On-the-spot Observation and Nutrient Dynamics at Rice Paddy Fields in Seven of Large-scale Environment-friendly Agricultural Districts

광역친환경 논 농업단지 7개소 현장실사 및 양분동태

After carrying out on-the-spot observation targeting each farmhouse of large-scale environment-friendly agricultural district (LEAD), Suncheon, Sancheong, Jangheung, Yeongam, Hamyang, Okcheon, and Jeongseon in 2015, only one LEAD, a farmhouse in Jangheung had used sustainable compost coming out under their own non-antibiotic livestock. The soil pH and EC at a depth of 0-20 cm in the seven LEADs were ranged between 5.3-6.6 and $0.4-1.2dS\;m^{-1}$, respectively, with 0.03- 0.27% for T-N concentration, $22-322mg\;kg^{-1}$ for P, and $0.05-0.29mg\;kg^{-1}$, which were, in particular, low a farmhouse in Jeongseon. When intensively surveying on each farmhouse of Suncheon, Jangheung, and Okcheon for a growing period, seasonal soil pH was maintained above 6.0 and high in a farmhouse in Okcheon, with similar soil EC observed among the three LEADs. Seasonal soil T-N was 0.1% higher on the farmhouse in Suncheon than other two LEADs, with higher seasonal soil P observed on the farmhouse in Okcheon and higher soil K in the Jangheung. T-N concentration in rice (Oryza sativa L.) crops was the highest in Jangheung, and concentrations of T-N, P, and K decreased in a season. Plant height and number of tillers per hill were the highest on the farmhouse in Okcheon, where was similar or low plant diameter and SPAD levels compared to other two LEADs. Dry weight (DW) before harvest was ranged between 52-63 g, and DW, rough rice yield (kg), brown rice/rough rice (%), brown rice yield (kg), head rice (%), and broken rice (%) were not significantly different among the three LEADs. Total annual gross production ha-1 was the highest on the farmhouse in Okcheon (16,230,000 won) planting with high class of variety, 'Milky queen' at early maturation, which was expected to be increased on an agricultural income. However, high amount of fertilizer was applied for growing the following crops on the farmhouse in Okcheon, affecting the highest balance of T-N, P, and K more than $200kg\;ha^{-1}$.

광역친환경 농업단지 7곳(순천, 산청, 장흥, 영암, 함양, 옥천, 정선)의 농가를 대상으로 2015년에 현장 실사한 결과, 단 1곳(장흥)만이 무항생 가축을 사육하여 나온 친환경 퇴비를 이용하였다. 광역친환경 농업단지 7곳의 0~20 cm 깊이의 토양 pH는 5.3~6.6, EC는 $0.4{\sim}1.2dS\;m^{-1}$, 전질소는 0.03~0.27%, 인산은 $22{\sim}322mg\;kg^{-1}$, 칼륨은 $0.05{\sim}0.29mg\;kg^{-1}$이었고 특히 정선 지역의 농가에서 전체적으로 낮은 수준을 보였다. 순천, 장흥, 옥천의 3농가만을 재배 기간 동안 집중적으로 조사하였을 때 시기별 토양 pH는 6.0 이상을 유지한 옥천 농가에서 높았고 EC는 별다른 차이가 나타나지 않았다. 시기별 토양 전질소 농도는 순천 농가에서 다른 농가 보다 0.1% 이상 높았고 인산과 칼륨은 옥천과 장흥에서 각각 높게 나타났다. 벼의 전질소 농도는 장흥에서 가장 높았고 시기별 전질소, 인산, 칼륨 농도는 감소하는 경향을 보였다. 초장과 분얼수는 옥천 농가에서 가장 높았지만 직경이나 SPAD 수준은 비슷하거나 낮게 관찰되었다. 건물중은 수확 직전에는 주 당 52~63 g으로 별다른 차이가 없었고, 정조중(kg), 정현비율(%), 현미수량(kg), 완전립(%), 싸라기율(%)도 농가 간에 차이가 나타나지 않았다. 연간 조수입은 조생종이면서 고급품종인 '밀키퀸'을 식재한 옥천 농가가 ha당 1,623만원으로 가장 높아 농업소득 증대효과가 기대되었다. 하지만 옥천 농가는 후작물을 재배하는 관계로 비료투입량이 높아서 전질소, 인산, 칼륨 수지가 ha당 200 kg 이상으로 가장 높은 수준을 보였다.