• 한국토양비료학회지
• /
• 제35권6호
• /
• pp.372-380
• /
• 2002

표고 750m인 고랭지에서 마사토의 일종인 척박한 모재토를 채취하여 1.5m로 두텁게 성토한 포장조건에 인산증시, 유기물 및 석회질비료 등을 혼용하였을 때 토양화학성분 함량의 변화와 수량성을 검토하기 위하여 1999년에서 2001년까지 3년간 포장시험으로 수행하였다. 유기물, 유효인산 및 치환성칼륨 등 화학성분 함량이 매우 낮은 양질사토인 토양에 감자 "수미"와 배추 "고랭지 여름배추"를 여름재배하였다. 연차의 경과에 따른 토양의 유효인산과 치환성칼륨 함량은 인산 및 칼리질비료의 증비로 증가하였으며, 특히 3년차에서 현저히 증가한 반면, 유기물 함량은 완만한 증가를 나타내었다. 작물 재배지에 모재토(C horizons) 성토시는 매년 표준량의 퇴비연용 및 석회중화량 시용(감자는 더뎅이병 발생 경감을 위하여 1/2량 시용)과 병행하여 토양검정에 의한 인산(흡수계수 5% 조절량) 및 칼리(포화도 5% 조절량)를 증비하는 화학성 개량만으로도 2~3년내 조기 숙전화가 가능함을 알았다. 토양의 유효인산과 치환성칼륨 함량의 증가가 컸던 화학성 개량구의 2~3년차 수량증가율은 표준구에 비하여 감자 5~22%, 배추 6~25% 이였다. 감자 및 배추의 3년차 건물중은 표준구에 비하여 모두 높았고, 생육도 전반적으로 양호한 결과로 나타났다.

• 한국토양비료학회지
• /
• 제43권3호
• /
• pp.260-267
• /
• 2010

As sloped farmland is subject to runoff and soil erosion and consequently require appropriate vegetative coverage to conserve soil and water, a field study was carried out to evaluate the impact of crop canopy coverage on soil loss and runoff from the experimental plot with three different textural types (clay loam, loam, and sandy loam). The runoff and soil loss were examined at lysimeters with 15% slope, 5 m in length, and 2 m in width for five months from May to September 2009 in Suwon ($37^{\circ}$ 16' 42.67" N, $126^{\circ}$ 59' 0.11" E). Red pepper (Capsicum annum L. cv. Daechon) seedlings were transplanted on three different dates, May 4 (RP1), 15 (RP2), and 25 (RP3) to check vegetation coverage. During the experimental period, the vegetation coverage and plant height were measured at 7 day-intervals and then the 'canopy cover subfactor' (an inverse of vegetation cover) was subsequently calculated. After each rainfall ceased, the amounts of soil loss and runoff were measured from each plot. Under rainfall events >100 mm, both soil loss and runoff ratio increased with increasing canopy cover subfactor ($R^2$=0.35, p<0.01, $R^2$=0.09, p<0.1), indicating that as vegetation cover increases, the amount of soil loss and runoff reduces. However, the soil loss and runoff were depending on the soil texture and rainfall intensity (i. e., $EI_{30}$). The red pepper canopy cover subfactor was more highly correlated with soil loss in clay loam ($R^2$=0.83, p<0.001) than in sandy loam ($R^2$=0.48, p<0.05) and loam ($R^2$=0.43, p<0.1) plots. However, the runoff ratio was effectively mitigated by the canopy coverage under the rainfall only with $EI_{30}$<1000 MJ mm $ha^{-1}hr^{-1}$ ($R^2$=0.34, p<0.05). Therefore, this result suggested that soil loss from the red pepper field could be reduced by adjusting seedling transplanting dates, but it was also affected by the various soil textures and $EI_{30}$.

• 한국대기환경학회지
• /
• 제4권1호
• /
• pp.33-44
• /
• 1988

For the purpose of examining the effects of simulated acid rain on the chemical properties of the experimental soil in Pinus densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils (nursery soil: forest soil of siliceous sandy loam = 1 : V/V)in the early spring of 1985. The regime of artificil acid rain, in terms of spray frequency per monthly and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain (pH 2.0, pH4.0, and pH 5.5 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (May 1 to August 31) in 1985. THe results obtained in this study were as follows; 1. Soil acidity was dropped, and exchangeable aluminum contents in the soil was dramatically increased in both species, with decreasing pH levels of acid rain. 2. Exchangeable potassium, clacium, magnesium contents, and base saturation degree of the soil were highly drcreased in two species as the pH levels of acid rain decreased. 3. In two species, sulfate concentrations in the soil were decreased of pH 4.0 treatment, and remarkably increased at pH 2.0 treatment of acid rain in comparison with control. 4. Total nitrogen and available phosphate contents of the soil were not affected by acid rain treatment in the both species, and Fe contents at pH 2.0 treatment were highest among three acid rain treatments.

• 한국농공학회논문집
• /
• 제55권4호
• /
• pp.37-44
• /
• 2013

We have examined the effect of rice straw mat (RSM) on the reduction of non-point source (NPS) pollution loads at soybean cultivations. The slope of the experimental plot was about 3 %. Monitoring was carried out for four years at conventional tillage (CT) in 2008~2009 years and RSM covered tillage in 2010~2011 years. Thirty-two rainfall events were monitored and analyzed during the study period. During the 2 years of 2008 and 2009, 20 rainfall runoff events were monitored. But in 2010 years, only 2 rainfall runoff events could be monitored. And in 2011 years, 10 rainfall runoff events was monitored. It was because the RSM cover enhanced infiltration and reduce runoff in 2010 and 2011. Average NPS pollution load (organic matters) of the RSM covered field was reduced by 72.1~94.2 % compared to that of CT field. NPS pollution load of TN and TP reduced by 67.5 % and 55.7 %, respectively. Especially, SS pollution load was reduced by 97.3 %. Based on the results, rice straw mat cover was considered as a promising best management practices (BMP) to reduce NPS pollution load. However, it was recommended that the results are limited to the field conditions and the same experiments must be performed on different soil textures, slopes, and crops if it is applied to the development of policies.

• 한국토양비료학회지
• /
• 제45권1호
• /
• pp.59-65
• /
• 2012

Plant growth-promoting effects of rhizobacterial inoculation obtained in pot experiments cannot always be dependably reproduced in fields. In this study, we investigated the effect of inoculation with Azospirillum brasilense and Methylobacterium oryzae, which have displayed growth promoting effects in several pot experiments, on growth and fruit yield of red pepper under field condition in a plastic-film house. Four rows spaced 90 cm apart were prepared after application of compost ($10Mg\;ha^{-1}$), and red pepper seedlings (Capsicum annum L., Nocgwang) were transplanted in each row with 40-cm space. Experimental treatments were consisted of A. brasilense CW903 inoculation, M. oryzae CBMB20 inoculation, and uninoculated control. Twelve plots, 10 plants per plot, were allotted to the three treatments with four replicates in a completely randomized design. At the time of transplanting, 50 mL of each inoculum ($1{\times}10^8cells\;mL^{-1}$) was introduced into root zone soil of each plant, and re-inoculated at 7 and 14 days after transplant. Plant growth and fruit yield were measured during the experiment. Both A. brasilense CW903 and M. oryzae CBMB20 could not promote growth of red pepper plants. All growth parameters measured were not significantly different among treatments. There were large variations in fruit yield recorded on plot basis, and no statistically significant differences were found among treatments. The failure to demonstrate the expected plant growth promoting effect of the inoculants is possibly due to various environmental factors, including weather and soil characteristics, reducing the possibility to express the potential of the inoculated bacterial strains.

• 한국토양비료학회지
• /
• 제47권6호
• /
• pp.491-495
• /
• 2014

Phytoremediation is a technology using plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is regarded as a cost-effective, efficient, eco-friendly, and solar-driven technology with good public acceptance. This study was conducted to find the plants accumulating heavy metals in soils contaminated with Cd and Pb. Experimental plots (plot size: $0.81m^2$) was artificially contaminated using a contaminated soil collected from a field in vicinity of Wondong mine (WD). Sunflower, corn and castor were tested for their potential to remove heavy metals from the contaminated soils. The results indicated that sunflower was most effective in accumulating heavy metals and thus remedying the soils among the three crops. Dry weight and heavy metal uptake of sunflower shoot differed with growth period. For example, the Cd content of shoots including leaf and stem were 0.31mg, 2.23 mg, and 0.96 mg per plot at 4, 8 and 12 weeks after planting in Cd4-WD treatment; in addition, the dry weight of the shoots in Cd8-WD treatment was reduced due to heavy metal toxicity. This experiment showed that sunflower absorbed Cd, Pb and Zn in their shoots up to 8 weeks of planting; thereafter heavy metals uptake was diminished. This implies that the efficiency of these plants in cleaning the contaminated soils may be high at the early stage of plant growth.

• 한국약용작물학회지
• /
• 제7권2호
• /
• pp.89-93
• /
• 1999

구기자의 비닐 하우스 재배에서 재배방법에 따른 생육, 수량성 및 병해충 발생정도를 알아보기 위하여 충남 청양군 청양농공업고등학교 실습 포장의 비닐 하우스에서 1997년 2월 20일부터 98년 10월5일까지 ‘청양 재래’ 품종을 재식거리, 적심시기 및 적심횟수를 달리하여 재배한 시험 결과를 요약하면 다음과 같다. 1. 재식거리가 멀수록 분지수가 적어졌고, 경장, 경직경, 분지당 엽수, 엽장, 엽폭은 증가하였으며, 개화기 차이는 없었다. 2. 재식거리가 멀수록 분지당 화수, 착과수, 생과중, 전과중은 증가하였으나, 총 수량은 단위면적당 총 주수가 많은 재식거리 $60\;{\times}\;20cm$에서 가장 높았다. 3. 적심시기가 5월5일에서 6월5일로 늦어질수록 생육형질인 경장, 경직성, 분지수, 분지당 엽수, 엽장, 엽폭은 낮았고, 분지당 화수, 착과수, 생과중, 건과중도 모두 낮았다. 4. 적심횟수가 증가할수록 분지수는 많아졌지만, 경장, 경직경, 분지당 엽수, 엽장, 엽폭 모두 감소하였다. 5. 적심횟수가 증가할수록 분지당 개화수, 과립수, 착과율은 감소하였지만, 주당 생과중, 건과중은 증가하였다.

• 한국작물학회지
• /
• 제62권2호
• /
• pp.134-142
• /
• 2017

Crop production in rice paddy fields is of great importance because of declining rice consumption and the low self-sufficiency ratio for field crops in Korea. A controlled drainage system (CDS) is recognized as an effective means to adjust water table (WT) levels as needed and control soil water content to improve the soil environment for optimum crop growth. The present study evaluated the effects of a CDS on soil characteristics, including soil water distribution and soybean development in paddy fields. The CDS was installed with two drain spacing (3 m and 6 m) at the experimental paddy field at the National Institute of Crop Science, Miryang, Korea. It was managed with two WT levels (0.3 m and 0.6 m) during the growing season. Soil water content, electrical conductivity and plant available nitrogen content in the soil were significantly greater in the 0.3 m WT management plots than in the 0.6 m plot and the control. At the vegetative stage, chlorophyll content was significantly lower with higher WT control because of excess soil moisture, but it recovered after the flowering stage. Soybean yield increased with WT management and the 0.6 m WT treatment produced the greatest grain yield, $3.38ton\;ha^{-1}$, which was 50% greater than that of the control. The CDS directly influenced outflow through the drains, which significantly delayed nutrient loss. The results of this study indicated that WT management by CDS can influence soil characteristics and it is an important practice for high yielding soybean production in paddy fields, which should be considered the crop growth stages for stable crop production.

• 한국농공학회논문집
• /
• 제57권5호
• /
• pp.123-128
• /
• 2015

This study conducted a series of field experiments using soil conditioners, Polyacrylamide(PAM) and gypsum, to evaluate their effects in reducing sediment loss and surface runoff. In addition, the correction factors (K-alpha) for the erodibility factor (K) were determined to reflect the effects of PAM and PAM+gypsum in applying the USLE equation. Experimental erosion plots individually sized $10m^2$ (5 m long, 2 m wide and 1 m deep) have different slopes (10, 20 and 30%). Erosion plots were prepared for one control (C; no PAM and gypsum) and two treatments (P; PAM 20 kg/ha, PG; PAM 20 kg/ha+gypsum 3,000 kg/ha). The amounts of soil eroded and runoff were continuously monitored from July $1^{st}$ to Oct. $31^{st}$ in 2010 and compared to each other. The amount of sediment loss from a control plot was 399.2 ton/ha and the relative reduction of sediment loss were 11.4% and 33.4% for PAM-treated and PAM+gypsum treated plots, respectively. This study also determined the K-alpha factors in the USLE equation to account for the erosion control effectiveness of PAM and gypsum application. The K-alpha factors were calculated as 0.92 for PAM-treated plot and 0.69 for PAM+gypsum-treated plot. The findings of this study revealed that soil conditioners (PAM and gypsum) could play a significant role in controlling soil erosion. In addition, the modified USLE equation using the K-alpha could provide valuable information to make better decision on establishment of best management practice for soil erosion control in agriculture.

• Applied Biological Chemistry
• /
• 제6권
• /
• pp.51-56
• /
• 1965

누수과다답(漏水過多沓)에서 미분탄회(微粉炭灰)의 시용(施用)이 수도수량(水稻收量) 및 수량구성요소(收量構成要素)에 미치는 영향(影響) 및 규산고토석회(硅酸苦土石灰), 석회(石灰) 등(等)과의 비효(肥效)를 비교(比較)하고저 실험처리구(實驗處理區)로 10a당(當) 규산고토석회(硅酸苦土石灰) 75kg구(區), 석회(石灰) 150kg구(區), 미분탄회(微粉炭灰) 75kg구(區), 150kg구(區), 225kg구(區), 300kg구(區), 375kg구(區), 450kg구(區) 및 무처리대조구(無處理對照區)를 두고 수도품종(水稻品種) 팔달(八達)을 공시(公試)하여 실험(實驗)하였는데 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 미분탄회(微粉炭灰), 규산고토석회(硅酸苦土石灰) 및 석회(石灰)의 시용(施用)은 무처리(無處理)에 비(比)하여 각구(各區) 모두 수도생육(水稻生育) 및 수량(收量)을 증대(增大)시키는 경향(傾向)을 보였다. 특히 수량구성요소적(收量構成要素的)으로 보면 임실율(稔實率)을 높이는데 효과(?果)가 컸다. 2. 미분탄회(微粉炭灰)의 시용(施用)은 그 양(量)을 증가(增加)시킬수록 수량(收量)도 증가(增加)되는 경향(傾向)을 보였는데 10a당(當) 300kg 이상(以上)의 시용구(施用區)에 있어서는 큰 차이(差異)가 인정(認定)되지 않았으며, 이것은 규산고토석회시용구(硅酸苦土石灰施用區)의 수량(收量)과 거의 비슷한 것이었고 미분탄회(微粉炭灰) 225kg 시용구(施用區)는 석회시용구(石灰施用區)와 거의 그 수량(收量)이 동등(同等)하였다. 3. 따라서 미분탄회(微粉炭灰)의 시용량(施用量)은 10a당(當) 300kg내외(內外)가 효과적(?果的)인 것으로 보인다.