• Korean Journal of Organic Agriculture
• /
• v.25 no.3
• /
• pp.603-617
• /
• 2017

The occurrence and management of disease and pests in six organic peach orchards were surveyed from March 2015 to March 2017. In this period, the number of certified organic and non-chemical peach farms increased to 65.5% and 31.7%, respectively. Certified organic peach farms were selected based on more than $4,000m^2$ of cultivation area and three tons of production, and their cultivation status was examined. All of the farms were either cultivated green manure crop or sod, and limited vegetation control to a minimum. For the management of soil nutrients, many farmers used livestock manure, oilcake and self-manufacturing liquid fertilizer. It was surveyed that bordeaux mixture, lime sulfur, pheromone for mating disruption of moths and plant extract were used for disease and pest control. The damage caused by the pests and diseases were 31.6% and 24.1%, respectively. The oriental fruit moth showed the highest damage rate (13.5%) in the organic peach orchards, followed by the brown rot (13.0%), peach fruit moth (7.3%) and bacterial shot hole (7.3%).

• Korean Journal of Environmental Agriculture
• /
• v.38 no.4
• /
• pp.237-244
• /
• 2019

BACKGROUND: Impact of incorporating hairy vetch into soil on mitigating nitrous oxide (N₂O) emissions from maize field in South Korea has not been investigated, whereas impacts on soil properties and nutrients for crops have been investigated. Therefore, this study was conducted to examine N₂O emission from upland soil incorporated with hairy vetch for one year in maize field. METHODS AND RESULTS: Hairy vetch was grown in an upland soil from November, 2017 to May, 2018 and incorporated into soil on May 25 of 2018. Control and conventional treatment (NPK) were included for comparison. Gas samples were collected weekly for a year to examine N₂O emissions from the soil. Chemical nitrogen (N) fertilizer stimulated N₂O emission in short term resulting in the greatest cumulative N₂O emission in NPK (6.72 kg N₂O ha^-1) compared to the control (4.04 kg N₂O ha^-1) and hairy vetch-incorporated field (5.43 kg N₂O ha^-1), and the greatest yield of maize from NPK, because total N input was much greater by NPK (186 N kg ha^-1) than by hairy vetch (81.6 N kg ha^-1). CONCLUSION: Incorporation of hairy vetch reduced N₂O emissions from the maize compared to the NPK-treated field. However, further research on improving crop productivity with incorporation of hairy vetch is needed.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.303-303
• /
• 2009

시설재배지의 연작장해 원인이 토양병해 35%, 염류집적 30%로 분석하고 있으며, 시설재배지의 40% 이상이 토양EC 4dS/m 이상으로 작물생육에 부적합한 염류집적 토양으로 추정하고있다. 연작 및 집약적인 시설 재배의 불가피성을 감안한 시설재배의 장기적인 토양관리를 위하여 녹비작물을 활용한 물질순환적 토양관리를 위하여 토양 EC가 상이한 3개(<2.0dS/m, 2.0~6.0dS/m, 6.0dS/m<)토양에 거울철 휴한기에 호밀, 밀, 청보리를 재배하고 토양에 환원한 후 수박을 재배하여 시험을 수행하였다. 녹비작물의 건물중생산량은 호밀이 601~722kg/10a, 밀이 433~607kg/10a, 청보리가 648~690kg/10a 이었으며, 토양EC가 높은 토양(6.0dS/m<)에서 가장 낮은 경향이었다. 녹비작물 재배 후 토양의 EC는 호밀재배에서 24~44%, 밀재배에서 19~38%, 청보리재배에서 23~39% 경감효과가 있으며, 3개 토양 평균 각각 녹비작물별 토양EC 경감 효과는 호밀, 밀 그리고 청보리 각각 37%, 31% 및 35%의 경향을 보였다. 녹비작물 재배 후 수박을 재배한 결과 수박의 생육 및 수량성은 토양 및 녹비작물 간에 뚜렷한 차이를 보이지 않았으나, 무재배에 비해서는 녹비작물재배 토양에서 약간 양호한 경향을 보이고 있어, 장기적으로 계속 재배할 경우 토양의 물리화학성 개선 및 작부체계 개선에 의한 연작장해 경감 효과를 기대할 수 있을 것으로 사료되었다.

• Korean Journal of Organic Agriculture
• /
• v.20 no.2
• /
• pp.173-183
• /
• 2012

This study was conducted to select promising green manure crops, providing sufficient amount of nutrients for satisfying fruit tree growth, with the overwintering cover crops grown in organic orchards in 2009. The cover covers were investigated in 13 organic orchards in Chonnam province in April and June. The dry matter in cover crops observed in April and June was the highest for Lolium multiflorum Lam. and Bromus japonicus Thunb., respectively. Total N and K production in April was the highest for Lolium multiflorum Lam, Vicia hirsuta (L.) S. F. Gray and Vicia angustifolia var. segetilis (Thuill.) K. Koch., respectively, with Bromus japonicus Thunb. in June. This study showed that the leguminous crops, Vicia hirsuta (L.) and Vicia angustifolia, would be the prospective cover covers as the both crops provided sufficient amount of N and $K_2O$ into the soil. Amount of $P_2O_5$ producing from all cover crops provided less than nutrient levels than those of recommended nutrient requirement for satisfying 10- to 15-year-old fruit tree growth.

• Korean Journal of Organic Agriculture
• /
• v.15 no.4
• /
• pp.399-411
• /
• 2007

Korean organic farming has been well developed over the last two decades. It demonstrates that the number of certificated farm for organic agriculture and products have been drastically increased in recent year. However, the organic farmers have thought that organic farming rely only on organic fertilizer and they don't keep organic farming principle in which organic farmer should enhance biological activity and crop rotation. This study was to compare nutrient input, recommendation, cropping system and organic product circulation between the early $20^{th}$ century and beginning of the $21^{st}$ century. The population of Korea has increased 7.3 times more than that of a century ago but cultivated land has been decreased during 100 years. The rice production in 2002 was 4.2 times higher than that of production in 1912. The input of N, P and K in 1907 on the basis of King's suggestion was 95.6kg/ha, 15.9kg/ha and 3.0kg/ha, respectively. Nitrogen came from excreta (40%), green manure (55%) and compost (5%) in the early 20th century. On the other hand, organic farmer input organic resources such as wood chip (30.1%), compost (27.8%), rice straw (14%) and others (25%) these days. In terms of nutrient balance calculated nutrient and absorption by plants, organic rice farmer apply excessive nitrogen and phosphorus to the soil. They was used to put $7{\sim}10$ times more nitrogen than that of a century ago. Nutrient recommendation was similar in N and P between early 20th century and early $21^{st}$ century. Farmers in both century did not rotate crops in the field. Today, organic farmers engaged in more continuous cultivation than in early 20th century. Farmers in the early $20^{th}$ century produced locally, consumed locally the agricultural products, but organic farmers in the $21^{st}$ century produce the organic product in the local farmland and consumed in the large city and also a lot of foreign organic products have been imported in recent year.

• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.5
• /
• pp.436-441
• /
• 2015

The chemical properties of paddy fields in Gyeonggi province were monitored every 4 years from 1999 to 2015 in order to provide basic information for soil fertility management of paddy fields. In 2015, the soil chemical properties of paddy fields were 5.9 in pH, $23g\;kg^{-1}$ in organic matter (OM), and $84mg\;kg^{-1}$ in available phosphate (Avail. $P_2O_5$). Exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 0.30, 5.1 and $1.3cmol_ckg^{-1}$, respectively, and available silicate (Avail. $SiO_2$) was $129mg\;kg^{-1}$. In the long-term analysis, the contents of Avail. $SiO_2$, Exch. Ca and pH of paddy soils showed increasing tendency. However, Avail. $P_2O_5$ and Exch. K tended to decrease, and there were no significant changes in the contents of OM and Exch. Mg. Paddy soil within appropriate pH range increased from 44% in 1999 to 76% in 2003, 84% in 2007, 63% in 2011, and 80% in 2015. But soil within appropriate range of Exch. Ca tended to decrease, showing 36% in 1999, 42% in 2003, 38% in 2007, 37% in 2011 and 32% in 2015. In case of Avail. $SiO_2$, soil within appropriate range increased from 14% in 1999 to 17% in 2003, 18% in 2007, 16% in 2011, and 31% in 2015. As a result, paddy fields with less in nutrient level need to be more fertilized based on soil analysis. And the application of silicate fertilizer is strongly recommended to those of paddy fields in need. Also soil management such as the cultivation of green manure crop or application of rice straw will be necessary to increase the organic matter content of paddy soil.

• Korean Journal of Organic Agriculture
• /
• v.28 no.4
• /
• pp.579-589
• /
• 2020

This study was carried out to evaluate the effect of rye as green manure crop on the improvement of soil environment and reduction of Phytophthora blight in red pepper of open field where Phytophthora blight occurred frequently. Soil physical properties such as bulk density and porosity were increased in rye cultivation. In addition, gaseous was increased but liquid was decreased compared with conventional cultivation. The analysis of phospholipid fatty acids extracted from soil showed that rye cultivation significantly increased relative abundance of microbial community and ratio of aerobic to anaerobic bacteria. Furthermore, ratio of saturated to unsaturated fatty acids and cyclo-fatty acids to precursor. the indicators of increasing in environmental stresses, were reduced in rye cultivated field. Occurrence of Phytophthora blight in rye cultivation was reduced 30.7% compared with conventional cultivation. These results suggest that rye cultivation in red pepper of open field where Phytophthora blight occurred can improve soil environment and reduce damage of Phytophthora blight.

• Korean Journal of Breeding Science
• /
• v.41 no.4
• /
• pp.625-629
• /
• 2009

"Olgreen" (Scale cereal L.), a new rye variety was developed by National Institute of Crop Science(NICS), RDA. It was released in 2008 because of its high biomass yield potential and early maturity. It was developed from an open pollination within 10 rye varieties or lines including "Chochun" in 1995. The line 'SR95POP-S1-1072-1-2-4' was selected for its early maturity and excellent agronomic appearance, and placed in yield trials for two years from 2004 to 2005. It was designated "Homil 38" and placed in regional yield trials at the four locations around Korea from 2006 to 2008, from which the name "Olgreen" was given. Over three years, "Olgreen" averaged 8.88 ton ha-1 of forage yield (based on dry matter) harvested at late April and superior to other varieties with an increase of 10% more than the check variety "Olhomil", and 9% more than the introduced rye "Koolgrazer". Heading date of "Olgreen" was April 20 which was 3 days earlier than that of "Olhomil". It would be recommended as an early rye variety for forage or green manure in South Korea.

• Journal of Food Hygiene and Safety
• /
• v.35 no.5
• /
• pp.477-488
• /
• 2020

Recently, foodborne illness outbreaks linked to fresh produce are being increasingly reported in the United States, the EU, and Korea as well. Some of this increase may be due to improved surveillance, increase in consumption, change in consumers' habits, and complex distribution systems. Garlic chive is a green, fresh-cut vegetable consumed year-round as a nutrition-rich herb in Korea. It is also prone to contamination with foodborne pathogens during pre-harvest, as amendment with high amounts of livestock manure or compost to soil is required in its cultivation. Our aim in this study was to evaluate microbial contamination of garlic chives, garlic chives cultivation soil, compost, and irrigation water in the southern part of Korea. Samples were collected in A, B, and C regions in 2019 and 2020, and 69, 72, 27, and 40 of garlic chives, soil, compost, and irrigated water, respectively, were analyzed for the presence of sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), Bacillus cereus, Staphylococcus aureus, pathogenic E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp. In A, B, and C regions, levels of total aerobic bacteria, coliform, B. cereus, and S. aureus on all samples were between 1.14 and 8.83 log CFU/g, 0.43 and 5.01 log CFU/g, 0.41 and 5.55 log CFU/g, and 1.81 and 6.27 log CFU/g, respectively. B. cereus isolated from garlic chives and environmental samples showed β-hemolysis activity. Incidence of S. aureus in garlic chive and its production environments in 2020 was different from 2019. In this study, B. cereus and S. aureus were the only pathogenic microorganisms detected in all samples. As a result, this work suggests that continuous monitoring in the production and pre-harvest environment is required to improve hthe hygiene and safety of garlic chive.

• Journal of Bio-Environment Control
• /
• v.20 no.2
• /
• pp.134-138
• /
• 2011

This study was conducted to evaluate the effects of seeding time of ryegrass+hairy vetch on the nutrient contribution and growth of the crops. in order to develop utilization of cover crops as an organic nutrient source in a pear orchard. The study was conducted at a diligent farmer in Boseong in Chonnam, and the both ryegrass and hairy vetch applied on 1) 27 September, 2) 15 October, 3) 8 November, and 4) 10 December of 2008 as a cover crop treatment. Sod culture was refereed as a control. Growth of ryegrass was not affected by seeding time, but hairy vetch had fewer leaf and shoot number as seeding time advanced from September to December, and the similar trend was observed for the dry weight of the crops by seeding time. Seeding of cover crop on September was 2.6 times greater dry weight than those of the sod culture (362 kg/10a). Higher N concentration in cover crops occurred on early seeding time, and estimated N contribution from the cover crops was 16.9 kg/10a, which was 2.6 times greater than those of sod culture. $P_2O_5$ production from the cover crops was the greatest on seeding of October, and $K_2O$ production increased at earlier seeding time.