## 4 Conclusions  
Our literature review revealed a lack of information on testing the impact of organic amendments on plants' phytochemical composition and their nutritional and antioxidant properties. Investigators have focused on the plant yield and soil's physical and chemical characteristics following the incorporation of organic and inorganic fertilizers with very little information on the plant's nutritional and antioxidant contents. The use of animal manure as fertilizer has properties that cannot be acquired from the use of synthetic inorganic fertilizers. Health benefits of Brassicaaceae plants are attributed to glucosionlates (GSLs) vitamin C, and phenol compounds due to their antioxidant activity. The presence of microorganisms in animal manure facilitates the slow release of the three main plant nutrients, N, P, and K, from soil organic matter to growing plants. Animal manure contains algae, protozoa, fungi, and bacteria. These microorganisms' secrete a variety of hydrolyzing enzymes such as invertase, dehydrogenase, cellulase, amylase, urease, and acid and alkaline phosphatase capable of degrading hazardous chemicals and of the mineralization of organic compounds in soil systems resulting in the release of nutrients for plant uptake. On average and regardless of the turnip variety tested, turnip shoot, root, and plant weight gained from chicken manure (CM)-amended soil was significantly (\(P\leq 0.05\)) greater (490, 303, and 793 g, respectively) compared to the yield obtained from inorganic fertilizers (422, 267, and 689 g, respectively).  
Results revealed that phytochemical concentrations varied significantly among plant species and among plants of the same species cultivated under different animal manure. Ascorbic acid (vitamin C) and phenol concentrations in arugula were greater in plants grown in SS-, CM-, and HM-amended soils compared to plants grown in the control treatment. Animal manure used as organic amendments are exceptional fertilizers. However, there is an emerging concern regarding the impact of endocrine-disrupting compounds (EDCs) in municipal sewage sludge (SS), chicken manure (CM), and horse manure (HM). Most livestock raised worldwide are raised in large-scale concentrated animal-feeding operations, which require the use of antibiotics, and inorganic and organic compounds (heavy metals, hormones, antibiotics, and pesticides) that when incorporated into soil might constitute a pollution problem and therefore might impact the activity of soil microorganisms and their enzymatic secretions. The increasing consumer awareness of the value of vegetables in the human diet requires continuous investigation and monitoring of plants' phytochemicals composition and the growth factors that impact the antioxidant content of the different varieties of edible plants grown under different agricultural soil  
Figure 9: Overall concentrations of soluble sugars, ascorbic acid, and phenols \(\pm\) std. error under four soil management practices (sewage sludge, SS; chicken manure, CM; horse manure, HM; and no manure, NM), regardless of crop type. Statistical analysis was performed among four soil management practices. Values with the same letter are not significantly different (\(p\geq 0.05\)).  
management practices such as animal manures used in land farming as an alternative to inorganic fertilizers.  
This investigation was supported by a grant from the United States Department of Agriculture, National Institute of Food and Agriculture (USDA/NIFA) to Kentucky State University under agreement # KYX-10-18-65P Accession 1017900.  
Not applicable.  
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