• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.181-192
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• 2023

Appropriate fertilization methods are required according to species to supply necessary nutrients to plants and prevent soil environmental contamination in nurseries. In this study, the effects of nitrogen and phosphorus fertilization on the growth of Liriodendron tulipifera and soil characteristics were investigated. After 16 fertilization treatments (4 levels of nitrogen × 4 levels of phosphorus) were applied to one-year-old L. tulipifera seedlings at the Yongmun Nursery Station of the Korea Forest Service, height, root collar diameter (RCD), biomass, leaf nutrients, and soil characteristics were investigated. The height increased as the amount of nitrogen and phosphorus fertilization increased, and the RCD was the highest in the ×2 treatment. Biomass growth was on average 40.0% higher for the treatment with high nitrogen fertilization compared to the low nitrogen treatment. The seedling quality index was the highest with nitrogen and phosphorus ×2 treatment. Leaf phosphorus and magnesium concentrations decreased when nitrogen fertilization was applied, and leaf potassium concentrations decreased as nitrogen fertilization increased. Soil pH and exchangeable potassium decreased as the amount of phosphorus application increased, and exchangeable magnesium decreased as the amount of nitrogen application increased and increased as the amount of phosphorus application increased. Considering the growth of L. tulipifera seedlings and changes in the soil characteristics at the nursery stage, twice the standard fertilization amount is the appropriate fertilization amount for nursery of the Yongmun Nursery Station. It is expected that this study will contribute to improving nursery soil fertilization management technology for healthy seedling production.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.191-197
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• 2005

Green house soils have been intensively cultivated with excessive application of compost and chemical fertilizer for vegetable growth. The objective of this study was to establish the reasonable fertilizer application system for rice cultivation in green house soil. Field experiment was carried out with rice cv. Geumo-byeo 1 in Jisan series soil (fine loamy, mixed, mesic family of Fluventic Haplaquepts) that was previously cropped with green pepper (Capsicum annuum L.) for the last 3 years. Treatment consisted of conventional fertilization $(N-P_2O_5-K_2O=11-4.5-5.7kg\;10a^{-1})$, no basal fertilization, 50% reduction of basal fertilization no top dressing, bulk blending fertilizer, and no fertilizer. The value of pH, available phosphate, and exchangeable potassium after experiment was lower than those before experiment while organic matter content was not difference in all treatment. The value of salt elusion was the highest in no basal fertilization plot. The amount of $NH_4-N$ in soil was higher in growth stage of rice as fertilizer amount increased in 1998. The changes of plant height and tiller were higher as fertilizer amount increased. Thousand-grain weight as yield component was higher in no basal fertilization plot all the year because of decreasing panicle. There was no significant difference in rice yield between treatments in 1998. However, conventional fertilization resulted in significantly increased rice yield in 1999. Nitrogen use efficiency was the highest in no basal fertilization plot in 1998 and in conventional fertilization plot in 1998. Our results suggest that no basal fertilization be best to increase salt elusion with slightly increased yield in first year for rice cropping after vegetable harvesting, which method improves fertilization efficiency. However, conventional fertilization was good for second rice cropping after vegetable harvesting in greenhouse.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.119-123
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• 2019

BACKGROUND: Estimation of soil nitrogen supply is essential to manage nitrogen fertilization in arable land. In Korea, nitrogen fertilization is recommended based on the soil organic matter content because it is difficult to assess nitrogen (N) mineralization of upland soils directly. In this study, the relationship between soil organic matter (SOM) content and N mineralization was investigated to explore the limitation of using SOM in predicting soil N mineralization. METHODS AND RESULTS: Soil samples from the 0 to 10 cm depth were collected from 18 individual pepper cultivated fields in Tae-an and Chung-yang provinces before fertilization. N mineralization in the soils was quantified using incubation for 70 days at $30^{\circ}C$. The mineralizable soil N (MSN) was positively correlated with SOM, and the relation equation between MSN and SOM was '$MSN(kg\;10a^{-1})=0.2933{\ast}SOM(g\;kg^{-1})+0.0897$ ($r^2=0.6224$, p<0.001)'. However, the differences of N mineralization among the soils with the similar concentrations of soil organic matter were about 3 to 4.6 times, suggesting that the other soil factors such as total N concentration or EC should affect N mineralization. CONCLUSION: We concluded that SOM alone could not reflect the capacity of soil to supply N that is used for recommendation of N fertilization rate. Therefore, other soil properties should be considered to improve N fertilization management in arable land for sustainable agriculture.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.141-146
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• 2017

BACKGROUND: Phosphorus(P) is a vital factor for rice but excess input of phosphorus fertilizer can cause environmental risk and waste of fertilizer resources. We studied to assess the change of available phosphate, P balance, critical concentration of available phosphate under a rice single system. METHODS AND RESULTS: The changes of available phosphate of paddy soil were examined from long-term fertilization experiment which was started in 1954 at the National Academy of Agricultural Science. The treatments were no phosphate fertilization(No fert., and N), phosphate fertilization(NPK, NPKC, and NPKCLS). The available phosphorus concentrations in treatments without phosphate fertilizer (No fert. and N) were decreased continuously. But, after 47 years, available phosphate content in phosphate fertilizer treatment (NPK, NPKC, and NPKCLS) reached at the highest ($245{\sim}331mg\;kg^{-1}$), showing a tendency to decrease afterward. The mean annual P field balance in these treatments (NPK, NPKC, and NPKCLS) had positive values that varied from 16.6 to $17.5kg\;ha^{-1}year^{-1}$, and ratio of residual P were increased. These showed that phosphate fertilizer in soil were converted into the form of residual phosphorus which was not easily extracted by available phosphate extractant. Also, It was estimated that the critical value of available phosphate for rice cultivation was $120mg\;kg^{-1}$ using Cate-Nelson equation. CONCLUSION: We concluded that no more phosphate fertilizer should be applied in rice single system if soil available phosphate is higher than the critical P value.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.491-497
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• 1998

Four types of serum supplements viz. estrus cow serum (ECS), estrus buffalo serum (EBS), pro-estrus buffalo serum (PrBS) and post-estrus buffalo serum (PtBS), added to TCM-199, were evaluated for in vitro maturation and fertilization of buffalo follicular oocytes. The oocytes were recovered from buffalo ovaries after slaughter, using either aspiration or scoring (multiple incisions) method. The recovered oocytes were categorized as A, B and C based on their cumulus investment and ooplasm homogeneity and cultured in four media. The in vitro matured oocytes were inseminated with $1{\times}10^6$ spermatozoa washed in 2.9% sodium citrate solution. The scoring method yielded greater number of morphologically good oocytes than the aspiration method (3.85 vs 1.76 per ovary, p < 0.01). The maturation rates of three categories of oocytes did not differ from one another. The maturation rates of 80.00, 82.08, 78.77 and 66.23%, while the fertilization rates of 54.54, 55.38, 52.80 and 36.76% were recorded for media containing ECS, EBS, PrBS, and PtBS, respectively. The medium containing PtBS gave lower maturation, as well as fertilization, rates than the other three media (p < 0.05). Thus, the scoring method was better than the aspiration method for the recovery of follicular oocytes. The oocytes categorized A, B and C had similar maturation capabilities. The TCM-199 containing buffalo/cow serum collected at pro-estrus or estrus appeared better for in vitro maturation and fertilization of buffalo follicular oocytes than that containing serum collected at post estrus.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.17-21
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• 1991

A field experiment was carried out to determine the effects of nitrogen(N) fertilization levels(0, 30, 60, 90 and 120 kg/ha) in early spring on the growth, dry matter(DM) yield, seasonal distribution of production and nutritive value of grasses. Additional N after the first, second and third harvest were applied as 60, 60 and 30 kg/ha, equally in 1989. Grass growth and DM yield were significantly increased(p$NO_3$-N concentration was not affected by N level of early spring. It is suggested that, therefore, N application in early spring is essential, and 60 to 90 kg/ha of N application may be desirable in early spring.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.57-63
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• 1990

The purpose of this study is to improve fertilization rate in IVF-ET program of patients with male infertility used micromanipulation technique, partial zona dissection (PZD) or micro-insemination by sperm transfer (MIST). The results were as follows 1. The fertilization rate of non-micromanipulated oocytes and micromanipulated (PZD) oocytes were 12.5% (n=2) and 42.2% (n=19), respectively, and showed significant differences between two groups (p<0.05). 2. The fertilization rate of micromanipulated (MIST) oocytes was 30% (n=27). 3. The damage rate of Group 1 (PZD) and Group 2 (MIST) were 15.7% (3/19) and 29.6% (8/27), respectively. 4. One pregnancy resulted following replacement of micromanipulated (MIST) embryos in 4 patients.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.148-151
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• 2007

This experiment was carried out to investigate the effect of several organic fertilizers on the growth and root yield of Liriope platyphylla was planted 30 cm ${\time}$ 10 cm in field from 1998 to 1999. Six treatments of organic fertilizers applied : N.P.K, NPKC (N,P,K+Compost), NPKCO (N.P.K+Compost+Oilcake),NPKCOF (N.P.K+Compost+Oilcake+Fowldropping), NPKCOFP (N.P.K+Compost+ Oilcake+Fowldropping+plant ash), CO (Compost+Oilcake), COF (Compost+Oilcake+fowldropping). Organic matter, available phosphate, and MgO are NaO of soil increased in all of plots with the addition of organic fertilizers. The leaf length, number of leaves and of tillers were increased by the use of organic fertilizers compared to N.P.K fertilizers compared with N.P.K fertilization. The number of tubers were increased by using the organic fertilization N.P.K fertilization and showed higher in the soil depth of 0${\sim}$20 cm. The dry root yield was showed higher in organic fertilizers than in N.P.K fertilizer and highest dry root yield resulted from NPKOF 39% and NPKCOFP 49%.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.195-202
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• 2017

The volcanic ash soils from the Jeju province have low available phosphate because of the high phosphate fixing power of the soils. Phosphorus fertilizerwas dressed after cultivating green manure crops and before cultivating potatoes in order to investigate potato yields, the available phosphate contents, and phosphorus balance in the soils. Green manure crops cultivated in this study were hairy vetch alone and hairy vetch and rye. During potato cultivation, four treatments were conducted in the experiments; NF (non fertilizer), P fertilizer ($N-P-K=0-25-0kg\;10a^{-1}$), NK fertilizer ($N-P-K=18-0-19kg\;10a^{-1}$), and NPK fertilizer ($N-P-K=18-25-19kg\;10a^{-1}$). There were no differences in the yields of potato stem and tuber from the cultivation plots of different green manure crops. However, in the plots with single-sown hairy vetch and mixed-sown hairy vetch and rye, the yields of potato stem and tuber were higher in the P fertilizer plot than in NF plot. The yield of tuber among the treatments with mixed-sown hairy vetch and rye was the highest in the NPK fertilizer plot. The available phosphate content in soils initially increased with time in all plots, but began to decrease gradually after Oct. 18. The available phosphate contents were high in the plots for phosphate fertilization, and the difference in available phosphate content between non-phosphorus fertilizer plots and phosphorus fertilizer plots increased with time. In the single-sown hairy vetch and mixed-sown hairy vetch and rye plot, the phosphorus balances in NF plot and NK fertilizer plot were very low, while those in the P fertilizer plot and NPK fertilizer plot were high. In conclusion, available phosphate contents in soil and the potato yields were increased by phosphorus fertilization when potatoes planted after cultivating hairy vetch and rye together, compared to hairy vetch alone.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.115-122
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• 1999

Investigation of nutrient movement in soil and soil water is necessary to clarify water purification functions and nutrient circulation within a forest ecosystem. In this study, seasonal changes in the nutrient content of soil and soil water was investigated in Korean white pine(Pinus koraiensis) and Japanese larch(Larix leptolepis) forest applied urea ($150kg\;ha^{-1}$). Soil pH was decreased rapidly in Japanese larch plot for a long period. On the other hand, soil pH was increased slightly in Korean white pine plot. T-C and T-N content were increased in both plots. In Japanes larch plot, exchangeable Ca and Mg contents were decreased remarkably than those in korean white pine plot while exchangeable K was increased rapidly after application. The effect of urea application on exchangeable K was not obvious compared to other cations. The pH, Ca, $NH_4-N$, $NO_3-N$, $SO_4-S$ and Cl concentrations in the sampled soil water at surface soil were increased only temporarily after fertilization, with the only exception of the decrease in pH of the soil water in Japanese larch plot. On the other hand, the peak value of K, Mg concentrations in the soil water was shown between 2 and 5 months after fertilization. The concentrations of Ca, $NO_3-N$, $SO_4-S$ and Cl returned to the values found before fertilization after about 1 month. Those of K, Mg, and $NO_3-N$ after 6-12 months.