• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.312-318
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• 1995

To investigate the effect of N split application on the increasing ratio of yield and the yield of rice, urea and slow-releasing complex for sideband placement of fertilizer were applied in Jeonbuk series of Honam plain area. Increasing ratio of yield by N split application was higher in puddled drill seeding (PDS) than flooded direct seeding surface (FDSS) under split application of 40-0-30-30% and 70-0-0-30% at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. It was also higher in LCU application of 70 % of total urea amount than urea application but was not different between two methods of seeding in urea application. Nitrogen ratio transfered to rough grain of rice was higher in FDSS than PDS, errespective of methed of split application, except for the split application of 0, 40, 30 and 30% N fertilizer at basal, 3 leaf, 5 leaf and panicle initiation stage, respectively. Nitrogen amount outflowed by artificial drainage for paddy field drying in a day after application of fertilizer was 1,134g/10a in PDS. $NH_4-N$ incerased higher in PDS than FDSS under split application of urea, while was versa under LCU application.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.25-29
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• 2012

Agriculture activities account for 58% of total anthropogenic emissions of nitrous oxide ($N_2O$) with global warming potential of 298 times as compared to carbon dioxide ($CO_2$) on molecule to molecule basis. Quantifying $N_2O$ from managed soil is essential to develop national inventories of greenhouse gas (GHG) emissions. The objective of the study was to compare $N_2O$ emission from livestock compost applied arable land with that for fertilizer treatment. The study was conducted for two years by cultivating Chinese cabbage (Brassica campestris L.) in Chuncheon, Gangwon-do. Accumulated $N_2O$ emission during cultivation of Chinese cabbage after applying livestock compost was slightly greater than that for chemical fertilizer. Slightly greater $N_2O$ emission factor for livestock compost was observed than that for chemical fertilizer possibly due to lump application of livestock compost before crop cultivation compared with split application of chemical fertilizers and enhanced denitrification activity through increased carbon availability by organic matter in livestock compost.

• Environmental Engineering Research
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• v.21 no.1
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• pp.29-35
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• 2016

This study evaluated the fertilizing value of struvite deposit recovered from swine wastewater in cultivating lettuce. Struvite deposit was compared to complex fertilizer, organic fertilizer and compost to evaluate the fertilizing effect of struvite deposit. Laboratory pot test showed that the struvite deposit better enhanced lettuce growth in comparison to commercial fertilizers. It was revealed that the growth rate of lettuce was simultaneously controlled by phosphorus (P) and magnesium (Mg). Moreover, nutrients such as nitrogen (N), P, K, calcium (Ca) and magnesium (Mg) were abundantly observed in the vegetable tissue of struvite pot. Meanwhile, struvite application led to the lower accumulation of mercury (Hg), lead (Pb), chromium ($Cr^{6+}$) and nickel (Ni). In addition, no detection of cadmium (Cd), arsenic (As) and nickel (Ni) in the lettuce tissue was observed in struvite application pots. The experimental results proved that the optimum struvite dosage for lettuce cultivation was 0.5 g struvite/kg soil. The column experiments clearly showed that ammonia nitrogen was more slowly released from struvite deposit than from complex fertilizer. Consequently, it was concluded that the struvite deposits recovered from swine wastewater were effective as a multi-nutrient fertilizer for lettuce cultivation.

• Food Science and Preservation
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• v.5 no.2
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• pp.123-126
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• 1998

This study was carried out investigate to optimum levels of nitrogen and phosphate fertilizer to get a higher yield and a quality of an onion(Allium Cepa L.) from 1993 to 1994. Three fertilizer levels were applied with 120, 240 and 360kg/ha of nitrogen and 100, 200 and 300kg/ha of P2O5 during the onion growing season. After harvesting the onion, it was storaged at given deposit. The growth and yield of the onion were better at the fertilizer levels of both 240 and 360kg/ha of nitrogen and of both 200 and 300kg/ha of P2O5 than at the level of 120kg/ha in nitrogen and 100kg/ha of P2O5. The content of total nitrogen and P2O5 in plant was decreased with reduced application levels of nitrogen and phosphate fertilizer. The rotting rate was higher at the levels of both 360kg/ha in nitrogen and 300kg/ha in P2O5 than the other treatment during the storage period. The sprouting rate tended to be high at 240kg/ha of nitrogen and 100kg/ha of P2O5.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.528-534
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• 2015

Green manure crops have been well recognized as the alternative for chemical fertilizer, especially N fertilizer, because of its positive effect on soil and the environment. Hairy vetch and green barley are the most popular crops for cultivation of rice in paddy field. This study was conducted to evaluate effects of hairy vetch and green barley on soil microbial community and chemical properties during short-term application (three years). For this study, treatments were composed of hairy vetch (Hv), green barley (Gb), hairy vetch + green barley (Hv+Gb), and chemical fertilizer without green manure crops (Con.). Hv+Gb treatment showed the highest microbial biomass among treatments. Principal component analysis (PCA) showed that PC1 (73.0 %) was affected by microbial biomass and PC2 (21.5 %) was affected by fungi, cy19:0/18:$1{\omega}7c$ (stress indicator). Combined treatment with hairy vetch and green barley could be more efficient than green manure crop treatment as well as chemical fertilizer treatment for improvement of soil microorganisms.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.420-425
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• 2018

Purpose: Chemical fertilizers contribute to agricultural productivity. Annually, 450,000 tons of chemical fertilizers are used in Korea, which is 268 kg per hectare (MAFRA, 2016). However, excessive use causes problems such as environmental pollution and soil acidification. This study proposes use conditions for a fertilizer distributor that can reduce excessive fertilization by analyzing distribution patterns. Methods: This study analyzed fertilizer application uniformity according to the number of blades on a centrifugal fertilizer distributor (three or four blades), orifice gate open ratio (50 or 100%), and blade rotation speed (400, 500, or 600 rpm). Results: When using four blades, the coefficient of variation (CV) was lower than when using three by 11-13% points, and the CV using the 50% open ratio was 10-30% points lower than using the 100% open ratio. The CV at 500 rpm blade rotating speed was 9-12% points lower than that for 400 and 600 rpm. Conclusions: The CV with four blades, 50% orifice gate open ratio, and 500 rpm of blade rotating speed was 18.4%, which provided the most uniform fertilization.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.375-381
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• 2000

Quantifying the changes of soil microbial biomass and activity of enzymes are important to understand the dynamics of active soil C and N pools. The dynamics of soil microbial biomass C and N and the activity of enzymes over entire growth period of soybean-(Glycine max (L) Merr.)-wheat (Triticum aestivum L.) sequence on a Typic Haplustert as influenced by organic manure and inorganic fertilizer N were investigated in a field experiment. The application of farmyard manure at 4 to 16 $Mg{\cdot}ha^{-1}\;y^{-1}r^{-1}$ along with fertilizer nitrogen at 50 or 180 $kg{\cdot}ha^{-1}$ increased the mean soil microbial biomass from 1.12 to 2.05 fold over unmanured soils under soybean-wheat system. Irrespective of organic and chemical fertilizer N application, the soil microbial biomass was maximum during the first two months at active growing stage of the crops and subsequently declined with crop maturity. The mean annual microbial activity was significantly increased when manure and chemical fertilizer at 8 $Mg{\cdot}ha^{-1}$ and 50/180 N $kg{\cdot}ha^{-1}$, respectively were applied. The C turnover rate decreased by 47 to 72 % when the level of farmyard manure was increased from 4 to 8 and 16 $Mg{\cdot}ha^{-1}$. There were significant correlations between biomass C, available N, dehydrogenase, phosphatase and yield of the crops.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.387-394
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• 2002

This study was conducted to compare an econamical efficiency of a recommended rate of fertilizer with the criterion of the sustainable agriculture direct income support system(SADISS). Red pepper was cultivated with different fertilizer application levels of the standard amount of fertilizer for red pepper(SAFR), fertilizer recommended by soil testing for red pepper(FRST) and decrement of 20, 40, 60 and 80 percent of fertilizer recommended by soil testing for red pepper(DFRST 20, 40, 60, 80) and that of farmer's habitual practies fertilization (FHPF). The changes by different levels of applied fertilizer was compared with those of SADISS. The results were summirized as follows: No yield difference was found among the FHPF, SAFR, FRST and DFRST20, but yield decrease in FRST40, 60 and 80. T-N, $P_2O_5$ and $K_2O$ in FHPF were 24, 9 and 53 percent respectively, and it were the lowest ones among the treatments. Fertilizer efficiency of red pepper was decreased with application rate of fertilizer. Fertilization ratio of N and P in DFRST(40, 60, 80 percent) was not sufficiency for red pepper. Economical efficiency of FRST and DFRST20 showed sufficiently in comparison with FHPF. Therefore, it could be possible that FRST and DFRST20 were recommended as methods for SADISS in red pepper cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1118-1123
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• 2011

The changes of available silicate (Avail. $SiO_2$) contents in paddy soils (sandy loam) were assessed from data of the 41 years fertilization plots in which the continuous rice cropping experiment started in 1954 at the National Academy of Agricultural Science. The treatments were no fertilization (O), inorganic fertilization (NPK), inorganic fertilizer plus rice straw compost (NPK+C), inorganic fertilizer plus silicate fertilizer as a soil amendment (NPK+S), inorganic fertilizer plus rice straw compost and silicate fertilizer (NPK+CS) and inorganic fertilizer plus rice straw compost, silicate fertilizer and lime (NPK+CSL). Available silicate contents in NPK+S, NPK+CS and NPK in surface soil reached at the highest content ($255{\sim}330mg\;kg^{-1}$) after 41 years and then levelled off. Available silicate contents in subsurface soil (25~30 cm) were higher in NPK+C and NPK+S treatments than those in other treatments. Continuous application of silicate fertilizer affected significantly on the levels of available silicate in surface and subsurface soils. Silicate uptake of top rice was more increased by 98% in NPK+CS and NPK+CSL over NPK. Grain yield also increased by 37~47% in NPK+CS and NPK+CSL as compared to NPK. The combined applications of inorganic fertilizers with silicate as a soil amendment are recommended as the best fertilization practice for fertilizer use efficiency, enhancement of soil fertility status in the continuous rice cropping system in Korea.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.53-58
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• 2007

This study was carried out to determine the effect of continuous application of animal liquid slurry on the growth and yield of rice in 2005. Field experiment was conducted under variable continuous application years of animal liquid slurry; 1, 3, 5 application years of slurry and chemical fertilizer as control plot. The effects of different application years of slurry on the growth characteristics and yield of rice were determined. The plant height and tiller's number of 1 year application of liquid slurry were lower than those of the chemical fertilizer plot. But in the plot of 5 years continuous application of animal slurry, the height and tillers of rice were higher than those of 1 year application. And the color of leaf 5 years application years plot was darker than that of the chemical fertilizer. Yield of the 5 years continuous application of slurry was 4% higher than that chemical fertilizer, but that of 1 year application was decreased 6% compared with chemical fertilizer. The long time application of animal slurry was increased content of organic matter, $P_2O_5$ and exchangeable caution(K) in soil.