• Korean Journal of Agricultural Science
• /
• v.36 no.2
• /
• pp.135-145
• /
• 2009

This research was conducted to investigate the effect of various phosphorus concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' egg plant (Solanum melongena L.). Tissue and soil analyses were also conducted to set the threshold levels of phosphorus in plants when disorders develop for phosphorus deficiency or excess. Brown and purple areas developed on the margin of mature leaves and it enlarged rapidly in P deficient plants. The fruits in P deficient plants were small and dull purple in color. When P were excess in fertigation solution, the margins of lower leaves became scorched and it enlarged to inner part of the leaves. The fruits of P excess plants became small and had the curl shape. The tissue $PO_4$-P contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed quadratic response ($y=0.7887+0.2394x-0.0197x^2$) and cubic response ($y=10.43+14.47x-4.7642x^2+0.3977x^3$) to elevated $PO_4$-P concentrations, respectively. When 10% reduction in dry weight set to threshold levels, optimum tissue $PO_4$-P contents are between 0.98 to 1.35%. The yield determined at 150 days after transplanting also showed cubic response to elevated phosphorus concentrations in fertigation solution ($y=1194.6+1502.2x-454.5x^2+35.64x^3$). When the 10% reduction in yield is set to threshold levels, the tissue $PO_4$-P contents for maximum yield should be around 1.53% to 2.25% in most recently fully expanded leaves at 150 days after transplanting.

• Journal of Korean Society of Forest Science
• /
• v.104 no.1
• /
• pp.26-34
• /
• 2015

This study was carried out to evaluate the growth characteristics, carbon and nitrogen content of containerized 1-0 Chamaecyparis obtusa seedlings at various levels of fertilizer (2 g/L, 1 g/L, control) and three container volumes (500 mL, 400 mL, 320 mL). The growth of root collar diameter was highest in the 2 g/L (3.14 mm), followed by the 1 g/L (2.75 mm) and control (2.41 mm) treatments, while the height of seedling was significantly higher in the 1 g/L (21.88 cm) than other treatments (2 g/L: 20.92 cm; control: 19.06 cm). The growth of root collar diameter by container volume was better in the 500 mL than in the 320 mL. Dry weight of seedling was the highest in the 1 g/L ($4.41g\;seedling^{-1}$), followed by the control ($3.67g\;seedling^{-1}$) and the 2 g/L ($2.92g\;seedling^{-1}$) treatments. The dry weight of seedlings by container volume was significantly higher in the 500 mL than in the 320 mL. Nitrogen concentration in foliage was ranged from 1.51% in the control to 2.45-2.60% in the fertilizer treatments. However, carbon concentration of seedlings was not affected by the fertilizer or the container volume treatments. The growth of seedlings following planting in mountain area was better in the fertilized seedlings compared with in the unfertilized seedlings. The results indicate that the 1 g/L fertilization was an optimum rate for growth following planting of Chamaecyparis obtusa seedlings.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.38 no.1
• /
• pp.44-52
• /
• 2018

This experiment was conducted at Suwon, Korea from 2013 to 2015. The objective of this study was to establish the optimum seeding rate, and to clarify the nitrogen fertilizer level for rye seed production in central and north area of Korea. We used Korean rye cultivar 'Gogu' for this test. We employed a split-plot design with three replications. The main plots were designed by three seeding levels (3, 5 and $7kg\;10a^{-1}$), but other sub-plots were randomly seeded. The plots were treated with three different nitrogen fertilizer levels (3, 6 and $9kg\;10a^{-1}$). The percentage of productive tiller, number of grain per spike, fertility rate, 1 liter weight, and 1000-grain weight decreased as seeding rate increased from $3kg\;10a^{-1}$ to $7kg\;10a^{-1}$, whereas the number of spike per $m^2$ increased. Therefore the grain yields of rye had less of an effect by increasing seeding rate. There was an increase in number of spike per $m^2$, number of grain per spike, and fertility rate as nitrogen fertilizer level increased from $3kg\;10a^{-1}$ to $9kg\;10a^{-1}$, but grain yields significantly not affected by the interaction of seeding rate ${\times}$ nitrogen fertilizer levels. However, the best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and $5{\sim}6kg\;10a^{-1}$, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.

• Korean Journal of Soil Science and Fertilizer
• /
• v.7 no.3
• /
• pp.177-184
• /
• 1974

An attempt was made to determine simple and the most reasonable fertilizer recommendation for barley utilizing the present knowledge about the effect of soil and climatic factors on barley response to NPK fertilizer in Korea and establishing the critical contents of available nutrients in soils. The results were summarized as follows. 1. The relationships between relative yields or fertilizers rates for maximum yields from quadratic response curves and contents of organic matter, available $P_2O_5$, exchangeable K in soils were examined. The trend was more prospective with relative yields because of smaller variation than with fertilizer rates. 2. Since the relationship between N relative yields and organic matter contents in soils was almost linear over the practical range, it was difficult to determine the critical content for nitrogen response by quadrant methods. However, 2.6%, country average of organic matter content in upland soils was recommended as the critical point. 3. There showed a trend that average optimum nitrogen rater was higher in heavy texture soils, colder regions. 4. The critical $P_2O_5$ contents in soil were 96 or 118 ppm in two different years, which were very close to the country average, 114 ppm of $P_2O_5$ contents in upland soils. The critical K content in soil was 0.32 me/100g, which was exactly coincident to the country average of exchangeable K in upland soils. 5. According to the contents of avaiiable $P_2O_5$ and exchangeable K, several ranges were established for the purpose of convenience in fertilizer recommendation, that is, very low, Low, Medium, High and very High. 6. More phosphate was recommended in the northern region, clayey soils, and paddy soils, whereas less in the southern region and sandy soils. More potash was recommended in the northern region and sandy soils, whereas less in the southern region and clayey soils. 7. The lower the PH, the more fertilizers were recommended. However, liming was considered to be more effective than increas in amount of fertilizers.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.6
• /
• pp.747-756
• /
• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.38 no.2
• /
• pp.91-98
• /
• 2018

This study was conducted in 2014 in the Gangjin area of Jeonnam province for the purpose of confirming the potential of Kenaf as an alternative feed crop of rice. The weather and soil conditions were favorable and there was no adverse effect on the growth of Kenaf. The amount of seeding was given at 10 kg, 15 kg and 20 kg. As the seeding volume increased, plant height and dry matter yield increased, and stem diameter and number of nodes decreased. The highest growth rate was observed between 75 and 90 days from the date of planting(p<0.05). As the growth progressed, stem rate increased and leaf rate decreased(p<0.05). Increased amount of seeding and growth resulted in decreased CP and TDN and increased ADF and NDF, which resulted in the decreased economic value of Kenaf as a feed crop. The result of increasing the use of organic fertilizer to 20 kg and 30 kg was similar to increasing the amount of seeding. As organic fertilizer usage increased, dry matter yield and growth rate improved(p<0.05).

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.4
• /
• pp.267-274
• /
• 2022

The effect of year, varieties, nitrogen application, and transplant time were examined in relation to rice of protein. An experiment was conducted using 12 rice varieties to investigate the effect of management and weather conditions on brown rice protein of during the filling stage. The transplanting time was set to be three groups including early, medium, and late timing. The nitrogen application was set to be 0 N kg / 10a, 9N kg / 10a and 18 N kg / 10a to examine the effect of fertilizer management on protein content. Field experiments were conducted in three growing seasons including 2019, 2020, and 2021. The brown rice of protein content were 5.7%, 5.9%, and 6.6% under early, medium, and late transplanting time conditions, respectively. The protein content differ by variety. For example, Chucheong, Hopum, Ilpum, Mipum, Odae, Saenuri, and Saeilmi had more than 6.1%, and Chindeul, Shindongjin, Samkwang, Unkwang, Younhojinmi were less than 6.1%. Nitrogen content was 5.7% for 0kgN /10a, 6.1% for 9kgN /10a, and 6.8% for 18kgN /10a. The contribution of the characteristics to the protein content was highest in nitrogen content (38.8%), followed by transplanting time (13.7%), variety (8.2%), and year (3.5%). The average temperature for 20 days after heading time was the highest (9.3%), followed by sunshine duration (3.9%) and solar radiation (3.5%). Our results revealed that brown rice protein content was determined to be affected by changes in average temperature, sunshine duration and solar radiation for 20 days after heading time. This suggested that assessment of temperature and solar radiation after heading time would indicate the degree of rice quality in terms of protein.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.3
• /
• pp.239-252
• /
• 2013

Agronomic characteristics and grain properties of Korean wheat of 175 farmers in nationwide for two years, 2010/2011 and 2011/2012, were evaluated to support basic data for improving grain quality of Korean wheat and enhancing Korean wheat consumption. Agronomic characteristics, including culm length, spike length, number of $spike/m^2$ and rate of off-type plant, and grain properties, including 1000 kernel weight, test weight, moisture, ash and protein content, were influenced by year and location. Number of $spike/m^2$, test weight, moisture, ash and protein content of wheat cultivated in 2011 were higher than those of 2012 and culm length, spike length, rate of off-type plant and 1000 kernel weight of 2012 were higher than those of 2011. Wheat cultivated in southern part of Korea showed higher culm length and 1000 kernel weight and lower test weight than those of northern part of Korea. Spike length, number of $spike/m^2$ and test weight were reduced by additional fertilization after mid of March, although there was no significant difference between date of additional fertilization and grain properties. Cultivated wheats in Jeollabuk-do showed lower ash content and higher protein content than those of other provinces and cultivated wheats in Jeollanam-do exhibited higher ash content than that of other provinces. As amount of fertilization increased, culm length, 1000 kernel weight and protein content increased and spike length and ash content were decreased, although date of additional fertilization did not effect on agronomic characteristics and grain properties. Amount of fertilization was positively correlated with 1000 kernel weight and protein content (r = 0.159, P < 0.05 and r = 0.212, P < 0.01, respectively) and was negatively correlated with ash content (r = -0.185, P < 0.05). Thousand kernel weight was negatively correlated with ash content (r = -0.226, P < 0.01) and positively correlated with protein content (r = 0.207, P < 0.01). Ash content increased as test weight and culm length decreased and 1000 kernel weight was influenced by culm and spike length (r = 0.397, P < 0.001 and r = -0.205, P < 0.01, respectively).

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.2
• /
• pp.103-110
• /
• 1993

This study was made to evaluate the chemical properties of 481 farmers' orchard fields in An-Seong area. And the reasonable ferilizer rates were recommended utilizing the result of soil analysis. The results are summarized as follows : 1. As the soil fertility status of collected soil samples were evaluated on the basis of temporary optimal range for each soil chemical properties, 12.7 to 49.6% of the total 481 farmers' fields were range for soil improvement. 2. The contents of chemical component have a tendancy to decrease with depth gradually from surface to subsoil. 3. According to the relationship between the contents of soil component in subsoil and those in surface soil, the fertility condition of subsoil could be estimated on the basis of analysis data of surface soil. 4. The multiple regression equation for pear yield prediction to the organic matter and exchangable calcium contents in the soil were obtained. 5. Referring the average value, distribution ratio compared to the optimum level for each soil chemical properties and standard fertilizer rate, the soil fertility status could be categorized as "High" "Medium" and "Low". For each category, the recommended amounts for NPK and organic matter application were established. 6. The recommended rates through soul fertility diagnosis were less than farmer's dosage in the range 7.1~7.7 kg/10a for N, 0.8~11.5 kg/10a for $P_2O_5$, 7.1~19.9 kg/10a for $K_2O$ and 90~116 kg/10a for lime.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.6
• /
• pp.545-553
• /
• 1991

To find out the basic data for the possibility of agricultural utilization for GSA (Glutamine Synthetase Activity), the effect of nitrogen on the GSA in wheat leaf discs, the variation of GSA after light treatment and the comparative activity of GS during preservation were studied. The result of this study suggested that GSA could play an important and direct regulatory role in the nitrogen assimilation by wheat. During the growth stage of wheat its integral activity was found to closely match the organic nitrogen content. GS may therefore be the rate limiting enzyme in inorganic N assimilation. Moreover, integral GSA was closely correlated with grain yield and grain nitrogen. GSA could be suitable to utilize as a parameter for super type selection and an indicator for optimum nitrogen fertilization. Throughout the experiment, the contents of NO; were increased by N fertilization so that the NO; content was not attributable to change in the level of GSA. At investigation during dark-light transition of culture, no change in the level of GSA was observed until after 8-14 hours in the light treatment. And the level of GSA in wheat leaf discs during preservation at refrigerated storage $(-20^{\circ}C)$ was stable until 12 weeks, when its leaf discs were sampled with liquid nitrogen.