• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.409-425
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• 2018

Occurrence and yield characteristics of lepidopteran insect pests in both PUR (paddy-upland rotation) and CU (continuing upland) fields for 8 maize (Eolrukchal 1, Heugjeom 2, Miheukchal, Ilmichal, Heukjinjuchal, Chalok 4, Mibaek 2, Daehakchal) and 7 sorghum (Hwanggeumchal, Anzunbaengisusu, Moktaksusu, Sodamchal, DS-202, Nampungchal, Donganme) varieties was surveyed. The population of Ostrinia furnacalis adults showed 3 times highest peaks in 2016. In addition, the damaged ratios of maize and sorghum leaves and stems were increased depending on the growth periods of the crops and those by O. furnacalis larvae were also increased steeply in mid August. The damaged ratios of maizes such as Miheukchal, Eolrukchal 1, Ilmichal, Heugjeom 2, and Mibaek 2 by O. furnacalis larvae were statistically different (P=0.05) between organically managed PUR and CU fields. Except for DS202 among sorghum varieties, the damaged ratios of the other ones were high and similar (50-92%) in the CU field. The ear damaged ratio of maize varieties by lepidopteran larvae including O. furnacalis and Helicoverpa armigera was from 5 to 38% in Chalok 4 and Heukjinjuchal, respectively, and Daehakchal gave relatively higher damage ratio in the PUR field (33%) than in the CU field (14%). The ear ratio of Sodamchal and DS-202 varieties in the PUR field was 94 and 82%, and all sorghum varieties were damaged over 78% by lepidopteran larvae in the CU field. Interestingly, the correlation coefficients between the damaged ratio and invasive pores on their stems by O. furnacalis larvae were positive (maize $r=0.69_{paddy-upland}$, $0.95_{continuing}$; sorghum $r=0.93_{paddy-upland}$, $0.97_{continuing}$, respectively). Additionally, the correlation coefficients between the damaged ratio and the ear weight or the thousand kernel weight (g) of maizes and sorghums by lepidopteran larvae were negative (maize $r=-0.38_{paddy-upland}$, $-0.49_{continuing}$; sorghum $r=-0.70_{paddy-upland}$, $-0.57_{continuing}$, respectively). These results indicate that the focused management on lepidopteran insect pests occurring maizes and sorghums cultivated in PUR and CU fields is an important strategy to secure their yields.

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.185-198
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• 2011

This study was carried out to select a proper forage crop, and to estimate the proper level of application of cattle manure and carrying capacity of organic livestock per unit area. Corns and forage sorghum hybrids were cultivated with different types of livestock manures and different amount of them to produce organic forage. For both corns and forage sorghum hybrids, no fertilizer plots had significantly (p<0.05) lower annual dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) yields than those of other plots, whereas the N-P-K (nitrogen-phosphorous-kalium) plots ranked the highest yields, followed by 150% cattle manure plots and 100% cattle manure plots. DM, CP and TDN yields of in cattle manure plots were significantly (p<0.05) higher than those of no fertilizer and P-K (phosphorous-kalium) plots. The yields of in cattle slurry plots tended to be a little higher than those of in composted cattle manure plots. Assuming that corn and forage sorghum hybrids produced from this trial were fed at 70% level to 450kg of Hanwoo heifer for 400g of average daily gain, the carrying capacity (head/year/ha) of livestock ranked the highest in 150% cattle slurry plots (mean 6.0 heads), followed by 100% cattle slurry plots (mean 5.3 heads), 150% composted cattle manure plots (mean 4.7 heads), 100% composted cattle manure plots (mean 4.4 heads), and no fertilizer plots (mean 2.8 heads) in corns (or the cultivation of corns). Meanwhile, in the case of forage sorghum hybrids, 150% cattle slurry plots (mean 6.4 heads) ranked the highest carrying capacity, followed by 150% composted cattle manure plots (mean 4.8 heads), 100% cattle slurry plots (mean 4.4 heads), 100% composted cattle manure plots (mean 4.1 heads), and no fertilizer plots (mean 2.8 heads). The results indicated that the application of livestock manure to cultivated soil could enhance not only DM and TDN yields, but also the carrying capacity of organic livestock as compared with the effect of chemical fertilizers. In conclusion, the production of organic forage with reutilized livestock manure will facilitate the reduction of environmental pollution and the production of environmentally friendly agricultural products by resource circulating system.

• Korean Journal of Organic Agriculture
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• v.24 no.2
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• pp.235-251
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• 2016

After carrying out on-the-spot observation targeting each farmhouse of large-scale environment-friendly agricultural district (LEAD), Suncheon, Sancheong, Jangheung, Yeongam, Hamyang, Okcheon, and Jeongseon in 2015, only one LEAD, a farmhouse in Jangheung had used sustainable compost coming out under their own non-antibiotic livestock. The soil pH and EC at a depth of 0-20 cm in the seven LEADs were ranged between 5.3-6.6 and $0.4-1.2dS\;m^{-1}$, respectively, with 0.03- 0.27% for T-N concentration, $22-322mg\;kg^{-1}$ for P, and $0.05-0.29mg\;kg^{-1}$, which were, in particular, low a farmhouse in Jeongseon. When intensively surveying on each farmhouse of Suncheon, Jangheung, and Okcheon for a growing period, seasonal soil pH was maintained above 6.0 and high in a farmhouse in Okcheon, with similar soil EC observed among the three LEADs. Seasonal soil T-N was 0.1% higher on the farmhouse in Suncheon than other two LEADs, with higher seasonal soil P observed on the farmhouse in Okcheon and higher soil K in the Jangheung. T-N concentration in rice (Oryza sativa L.) crops was the highest in Jangheung, and concentrations of T-N, P, and K decreased in a season. Plant height and number of tillers per hill were the highest on the farmhouse in Okcheon, where was similar or low plant diameter and SPAD levels compared to other two LEADs. Dry weight (DW) before harvest was ranged between 52-63 g, and DW, rough rice yield (kg), brown rice/rough rice (%), brown rice yield (kg), head rice (%), and broken rice (%) were not significantly different among the three LEADs. Total annual gross production ha-1 was the highest on the farmhouse in Okcheon (16,230,000 won) planting with high class of variety, 'Milky queen' at early maturation, which was expected to be increased on an agricultural income. However, high amount of fertilizer was applied for growing the following crops on the farmhouse in Okcheon, affecting the highest balance of T-N, P, and K more than $200kg\;ha^{-1}$.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.55-64
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• 2011

To investigate a comparison of rice yield and quality by a utilization of green crops using barley and hairyvetch, this study was carried out in rice (Oryza sativa L.) organic cultivation field. Convention barley harvest (CBH), Green barley crop (GBC), Green barley+Green Hairyvetch crop (GB+HVC), and Non-Green crop (NGC) were treated in rice cultivation field. The results obtained as following: 1) Culm length and pancile length in Convention barley harvest (CBH) cultivation were longer than organic cultivation but were not significant difference in all treatments. Yields of milled rice in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were by 90.3% and 95.9%, respectively. 2) Protein contents in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were by 5.7% lower than 6.6% in Convention barley harvest (CBH) cultivation. Amylose contents in all treatment were similar as range 18.8% to 19.1%. Whiteness contents in Green barley crop (GBC) and Green barley+Green Hairyvetch crop (GB+HVC) were slightly higher by 38.9% and 39.1%, respectively, than 37.7% in Convention barley harvest (CBH) cultivation. 3) Palatability values in Barley harvest (BH) and Non-Green crop (NGC) were slightly higher by 82.0 and 83.8, respectively, than 77.6 in Convention barley harvest (CBH) cultivation. 4) Head rice in Non-Green crop (NGC) was 95.5%, while that of Convention barley harvest (CBH), Green barley crop (GBC), and Green barley+Green Hairy-vetch crop (GB+HVC) were slightly low as range 93.8% to 94.2%. White core and belly rice in Convention barley harvest (CBH) cultivation was the highest level by 1.7%. 5) Leaf blast, neck blast, sheath blight, rice stem maggot, rice leaf roller, rice leaf-tier, and green rice leafhopper were occurred lightly in rice field.

• Korean Journal of Organic Agriculture
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• v.21 no.2
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• pp.207-217
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• 2013

This study was conducted to estimate organic Hanwoo carrying capacity when whole crop wheat and triticale as winter forage crops were grown on different applying sources (no fertilizer, organic fertilizer or cattle slurry), and mixed sowing in combination with hairy vetch and forage pea at the level of 50% cattle slurry application during the period of 2009~2011. The experimental plots were consisted of 5 treatments. Each treatment was triplicates and allocated in the randomized complete block design. For whole crop wheat, annual mean dry matter (DM) yield was significantly (P<0.05) higher for fertilizer application treatments than for no fertilizer treatment, and crude protein (CP) yield was significantly (P<0.05) higher for forage pea and hairy vetch-mixed sowing treatments than for no fertilizer and organic ferilizer treatments. Mean CP, total digestible nutrients (TDN) and relative feed value (RFV) contents of legumes-mixed sowing treatments was significantly (P<0.05) higher than those of other treatments. As diets replaced with 70% whole crop wheat were provided for 450kg of Hanwoo heifers, legumes-mixed sowing treatments could raise more heifers than organic fertilizer and no fertilizer treatments. For triticale, annual mean DM, CP and TDN yields were significantly (P<0.05) higher for fertilizer application treatments than for no fertilizer treatment, and CP content of legumes-mixed sowing and cattle slurry application treatments was significantly (P<0.05) higher than that of other treatments. When 450kg of Hanwoo heifers were fed on diets replaced with 70% triticale, it was estimated that legumes-mixed sowing treatments at the level of 50% cattle slurry application could rear average 3.3~3.4 heads/ha/year, which was significantly (P<0.05) higher than no fertilizer treatment (2.5 heads/ha/year). It was indicated that DM yields of whole crop wheat and triticale were much more effective in cattle slurry application than organic fertilizer, and Legumes-mixed sowing at the level of 50% cattle slurry application rather than whole crop wheat or triticale alone increased yields per unit area and nutritional value such as CP content. In conclusion, it is conceived that whole crop wheat or triticale produced in the manner above can be used instead of grains imported as dietary protein sources in the organic Hanwoo feeding regimen.

• Korean Journal of Organic Agriculture
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• v.32 no.2
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• pp.247-265
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• 2024

The aim of the study was to assess whole farm nitrogen (N)-balance in organic Hanwoo farms of different recycling types. N input, output and within-farm N flows were calculated as a farm-gate balance on 12 organic Hanwoo farms. The observed farms were divided into three groups: as (a) recycling farms, with a forage cultivation area (more than 0.1 ha), (b) semi-recycling farms (0.01-0.1 ha) and (c) with non-recycling farms (less than 0.01 ha). The self-sufficiency forage crops for animal feed was 44.4, 15.0, and 4.2% in recycling farms, semi-recycling farms and non-recycling, respectively. The recycling rate of compost was 98.8, 63.8, and 20.6% in recycling farms, semi-recycling farms and non-recycling farms, respectively. The annual farm-gate N surplus (input-output) per head was 42, 47, and 55 kg in recycling farms, semi-recycling farms and non-recycling, respectively. The mean annual N balance per head in recycling farms was less than 28% of non-recycling. The field nitrogen budgets showed 234, 1,161, and 5,476 kg N ha^-1 year^-1 in recycling farms, semi-recycling farms and non-recycling farm, respectively. N-surplus reductions of in recycling farms was 5-23 times lower compared to the semi-recycling farms and non-recycling farm. The nitrogen use efficiency (NUE) was 54, 36, and 29%, in recycling farms, semi-recycling farms, and non-recycling farm, respectively. Results showed that compost recycling through crop-livestock recycling farm is significant in the contributing to circulating N balance and to greater efficiency and productivity. The recycling organic Hanwoo farm had the low N balance and the high NUE. To reduce the N balance, we considered how to increase the amount of recycling by using self production compost. The self production forage crops was mainly considered to reduce the N balance by decreasing input of purchased feeds and increasing crop production and recycling rate of compost.

• Journal of the Korean association of regional geographers
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• v.1 no.1
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• pp.69-80
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• 1995

As Korean traditional peasant farming has come to a commercialization since 1970s, the spatial structure of Korean agriculture also has been gradually restructured by principle of not subsistance but economy. This epochal transformation of agriculture and its spatial structure in Korea are comparable with the first agricultural revolution in Europe. Facing this turning point, it is essential to redefine the nature and significance of agricultural geography in Korea through the review of the outcomes of about 200 studies published since 1950s in Korea of which twelve is concerned with locational analysis. The purpose of this study is to review the trend and characteristics of location studies on Korean agriculture. Major findings are as follows: (1) Since 1950s the location studies of agriculture recorded only 12 papers which occupy no more than 6% of studies of agricultural geography in Korea. This fewness suggests that the location study of agriculture in Korea is yet at the stage of beginning. (2) In spite of the fewness the studies, carried out mainly in 1980s, contributed considerably to clarify the locational characteristics of Korean agriculture especially in the spatial variations of crops, dairy farming and cropping system, the impacts of agricultural labors, the location strategy of mountain agriculture, and the responses of farmers to hazard. (3) In approach and methodology, two thirds of the studies has taken traditional empiricist view and other, positivist. And most studies adopted classic and neo-classic locational theories as their theoretical base in description and explanation. In degree of development, the location studies of agriculture in Korea seems to be about 20 years delayed compared to that of the advanced countries in terms of approach and methodology. (4) Such tradition of the location studies reflects not only the conservative nature of agricultural geography of Korea but also the early stage of capitalism of Korean agriculture.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.27-36
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• 2020

The study was compared for growth and yield of cherry tomato (Lycopersicon esculentum var. cerasiforme) crops as affected by various homemade liquid fertilizer (LF), commonly applied in the environmentally friendly farmhouses. LF treatment included UT (untreatment, water), OC (oil cake), BF (bone+fish meal), FA (fish amino meal), SO (sesame oil meal), and SF (starfish). Seasonal pH and EC in SO- and SF-LF rapidly decreased at 30 days after the storage, which were the highest EC of 0.6 - 0.8 dS/m, followed by BF-LF with 0.4 dS/m EC. T-N concentration in LF was the highest on the SF (0.0062%), followed by SO (0.0059%) and BF materials (0.0030%), which were all the great for the K concentration in the LF. P and Ca concentrations were the highest on the FA-LF, with the highest Mg concentration observed on the vegetable SO-LF. Soil EC was the highest on the SF-LF plots of 0.74 dS/m, with no significant differences between the treatments observed on the macro-nutrient concentrations in the soil and leaf. Leaf dry weight, leaf temperature, stem diameter, and plant height were investigated at once per 15 days. UT-LF reduced the leaf dry weight at all the measurement time while the plant height was low at an initial measurement but increased and similar to the other homemade LF treatments at a later measurement. Fruit yield and average fruit weight were the lowest on the UT-LF plots at 75 days after fertigation. Fruit diameter was increased by the BF-LF and SF-LF, with the highest fruit soluble solid contents and fruit coloring observed on the FA-LF. BF-LF maintained high fruit firmness.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.75-86
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• 2002

This study was performed to investigate situation of livestock manure generated from Kangwon-do and to evaluate its composting probability. The scale of livesrock-farming is bigger and bigger in Korea. Regulation based on the heads of livestock is slightly different from that based on livestock-farming household. So it is needed ro evaluate regulations for livestock head and livestock-farming household. Composting and liquid fertilization were thought to be appropriate technologies to the trearment of Korean cattle and pig manures, respectively. Generation quantity of pig manure was the greatest among pig, Korean cattle, cow and chicken manures. Pig manure generated the greatest amounts of BOD in Kangwon-do. Pig manure contained nitrogen, Korean cattle manure contained $K_2O$, and chicken and pig manures contained $P_2O_5$ in great amount. Alternative ratio of livestock manure to crops-fertilizer was 51% for nitrogen, 38% for $K_2O$, and 34% for $P_2O_5$.

• Journal of Korea Water Resources Association
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• v.50 no.6
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• pp.387-395
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• 2017

Sea level rise, accompanied by climate change, is expected to exacerbate seawater intrusion in the coastal groundwater system. As the salinity of saturated groundwater increases, salinity can increase even in the unsaturated soil above the groundwater surface, which may cause crop damage in the agricultural land. The other adverse impact of sea level rise is reduced unsaturated soil thicknesses. In this study, a composite model to assess impacts of sea level rise in coastal agricultural land is proposed. The composite model is based on the combined applications of a three dimensional model for simulating saltwater intrusion into the groundwater and a vertical one dimensional model for simulating unsaturated zone flow and transport. The water level and salinity distribution of groundwater are calculated using the three dimensional seawater intrusion model. At some uppermost nodes, where salinity are higher than the reference value, of the 3D mesh one dimensional unsaturated zone modeling is conducted along the soil layer between the ground water surface and the ground surface. A particular location is judged salinized when the concentration at the root-zone depth exceeds the tolerable salinity for ordinary crops. The developed model is applied to a hypothetical agricultural reclamation land. IPCC RCP 4.5 and 8.5 scenarios were used as sea level rise data. Results are presented for 2050 and 2100. As a result of the study, it is predicted that by 2100 in the climate change scenario RCP 8.5, there will be 7.8% increase in groundwater saltwater-intruded area, 6.0% increase of salinized soil area, and 1.6% in increase in water-logging area.