벼 재배양식별(栽培樣式別) 피복요소(被覆尿素) 복합비료(複合肥料)의 시용량(施用量)이 생육(生育) 및 미질(米質)에 미치는 영향

Effect of Coated Urea Complex Fertilizer Application Levels on Growth and Grain Quality in Rice Cultural Methods

벼 휴립세조건답직파(畦立細條乾畓直播) 재배(栽培)와 어린모 기계이앙 새배에서 피복요소 복합비교의 시비량을 달리하여 사양토(砂壤土)와 식양토(埴壤土)에서 벼의 생육(生育)과 미질(米質)에 미치는 효과를 검토하였다. 1. 피복요소가 처리된 토양에서 질소의 용출률(溶出率)은 직파의 경우 3.5개월째 사양토(砂壤土) 83%, 식양토(埴壤土) 81% 이었으며, 어린모 기계이앙의 경우 이앙후 4개월째 사양토(砂壤土), 식양토(埴壤土) 모두 89%이었다. 2. 벼 잎색도(色度)는 재배양식에 관계없이 출수기(出穗期) 때에 가장 높았고, 피복요소 복합비료 사용의 경우 시용량이 증가할 수록 높았으며, 특히 수확기(收穫期) 때에 100% 시용구에서 관행(慣行)시비구보다 높았다. 3. 완전미율(完全米率)은 직파재배보다 어린모 기계이앙 재배에서 높았으나, 피복요소 복합비료 사용의 경우 시용량이 증가할 수록 낮아졌다. 부완전미율(不完全米率)중 청미률(靑米率)은 직파재배에서 높았으며, 동할미율(胴割米率)은 어린모 기계이앙 재배에서 높았다. 한편, 심복백입율(心腹白粒率)은 어린모 기계이앙에서보다 직파에서 양토양 모두 낮았으며, 피복요소 복합비료의 시용량이 증가할수록 높았다. 4. 쌀의 Hon치(値)는 토성(土性)에 관계없이 직파재배에서 피복요소 복합비료 시용구가 관행(慣行) 시비구보다 높았으나, 어린모기계이앙 재배에서는 그 반대현상 이었고, 피복요소 복합비료 사용량간에는 시용량이 감소할수록 낮은 경향이었다. 또한 쌀의 단백질 함량도 Hon치(値)와 같은 경향을 나타내었다. 밥알의 호응집성(糊凝集性)은 재배양식에 관계없이 사양토(砂壤土)에서 피복요소 복합비료 시용량이 증가될수록 길어졌으나, 식양토(埴壤土)에서는 일정한 경향이 없었다. 5. 쌀수량(收量)은 직파재배의 경우 사양토(砂壤土)와 식양토(埴壤土)에서 모두 피복요소 복합비료 100~60% 수준 범위내에서 통계적(統計的) 유의성(有意性)이 없었으며, 이러한 결과는 식양토(埴壤土)의 어린모 기계이앙 재배에서 같은 경향을 나타내었다. 따라서 피복요소 복합비료의 시용량은 60% 수준까지 가능한 것으로 인정되었다.

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.