Fertilizer produced from abattoir waste can contribute to phosphorus sustainability, and biofortify crops with minerals

Abstract

Our food security depends on finding a sustainable alternative to rock phosphate for fertilizer production. Furthermore, over 2 billion people worldwide are currently affected by micronutrient deficiencies, and crop concentrations of essential minerals are declining. This paper examines whether a novel multi-element fertilizer, Thallo ® , can produce crop yields comparable to conventional rock phosphate derived fertilizers, and have an additional benefit of increasing essential mineral concentrations. Thallo ® , produced from abattoir and recycled industrial by-products, was tested against conventional mineral fertilizers in a pot trial with wheat and grass. In soil, yields were comparable between the fertilizer types, but, in a low-nutrient substrate, Thallo ® showed a yield benefit. Elemental concentrations in the plant material typically reflected the relative concentrations in the fertilizer, and Thallo ® fertilized plants contained significantly more of some essential elements, such as selenium and zinc. Furthermore, concentrations of the toxic element cadmium were significantly lower in Thallo ® fertilized crops. Among the fertilizers, manganese concentrations were greatest in the Thallo ® , but within the fertilized plants, they were greatest under the mineral fertilizer, showing the complexity of assessing whether nutrients will be taken up by crops. In summary, fertilizers from livestock waste have the potential to improve wheat and grass concentrations of essential elements while maintaining yields.

Abattoir waste use in livestock diets: Uganda’s current situation

“…Rumen contents were mostly piled into pits and sold as manure for peri-urban agriculture by 59% of the respondents. This is in line with the findings by Darch et al (2019) that fertilizers produced from abattoir wastes contribute to the plants mineral requirements for proper growth. Only 16% of the respondents sold dried rumen contents for livestock feeds.…”

The Mineral Composition of Wild-Type and Cultivated Varieties of Pasture Species

“…This may be intra-annual, as species differ in their heading date, or inter-annual, as some species are less persistent than others [49]. Grassland management, such as the application of lime or fertilizers, is also known to affect mineral concentrations of swards [23], and there is a lack of knowledge on mineral concentrations required in different soil types, and antagonistic effects between minerals [50]. It is also necessary to further investigate the effect of grazing management, which can affect the ratio of leaves and stems in the sward, the former being known to contain higher concentrations of minerals [51], and thus affect the mineral content of the sward.…”

Assessment of Growth, Yield and Fruit Nutritional Composition of Tomato and Sweet Pepper Irrigated with Abattoir Wastewater

“…i [51] ireported similar results in a greenhouse experiment on AWW on maize. In a previous study, concentrations of nutrients, including N, P, K, Ca, Mg and Na were found higher in Lolium perenne and Triticum aestivum grown in soil treated with fertilizer produced from abattoir wastes [17]. Also, Matheyarasu and Bolan [47] reported the application of AWW to cause an abundance of nutrient accumulation in Pennisetum purpureum, Medicago sativa, Sinapis alba and Helianthus annuus.…”

“…Furthermore, yield improvement in plants grown in wastewater treated soil conforms to that of Matheyarasu and Bolan [47] who found about 70% lower yields in Pennisetum purpureum, Medicago sativa, Sinapis alba and Helianthus annuus grown under tap water compared to the abattoir wastewater irrigation. Similarly, in a pot experiment, fertilizer produced from abattoir waste products was found to significantly increase biomass yield of AberMagic grass (Lolium perenne) and wheat (Triticum aestivum) compared with the Nil treatment pots [17]. They reported more grain production in wheat and AberMagic grass when AWW was applied and concluded that it is a sustainable alternative to conventional fertilizers.…”

“…Although chemical fertilizers can improve crop yield, they are most often not readily available and expensive [8]. This has brought about increased advocacy for alternative sources of nutrients in infertile soils such as recycling of organic-based wastewater for crop production [1,[9][10][11][12][13][14][15][16][17].…”