• 한국작물학회지
• /
• 제44권2호
• /
• pp.97-101
• /
• 1999

No-till direct seeding cultivation of rice has major advantages such as saving of labor and cost by eliminating tillage, preparation of seed bed and trans-planting procedure compared to the conventional transplanting cultivation. A field experiment was conducted to evaluate the effects of straw treatment and nitrogen levels on the rice growth in no-till direct-seeding cultivation. Rice straw, vetch straw, and the mixture of both of the straws were mulched on the surface of soil before seeding while 4 levels of nitrogen fertilizer, 0, 7, 9, and 11 kkg/10a respectively, were applied at 3 split times, 3-weeks after sowing, 5-weeks after sowing and the panicle initiation stage. Mulching of vetch straw significantly reduced seedling establishment of rice which may be attributed to low oxidation-reduction potential of soil by vetch mulching treatment. Vetch straw increased the concentration of soil ammonium leading to an extension of the greenish leaf to panicle initiation stage. Agronomic nitrogen use efficiency (AD $E_{N}$) in heavy-mixed straw mulching plots was lower than other treatments. Grain yield and AU $E_{N}$ in the vetch treatment were less affected by fertilized N levels. Conclusively, it is suggested that heavy straw mulching was not efficient for rice seedling establishment and nitrogen usage.e.

• 한국초지조사료학회지
• /
• 제21권2호
• /
• pp.59-66
• /
• 2001

In order to determine the influence of nitrogen on agronomic characters, forage yield and quality, a Kenaf was cultured on the volcanic ash soil at the Experimental Farm of Cheju national University under the seven levels of nitrogen rates(0, 50, 100, 150, 200, 250kg/ha) from April 25 to Dec. 25, 1999. The plant height increased by increase of nitrogen rate, showing longest 250kg/ha with 286.6cm and shortest at no application plot with 255.7cm. The difference on leaf number, leaf withering number, stem diameter and branches number by nitrogen rate showed a similar tendency to the plant height. Increasing N rate from 0 to 250kg/ha fresh forage yield form 55.8 to 99.8MT/ha, dry matter (DM) yield from 8.8 to 15.8MT/ha, crude protein(CP) yield form 1.2 to 3.1MT/ha, total digestible nutrients (TDN) yield from 3.8 to 8.6MT/ha. However, no significant differences in these yields were found between 200 and 250kg N/ha. Nitrogen uptake increased form 192.9 to 496.2 kg/ha but N use efficiency decreased form 95.0 to 66.6 kg DM$^{a}$ /kg N with increasing from 0 to 250 kg/ha. As N rate increased from 0 to 250kg/ha, leaf and stem out of CP, crude fat (CF), nitrogen free extract (NFE), TDN contents increased from 20.1% to 25.8% and from 9.7% to 12.4%, from 5.6% to 8.1% and from 3.3% to 4.4%, from 36.1% to 40.2% and from 21.9% to 32.4%, from 59.3% to 75.0% and from 32.2% to 38.2%, respectively, while leaf and stem out of crude fiber decreased from 18.5% to 16.7% and from 51.5% to 39.3%. Based on the these findings, the optimum N rate for forage production of kenaf seems to be about 200 kg/ha in atmospheric phenomena and volcanic ash soils of jeju island.

• 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.

• 한국토양비료학회지
• /
• 제39권6호
• /
• pp.345-350
• /
• 2006

본 시험은 벼 종이멀칭이앙 시 적정한 완효성비료의 시용량을 구명하고자 경기도 수원에 위치한 작물과학원 벼 연구 포장 강서통에서 대안벼를 2004년 5월 28일에 중묘를 멀칭기계 이앙하였다. 시험에 사용한 완효성비료는 LCU (Latex Coated Urea, 21-7-9) 복비를 시용하였다. 피복재료는 생분해성 폴리에스터 (PES $10{\mu}m$)+재생지를 이용하여 피복하였다. 처리내용은 관행질소시비량 ($110kg\;ha^{-1}$)을 기준으로 하여 완효성비료호 기준시비량의 60%, 80%구, 100%구와 관행 및 무질소구를 두고 시험을 수행하였다. 벼 멀칭이앙 시 모의 결주율은 무피복의 관행이앙과 차이가 없었다. 잡초발생 및 방제가는 시비량이 적을수록 잡초가 다양해지고 잡초방제가가 낮아지는 경향이었다. 벼 이앙 후 일수가 진전됨에 따라서 시비량이 많을수록 초장와 경수가 크거나 많아지는 경향이었고 완효성비료 80%구의 벼 생육이 관행시비구와 차이가 없는 경향이었다. 엽색도와 토양 중 $NH_4{^+}-N$도 유사한 경향을 보였다. 따라서 수량구성요소 중 $m^2$당 이삭수의 증가로 인하여 완효성비료 80%구가 관행과 수량 차이가 없었다. 농업적 질소이용 효율은 시비량이 적을수록 증가하였다. 벼 종이멀칭이앙 시 벼 수량 및 수량구성요소, 잡초발생 및 방제가, 시비효율 등을 종합적으로 고려하여 관행질소 시비량의 80%를 완효성비료로 이앙 전에 밑거름으로 전층시비 하는 것이 알맞을 것으로 생각된다.

• Journal of Crop Science and Biotechnology
• /
• 제11권2호
• /
• pp.141-150
• /
• 2008

The response of grain yield(GY) and milled-rice protein content(PC) to crop growth status and nitrogen(N) rates at panicle initiation stage(PIS) is critical information for prescribing topdress N rate at PIS(Npi) for target GY and PC. Three split-split-plot experiments including various N treatments and rice cultivars were conducted in Experimental Farm, Seoul National University, Korea in 2003-2005. Shoot N density(SND, g N in shoot $m^{-2}$) and canopy reflectance were measured before N application at PIS, and GY, PC, and SND were measured at harvest. Data from the first two years(2003-2004) were used for calibrating the predictive models for GY, PC, and SND accumulated from PIS to harvest using SND at PIS and Npi by multiple stepwise regression. After that the calibrated models were used for calculating N requirement at PIS for each of nine plots based on the target PC of 6.8% and the values of SND at PIS that was estimated by canopy reflectance method in the 2005 experiment. The result showed that SND at PIS in combination with Npi were successful to predict GY, PC, and SND from PIS to harvest in the calibration dataset with the coefficients of determination ($R^2$) of 0.87, 0.73, and 0.82 and the relative errors in prediction(REP, %) of 5.5, 4.3, and 21.1%, respectively. In general, the calibrated model equations showed a little lower performance in calculating GY, PC, and SND in the validation dataset(data from 2005) but REP ranging from 3.3% for PC and 13.9% for SND accumulated from PIS to harvest was acceptable. Nitrogen rate prescription treatment(PRT) for the target PC of 6.8% reduced the coefficient of variation in PC from 4.6% in the fixed rate treatment(FRT, 3.6g N $m^{-2}$) to 2.4% in PRT and the average PC of PRT was 6.78%, being very close to the target PC of 6.8%. In addition, PRT increased GY by 42.1 $gm^{-2}$ while Npi increased by 0.63 $gm^{-2}$ compared to the FRT, resulting in high agronomic N-use efficiency of 68.8 kg grain from additional kg N. The high agronomic N-use efficiency might have resulted from the higher response of grain yield to the applied N in the prescribed N rate treatment because N rate was prescribed based on the crop growth and N status of each plot.

• 현장농수산연구지
• /
• 제20권1호
• /
• pp.175-185
• /
• 2018

개체군생장율(CGR)은 유수형성기와 출수기 사이에 가장 높았는데, 주남벼, 낙동벼, 소비벼 등이 높았으며, 이삭의 등숙속도는 시비량이 증가할수록 증가하였고, 출수 후 20일까지 가장 많이 증가하고, 그 이후에는 점차 감소하는 경향이었는데, 주남벼, 소비벼에서 빨랐다. 관행재배에서 수량이 높은 품종은 소비재배에서도 수량이 높았으며, 소비재배시 수량에 가장 많은 영향을 미치는 수량구성요소는 단위면적당 영화수로, 고도의 정의 상관관계를 나타냈다. 또한 백미품위는 시비량이 증가할수록 감소하였는데, 소비벼의 품위가 가장 낮았으며, 사미와 분상 질립의 증가가 원인이었다.

• 한국토양비료학회지
• /
• 제43권6호
• /
• pp.962-967
• /
• 2010

가축분퇴비 시용시 시비질소의 이용효율 증진 도모를 위한 기초자료를 얻고자 토양 비옥도가 다른 두 토양 (Soil-L와 Soil-H)에서 돈분 퇴비와 질소비료 (요소)의 혼용비율을 달리하여 포장조건에서 배추를 포트 재배시험을 실시하였다. 배추수량은 Soil-L에서는 시용질소를 전량 화학비료로 시비한 NPK 대비 돈분퇴비로 시용한 COM 100 처리구에서 17% 감소한 반면, 화학비료 질소와 퇴비를 혼용한 3처리 (COM 70+N30, COM50+N50 및 COM30+N70) 에서는 통계적 유의한 차이가 없었다. Soil-H에서는 NPK 대비 COM100 처리구에서 23.6%의 수량감소를 보였다. 배추의 질소흡수량은 두 토양 공히 NPK 처리구와 N70+COM30 처리구에서 가장 많았다. 시비 질소에 대한 배추의 생산효율은 두 토양 모두 화학비료의 시비량이 증가함에 따라 증가되었다. 그리고 화학비료를 전량 시비한 NPK 처리구에서 두 토양의 질소 생산효율은 큰 차이를 보이지 않았지만, 질소 시비량을 전량 퇴비로 시용한 COM 100 처리구에서는 Soil-L에서 28.8 g $g^{-1}$으로 Soil-H 16.2 g $g^{-1}$보다 현저히 높았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권4호
• /
• pp.629-632
• /
• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• 한국토양비료학회지
• /
• 제33권2호
• /
• pp.114-120
• /
• 2000

폐지섬유를 이용한 완효성 요소비료(시제품)의 벼에 대한 실용화 가능성을 검토하기 위하여 pot시험으로 무질소구, 요소구(대조구), 시제품구 처리에 벼(일미벼)를 공시하여 생육, 엽록소 함량 및 광합성능력, 수량 및 수량구성요소, 식물체중 무기성분 함량, 질소이용율 토양의 이화학성 등을 조사하였다. 초장과 분얼수는 생육초기에 시제품구가 요소구보다 다소 증가하였으나, 생육후기에는 비슷한 경향을 보였다. 이앙 후 40일의 엽록소 함량은 시제품구에서 요소구보다 다소 높았으나, 광합성능력은 요소구보다 낮았다. 수량 및 수량구성요소는 시제품구보와 요소구간에 통계적인 유의성은 없었으나, 시제품구가 요소구보다 다소 높았다. 수확기에 식물체중 전질소함량은 시제품구가 요소구보다 정조에서는 높았으나, 짚에서는 낮았다. 수확기의 질소흡수량은 시제품구가 요소구보다 정조에서 4% 높았으나, 짚에서는 20% 낮았으며, 질소이용율은 시제품구가 요소구보다 약간 낮았다. 시험 후 토양중 전질소 함량은 시제품구가 요소구보다 낮았다.

• 한국작물학회지
• /
• 제43권1호
• /
• pp.49-53
• /
• 1998

Direct-seeding has major advantages such as labor and cost saving by eliminating preparation of seed bed and transplanting. But, it required increased input of fertilizers and pesticides because of the extended paddy period. Direct seeding in wet paddy (DSWP) gives faster growth and more uniform seedling emergence than direct-seeding in dry paddy. This research had an objective to develop an efficient N management practices for DSWP with split application of N fertilizer. A paddy field experiment was conducted to evaluate effects of starter N and N-topdressing which was delayed N application until 5-leaf stage, with comparison to transplanting (TP). Total amount of N application were two levels; 110kg and 77kg/ha. The N applications were split four times during rice growth stages; starter, topdressing at 5-leaf stage, top dressing at tillering stage, and topdressing at panicle initiation stage. DSWP had more tillers/$m^2$ than TP, but with the delayed heading. The DSWP plots which received N-topdressing at 5-leaf stage without starter N had higher leaf area index (LAI) and leaf greenness than the TP plot. Also, these DSWP plots had high leaf-N concentration at the heading stage, as calculated from leaf chlorophyll meter readings. Rice yield in DSWP with N-topdressing at 5-leaf stage was significantly higher than that in TP and in DSWP with starter N. Energy and N use efficiency were improved in DSWP with N-topdressing at 5-leaf stage. But, there were no significant differences in grain yield between the two levels of total amounts of N applications, 77kg and 110kg/ha. We concluded that starter N could not be used effectively by rice seedlings, but topdressing N at 5-leaf stage was an efficient N management for rice growth and yield in DSWP system.