Application of recycled slaughterhouse wastes as an organic fertilizer for successive cultivations of bell pepper and amaranth

Agronomic Efficiency of Animal-Derived Organic Fertilizers and Their Effects on Biology and Fertility of Soil: A Review

“…During field cultivations of tomato, Roy et al [41] applied the same fertilizer (3:1), which contained 4.9% N, 0.6% P and 0.9% K along with a 4.8 C/N ratio. In our recent study, Bhunia et al [15] showed agronomic potential of tray-dried slaughterhouse waste, where the mixture (in 3:1 ratio) was dried at 100-120 • C for 6-8 h using a designed tray dryer system. Drying type and process temperature had significant influence on the quality of end product as we observed during our research.…”

“…Our recent work, Bhunia et al [15], demonstrated recycling of rural slaughterhouse waste through tray-drying and showed its agronomic efficiency during successive cultivation of bell pepper and amaranth, where N fertilization at a rate of 80 kg ha −1 produced higher yield and better fruit characteristics. Earlier, Roy et al [40,41] applied sun-dried mixture of bovine blood and rumen digesta as major N source for the cultivation of solanaceous vegetables in India.…”

“…Such practices encourage quality food production excluding the use of pesticides and synthetic fertilizers, and targets equilibrium in soil dynamics. The addition of animal-derived amendments to soils promotes plant growth, crop yield and fruit quality due to balanced supply of C, N and P as well as supplying micronutrients such as zinc (Zn), manganese (Mn), boron (B), copper (Cu) and iron (Fe) for crop improvement [14,15]. Organic farming makes the soil friable and fertile: It enhances cohesion of aggregates, accumulates massive organic matter (SOM) in soil and influences microbial communities and their co-occurrences [16].…”

“…Labile C fractions are O-substituted alkyl, carbonyl and methoxyl C generally abundant in animal waste that are readily available to copiotrophs as energy source [21]. Recently, Bhunia et al [15] found copiotrophs to be abundant in soils fertilized with recycled slaughterhouse waste, although it could vary with the type of organic substances amended [16]. Simultaneously, organically treated soils attained higher urease, dehydrogenase and acid phosphatase activities, which have a key role in nutrient recycling and decomposition of soil organic matter [22].…”

“…Due to emergence of antibiotic-resistant genes, an estimated 10 million human deaths will occur per year by 2050 [36]. Moreover, even plants die due to overuse of raw organic amendments in agriculture [15,21]. To minimize such adverse effects and to ensure biosecurity, waste recycling is necessary before reusing them in agriculture, which may also support the concept of circular bio-economy.…”