This experiment was conducted to confirm the efficiency of introducing natural organic matter, crushed kenaf (Hibiscus cannabinus L.), which could lead to soil physicochemical improvement and crop growth improvement in reclaimed land. The plant height of economical crop kenaf after adding crushed kenaf per 3,000 kg 10a-1 as organic matter in 2020 was 219.5 cm. This was 7% less growth than the kenaf grown in standard fertilization, and 13.4% higher than the kenaf grown under in natural non-managed state without fertilization. The kenaf yield in the first year of organic matter treatment in non-developed reclaimed land was 3,215 kg 10a-1 which was 14.7% higher compared to that of under in natural non-managed state without fertilization and 83.9% yield of standard fertilization treatment. However, in the second year of cultivation, the growth and yield of treated with crushed kenaf as an organic matter were increased significantly. The main reason is that enough time was given for the decomposition of the input crushed kenaf, and the effect of kenaf cultivation as a crop on improving the soil environment was clearly appeared. So, the plant height in the second year of kenaf treated with crushed kenaf as an organic matter was 320.9 cm, which was 46.2% higher than that in the first year. In addition, yield also increased significantly, reaching 5,916 kg 10a-1, an 84% higher compared to that of the first year. This rate of yield increase was larger than 15% of in natural non-managed state without fertilization or 33% of standard fertilization treatment, which showed that using kenaf as an organic matter was much more effective in improving the soil environment of reclaimed land and improving crop growth and yield.The annual changes of soil chemical properties when returning of grown kenaf as an organic matter in reclaimed land. Division pH (1:5) EC (dS m-1) OM (g kg-1) Avail. P2O5 (mg kg-1) Exch. cations (cmolc kg-1) K Ca Mg Na 2019 (before input) 7.9 a† 2.04 a 4.6 c 24 c 0.74 c 1.42 b 5.06 a 0.68 a After input 2020 7.2 b 1.22 b 10.4 b 67 b 0.94 b 1.86 a 4.88 b 0.28 b 2021 6.7 c 0.56 c 14.2 a 86 a 1.14 a 1.72 ab 3.81 c 0.19 c †Values within columns having the same letters are not significantly different at the 0.05 as determined by DMRT.

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Information and Communication Technology (ICT) remote soil moisture control system including soil sensing, automatic water supply chain, and remote alarming system was established on reclaimed land and operated stably. The system was operated using river water around the reclaimed land without fertilizer. On applying this system to control soil moisture, the kenaf germination rate was improved up to two times. Kenaf biomass was 4,748 kg/10a and was higher than that of untreated soil moisture management. When the nutritious liquid fertilizer was used, kenaf yield reached 8,390 kg/10a, which was lower than 10,848 kg/10a of the non-reclaimed land treated with standard chemical fertilizers. As the soil moisture was managed stably through the ICT remote soil moisture control system, the quality of the kenaf crop was improved, resulting in a 7% increase in dry weight, and a 11.5% increase in plant hardness. The estimated kenaf yield was 5,039 kg/10a when 800 tonnes of water were supplied by the ICT remote soil moisture control system with the stream water around Saemangeum reclaimed land without chemical fertilizers and organic matter.

This experiment was carried out to investigate the effects of shading materials (aluminum specific-shading screen and polypropylene non-woven fabric) and shading ratio (50% and 70%) on climatic changes, cut-flower quality, and yield of spray rose cultivars for export during high temperature periods. The daily cumulative solar radiations were higher with the aluminum specific-shading screen, especially with 50% shading compared to polypropylene non-woven fabric. Air temperature and root zone temperature within rockwool media greatly decreased with the aluminum specific-Shading screen, but relative air humidity was not different among shading methods. Chlorophyll contents (SPAD values) were slightly higher with aluminum-specific shading screen than with polypropylene non-woven fabric, and were higher with 50% than with 70% aluminum specific-shading screen. Except for 'Lovely Lydia', marketable and exportable yields of all cultivars were higher with 50% than with 70% aluminum shading treatment. In addition, flower stalk length, stem diameter, number of node and 7ea-leaflet, and floret number tended to be better with aluminum specific-shading screen. Flower stalk length was higher with 70% than with 50% aluminum shading treatment. Chromaticity of petals slightly increased, and vase life was 0.5-2.5 days longer for each cultivar with aluminum specific-shading screen than with polypropylene non-woven fabric.