Korean Journal of Soil Science and FertilizerISSN:0367-6315(Print) 2288-2162(Online)한국토양비료학회

Soil moisture conditions are critical for seed emergence in soils. As soils of Saemangeum reclaimed land are coarse-textured, the soil moisture conditions may not be suitable for upland cultivation due to low soil water holding capacity. This study was performed to investigate emergence rates of sesame (Sesamum indicum L.), perilla (Perilla frutescens L.), peanut (Arachis hypogaea L.), and sorghum (Sorghum bicolor L.) under soil moisture conditions in Saemangeum reclaimed land. Three experiment was conducted. The first experiment compared the emergence rates with four levels (10, 15, 20, and 25% (v v^-1)) of soil moisture contents (SMC) between Saemangeum soil and Wanju soil. In the second experiment, sesame, perilla, peanut and sorghum were selected for each of 5 varieties and the emergence rate was investigated under the drip irrigation condition (based on a water supply depth of 20 cm). In third experiment, emergence rates of the seeds were investigated under different soil amendments (control, rice straw, gypsum, high ridge, gypsum and rice straw) in the open field non-irrigated conditions. Regarding experiment 1, no difference of emergence rates was found between sesame, perilla and peanut but that of sorghum was lower than that of other plants at 10% of SMC in Saemangeum soil (-31 kPa, p < 0.05). The emergence rates in Wanju soil showed highest values in 25% (-11 kPa) and 20% (-27 kPa) of sesame and 25% (-11 kPa) in perilla, and indicated significantly lower values at 10% (-399 kPa) in both peanut and sorghum (p < 0.05 and p < 0.001). For experiment 2, emergence rates were in the order of peanut 98.2%, sesame 93.2%, and sorghum 81.5% (p < 0.001, perilla did not emerged). In experiment 3, the seed emergence rates were significantly higher in sesame (33.0% at high ridge and 28.9% at gypsum, p < 0.05) and peanut (50.0% at gypsum, p < 0.001). In conclusion, in order to increase the crop emergence rate in the Saemangeum soil, it is necessary to create an environment with a soil moisture content (tension) of 10% (-31 kPa) or more during the sowing period.

Changes in emergence rates of a) sesame (SSM), b) perilla (PR), c) peanut (PN), and d) sorghum (SG) as affected by soil moisture contents for soils in Saemangeum.