• 제목/요약/키워드: Variable rate nitrogen application

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Development of a Nitrogen Application System for Nitrogen Deficiency in Corn

  • Noh, Hyun Kwon
    • Journal of Biosystems Engineering
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    • 제42권2호
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    • pp.98-103
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    • 2017
  • Purpose: Precision agriculture includes determining the right amount of nitrogen for a specific location in the field. This work focused on developing and validating a model using variable rate nitrogen application based on the estimated SPAD value from the ground-based image sensor. Methods: A variable rate N application based on the decision making system was performed using a sensor-based variable rate nitrogen application system. To validate the nitrogen application decision making system based on the SPAD values, the developed N recommendation was compared with another conventional N recommendation. Results: Sensor-based variable rate nitrogen application was performed. The nitrogen deficiency level was measured using the image sensor system. Then, a variable rate application was run using the decision model and real-ti me control. Conclusions: These results would be useful for nitrogen management of corn in the field. The developed nitrogen application decision making system worked well, when considering the SPAD value estimation.

멀티스펙트랄 이미지 센서를 이용한 전자 지도 기반 변량 질소 살포 (Map-based Variable Rate Application of Nitrogen Using a Multi-Spectral Image Sensor)

  • 노현권
    • Journal of Biosystems Engineering
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    • 제35권2호
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    • pp.132-137
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    • 2010
  • Site-specific N application for corn is one of the precision crop management. To implement the site-specific N application, various nitrogen stress sensing methods, including aerial image, tissue analysis, soil sampling analysis, and SPAD meter readings, have been used. Use of side-dressing, an efficient nitrogen application method than a uniform application in either late fall or early spring, relies mainly on the capability of nitrogen deficiency detection. This paper presents map-based variable rate nitrogen application based using a multi-spectral corn nitrogen deficiency(CND) sensor. This sensor assess the nitrogen stress by means of the estimated SPAD reading calculated from the corn leave reflectance. The estimated SPAD value from the CND sensor system and location information form DGPS of each field block was combined into the field map using a ArcView program. Then this map was converted into a raster file for a map-based variable rate application software. The relative SPAD (RSPAD = SPAD over reference SPAD) was investigated 2 weeks after the treatments. The results showed that the map-based variable rate application system was feasible.

정밀 농업을 위한 직파 벼 재배 논에서 포장 변이성 조사와 질소의 변량 시비 (Field Variability and Variable Rate Fertilization of Nitrogen in a Direct Seeding Paddy for Precision Agriculture)

  • 정영상;이호진;정지훈;박정근;강창식
    • 한국토양비료학회지
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    • 제38권4호
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    • pp.202-210
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    • 2005
  • 정밀 농업 시행에 있어서 포장 변이성에 대한 이해가 필수적이므로, 직파 재배 논에서 포장 변이성 조사와 토양 검정 결과에 다른 질소 변량 시비에 대한 현장 시험이 전북 김제의 직파 재배 논 시험 포장과 농가 시범 포장에서 이루어졌다. $35m{\times}112m$ 단위 포장에서 10 m 간격의 방격형으로 표토의 토양 시료를 채취하여 분석하였다. 토양 유기물, 유효 인산 및 규산, 그리고 치환성 칼륨 등에 대한 분석이 이루어졌다. 시험 포장에 대한 토양 검정 결과에 의해 다수확과 저투입 농업을 위한 질소 시비 추천량을 계산하여 그 분포도를 작성하였다. 2001년과 2002년의 시험 포장에서의 질소 변량 시험을 토대로, 2003년에는 농가 포장 3개를 선정하여 저투입 질소 시비량을 기준으로 질소 변량 시비에 대한 농가 실증 시험을 하였고, 경제성을 분석하였다. 변량 시비에 의해 수량 중가 및 수량 변이 감소 효과를 알 수 있었다. 변량 시비에 의한 수량 증가와 시비량 절감에도 불구하고, 토양 검정에 소요되는 비용이 절감 비용을 초과하였다.

On-the-go Nitrogen Sensing and Fertilizer Control for Site-specific Crop Management

  • Kim, Y.;Reid, J.F.;Han, S.
    • Agricultural and Biosystems Engineering
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    • 제7권1호
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    • pp.18-26
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    • 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.

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토양특성(土壤特性)에 따른 질소시용(窒素施用)의 환경(環境) 경제적(經濟的) 효과(效果) (Effects of the Site-Specific Nitrogen Management on Economic Feasibility and Environmental Sustainability)

  • 강충관;박주섭;이상용;김한명
    • 한국토양비료학회지
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    • 제34권1호
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    • pp.42-54
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    • 2001
  • 질소비료는 작물의 생장에 있어서 가장 핵심적인 영양소라 할 수 있으며, 질소의 효율적 이용은 안정적인 수확량의 확보 뿐만 아니라 비용절감 및 환경오염원 감축 등 다양한 편익을 제공할 수 있을 것이다. 정밀농업은 토양의 특성에 따라 작물에 필요한 적정량의 시비로 영양분의 이용효율을 높임으로써 환경 경제적 편익을 동시에 추구하는 농법이라 할 수 있다. 본 연구는 GIS를 이용하여 구축한 455개 표본농경지의 토양 및 지형에 관한 Database에 근거하여 각 농경지내에서 토양을 세분하여 적정 시비를 할 경우(site-specific management)와 농경지별 적정 시비를 하였을 경우(uniform rate application) 비료의 사용량, 수확량, 수질오염 정도 등을 EPIC모델을 이용하여 비교분석 하였다. 전체 농경지에서의 가중평균적인 환경 경제적 효과는 큰 차이를 보이지 않지만 각각의 농경지가 다양한 토양으로 구성되어 있고 다양한 토양에 대한 최적의 질소량이 큰 차이를 나타낼 때는 정밀농업의 실천이 경제적 및 환경적 측면에서 충분한 잠재력이 있는 것으로 나타났다.

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Response of Rice Yield to Nitrogen Application Rate under Variable Soil Conditions

  • Ahn Nguyen Tuan;Shin Jin Chul;Lee Byun-Woo
    • 한국작물학회지
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    • 제50권4호
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    • pp.247-255
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    • 2005
  • ice yield and plant growth response to nitrogen (N) fertilizer may vary within a field, probably due to spatially variable soil conditions. An experiment designed for studying the response of rice yield to different rates of N in combination with variable soil conditions was carried out at a field where spatial variation in soil properties, plant growth, and yield across the field was documented from our previous studies for two years. The field with area of 6,600 m2 was divided into six strips running east-west so that variable soil conditions could be included in each strip. Each strip was subjected to different N application level (six levels from 0 to 165kg/ha), and schematically divided into 12 grids $(10m \times10m\;for\;each\;grid)$ for sampling and measurement of plant growth and rice grain yield. Most of plant growth parameters and rice yield showed high variations even at the same N fertilizer level due to the spatially variable soil condition. However, the maximum plant growth and yield response to N fertilizer rate that was analyzed using boundary line analysis followed the Mitcherlich equation (negative exponential function), approaching a maximum value with increasing N fertilizer rate. Assuming the obtainable maximum rice yield is constrained by a limiting soil property, the following model to predict rice grain yield was obtained: $Y=10765{1-0.4704^*EXP(-0.0117^*FN)}^*MIN(I-{clay},\;I_{om},\;I_{cec},\;I_{TN},\; I_{Si})$ where FN is N fertilizer rate (kg/ha), I is index for subscripted soil properties, and MIN is an operator for selecting the minimum value. The observed and predicted yield was well fitted to 1:1 line (Y=X) with determination coefficient of 0.564. As this result was obtained in a very limited condition and did not explain the yield variability so high, this result may not be applied to practical N management. However, this approach has potential for quantifying the grain yield response to N fertilizer rate under variable soil conditions and formulating the site-specific N prescription for the management of spatial yield variability in a field if sufficient data set is acquired for boundary line analysis.

크리핑 벤트그라스 훼어웨이에서 관수회수.예지물과 질소시비수준이 엽조직 및 토양 질소함유량에 미치는 효과 (A Three-year Study on the Leaf and Soil Nitrogen Contents Influenced by Irrigation Frequency, Clipping Return or Removal and Nitrogen Rate in a Creeping Bentgrass Fairway)

  • 김경남;로버트쉬어만
    • 아시안잔디학회지
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    • 제11권2호
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    • pp.105-115
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    • 1997
  • Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

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Using Chlorophyll(SPAD) Meter Reading and Shoot Fresh Weight for Recommending Nitrogen Topdressing Rate at Panicle Initiation Stage of Rice

  • Nguyen, Hung The;Nguyen, Lan The;Yan, Yong-Feng;Lee, Kyu-Jong;Lee, Byun-Woo
    • Journal of Crop Science and Biotechnology
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    • 제10권1호
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    • pp.33-38
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    • 2007
  • Nitrogen management at the panicle initiation stage(PI) should be fine-tuned for securing a concurrent high yield and high quality rice production. For calibration and testing of the recommendation models of N topdressing rates at PI for target grain yield and protein content of rice, three split-split-plot design experiments including five rice cultivars and various N rates were conducted at the experimental farm of Seoul National University, Korea from 2003 to 2005. Data from the first two years of experiments were used to calibrate models to predict grain yield and milled-rice protein content using shoot fresh weight(FW), chlorophyll meter value(SPAD), and the N topdressing rate(Npi) at PI by stepwise multiple regression. The calibrated models explained 85 and 87% of the variation in grain yield and protein content, respectively. The calibrated models were used to recommend Npi for the target protein content of 6.8%, with FW and SPAD measured for each plot in 2005. The recommended N rate treatment was characterized by an average protein content of 6.74%(similar to the target protein content), reduced the coefficient of variation in protein content to 2.5%(compared to 4.6% of the fixed rate treatment), and increased grain yield. In the recommended N rate treatments for the target protein content of 6.8%, grain yield was highly dependent on FW and SPAD at PI. In conclusion, the models for N topdressing rate recommendation at PI were successful under present experimental conditions. However, additional testing under more variable environmental conditions should be performed before universal application of such models.

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Managing Within-Field Spatial Yield Variation of Rice by Site-Specific Prescription of Panicle Nitrogen Fertilizer

  • Ahn Nguyen Tuan;Shin Jin Chul;Lee Byun-Woo
    • 한국작물학회지
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    • 제50권4호
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    • pp.238-246
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    • 2005
  • Rice yield and protein content have been shown to be highly variable across paddy fields. In order to characterize this spatial variability of rice within a field, two-year experiments were conducted in 2002 and 2003 in a large-scale rice field of $6,600m^2$ In year 2004, an experiment was conducted to know if variable rate treatment (VRT) of N fertilizer, that was prescribed for site-specific management at panicle initiation stage, could reduce spatial variation in yield and protein content of rice while increasing yield compared to conventional uniform N topdressing (UN, 33kg N/ha at PIS) method. VRT nitrogen prescription for each grid was calculated based on the nitrogen (N) uptake (from panicle initiation to harvest) required for target rice protein content of $6.8\%$, natural soil N supply, and recovery of top-dressed N fertilizer. The required N uptake for target rice protein content was calculated from the equations to predict rice yield and protein content from plant growth parameters at panicle initiation stage (PIS) and N uptake from PIS to harvest. This model· equations were developed from the data obtained from the previous two-year experiments. The plant growth parameters for the calculation of the required N were predicted non-destructively by canopy reflectance measurement. Soil N supply for each grid was obtained from the experiment of year 2003, and N recovery was assumed to be $60\%$ according to the previous reports. The prescribed VRT N ranged from 0 to 110kg N/ha with an average of 57kg/ha that was higher than 33 kg/ha of UN. The results showed that VRT application successfully worked not only to reduce spatial variability of rice yield and protein content but also to increase rough rice yield by 960kg/ha. The coefficient of variation (CV) for rice yield and protein content was reduced significantly to $8.1\%$ and $7.1\%$ in VRT from $14.6\%$ and $13.0\%$ in UN, respectively. And also the average protein content of milled rice in VRT showed very similar value of target protein content of $6.8\%$. In conclusion the procedure used in this paper was believed to be reliable and promising method for reducing within-field spatial variability of rice yield and protein content. However, inexpensive, reliable, and fast estimation methods of natural N supply and plant growth and nutrition status should be prepared before this method could be practically used for site-specific crop management in large-scale rice field.

Ureaform, SCU, Melamine의 질소공급력(窒素供給力)과 보리 생육(生育)에 대(對)한 효과(效果) (Effect of Ureaform, SCU and Melamine on Barley Growth and their Nitrogen Supplying Ability)

  • 임선욱;오남순
    • 한국토양비료학회지
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    • 제17권3호
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    • pp.265-273
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    • 1984
  • 본 시험은 우리나라의 밭 토양조건에서 몇 가지 완효성 질소질 비료의 보리에 대한 질소 공급효과를 시험하고저 한 것이며 공시비료는 황입힌 요소 SCU, ureaform, melamine 등의 완효성 질소비료와 대조로써 요소를 사용하였으며 질산화 저해제로는 thiourea를 처리하였다. 토양조건은 수분함량, pH 그리고 온도를 달리하여 사질양토의 보통 밭토양으로 pot시험 및 실내 배양시험하여 질소 공급력과 보리의 생장에 대한 효과를 생육시기별로 조사하여 얻은 결과를 다음과 같이 요약 보고한다. 완효성 질소질비료의 공급능력을 조사한 항온처리 실험에서 항온처리의 초기 2주에서 암모늄태질소로의 최고 전환율을 보였으며, urea, SCU, ureaform 순으로 27~59%, 25~39%, 9~34%이었고 melamine은 5주동안 0.7~4.3%의 낮은 분해를 보였다. 질산화작용에 의한 $NO_3-N$의 생성은 pH6.54와 pH5.84에서는 유사하였으며 pH6.54는 pH4.73보다 더 많은 양이 생성되었다. 토양수분은 암모니아화작용과 질산화작용에 큰 영향을 미쳐 수분함량 20%가 풍건상태보다 $NH_4-N$$NO_3-N$ 생성이 많았다. Thiourea는 4주까지는 질산화작용을 현저히 억제하였고 그 이후에 $NO_3-N$ 생성량이 증가하였으나 thiourea 무처리보다는 적었다. Pot시험으로 조사된 전 생육기 (출수후 유숙기까지)에 걸친 질소공급력은 SCU, urea가 ureaform, melamine 보다 높았으며 파종전 melamine 처리는 작물에 대하여 장애를 일으켰다. urea에 thiourea 혼합처리는 속효성으로 인한 urea의 과잉 질소 공급을 억제하여 보리의 후기생육에 도움을 주었으며 완효성 질소질비료에 소량의 urea 혼합처리는 조사된 생육기간 동안 질소공급에 크게 기여하였다.

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