신간척지에서 청보리의 안정재배를 위한 토양 염농도를 제시하기 위하여 새로 조성된 새만금간척지에서 토양염농도(EC) 0.8, 3.1, 6.5, 11.0 dS/m에 해당하는 지점을 선정하고, 화학비료로 $N-P_2O_5-K_2O$=150-100-100 kg/ha를 시용한 후 2011년 10월 26일에 영양보리를 220kg/ha 파종하였다. 재배기간중 토양 염농도는 수확기>출수기>파종기>월동기 순으로 파종기에 비해 수확기에 1.4~4.2배 상승하였다. 염농도가 높을수록 발근에 지장을 초래하여 지상부 생육도 저조하였고 특히 EC 11.0 ds/m에서 출현은 하였으나 겨울철이 지난 후 고사하였다. 수량은 토양염농도 0.8 dS/m(8.8 MT/ha)에 비해 3.1 dS/m과 6.5 dS/m에서 각각 68 %, 35 % 수준이었다. Proline함량은 생육초기가 수확기보다, 그리고 염농도가 높을수록 많았다. 수확기의 $Na_2O$와 MgO 함량은 염농도가 높을수록 많았고 N, $P_2O_5$, $K_2O$ 및 CaO 함량은 염농도가 높을수록 적었다. 따라서 토양 염농도가 3.1 dS/m이상으로 높아짐에 따라 청보리의 지하부와 지상부에 심각한 생육저해로 양분의 불균형 흡수를 초래하여 수량이 저조하기 때문에 안정한 청보리 생산을 위해서는 지하 배수시설 또는 관개수를 이용하여 3.1 dS/m이하로 염농도를 떨어뜨린 후 재배하는 것이 바람직할 것으로 판단된다.
BACKGROUND: Newly reclaimed land has poor soil environment for crop growth since it is high in salt concentration but low in organic content compared with ordinary soil. It is known that whole-crop-barley can grow better in the soil of relatively high salt concentration than other crops but, the growth is poor at the concentration if higher than certain amount and it is a difficulty to secure productivity. Hence, the level of soil salt concentration suitable for the production of bulky feed in newly reclaimed land has been investigated. METHODS AND RESULTS: At Saemanguem reclaimed land, the land for the soil salt concentration electrical conductivity (EC) 0.8, 3.1, 6.5, 11.0 dS/m was selected; and chemical fertilizer $N-P_2O_5-K_2O$ (150-100-100kg/ha) was tested; and forage barley 220kg/ha were sown. The soil salt concentration during the cultivation period decreased in the order of harvest season>earing season>sowing season>wintering season, and the salt concentration in harvest season is 1.4-4.2 times higher than that of the sowing season. The higher the salt concentration, the poorer the over ground growth due to poor rooting; especially at EC 11.0 ds/m there was emergence but, it blighted after wintering. The Yield from the soil salt concentration 3.1dS/m and 6.5 dS/m was 68% and 35% from that of the soil salt concentration 0.8 dS/m (8.8 MT/ha) respectively. The proline content in early life stage was more than that of the harvest season, and it increased with salt concentration. The higher salt concentration, the more $Na_2O$ and MgO content in harvest season; but the higher the salt concentration, the less the content of N, $P_2O_5$, $K_2O$ and CaO. CONCLUSION(S): When the soil salt concentration becomes higher than 3.1 dS/m, the yield becomes poor because there is serious growth inhibition of forage barley both in root part and above aerial part that results in unbalanced absorption of nutrients. Therefore, it is recommended that the salt concentration should be lowered below 3.1 dS/m by underground drainage facilities or irrigating water for the stable production of whole-crop-barley.
