• 한국작물학회지
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• 제47권2호
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• pp.108-115
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• 2002

The effects of long-term fertilization on soil properties and nutrient availability are not well documented for cassava cultivation in Vietnam. In 1990, a field research plots were established with 12 treatments to test the effect of different rates of nitrogen (N), phosphorus (P) and potassium (K) on soil properties in Acrisols at Thai Nguyen University in Northern Vietnam. In 1999, composite soil samples (0 to 20cm depth) were collected from eight selected plots for measurements of nutrient supply rates by ion exchange membrane probes and for growing corn and canola in a growth chamber with and without added lime. Generally, long-term nitrogen (N) fertilization increased available N supply rates but decreased available potassium (K) and magnesium (Mg). Long-term phosphorus(P) applications increased canola N, calcium (Ca) and Mg uptake. Canola P uptake increased with increased P rates only when lime was added. Long-term K applications increased canola N, K, Ca, Mg uptake but only significantly increased corn N uptake. Liming significantly increased uptake of N, P, K, Ca, Mg and S for both corn and canola. However, N $H_{4-}$N, K and Mg soil supply rates were reduced when lime was added, due to competition between Ca from the added lime and other nutrients.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.157-164
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• 2021

Smart agriculture requires sensing systems which are fundamental for precision agriculture. Adequate and appropriate water and nutrient supply not only improves crop productivity but also benefit to environment. However, there is no available soil sensor to continuously monitor nutrient status in soil. Electrical conductivity (EC) of soil is affected by ion contents in soil and can be used to evaluate nutrient contents in soil. Comparison of various commercial EC sensors showed similar water content and EC values at water content less than 20%. Soil EC values measured by sensors decreased with decreasing soil water content and linearly correlated with soil water content. EC values measured by soil sensor were highly correlated with water soluble nutrient contents such as Ca, K, Mg and N in soil indicating that the soil EC sensor can be used for monitoring changes in plant available nutrients in soil.

• 한국작물학회지
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• 제61권3호
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• pp.163-170
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• 2016

Heading time is important element for yield and quality in crops. Among day length and temperature which influence on heading, temperature effect has not been investigated well. To investigate temperature effect on heading, heading date and plant growth characters were checked under the low and high temperature conditions in short day length. Analyzing heading date of six Korean varieties under the high and low temperature condition, heading date of varieties were delayed under low temperature. In the low temperature condition, dry weight and area of leaf were reduced. Varieties showing more delay of heading under low temperature also showed more reduction in leaf area. After selecting three varieties showing significant difference in leaf growth and heading date under different temperature conditions, nutrient contents of plant were analyzed. Nitrogen content was reduced in leaf and shoot under the low temperature condition. OsNRT2.3, nitrate transporter, was significantly down regulated in varieties showing more heading delay. Available phosphate content was decreased in leaf, but increased in shoot due to reduction of phosphate mobility. OsPT1, phosphate transporter regulating phosphate uptake, was more down regulated in varieties showing more heading delay. OsPT6, phosphate transporter regulating phosphate transport in plant, was also significantly down regulated in those varieties. With these data, we expected that active nitrogen and available phosphate uptake and transport in plant would increase leaf growth then might reduce heading delay under the low temperature condition.

• 한국가구학회지
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• 제29권1호
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• pp.18-23
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• 2018

The purpose of this study was to develop wood pots for create Optimum environment of plant growth using unused wood. to prove this, we examined the effects of cycle of water supply and nutrient concentration in wood pots on plant germination rate and growth factors (leaf number, stem diameter and length). The results are as follows. 1) The growth rate was higher at once of 2 days watering period. This suggests that the growth of the plants was better than that of the less water because the larch pots itself has the water retention capacity inside. 2) Germination rate and growth rate were better than other treatment groups when the concentration of nutrient solution was 0.5%. 3) Nitrogen, available phosphoric acid, and potassium showed higher contents than the nutrient - treated soil at 0.5% concentration of nutrient solution. This indicates that the nutrient solution absorbed from the larch affected the soil and plant growth in the inside.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.91.2-92
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• 2003

In order to elucidate influence of nutritional status on rice brown spot caused by Cochliobolus miyabeanus, rice cultivation soils and rice straws were collected from paddy fields where ice brown spot occurred severely, moderately, a little and none respectively. Rice plant materials were analyzed to measure inorganic nutrients in rice straws and rice seeds. Analysis of chemical properties of rice paddy soil showed that EC and contents of available phosphate, cation and silicic acid in soil with severe infections were lower than those in healthy soil. This result suggests that amount and holding capacity of nutrient contents in soils collected from paddy field with infection of C. miyabeanus are relatively low compared to those in soils collected from healthy paddy field. Analysis of inorganic nutrients in rice straws showed that amount of macronutrient elements such as silicic acids, available phosphate and total nitrogen, and micronutrients such as copper, iron and zinc in rice straws from paddy field with infection were lower than those in healthy soil. Especially amount of iron and silicic acid were very low in rice straws from paddy field soils with infection Amount of inorganic nutrients such as iron and zinc in rice seeds was the same trend as those of rice straws. These results showed that one of major factors affecting rice brown spot was amount of nutrient contents in soil and rice straw.

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1127-1142
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• 2011

The aim of this investigation was to select effective Pseudomonas sp. strains that can enhance the productivity of soybean-wheat cropping systems in Vertisols of Central India. Out of 13 strains of Pseudomonas species tested in vitro, only five strains displayed plant growth-promoting (PGP) properties. All the strains significantly increased soil enzyme activities, except acid phosphatase, total system productivity, and nutrient uptake in field evaluation; soil nutrient status was not significantly influenced. Available data indicated that six strains were better than the others. Principal component analysis (PCA) coupled cluster analysis of yield and nutrient data separated these strains into five distinct clusters with only two effective strains, GRP3 and HHRE81 in cluster IV. In spite of single cluster formation by strains GRP3 and HHRE81, they were diverse owing to greater intracluster distance (4.42) between each other. These results suggest that the GRP3 and HHRE81 strains may be used to increase the productivity efficiency of soybean-wheat cropping systems in Vertisols of Central India. Moreover, the PCA coupled cluster analysis tool may help in the selection of other such strains.

• 청정기술
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• 제8권2호
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• pp.77-83
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• 2002

본 연구는 국내하수처리장에서 발생되는 하수내 질소와 인을 생물학적 영양소 제거공정을 이용하여 효율적으로 처리할 수 있는 설계 및 운전기술을 정립하는데 목적을 두고 있다. 혐기조 전단에 설치한 내생탈질조(Endogenous nitrate respiration, ENR)는 외부탄소원 없이 내생으로 반송슬러지내 포함된 질산성질소를 연속적으로 탈질시켜 질산성질소를 3mg/L 이하로 줄여 혐기조로 이송시킨다. 공정에 대한 성능 실험은 파이롯에서 수행하였다. 실험결과 운전기간동안 유입수내 TCOD/TP 비는 40에서 60범위를 보였고 TCOD/TKN 비는 5~7을 유지하였다. 유출수는 총질소는 10에서 12mg/L을 유지한 반면 총인은 최저 1mg/L을 가리켰다. 혐기조에서 $SP_{rel}/SCOD_{rm}$는 0.13에서 0.17을 유지하였다. 실험실규모에서는 ENR 반응률을 산정하였는데 0.042에서 $0.057gNO_3-N/gMv.d.$를 보였다. 이들 인자들은 생물학적 영양소제거공정을 설계하는데 유용하게 이용될 수 있고 ENR 반응은 저농도 하수에서 질소, 인 처리시 효과적임을 알 수 있었다.

• Journal of Forest and Environmental Science
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• 제34권1호
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• pp.12-23
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• 2018

Quantitative information on biomass and available nutrients are essential for developing sustainable forest management strategies to regulate atmospheric carbon. An attempt was made at Chilapatta Reserve Forest in Duars region of West Bengal to quantify its above and below ground carbon along with available "N", "P" and "K" in the soil. Stratified random nested quadrats were marked for soil, biomass and litter sampling. Indirect or non-destructive procedures were employed for biomass estimation. The amount of these available nutrients and organic carbon quantified in soil indicates that the forest soil is high in organic carbon and available "K" and medium in phosphorus and nitrogen. The biomass, soil carbon and total carbon (soil C＋C in plant biomass) in the forest was 1,995.98, 75.83 and $973.65Mg\;ha^{-1}$. More than 90% of the carbon accumulated in the forest was contributed by the trees. The annual litter production of the forest was $5.37Mg\;ha^{-1}$. Carbon accumulation is intricately linked with site quality factors. The estimated biomass of $1,995.98Mg{\cdot}ha^{-1}$ clearly indicates this. The site quality factor i.e. tropical moist deciduous with optimum availability of soil nutrients, heavy precipitation, high mean monthly relative humidity and optimum temperature range supported luxuriant growth which was realized as higher biomass accumulation and hence higher carbon accumulated.

• 한국작물학회지
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• 제46권2호
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• pp.78-83
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• 2001

Two rice cultivars of the japonica type, ozone-resistant Ilpumbyeo (IL) and ozone-susceptible Keu-mobyeo#l (KM) were exposed to ozone ($O_3$) at 0.15 ppm for 30 days. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) within a basic fertilizer status (N, P, K; 15, 12, 12 kg l0$a^{-1}$). There was little difference on plant height between ozone-treated and nontreated plants. The most significant ozone stress on tiller number was shown on the 30th day of ozone exposure. Slight recovery from ozone stress was noted on the 60th day. On the 30th day, tiller number was greatly decreased by 40.8% in IL and 64.6% in KM, whereas at a high nitrogen supply regime (2N), it was decreased by 21.4% in IL and 42.7% in KM as compared to the control not treated with ozone at basic fertilizer status. The inhibition of tiller production caused by ozone exposure was alleviated on the 60th day. In both cultivars, number of spikelets per plant and weight of 100 grains were affected little by the ozone treatment irrespective of nutrient regime. However, the number of panicles per plant and yield were reduced significantly. In both cultivars, yield of ozone-treated plants with 2N status was 12.4-16.1 % higher than that of the ozone-treated plants with basic nutrient status. A significant yield decrease of 47.8% and 33.4% was observed for IL and KM, respectively, in ozone-treated plants with higher potassium (2K) status.

• Asian-Australasian Journal of Animal Sciences
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• 제11권4호
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• pp.344-350
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• 1998

Seasonal variations in the feeding behaviour of Jamunapari and Barbari goat breeds and their utilization of browse and grass nutrients was evaluated in a promising 3-tier (Leucaena leucocephala- Dichro-stachys nutan-Cenchrus ciliaris) reconstituted pasture during summer, rainy and winter season of the years 1987 and 1988. Distinct diurnal pattern of feeding was observed with both the breeds. Jamunapari goats spent significantly more time foraging during winter season (352.0 min) followed by summer (306.0 min) and least in rainy season (277.0 min). Though no significant difference was observed in the relative time spent by Barbari goats on grazing activities during summer and winter season, they spent significantly more (p < 0.05) time during rainy season as compared to other two seasons. The preference of grazing goats for certain plant species in relation to others was evident with distinct seasonal and breed variations. DM intake (g/kg $BW^{075}$) varied significantly (p < 0.05) from season to season. Among the browse. L. leucocephala was prefered over D. nutan irrespective of breed over the seasons. There was no breed difference in DM intake, or proximate composition and nutrient digestibility of ingested herbage. The available nutrient content of ingested forage was found sufficient to meet the nutrient requirements of adult goats for maintenance (NRC, 1981). The reconstituted 3-tier pasture dominated by plant species like L. leucocephala and Cenchrus species appear to have great potential to sustain the nutrient requirement of goats without adverse seasonal fluctuations in pasture quality.