The need to shift toward sustainable food production systems has forced farmers to explore alternative practices, such as the use of biological soil amendments of animal origin (BSAAOs), to fulfill consumer-driven requirements. However, concerns due to food safety regulations restrict the use of BSAAOs on crops consumed raw. The present study evaluated the effects of untreated BSAAOs, raw poultry litter (PL), cow manure (CM), and no BSAAO on soil fertility, microbial contamination indicators, and marketable yields in radish (Raphanus sativus) production over two growing seasons at the LSU AgCenter Burden Botanical Gardens. In the agronomic assessment, radish marketable yields were significantly enhanced by PL application, with an average yield of 8.13 lb. per 3.66 m² plot compared to 4.24 lb. in CM-treated plots and 4.62 lb. in no BSAAO amended plots. Moreover, the method of manure application further influenced radish yields, with tilled PL (PLT) plots yielding 9.45 lb. per plot versus 6.81 lb. in non-till (PLNT) plots. Poultry litter application sustained higher levels of nitrogen through the production cycle as well, during Year 1 only, in comparison to CM and no BSAAO application. The evaluation of the safety of raw manure application focused on indicator organisms. In Year 1, soil samples from PL-treated plots exhibited significantly higher Escherichia coli (E. coli) levels (1.81 and 1.75 log CFU/g, respectively, for tilled and not tilled plots) relative to no BSAAO and CM-amended plots (≤1 to 1.01 log CFU/g), while harvested radish samples from PL-amended plots registered 0.8 log CFU/radish compared to non-detectable levels (≤0.75 log CFU/radish) for CM and no BSAAO-amended plots. In Year 2, soil samples from cow manure tilled (CMT) plots had much higher E. coli counts at first (3.23 log CFU/g in Week 1), but these dropped to 1.17 log CFU/g by Week 3, while other treatments kept their counts steady around or below 1 log CFU/g. Results obtained in the present study demonstrate that raw poultry litter substantially improved radish yields by supplying richer nutrient inputs; it also elevated soil and produces microbial contamination indicator levels relative to cow manure and conventional chemical fertilizer. Although radish surface contamination by E. coli remained low, the observed trends highlight the necessity for optimized manure application practices, particularly regarding incorporation methods and waiting periods, to mitigate potential food safety risks and prevent foodborne illness outbreaks.
