This study aimed to produce livestock manure biochar to decrease environmental problems from livestock manure and evaluate its effectiveness as an organic fertilizer by examining the growth and nutrient use efficiency of crops. A plot experiment was conducted to investigate the characteristics of lettuce growth and nitrogen use efficiency in upland soils treated with cow manure biochar. The cow manure biochar was applied at rates of 0, 3, 5, 7, and 10 t ha⁻¹ (referred to as CMB0, CMB3, CMB5, CMB7, and CMB10, respectively), along with inorganic fertilizer (IF, NPK—200-59-12 kg ha⁻¹). The lettuce cultivation test was carried out for 42 days, during which the fresh weight, dry weight, length, and number of lettuce leaves were measured. Nitrogen use efficiency was evaluated by determining the agronomic efficiency of N and the apparent recovery fraction of N. Overall, as the cow manure biochar application rate increased, crop growth and nitrogen uptake improved. Soils treated with CMB5 and CMB7 showed higher lettuce growth, nitrogen content, and nitrogen uptake compared to soils under other treatments. Nitrogen use efficiency followed a pattern similar to that of crop productivity, with cow manure biochar application levels playing a significant role. In particular, the agronomic efficiency of N and the apparent recovery fraction of N, which are both related to crop nutrient utilization, were significantly higher in the CMB5 treatment compared to the IF treatment. These results indicate that nitrogen use efficiency can be enhanced through biochar application when growing crops on agricultural land. Therefore, it is suggested that the appropriate application of cow manure biochar can reduce inorganic fertilizer use and increase crop productivity, thereby enabling sustainable and eco-friendly agriculture.

Bed soil is a material with physical, chemical, and biological properties suitable for the production of high-quality seedlings. Moreover, it is a material that physically supports plants and supplies various nutrients and moisture necessary for the initial growth of crops. However, the price of cocopeat, the main raw material for bed soil, has risen sharply due to COVID-19 and the rise in international exchange rates, so a substitute for it is needed. Therefore, the aim of this study was to assess the effect of bed soil using livestock manure biochar (LMB) on the initial growth of Kimchi cabbage. The LMB complied with the process specifications of LMB in all other items except NaCl content, and the results of the fertilizer damage test showed no damage to crops. In the bed soil test, the germination rate, height, and leaf number of Kimchi cabbage were significantly higher in LMB0% and LMB2% treatments than any other treatments. However, the initial growth of Kimchi cabbage generally tended to decrease with the increasing rate of LMB application. Taken together, considering the benefits of livestock manure recycling, including environmental issues and carbon neutral, we propose the use of an appropriate LMB with a lower NaCl content in the bed soil cultivation.