Korean J. Soil Sci. Fert. Vol.51, No.3, pp.197-203, 2018 Korean Journal of Soil Science and Fertilizer Article https://doi.org/10.7745/kjssf.2018.51.3.197 pissn : 0367-6315 eissn : 2288-2162 A Study of the Urban Garden Soil Health in Busan Area Jin-Suk Kwag*, Eun-Jeong Cho, Mi-Eun Jeong, Kwang-Yong Ju, Dae-Young Jeon, and Hui-Cheol Jeong 1 Busan Metropolitan City Institute of Health & Environment, Busan 46616, Korea 1 Busan Metropolitan City Agriculture Technology Center, Busan 46702, Korea *Corresponding author: tnr302@korea.kr A B S T R A C T Received: May 23, 2018 Revised: June 14, 2018 Accepted: August 31, 2018 The study of urban agriculture is focused on conceptual, active and policy establishment, and studies on the health of the vegetable gardens are minimal. This study analyzed the chemical properties of urban vegetable soils. The area of 29 urban vegetable gardens in the Busan area was divided into suburban area and urban areas. In the urban areas, the soil of the vegetable garden was high in content of organic matter and exchangeable cations and it is believed that there is more fertilizer in urban areas. The average value and range of soil fertility items were 6.87 (5.64~8.04) for ph, 43.4 g kg -1 (6.6~88.3) for organic matters, 845.3 mg kg -1 (115.9~2758.1) for available phosphate, 1.30 cmol kg -1 (0.23~3.66) for K +, 17.27 cmol kg -1 (6.05~46.50) for Ca 2+, 2.88 cmol kg -1 (0.94~3.49) for Mg 2+, and 2.66 ds m -1 (0.53~10.40) for electrical conductivity. Keywords: Exchangeable cations, Organic matter, Urban agriculture Location map of the target area of the study. C The Korean Society of Soil Science and Fertilizer. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
198 Korean Journal of Soil Science and Fertilizer Vol. 51, No. 3, 2018 Introduction 도시농업이란우리나라의 도시농업의육성및지원에관한법률 에의하면도시지역의생활공간을활용하여농작물을재배하는행위이며, 농촌진흥청에서는 도시민이도시또는인근에서농사짓는행위를가리키는용어로서, 넓게는농작물, 관상용화초뿐만아니라가축을기르고가공 유통하는행위까지포함하는것 이라정의하고있다. 서울도시농업에서발간한서울시도시농업마스터플랜연구보고서에의하면우리나라는 1992년주말농장을가꾸면서도시농업이시작되었으며, 2012년 5월 도시농업육성및지원에관한법률 시행으로도시민들이도시농업에더욱관심을갖게되었다 (Park, 2016). 도시농업이주는경제적, 사회적인이점으로도시민들이도시농업활동에많이참여하고있는데도시농업은도시민에게자연과의접촉, 생산적여가활동, 지역커뮤니티활성화, 교육의기회를제공하며신선하고믿을수있는농작물을직접생산, 공급이가능하게하며이로인해자원을절약하는경제적인가치를가져다준다 (Im and Lee, 2011; Rhim et al., 2011; Lee, 2013; Nam and Jung, 2014). 또한음식물쓰레기를퇴비로만들거나빗물과하수를재활용하는등자원순환의효과도있으며가정주부나노인들에게소일거리를제공하여일자리창출에도큰효과를가져다준다 (Choi et al., 2014; Jang et al., 2016). 이와같이도시농업의관심증가로다양한프로그램도입등도시농업의활성화를위한연구는활발히수행되었으나도시농업에이용되는토양의양분상태가농작물을재배하는데적절한지에대한연구는아직부족한상태이다. 농업에비전문적인도시민들이비료를과다사용하여토양내양분불균형의문제가발생할수도있고, 이로인해농작물의생육이저해되어작물생산이원활하지못하는경우가있기때문에토양의양분상태를확인하는토양화학적특성에관한분석이수행되어야한다. 따라서본연구에서는부산지역내의도시텃밭토양의화학적특성을분석해농작물을재배하는데토양이적절하게비옥한지, 양분의불균형문제는없는지를확인하고자한다. Materials and Methods 조사지점선정부산지역내도시텃밭중부산을대표할수있는공영텃밭을포함한 21개지점을선정하여연구를수행하였고, 그중명지공영텃밭과동부산공영텃밭은면적이넓어 5개의구획으로나누어 A~E까지총 5개의지점으로분리하여총 29개지점으로분류하였다. Fig. 1과같이총 29개의지점에서명지공영텃밭을포함한 16개지점은도 Fig. 1. Location map of the target area of the study.
A Study of the Urban Garden Soil Health in Busan Area 199 심에서벗어난외곽지역으로분류하였으며, 나머지는구 군청에서실시한 2016년도시농업조성사업의대상텃밭으로도심지역으로분류하였다. 부산의도시텃밭에서텃밭면적의경우 Cho et al. (2015) 이조사한바에따르면 11~20 m 3 가가장많이분포하고있지만시료채취시접근성용이와다양한작물을재배할수있는가능성을토대로텃밭면적이 30 m 3 이상인지역을대상으로삼았다. 조사지점의평균면적은명지공영텃밭을비롯한도심외곽지역의텃밭은 3600 m 3, 도심지역의텃밭은 170 m 3 으로조사되었다. 조사항목및분석방법토양에서작물의생육에필요한양분을균형있게공급할수있는토양의능력인비옥도를알아보기위해토양의화학적특성 7항목 (ph, 유기물, 유효인산, K +, Ca 2+, Mg 2+, 전기전도도 ) 을부산농업기술센터에의뢰하여분석하였다. 토양의 ph는토양화학분석법에따라풍건토양 5g을 50ml 비이커에평량하고증류수 (distilled water) 25 ml를가한후 ph meter(metter TOLEDO) 로측정하였다. 유기물함량은풍건토양 1 g을 250 ml 초자삼각 flask에평량한뒤유기물분석시약으로전처리한후분광광도계 (soiltek KA-P 2) 로측정하였다. 유효인산은풍건토양 5g을 100ml 삼각 flask에평량한뒤유효인산분석시약으로전처리한후분광광도계 (soiltek KA-P 2) 로측정하였다. 전기전도도는풍건토양 10 g을 100 ml 삼각 flask에넣고전처리하여전기전도도계 (METTER TOLEDO) 로측정하였다. 치환성염기 (K +, Ca 2+, Mg 2+ ) 는풍건토양 5 g을 100 ml 삼각 flask에평량하고전처리한후분광광도계 (soiltek KA-P 2) 로측정하였다. Results and Discussion 토양의화학적특성부산지역내도시텃밭토양의비옥도를조사하기위하여 ph 등 7항목을분석한결과 Fig. 2 와같이나타났다. 총 29개지점의텃밭토양의 ph는 5.64~8.04의범위를나타내었으며평균 6.87로농촌진흥청작물생육 ( 상추기준 ) 적정범위인 6.5~7.0을벗어나지않는것으로조사되었다. 29개지점중 8개지점의 ph가적정범위보다아래인 5.6~6.2로약산성을띄는것으로조사되었다. 토양의 ph는양분흡수와관련하여강력한영향력을가지며작물생육과도관련이있는중요한토양화학적특성중하나이다 (Tagliavini et al., 1995; Kang et al., 2010). 토양이산성화되면농작물의생산성이급격히감소되며중금속을포함한대부분의금속의용해도가증가하여식물의생육에해를입히기쉬운상태가되기때문에토양개량을위한시비방법이절실히필요하다 (Park et al., 2001). 유기물은 6.6~88.3 g kg -1 의범위로조사되었는데이는비료의살포량이지점마다상이하다는것을알수있다. 평균값은 43.4 g kg -1 로적정범위인 20~30 g kg -1 보다높게나타났고특히도심지역에서높은값을나타내었는데이는도시텃밭조성시유기물질이많은유기배양토를상토로사용했기때문으로추정된다. 유기물의함유량이높으면과잉양분의용탈로수계오염과염류집적에의한작물수량의감소를유발할수있어적정량을유지하는것이좋을것으로판단된다. 유효인산은 115.9~2758.1 mg kg -1 의범위로, 평균 845.3 mg kg -1 으로조사되었는데이는적정범위인 250~350 mg kg -1 에비해높은값으로나타났다. 특히, 유기물의함유량이높은지역일수록유효인산의함유량이높게측정되었는데 Fig. 3을보면유기물함량과유효인산의함량과의관계가결정계수 (R 2 ) 0.2196으로정의상관관계를나타낸것으로확인할수있다. 이는퇴비의양에도영향이있는데일반작물에비해채소작물이가축분등의유기물질과인산고농도및유기질비료의복합비료를위주로한화학비료사용이많은것으로추정되며, 퇴비중인산의함량이높은가축분퇴비의사용량과토양의유효인산함량과는고도의정의상관관계를나타낸다고밝혀져있다 (Ha et al., 1997;
200 Korean Journal of Soil Science and Fertilizer Vol. 51, No. 3, 2018 Fig. 2. The value of ph, organic matter, available phosphoric acid, K +, Ca 2+, Mg 2+ and electrical conductivity in 29 sites. Yoon et al., 2015). 인산은에너지대사와단백질합성에필수요소이나과잉공급되면과잉된인은주변환경으로유출되어지하수오염이나하천의부영양화를일으킬가능성이있고, 지상부의생육이뿌리생육에비해빈약할수있으므로인산의함량이높은퇴비는인산을기준으로시비하는것이적절한것으로보인다. 치환성양이온의경우도평균 K + 1.30 cmol kg -1, Ca 2+ 17.27 cmol kg -1, Mg 2+ 2.88 cmol kg -1 으로적정범위인 0.5~0.6 cmol kg -1, 5.0~6.0 cmol kg -1, 1.5~2.0 cmol kg -1 보다높은수준으로나타났다. 치환성양이온함량과유기물함유량의상관관계를분석한결과, Fig. 3과같이결정계수 (R 2 ) 이 K + (R 2 =0.3601), Ca 2+ (R 2 =0.1897) 으로각각유기물과정의상관관계를나타내는것을알수있다. 치환성양이온은생육을촉진시키는필수조건이나칼리질비료나석
A Study of the Urban Garden Soil Health in Busan Area 201 Fig. 3. Relationships between the organic matter contents and the nutrient contents (n=29). 회질비료의과잉사용으로집적될경우길항작용으로타양분의흡수를저해하거나특정양분의결핍을초래할우려가있으므로적절한검토가필요한것으로보여진다 (Lee et al., 2015). 전기전도도는 0.53~10.40 ds m -1 의범위를가지며, 평균 2.66 ds m -1 로적정범위인 0.0~2.0 ds m -1 에비해다소높은값으로나타났다. 일반적으로비료가많이집적된곳에서양분이많아지면전기전도도의측정값은커지게되고, 식물에의해양분이소비되면측정값은작아지게된다. 전기전도도가높으면토양염류함유량이많아부영양화가진행될수있으며농작물에따른적절한전기전도도를유지하는것이중요하다. 항목별상관관계토양의화학적특성을나타내는 7항목간의상관성을살펴보기위해서 SPSS를사용하여피어슨상관분석을실시하였다. Table 1에서확인한결과, 토양의화학적특성항목중유기물은 ph와부의상관관계를가지며, 유효인산, 치환성양이온 (K +, Ca 2+, Mg 2+ ) 과는정의상관관계를나타내었는데이는 Fig. 3에서도확인할수있 Table 1. Correlation coefficients between analyzed elements in the 29 sites. ph OM P 2 O 5 K + Ca 2+ Mg 2+ EC ph 1 OM -.551** 1 P 2 O 5 -.339.469 1 K + -.371.600**.576** 1 Ca 2+ -.086.435.280.397 1 Mg 2+.303 -.020.032.313.522** 1 EC.300 -.428.054 -.152.132.381 1 **Correlation at the level of 0.01
202 Korean Journal of Soil Science and Fertilizer Vol. 51, No. 3, 2018 었으며인산고농도및유기질비료의복합비료를위주로한화학비료사용에의한것으로추정된다. 지역별분석조사지점 29개텃밭토양의비옥도를외곽지역과도심지역으로분류한뒤지역별로분석한결과는 Fig. 4와같다. 토양의화학적특성중유기물함량은외곽지역의평균인 28.9 g kg -1 보다도심지역에서평균 61.2 g kg -1 로약 2배가량더높게측정되었다. 이는비료량과연관성이있는것으로판단되며실제로외곽지역의텃밭은대부분이분양텃밭으로도심과는거리가멀어주기적으로비료를살포한흔적이거의발견되지않았으나도심지역의텃밭은대부분주택가근처에위치하여과잉으로비료를살포한흔적을많이발견할수있었다. 도심지역텃밭은도시텃밭조성시유기물질이많은유기배양토를텃밭토양의상토로사용한것도하나의요인으로추정된다. 칼륨의농도도도심지역이외곽지역보다높은데유기물과같은원인으로추정된다. 토양의 ph는반대로외곽지역이도심지역보다다소높아약알칼리성을보이는데도심지역은농촌진흥청작물생육 ( 상추기준 ) 적정범위인 6.5~7.0에크게벗어나지않는것으로보아 ph에따른산성화나알칼리화는일어나지않은것으로보인다. 전기전도도는외곽지역이도심지역보다높은값을나타내는지점이많은데전기전도도를적정범위로낮추기위해땅뒤집기, 새흙넣기등을실시하고축분등의과다사용을자제해야한다. Fig. 4. The distribution in soil samples according to the suburban and urban area sites. Conclusions 본논문에서는부산지역내총 29개지점의도시텃밭을외곽지역과도심지역으로분류하여토양의건강성을알아보기위해토양의화학적특성 7항목 (ph, 유기인, 유효인산, K +, Ca 2+, Mg 2+, 전기전도도 ) 을분석하였다. 분석한결과외곽지역에비해도심지역텃밭의토양이유기물, 치환성양이온의함량이높았으며이는비료의살포량과연관이있으며도심지역에서도시텃밭조성시유기물질이많은유기배양토를텃밭의상토로사용했기때문으로판단된다. 텃
A Study of the Urban Garden Soil Health in Busan Area 203 밭토양의비옥도를항목별로피어슨의상관관계를분석한결과, 유효인산, 치환성양이온 (K +, Ca 2+, Mg 2+ ) 과는정의상관관계를나타냈는데이는인산고농도및유기질비료의복합비료를위주로한화학비료사용에의한것으로추정된다. 향후도시텃밭의농작물의적절한생육을위해서는선행연구결과들을응용하여도시텃밭토양의비옥도상태에따른적절한비료사용에대한연구결과의축적이필요할것으로판단된다. Acknowledgement This work was carried out with support of International Suitability Infrastructure Project in the Environmental field Testing Inspection (Project No. NIER-2017-01-03-029) National Institute Environmental Research. References Cho, M.J. 2015. A study on the formation process of public urban farm. M.S. thesis. University of Dong-A, Korea. Choi, E.Y., Y.N. Jeong, and S.Y. Kim. 2014. Analysis of the relationship between the importance of urban farming ordinance factors and participation satisfaction as well as sustainability for vitalizing of the urban farming-focused on Seoul City urban farming participants. J. UDIK. 15:173-188. Ha, H.S., M.S. Yang, H. Lee, Y.B. Yee, B.K. Sohn, and U.K. Kang. 1997. Soil chemical properties and plant mineral contents in plastic film house in southern part of Korea. Korean J. Soil Sci. Fert. 30:272-279. Im, M.J. and E.H. Lee. 2011. Users perception analysis of urban allotments for vitalizing local community. J. People Plants Environ. 14:237-243. Jang, G.S., Y.H. Kim, Y.S. Choi, S.H. Kim, J.M. Kim, S.J. Bae, Y.G. Cho, and T.H. Koo. 2016. A research of soil environmental health in urban garden, Gwangju. Korean J. Environ. Agric. 35:87-96. Kang, Y.I., M.Y. Roh, J.K. Kwon, K.S. Park, M.W. Cho, S.Y. Lee, I.B. Lee, and N.J. Kang. 2010. Changes of tomato growth and soil chemical properties as affected by soil ph and nitrogen fertilizers. Korean J. Environ. Agric. 29:328-335. Lee, C.R., S.G. Hong, S.B. Lee, C.B. Park, M.G. Kim, J.H. Kim, and K.L. Park. 2015. Physico-chemical properties of organically cultivated upland soils. Korea J. Org. Agric. 23:875-886. Lee, C.W. 2013. Urban Farming in Seoul. A Presentation Material of Symposium at the 2nd Seoul Urban Farming Fair. Nam, T.H. and T.Y. Jung. 2014. The distribution and characteristics of use of Urban farms-a case study of the Siji region in Daegu metropolitan city-. J. KILA. 42:1-9. Park, B.Y., Y.W. Uh, S.Y. Yang, S.M. Jang, J.H. Kim, and D.H. Lee. 2001. A study on the acidification of soils. J. Environ. Sci. Int. 10:305-310. Park, S.Y. 2016. Nutrient status of the soils used for urban agriculture in metropolitan city of Seoul. M.S. thesis. University of Seoul, Korea. Rhim, J.H., I.S. Yoon, E.J. Yoon, K.M. Kang, and T.H. Ahn. 2011. Planning strategies for urban farming in the development project areas. Land & Housing Institute, Korea Land & Housing Corporation (LH). Tagliavini, M., A. Masia, M. Quartieri. 1995. Bulk soil ph and rhizosphere ph of peach trees in calcareous and alkaline soils as affected by the form of nitrogen fertilizers. Plant Soil. 176:263-271. Yoon, Y.E., J.H. Kim, S.Y. Kim, J.U. Im, M.S. Kong, Y.H. Lee, and Y.B. Lee. 2015. Determination of main indicator for the changes of chemical properties in greenhouse soils. Korean J. Environ. Agric. 34:355-358.