitigation strategies. Information was gathered from a total of N = 408 sampled chain actors (producers to consumers) and related institutions. Results revealed that losses of tomato due to improper care and handling of the commodity regardless of its high production in the study area were common problems for all chain actors. A loss of 20.5%, 8.6%, 2.9%, and 7.3% at the producer, wholesalers, retailers, and hotel and café level was recorded respectively with a total loss of 39.3%. Total losses across districts ranged from 17.2-33.3. Field, transportation and market display were major critical loss points identified. Practices such as market fluctuation, lack of temperature management, no/poor sorting and mixed handling of the crop, carelessness on the loss prevention and its impact were identified among the common causes for observed losses. Therefore, creating awareness on the effect of all causes of food loss and minimizing economic loss is recommended. Moreover, affordable and appropriate technology adaptation is needed to reduce observed food losses across the districts.