This study was conducted to investigate the effects of summer green manure crops as an alternative for imported expeller cake fertilizer on environment-friendly lettuce production. Sunnhemp, soybean, sudangrass, and sorghum, as summer green manure crops, were evaluated under the condition of a plastic film house. In the amount of nitrogen supplied through cultivation of green manure crops, soybean plot, which supplied 187 kg ha-1, was the highest, followed by sorghum plot, 156 kg ha-1. Since all green manure plots supplied more nitrogen than that required by soil testing, it was possible to replace the nitrogen supply of expeller cake fertilizer with the amount of nitrogen produced by green manures for autumn lettuce cultivation. N nutrient balances in sunnhemp, sudangrass, soybean, and sorghum plots were 13 kg ha-1, 28 kg ha-1, 30 kg ha-1, and 38 kg ha-1, respectively. The initial yield and total yield of lettuce showed no significant difference in green manure plots compared to the expeller cake plot, but . It was thought that all green manure crops could be substituted for expeller cake fertilizer used as nitrogen fertilizer, but it would be necessary to adjust the cultivation period and reduction point according to the type of green manure in order to maintain the C/N ratio, nitrogen supply, and nitrogen balance suitable for lettuce production.

As an aquaculture effluent is recognized as a source of water pollution, many methods are being researched to solve this problem. It has been reported that the aquaculture effluent contains many organic compounds containing nitrogen, phosphorus, potassium, and calcium. The purpose of this study was to investigate the possibility of using the effluent from bio-floc technology (BFT) inland aquaculture for fertilizing blueberry ‘Duke’ to promote the growth. The experiment was conducted in a commercial blueberry farm in Jinju, Gyeongsangnam-do, where blueberries are actually cultivated in order to find out the effects of fertilizers in situ. The experiment was carried out with five treatments: control with only irrigation, conventional nutrient solution fertigation, and the fertigation with three concentrations (×1, ×0.5, or ×0.25) of effluent from BFT (Bio-Floc Technology) inland aquaculture. The treatment period was from the beginning of April, when a new leaf of blueberry began to develop, to the middle of June, when the blueberry was harvested, for a total of 10 weeks. As a result of the experiment, the treatments with effluent from BFT inland aquaculture showed better growth qualities than those of control and conventional cultivation. However, there was no statistically significant difference among all treatments regarding the total fruit production. Based on these results, it was concluded that the effluent from BFT inland aquaculture can be used for the cultivation of blueberry because it is equivalent to conventional cultivation method. This study provided a new viewpoint of recycling the effluent from BFT for agricultural purpose to reduce water pollution problems due to aquaculture wastewater.

As the interest in urban agriculture and people’s demand for eco-friendly food grow, the number of urban gardeners who directly grow and harvest will increase. The aim of this study was to compare the effect of conventional fertilizer with the effluent water from the biofloc technology inland aquaculture in the concept of resource circulation as a substitute for fertilizer used in urban agriculture. In order to verify the effect of fertilizer on the cultivation of cherry tomato, tomato seedlings were transplanted on the horticultural soil without nutrients and treated for 8 weeks. Experimental treatment was carried out in five treatments: control, hyponex solution (HS), slow-released fertilizer (SF), effluent water daily treatment (DE), and effluent water treatment once a week (WE). The growth characteristics of the cherry tomatoes showed significant differences among the treatments except for root length. In the case of plant length was shown HS=WE›DE=SF›control, and stem diameter was shown DE=SF ›WE=HS›control. It was found that HS and WE were not significantly different in shoot length and diameter, and DE and SF showed no difference. In the case of number of leaves, HS, DE, and WE showed a significantly higher level than SF and control. In other growth characteristics, DE and SF showed higher growth. As for the growth of cherry tomato fruit, the sugar content did not show any significant difference among the treatments except control. Weight per fruit and yield were significantly higher in HS and WE than DE and SF. Based on these results, it is considered that the use of effluent water is comparable to the use of urban agricultural fertilizer as compared with chemical fertilizers in cultivating crops.