• 한국산림과학회지
• /
• 제87권1호
• /
• pp.98-105
• /
• 1998

은행나무 3년생 묘목에 각기 다른 수준의 질소, 인, 질소와 인 복합비료를 시비하고, 묘목의 생장 및 엽내 양분과 유용 추출물의 농도를 측정하였다. 시비 후 묘목의 잎, 줄기, 뿌리의 생체량은 고농도 질소와 인 복합비료 처리구 이외에서는 변화가 없었으며, 엽내 질소와 인 농도의 변화 정도는 시비량에 따라 차이가 있었다. 일반적으로 엽내 질소와 인의 농도는 시비량 증가에 따라 증가하나, 질소 시비량이 400kg/ha인 경우와 인 시비량이 100kg/ha에서는 오히려 감소하였다. 묘목 생장량과 엽내 양분 농도를 고려할 때 묘목은 질소와 인이 결핍된 상태에 있었던 것으로 볼 수 있었다. 시비 후 엽내 이차 대사 물질인 Ginkgo flavon glycosides와 terpene lactones의 농도는 감소하였으며, 은행나무 묘목에서 생체량과 이차 대사 물질량 사이에는 부의 상관관계 (r=-0.739, p=0.036)가 있는 것으로 나타났다.

• 한국환경농학회지
• /
• 제31권3호
• /
• pp.205-211
• /
• 2012

BACKGROUND: Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation to increase productivity. But higher N fertilization also increases the concentrations of nitrate ions and nitrous oxide in soil. In this experiment, the impact of N fertilization was studied on nitrous oxide ($N_2O$) emission to standardize the optimum fertilization level for minimizing $N_2O$ emission as well as increasing crop productivity. Herein, we developed $N_2O$ emission inventory for upland soil region during red pepper and Chinese milk vetch cultivation. METHODS AND RESULTS: Nitrogen fertilizers were applied at different rates to study their effect on $N_2O$ emission during red pepper and Chinese milk vetch cultivation. The gas samples were collected by static closed chamber method and $N_2O$ concentration was measured by gas chromatography. The total $N_2O$ flux was steadily increased due to increasing N fertilization level, though the overall pattern of $N_2O$ emission dynamics was same. Application of N fertilization higher than the recommended dose increased the values of both seasonal $N_2O$ flux (94.5% for Chinese cabbage and 30.7% for red pepper) and $N_2O$ emission per unit crop yield (77.9% for Chinese cabbage and 23.2% for red pepper). Nitrous oxide inventory revealed that the $N_2O$ emission due to unit amount of N application from short-duration vegetable field in fall (autumn) season (6.36 kg/ha) was almost 70% higher than that during summer season. CONCLUSION: Application of excess N-fertilizers increased seasonal $N_2O$ flux especially the $N_2O$ flux per unit yield during both Chinese cabbage and red pepper cultivation. This suggested that the higher N fertilization than the recommended dose actually facilitates $N_2O$ emission than boosting plant productivity. The $N_2O$ inventory for upland farming in temperate region like Korea revealed that $N_2O$ flux due to unit amount of N-fertilizer application for Chinese cabbage in fall (autumn) season was comparatively higher than that of summer vegetables like red pepper. Therefore, the judicious N fertilization following recommended dose is required to suppress $N_2O$ emission with high vegetable productivity in upland soils.

• 생물환경조절학회지
• /
• 제3권2호
• /
• pp.145-150
• /
• 1994

질소 시비수준이 치커리의 3가지 품종에 있어 생육과 품질에 미치는 영향을 조사하고자 수행한 본 실험의 결과는 다음과 같다. 1. 30kgN/10a 처리구에서 외형적인 생육이 가장 좋았지만 잎끝마름과 추대 발생율은 20kgN/10a 처리구와 10kgN/10a 처리구에서 보다 낮았다. 2. 품종간 비교에서 ‘Winter’가 다른 품종에 비해 생육이 양호하였으나, 잎끝마름과 추대 발생율도 높았다. 3. Vitamin C 함량은 모든 품종에서 10kgN/10a 와 20kgN/10a 처리구가 30kgN/10a 에 비해 높았고, 품종에서는 ‘Winter’가 높은 수치를 나타내었다. 4. 건물중의 경우 각 품종 모두 30kgN/10a 처리구에서 가장 높게 나타났으나 건물율에 있어서는 20kgN/10a 처리구와 10kgN/10a 에서 높게 나타났다.

• 한국초지조사료학회지
• /
• 제11권3호
• /
• pp.175-181
• /
• 1991

The purpose of this experiment was to evaluate the effects of shade and levels of N fertilization on the dry matter yield and chemical compositions of orchardgrass grown under floor of chestnut tree. Shading conditions consist of $S_0$, (full light), $S_1$, (about 6OC4 shade) and $S_2$, (about 70% shade). And, nitrogen fertilizer was applied at 3 levels, O($N_0$), 12($N_1$), and 30($N_2$) kg per 10a, respectively. The results are may be summarized as follows: 1. Maximum total dry matter yield of $S_0$, was obtained about 1.28 ton/lOa at $N_2$, level. But, total dry matter yields of N levels in $S_1$, and $S_2$, were decreased about 42-45% compared with $S_0$. 2. The response of the dry matter yield to N fertilization were differences between shading and levels of N. Thus, the dry matter yield of $S_1$, increased almost linear up to about 30 kg/l0a level, while the dry matter yield of S, was increased slightly up to 30 kgIl0a. But. $S_2$, was increased up to 12 kg/lOa and then decreased slightly with N fertilization over the 12 kg/l0a. 3. Average increase in total dry matter yield to N fertilization were 23.85 kg, 7.97 kg and 5.08 kg DM for $S_0$, $S_1$, and $S_2$, respectively. 4. The level of 12 kg N/lOa is the limiting N level to obtain dry matter production under 60-709 shading conditions. 5. The contents of crude protein arid nitrate nitrogen were increased with shading and incremental N fertilization up to 30 kg/l0a. But, water soluble carbohydrate content was decreased greatly with high shading and high levels of N. 6. Nitrate nitrogen content indicated highly significant positive correlation with crude protein, but significant negative correlation with water soluble carbohydrate content. 7. At 30 kg N level with $S_1$, was necessary to exceed the potentially toxic nitrate nitrogen level of 0.20%.

• 한국환경농학회지
• /
• 제26권3호
• /
• pp.223-227
• /
• 2007

토양의 질산태 질소를 이용하여 시설 오이의 적정 질소 시비량을 결정하고자 질산태 질소 함량이 67-343 mg/kg의 범위를 갖는 8곳의 시설재배 토양으로부터 오이를 공시작물로 표준시비구와 무시비구에 대한 생산력 검정시험을 포트 재배로 조사하였다. 오이의 수량은 최소 1,006 g/plant에서 최대 2,369 g/plant로 토양 질소함량 수준에 따라 다양한 생산능력의 차이를 보였다. 토양의 질산태 질소는 Agronomic efficiency(AE)과 N use efficiency(NUE)와는 부의 상관을 보였다. 질소 무비 재배를 위한 시험 전 토양의 질산태 질소 임계기준은 토양의 질산태 질소 함량에 대한 AE 및 NUE의 관계를 Cate-Nelson 일원분류의 분산분석법으로 비교하고 또한 무비구의 수량 및 지상부의 질소 흡수량과의 관계로부터 추정하였을 때 약 260 mg/kg으로 나타났다. 질소 표준 시비가 요구되는 시험 전 토양의 질산태 질소 임계기준은 70 mg/kg으로 추정되었다. 질산태 질소 함량이 70-260 mg/kg 범위의 토양에서는 Y=-1.032X + 269.2(Y: 질소시비량, kg/ha; X: 시험 전 토양의 질산태 질소 함량, mg/kg) 추천식으로 질소시비량을 결정할 수 있다.

• 한국산림과학회지
• /
• 제99권2호
• /
• pp.186-196
• /
• 2010

Fertilization increases the crop productivity and produces high quality seedlings for plantation. We quantitatively measured both physical performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted species in Korea, to nitrogen, phosphorus, and potassium fertilization. We analyzed the growth performances by using Dickson's quality index (QI) and the nutrient status by using vector diagnosis. Nitrogen or phosphorus treatment increased height and root collar diameter growth of F. rhynchophylla and F. mandshurica, however, did not increase those of P. koraiensis and A. holophylla. The order of QI was N > P > K > control for F. rhynchophylla, P ${\geq}$ N > Control ${\geq}$ P for F. mandshurica, P > Control ${\geq}$ K > N for P. koraiensis and A. holophylla. In F. rhynchophylla, fertilization diluted N concentration in tissues by 5-25% because growth responses were higher than fertilization uptake. P. koraiensis and A. holophylla showed N excess showing "toxic accumulation". F. rhynchophylla and F. mandshurica showed P deficiency with P fertilization, however, P. koraiensis and A. holophylla showed "luxury accumulation". Vector diagnosis indicated that more fertilization was applicable for F. rhynchophylla and F. mandshurica, and high fertilization rates were inefficient for P. koraiensis and A. holophylla. Both QI and vector diagnosis can be applied to verify seedling quality in the light of growth responses and nutrient status in fertilization trials.

• 한국토양비료학회지
• /
• 제49권6호
• /
• pp.677-681
• /
• 2016

Excessive nitrogen fertilization influences crop yields and quality as well as environmental pollution. In this study, yields, nitrogen use efficiency and free sugar contents of burdock (Arctium lappa L.) were evaluated at different levels of nitrogen fertilization. Nitrogen fertilizer was applied at 5 levels (0, 50, 100, 150, 200%) based on the conventional fertilization ($N=230kg\;ha^{-1}$), and phosphate and potassium fertilizer were treated by conventional P and K fertilization ($P_2O_5-K_2O=140-210kg\;ha^{-1}$) in all plots. The root yields of burdock were the highest in N 100~150% treatment plots. Nitrogen use efficiency and nitrogen recovery decreased from over N 150% treatment. Nitrogen uptake of root was greater than that of shoot in N 50~200% treatments. Fructose contents in root were inversely proportional to the level of nitrogen fertilization. As considering nitrogen recovery and root quality, economical burdock yield was obtained in N $230kg\;ha^{-1}$.

• Agricultural and Biosystems Engineering
• /
• 제7권1호
• /
• pp.18-26
• /
• 2006

In-field site-specific nitrogen (N) management increases crop yield, reduces N application to minimize the risk of nitrate contamination of ground water, and thus reduces farming cost. Real-time N sensing and fertilization is required for efficient N management. An 'on-the-go' site-specific N management system was developed and evaluated for the supplemental N application to com (Zea mays L.). This real-time N sensing and fertilization system monitored and assessed N fertilization needs using a vision-based spectral sensor and controlled the appropriate variable N rate according to N deficiency level estimated from spectral signature of crop canopies. Sensor inputs included ambient illumination, camera parameters, and image histogram of three spectral regions (red, green, and near-infrared). The real-time sensor-based supplemental N treatment improved crop N status and increased yield over most plots. The largest yield increase was achieved in plots with low initial N treatment combined with supplemental variable-rate application. Yield data for plots where N was applied the latest in the season resulted in a reduced impact on supplemental N. For plots with no supplemental N application, yield increased gradually with initial N treatment, but any N application more than 101 kg/ha had minimal impact on yield.

• 한국작물학회지
• /
• 제51권6호
• /
• pp.505-512
• /
• 2006

In Korea, silicate fertilization (SF) is being practiced every four years to enhance rice production. However, the relationship between nitrogen (N) and SF in view of growth characteristics and grain yield of rice has not been examined after watermelon cropping in plastic film house. This study was carried out to identify useful critical N and Si fertilizer levels to sustain grain yield and to improve N use efficiency for rice. The watermelon-rice cropping system has maintained for three seasons in each year from 1998 to 2001 by farmer before this experiment. Experiments on N and Si fertilization levels were evaluated with Hwayoungbyeo (Oryza sativa L.) in 2002 and 2003 at Uiryeong, Korea. The goal of this experiment was to find out the optimum N and Si levels to sustain rice yield by reducing excessive N fertilizer in watermelon-rice cropping system. Nitrogen fertilization (NF) levels were three ($0,\;57,\;114kg\;ha^{-1};0,\;50,\;100%$ of conventional NF amount) and five (0, 25, 50, 75, 100%) in 2002 and 2003, respectively, and combined with three SF levels ($70,\;130,\;180mg\;kg^{-1};100,\;150,\;200%$ which were adjusted with Si fertilizer in soil) were evaluated for the improvement of N and Si fertilization level in both years. Rice yielded 3.98-5.95 and 2.84-4.02 t/ha in 2002 and 2003, respectively. Our results showed the combinations of 50% and 100% of N with 200% level of Si produced the highest grain yield in both years, respectably. The grain yield was greatly improved in plot of N25% level when compared to conventional NF (Nl00%) in 2003. In conclusion, NF amount could be reduced about 50% compared to recommended level by specific fertilization of N and Si combination levels for rice growing and grain yield after cultivation watermelon in paddy field.

• 아시안잔디학회지
• /
• 제9권3호
• /
• pp.207-212
• /
• 1995

This experiment was conducted to investigate the effect of the nitrogen fertilization levels on the content of $NH_4^+$-N in soil of 'Suffolk' Kentucky bluegrass and zoysiagrass. The results obtained are summarized as follows : 1.According to the nitrogen fertilization levels, the content of $NH_4^+$-N in soil of Kentucky blue-grass and zoysiagrass was not significantly different. The content of $NH_4^+$-N in soil of Kentucky bluegrass and zoysiagrass was highest in June and December and lowest in March and September. 2.The content of $NH_3^-$-N in soil was increased by increasing the nitrogen fertilization levels in both Kentucky bluegrass and zoysiagrass. However, the deeper the depth of soil the less the content of $NO_3^-$-N in soil. In 40~60cm soil depth, the content of $NO_3^-$-N in soil was lower than 10ppm in average. Even in June, which was the highest month of the content of $NO_3^-$-N in soil, the content of $NO_3^-$-N in soil was not overpassed the degree of 20ppm.