• 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.

• Asian-Australasian Journal of Animal Sciences
• /
• 제23권6호
• /
• pp.719-723
• /
• 2010

Ingestion of forage containing a large quantity of soluble oxalate can result in calcium deficiency and even death of livestock. Fertilization is one of the most practical and effective ways to improve yield and nutritional quality of forage. An experiment was conducted to determine the effects of nitrogen (N) fertilization (150, 300 and 600 kg/ha) across varying levels (150, 300 and 600 kg/ha) of potassium (K) on oxalate accumulation in napiergrass (Pennisetum purpureum). Application of N at 300 kg/ha produced higher dry matter yield than at 150 or 600 kg/ha, while K fertilization had no effect on yield. In general, N fertilization did not affect the soluble and total oxalate contents, but slightly affected the insoluble oxalate content. Soluble oxalate content showed an increasing trend and insoluble oxalate content showed a decreasing trend with increasing K level, but total oxalate content remained relatively constant. There were significant interactions between N and K fertilization for the content of soluble and insoluble oxalate fractions. The greatest increase in soluble oxalate content with N level at 300 kg/ha was found at the high level (600 kg/ha) of K application. The greatest increase in insoluble oxalate content with N level at 600 kg/ha was found at the low level (150 kg/ha) of K application. These results indicated the possibility of controlling the content of soluble and insoluble oxalate fractions in forage by fertilization.

• Journal of Plant Biology
• /
• 제14권2호
• /
• pp.15-21
• /
• 1971

The present paper was designed to investigate the effect of nitrogen, phosphorus and potassium on the histological differentiation of the young leaves of soybean (Glycinemax, M.). Observations were made on the numbers of lamina cells and lateral veins, width and thickeness of the lamina and vascularization of the midrib in the 5th leaf, and the differentiation of leaves at 42$\mu$ from the apical tips of the shoot apecis. Samples were taken at the time when the 2nd leaf was completed. The experimental plots were divided into twelve parts. And the results obtained are as follows. 1) Nitrogen stimulated the differentiation of the leaf, the vascuralization of the midrib and increased the numbers of lamina cells and lateral veins. 2) Phosphorus promoted the differentiation of lamina at the first stage of soybean growth. It was more effective in the plots of excessive application than otherwise. It had a small effect on the differentiation of lateral veins. 3) Among the elements, a deficiency of postassium resulted in a reduced differentiation of the lamina potassium had no effect on the thickening growth of the lamina and the differentiation of the midrib. 4) It appeared that phosphorus might compensate for the negative effect of potassium in the potassium and phosphorus plots.

• 한국토양비료학회지
• /
• 제44권6호
• /
• pp.1023-1026
• /
• 2011

pH가 높은 바다부유물질로 만든 퇴비를 시용한 토양은 암모니아 휘산이 야기되어 토양 중 질산태 질소함량이 낮고, 딸기는 질소를 흡수하지 못하여 생육이상증상이 유발되었다. 이 토양의 pH를 질산을 처리하여 낮추어 주고 부족한 질소와 인산 및 칼륨을 공급한 결과 회복되었다. 이 결과로부터 pH가 높은 토양에서 발생하는 질소결핍증은 토양의 pH를 낮추어 주어야 회복시킬 수 있다고 판단되었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권8호
• /
• pp.1186-1194
• /
• 2009

The objective of this study was to estimate the optimum dietary essential amino acid pattern for male Taiwan country chicks. A series of experiments was conducted with chicks, 14 d of age, for 2 wks. A basal synthetic diet was established using a dose response test for all essential amino acids referring to the broiler requirements recommended by NRC (1994). Twelve chicks were sacrificed at the beginning to provide initial body nitrogen data, and every group of six birds received the basal diet or a diet with a deficiency in a single essential amino acid in twenty one treatments by intubation according to their daily metabolic body weight (MBW). Deposited body nitrogen was determined using comparative slaughtering. According to the daily intake from the limiting amino acid per unit of MBW and the body nitrogen accretion rates for every two deficient groups with the same limiting amino acid but at different levels, a corresponding straight line was computed for each essential amino acid to intersect with a horizontal line made by the body nitrogen accretion rate of the control group. The x coordinate of the intersection represented the daily requirement for growth plus maintenance based on MBW corresponding to the essential amino acid. The amino acid ratios can be considered as the optimum pattern of dietary essential amino acids. The results, expressed with respect to lysine = 100, were arginine 105, methionine 81, histidine 34, tryptophan 18, leucine 103, phenylalanine 135, isoleucine 69, threonine 65 and valine 79. This pattern could be utilized to compute the dietary requirements (g/kg feed) for all essential amino acids by multiplying by the requirement of a single essential amino acid cited from the literature.

• KSBB Journal
• /
• 제6권1호
• /
• pp.35-43
• /
• 1991

The production of poly-$\beta$-hydroxybutyrate(PHB) from methanol by batch and fed-batch cultivations of Methylobacterium sp. GL-10 was studied. PHB accumulation was stimulated by the nutrients deficiency including, NH4+, SO42-, and K+. The nitrogen deficiency was the most critical factor for PHB accumulation. In batch cultivation, the maximum cell concentration and PHB content were 1.86g/l and 0.62g/l, respectively, with 1.0%(v/v) of methanol and 0.5g/1 of ammonium sulfate. The mass doubling time of Methylobacterum sp. GL-10 was in the range of 4-5 hrs. The cell growth and PHB accumulation were severely inhibited at the methanol concentration over than 2% (v/v). To overcome methanol Inhibition, constant feeding and intermittent feedillg fed-batch cultivations were adopted, using C/N molar ratio as a control factor. In constant feeding fed-batch process, cell concentration was increased up to 2.67g/1, and PHB yield was enhanced from 0.33 of batch culture to 0.53. The relatively low cell concentration was caused by methanol accumulated in culture broth at late growth phase. To prevent methanol accumulation and to maximize PHB production, DO-state intermittent fed-batch cultivation was attempted. The cell and PHB concentration was reached up to 4.55g/1 and 1.80g/1, respectively. It was possible to maintain methanol concentration low and also to feed nutrient of desired C/N molar ratio.

• 대한한의학방제학회지
• /
• 제9권1호
• /
• pp.375-385
• /
• 2001

Objectives : This study was carried out to research the protective effects of Sagunja-Tang(SA) through in vivo experiments, and tried to investigate the relation between oxidation of liver tissues and deficiency of Qi. Methods : Acute liver injury which initiated from free radical induced by $CCl_4$, were applied to mice and metabolic data were obtained. In order to measure the degree of liver injury, serum level of alanine aminotransferase(AST), aspartate aminotransferase(ALT), creatinine, blood urea nitrogen(BUN), total protein(TP) and glucose were measured. Lipid peroxidation of liver slice was examined by measuring malondialdehyde(MDA), a product of lipid peroxidation. Results : SA had protective effects on $CCl_4$ induced acute liver injury by decreasing serum level of ALT. Kidney injury was induced by injection of $CCl_4$ too, and SA protected kidney injury by decreasing serum level of creatinine and BUN. Conclusions : Through this study, we found that SA have healing effects on liver and kidney injury of $CCl_4$ induced oxidative stress that is similar to deficiency of Qi. And further studies have to be followed to certify the mechanisms.

• Journal of Microbiology
• /
• 제35권1호
• /
• pp.61-65
• /
• 1997

A novel strategy was developed for isolating suppressors from sporulation-deficient mutants. The mutation in the BCY1 gene, which codes for the regulatory subunit of cAMP-dependent protein kinase, when homozygous, results in diploids being meiosis and sporulation deficient. Two plasmids, YCp-MAT.alpha. and YEp-SPOT7-lacZ, were introduced into MAT.alpha. BCY1$\^$+/ or MAT.alpha. bcy1 haploid cells. The transformant of the BCY1$\^$+/ haploid cell produced .betha.-galactosidase under nutrient starvation, but the bcy1 transformant did not. Using this system, the mutagenesis experiment performed on the bcy1 transformant strain resulted in a number of sporulation mutants that produced .betha.-galactosidase under nutrient starvation. One complementation group, sob1, was identified from the isoalted suppressor mutants and characterized as a single recessive mutation by tetrad analysis. Genetic analysis revealed that the sob1 mutation suppressed the sporulation deficiency, the failure to arrest at the G1 phase of the cell cecle, and the sensitivity to heat or nitrogen starvation caused by the bcy1 mutation. However, the sob1 mutation did not suppress the sporulation deficiency of ime1 and of ime2 diploids. These results suggest that the sob1 mutation affects a gene which functions as a downstream regulator in both meiosis and cell cycle regulation.

• 한국한의학연구원논문집
• /
• 제7권1호
• /
• pp.135-144
• /
• 2001

Objectives : This study was carried out to research the protective effects of Sagunja-Tang(SA) through in vivo experiments, and tried to investigate the relation between oxidation of renal tissues and deficiency of Qi. Methods : Acute renal injury which initiated from free radical induced by $HgCl_2$, were applied to mice and metabolic data were obtained. In order to measure the degree of renal injury, serum level of creatinine, blood urea nitrogen(BUN), total protein(TP) and glucose were measured. Besides, serum level of alanine aminotransferase(AST), aspartate aminotransferase(ALT) were measure too. Lipid peroxidation of renal cortex was examined by measuring malondialdehyde(MDA), a product of lipid peroxidation. Results : SA had protective effects on acute renal injury caused by decrease of glomerular filtration which was initiated by subcutaneous injection of $HgCl_2$. SA protected acute liver injury too. Conclusions : Through this study, we found that SA have healing effects on renal injury of $HgCl_2$ induced oxidative stress that is similar to deficiency of Qi. And further studies have to be followed to certify the mechanisms.

• International Journal of Safety
• /
• 제5권2호
• /
• pp.29-33
• /
• 2006

A numerical flow analysis of the case of a refrigeration warehouse where an unusual death of an operator occurred by deficiency of oxygen is performed by using STAR-CD program of the computational fluid dynamics (CFD) code. The refrigeration room of the warehouse for storing the fruits maintains an atmosphere of 95% nitrogen and 5% oxygen by volume. When the operator was found dead in the refrigeration room, the room was in normal operating conditions except for the fact that the auxiliary door had been left open. For the flow analysis, unsteady 3-dimensional natural convection with mass transfer is considered. The flow analysis result is compared with the oxygen concentration level measured against time during on-site investigation. The change in oxygen concentration level in the warehouse due to the opening of the auxiliary door is found to be negligible.