Effect of Polluted Irrigation Water on the Rice Growth and the Grain Quality

오염(汚染) 관개수(灌漑水)가 벼 생육(生育) 및 미질(米質)에 미치는 영향(影響)

This study was conducted to establish a safe cultivation technique of rice in the area irrigated with polluted water. The changes of water and grain quality were investigated in the two paddy soils which are located in the adjacent of Geumho river in 1991. The results obtained in this study are as follows : 1. The qualities of irrigation water were shown to be in the range of 6.7~7.4 in pH, 21.3~52.8ppm in COD. 3.2~5.3ppm in $NH_4-N$ and 1.6~6.0ppm in $PO_4$, respectively. Concentration of COD and $NH_4-N$ were over the standard levels. Therefore, the water pollution was mainly caused by organic waste matters. 2. Ranges of the Soil pH of Gyeongsan and Gyuam series were 5.6~6.0, 6.1~6.3 respectively. The contents of avaiable $P_2O_5$ and $SiO_2$ were high in the silicate treatment plots among other plots. 3. Degree of irrigation water pollution of Geumho river showed the highest peak in June. 4. Plant height, number of panicle and yield of rice grain were not decreased by the diminution of nitrogen fertilizer application. 5. The $Mg/(K{\times}N)$ ratio and Gel consistency of milled rice were increased in the nitrogen decreasing plot, but the alkali digestability value and protein content were decreased. Therefore, it was desirable to decrease the amount of nitrogen fertilizer application.

금호강(琴湖江) 하류(下流)의 오염(汚染)된 하천수(河川水)를 관개수원(灌漑水源)으로하는 농가답(農家畓) 두곳(경산통(慶山統):Gk, 규암통(窺岩統):Gy)에서 관개(灌漑)수의 오염도를 조사하고, 합리적(合理的)인 시비법(施肥法) 개선(改善)의 기초자료(基礎資料)를 얻고자 시험(試驗)을 실시(實施)하였다. 관개수질(灌漑水質)은 pH는 6.7~7.4, COD:21.3~52.8, $NH_4-N$:3.2~5.3ppm, $PO_4$:1.6~6.0ppm으로서 오염도(汚染度)는 6월(月)이 가장 심(甚)하였고 8월(月)은 적었다. 공시토양(供試土壤)의 화학적(化學的) 특성(特性)은 pH가 경산통(慶山統)은 5.6~6.0 규암통(窺岩統)은 6.1~6.3이었고, 인산(燐酸) 및 규산함량(珪酸含量)은 규산처리구(珪酸處理區)에서 가장 높았다. 벼 초장(草長), 경수(莖數) 및 수량(收量)은 질소감비구(窒素減肥區) 떨어지지 않았다. 백미중(白米中) $Mg/(K{\times}N)$비(比)와 호응집성(糊凝集性)은 질소감비구(窒素減肥區)에서 가장 높았고, 알카리붕 괴도와 단백질함량(蛋白質含量)은 적었다. 따라서 오염관개수(汚染灌漑水)가 유입(流入)되는 논에서는 식미(食味)를 감안할때 질소감비(窒素減肥)가 바람직하였다.