Identification and characterization of proteins, lipids, and metabolites in two organic fertilizer products derived from different nutrient sources

Abstract

The biochemical composition of organic fertilizers largely determines their nutrient supply characteristics following soil application as well as their potential impact on soil microbial communities. Yet, limited information is available regarding the biochemical composition of organic fertilizers derived from different nutrient sources. Here, we qualitatively analyzed the presence and abundance of proteins, lipids, and metabolites in a liquid fish fertilizer (LFF) product and a type of granular organic fertilizer (GOF) commonly used in organic vegetable production, using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Our results suggest that the presence and abundance of proteins, lipids, and metabolites differ greatly between GOF and LFF. The qualitative analysis shows LFF as a rich source of metabolites, while complex proteins and long-chain saturated fatty acids are dominant in GOF. The degree of biochemical composition complexity may help explain the varying impacts of different types of organic fertilizers on nutrient availability, soil health, and environmental quality.

Influence of Soil and Nutrient Management Practices on Crop Productivity and Quality in High Tunnel Organic Leafy Green Production

“…In this study, the granular organic fertilizer was primarily derived from hydrolyzed feather, bone, and blood meal, whereas the liquid organic fertilizer was derived from enzymatically digested fish proteins. As pointed out by Li et al (2021b), the slower release of N from the granular organic fertilizer may be associated with the presence of complex proteins and long-chain saturated fatty acids. Hartz and Johnstone (2006) compared the N availability of different types of organic fertilizers and found the N mineralization from the fish powder was significantly higher than that of blood meal, feather meal, and seabird guano within the first week at 10, 15, or 20 C. However, after 2 weeks, the mineralization of all fertilizers slowed down, highlighting the need for split applications of organic fertilizers.…”

“…These results were possibly associated with the residual nutrients from the previous crop season and reflected the long-term or legacy impact of cover cropping and organic fertilizer and compost application because no nutrient sources were applied during the catch crop season. Given that the composition of different organic fertilizers (Li et al 2021b) and cover crops (Woodruff et al 2018) may determine their shorter-and longer-term nutrient availability, it is likely that different organic fertilizer and cover crop combinations could show differential impacts on nutrient supply to vegetable crops, together with the site-specific environmental effects. Interestingly, the cover crop × fertilization × compost interaction on the first harvest of lettuce in Year 3 also indicated that Yard and Cow further enhanced crop yield of the Cowpea 1 Liquid combination compared with NC, but the compost effect was lacking in other cover crop and fertilization combinations (Table 5).…”

“…Fertilizers from various sources are commonly used in organic production to provide nitrogen (N) and other essential nutrients to crops; they may be derived from plant and animal materials or sourced from natural mineral deposits (Li et al 2021b). However, effectively matching crop N demands with the N supply from organic nutrient sources can be challenging due to the slow and unpredictable release patterns of N (Gaskell and Smith 2007;Li et al 2021a).…”