Korean J. Soil Sci. Fert. Vol.53, No.1, pp.59-69, 2020 Korean Journal of Soil Science and Fertilizer Article

Korean J. Soil Sci. Fert. Vol.53, No.1, pp.59-69, 2020 Korean Journal of Soil Science and Fertilizer Article https://doi.org/10.7745/kjssf.2020.53.1.059 pissn : 0367-6315 eissn : 2288-2162 The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System Cho-Rong Lee, Yura Oh, Bi-Na Song, Jung A Jung, Jeong-Lai Cho, Sang-Min Lee, and Nan-Hee An* National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea *Corresponding author: nanhee79@korea.kr A B S T R A C T Received: February 5, 2020 Revised: February 21, 2020 Accepted: March 2, 2020 ORCID Cho-Rong Lee https://orcid.org/0000-0002-4912-8035 Nitrogen added to farmland is used to plants or remains in soil, or is lost to environment. We incorporated 15 N-labeled materials (Chemical fertilizer (CF), green manure (GM), livestock compost (LC), GM+LC, and oil cake (OC) to soil and cultivated Chinese cabbages (Brassica rapa subsp. pekinensis) and analyzed the 15 N recovery of crop and soil to investigate the fate of nitrogen. The results follow. The 15 N crop recovery of chemical fertilizer (CF) was the highest, and that of organic materials differed by type. The 15 N soil recovery of CF was the lowest, and that of organic materials was 3-6 times higher than CF. The 15 N loss was not significantly difference between CF and organic materials (except GM+LC). As results, despite of the same amount of nitrogen input, there was the difference in plant uptake and soil residue between organic materials and CF. Nitrogen of CF is used to Chinese cabbages more than organic materials, however most of the remaining nitrogen is estimated to be lost to the environment. Therefore, CF might be hard to occur residual effect in the next cropping season. In organic materials, nitrogen is less used to Chinese cabbages than CF, but remains in soil more than CF. Therefore, organic materials might be useful for improving soil fertility and have a residual effect in the next cropping season. We suggest that these properties of organic materials should be taken into account in calculating the amount of applied fertilizer in organic farming where mainly organic materials are used. Moreover, it is necessary to investigate the cumulative and residual effects of continuous input of the same organic materials. Keywords: Organic materials, 15 N, Stable isotope, 15 N recovery, Nitrogen fate Distribution of 15 N derived from materials to Chinese cabbages-soil-environment system. Treatment 15 N distribution (%) Crop Soil Unaccounted Green manure (GM) 27 28 45 Livestock compost (LC) 8 47 45 GM+LC 25 50 25 Oil cake (OC) 25 23 51 Chemical fertilizer (CF) 50 6 44 is 15 N crop recovery of Chinese cabbages. is 15 N soil recovery in soil. is 15 N loss into environment (100-15 N total recovery). 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.

60 Korean Journal of Soil Science and Fertilizer Vol. 53, No. 1, 2020 Introduction 질소는작물재배에필수적인다량요구원소이며작물생산을위해서는적절한질소관리가중요하다 (Hirel, 2001; Samborski, 2009; Giambalvo, 2010; Muchecheti, 2016). 질소공급을위해서사용되는비료에는유안, 요소등의화학비료 ( 무기질비료 ) 와녹비작물, 가축분퇴비, 유박등유기질비료가있다. 무기질비료와유기질비료는질소공급특성이상이하다고알려져있다. 토양수용액에용해되어바로작물에이용되는속효성비료인화학비료와달리유기질비료는아미노산등의유기태질소로존재하기때문에작물에이용되기위해서는미생물의무기화과정이필수적이다 (Smith, 2018). 이러한화학비료와유기질비료의질소공급특성의차이는작물의생산성뿐만아니라토양및주변환경에도영향을미칠것이다. 작물생산성극대화에만중점을두던과거의농업과달리현재농업은친환경농업을지향하고있기때문에투입된비료의작물생산성증진과환경에미치는영향간의균형이필요하다 (Poffenbarger, 2018). 양분공급을목적으로토양에투입된질소는작물에이용되며남은질소는미생물체내로유기화과정을거쳐토양에남아있거나휘산 탈질 용탈등대기나수계로유실되는등다양하게순환한다 (Dittert, 1998; Cassman, 2002; Poffenbarger, 2018). 미생물체내로유기화된질소는토양에잔존하고있다가다음작기에분해되어작물에이용될가능성이있으며, 토양내질소가휘산과탈질작용을거쳐대기로유실되면토양비옥도감소뿐아니라온실가스 (Janzen, 1991; Galloway, 2002; Gardner, 2009) 와미세먼지 (Lee, 2017; Kim, 2017) 의발생을유발할수있다. 또한수계로유실된질소는청색증이나부영양화와같은수질오염을유발할수있다 (Carpenter, 1998; McIsaac, 2001; Gardner, 2009; Erisman, 2013; Valkama, 2015). 따라서농경지에투입한질소가작물에이용되는지, 이용되지않은질소가토양에잔존하여다음작기에질소를공급하는지대기나수계로유실되는지등의질소동태를추적하는것은매우중요하다고할수있다. 토양에투입된질소의동태를정량화하려면기존에토양에있던질소와구분하는것이필수적이다. 이러한구분과농경지내질소동태추적을위해대표적으로동위원소를활용하고있다 (Holbeck, 2013). 동위원소란같은양성자수를가지는원소중중성자의수가다른원소로화학적성질이동일하여식물이나미생물이동위원소를비특이적으로이용하기때문에특정물질의기원을추적할때많이사용하고있다. 이미국내에서도녹비작물에질소동위원소인중질소 ( 15 N) 을표지하여녹비작물내질소가콩에얼마나이용되는지를추정 (Seo, 2008) 하였으며, 일반돈분퇴비와중질소가농축된요소 ( 15 N-enriched urea) 를배추에시비하여배추체내의질소가퇴비와요소중어디서유래되었는지구명하였다 (Ro, 2003). 또한당밀발효농축액내포함된질소의토양중행동을연구하기위하여중질소를활용하여질산화, 유기화, 탈질등으로의행동을연구하였다 (Lee, 2002). 현재까지안정동위원소를이용한질소동태연구는작물이용성에중점을두고수행되어자재에서유래한질소가토양및환경에미치는영향을종합적으로고찰한연구는거의없는실정이다. 본연구는토양양분관리를위해사용하는다양한유기자원 ( 녹비작물, 가축분퇴비, 유박등 ) 에서유래된질소의작물, 토양으로의동태를조사하기위하여안정동위원소를활용하여연구를수행하였다. Materials and Methods 중질소표지유기자원확보및토양처리 실험에사용한유기자원은녹비작물 2 종 ( 헤어리베치, 호밀 ), 가축

The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System 61 분퇴비, 유박 ( 대두박 ) 으로유기자원에서유래한질소와기존에토양에있던질소를구분하기위하여유기자원에중질소를인위적으로표지 (labeling) 하였다. 표지방법은선행연구 (Seo, 2008; Lee, 2013) 를참고하여수행하였다. 녹비작물은고무포트에토양을충진하고질소비료로 10 atom% 유안 (Sigma-aldrich) 을물에녹여투입하여헤어리베치와호밀을각각재배하였다. 가축분퇴비의중질소표지는앞서중질소를 1차적으로표지한호밀 (5.4 atom%) 을표지원으로사용하였으며, 우분 (34%), 계분 (30%), 미강 (15%) 을주성분으로하는미숙퇴비원료를호밀과함께퇴비화를진행해약 1달동안중질소가표지되도록하였다. 유박은녹비작물과동일한방법으로콩 ( 참올 ) 을재배하여수확한후수분제거 (170 C), 가압착유 (600 kpa) 를거쳐기름이제거된콩찌꺼기 ( 유박 ) 를회수하여건조후사용하였다. 본시험의처리구는녹비작물 (GM), 가축분퇴비 (LC), 녹비작물 + 가축분퇴비혼용 (GM+LC), 유박 (OC), 화학비료 (CF), 무처리 (CON) 총 6처리 3반복으로구성하였다. 처리구디자인은난괴법으로수행하였다. 녹비작물은헤어리베치와호밀을 6:4 (w:w) 로혼합하여사용하였고, 녹비작물 + 가축분퇴비는 3:7 (w:w) 로혼합하여처리하였다. 유박은중질소를표지한유박이부족하여일반콩으로만든유박을 1:1.3 (w:w) 로혼합하여처리하였다. 화학비료는 10 atom% 유안 (Sigma-aldrich) 을질소비료로사용하였다. 처리구별투입된자재의 atom % 15 N 함량은 Table 1과같다. 배추재배공시작물은배추 (CR추월) 로 2018년 9월부터 12월까지토양 11 kg를채운 1/2000a와그너포트에토양검정질소시비량의 130% 인 45.6 kg N/10a에해당하는자재를처리후전북완주군소재의유리온실에서재배하였으며, 물관리는처리별로배추생육차이가발생하여생육상태를고려하여포트별로상이하게투입하였다. 시험전토양의토성은사양토이며이화학성분석결과는 Table 2와같다. 토양및식물체분석작물이이용하는형태의질소인무기태질소함량을분석하기위하여, 배추정식후 1, 3, 5, 7, 9, 11주간격으로토양을채취하여습토상태로 2 mm체친후 2M KCl로침출하여흐름주입분석기 (Lachat, QC8500, USA) 를이용하여암모늄태질소와질산태질소함량을각각 660 nm, 520 nm에서분석하였다. 배추수확후토양의미생물체내질소함량 (Microbial biomass nitrogen, MBN) 을알아보기위하여토양을습토상태로 10 g씩 Table 1. Chemical components of treatments in the experiment. Treatment atom % 15 N T-N (%) C/N ratio Green manure (GM) 5.00 3.5 11.2 Livestock compost (LC) 2.10 2.8 13.5 GM+LC 1.05 2.6 14.3 Oil cake (OC) 1.63 6.6 7.4 Chemical fertilizer (CF) 10 21 - GM is mixed of hairy vetch and rye at the ratio of 6:4 and GM+LC is mixed of green manure mixture and livestock compost at the ratio of 3:7. Table 2. Physico-chemical properties of the soil used in the experiment. T-N OM Available P 2 O 5 Exchangeable cation (cmol + kg -1 ) Soil texture ph (g kg -1 ) (g kg -1 C/N ) (mg kg -1 ) K + Ca 2+ Mg 2+ Sandy Loam 5.70.4 15 23 450 0.473.61 1.81 OM is organic matter

62 Korean Journal of Soil Science and Fertilizer Vol. 53, No. 1, 2020 데시케이터에넣고클로로포름으로훈증하여미생물을사멸시킨후 0.5M K 2 SO 4 로추출하여유기탄소측정기 (Shimadzu, TOC-LCPH, Japan) 으로 MBN 함량을분석하였다. 15 N 회수율분석시험에사용된유기자원과배추는 70 C에서건조하고, 토양은 7일이상풍건하여시료를볼밀러 (Retsch, Mixer Mill MM301, Germany) 를이용하여곱게갈아원소분석기 (Elementar, vario Max CN element analyzer, Germany) 를이용하여총질소함량을, 질량분석기 (Elementar, Isoprime IRMS, Germany) 를이용하여시료내질소동위원소비 ( 14 N/ 15 N) 인 δ 15 N을측정하였다. δ 15 N는대기중질소의동위원소비를기준으로시료의변이정도를나타내는값이며대기의 atom% 15 N (0.3663%) 을이용하여유기자원, 배추, 토양의중질소함량 (atom% 15 N) 을 (Eq. 1) 와같이계산하였다. 시료의 atom% 15 N=(δ 15 N/1000 + 1) 대기의 atom% 15 N (Eq. 1) 15 N 회수율 ( 15 N recovery, %) 은 15 N 표지원으로투입된 15 N 이시료로회수된비율로수확후배추 ( 15 N crop recovery) 와토양 ( 15 N soil recovery) 에대해 (Eq. 2) 와같이계산하였다 (Smith, 2018). 15 N recovery (%) = N sample (a b) / N fertilizer (c d) (Eq. 2) N sample 은시료 ( 배추또는토양 ) 의총질소함량이며 a는 15 N표지원이투입된시료의 atom % 15 N, b는무처리시료의 atom% 15 N를나타내며, N fertilizer 는 15 N표지원의질소함량이며, c는 15 N 표지원의 atom % 15 N, d는대기의 atom % 15 N (0.3663%) 이다. 배추와토양의총 15 N회수율 ( 15 N total recovery, %) 은배추회수율 ( 15 N crop recovery) 과토양회수율 ( 15 N soil recovery) 합하여계산하였고, 유기자원으로투입된 15 N 중배추와토양에서회수되지않은양 (100-15 N total recovery) 은환경으로유실된것 ( 15 N loss, %) 으로추정하였다. 통계분석자료의통계분석은 SPSS를이용한분산분석으로수행하였고, 95% 수준에서 Duncan s New Multiple Range Test로유의성정도를분석하였다. Results and Discussion 유기자원의중질소표지량분석 15 N를인위적으로표지한호밀, 헤어리베치, 대두박, 가축분퇴비의 15 N 함량은 Table 3와같다. 동일한조건에서중질소를표지하지않은호밀 (0.41%) 과헤어리베치 (0.43%) 의 15 N 함량은대기 (0.37%) 와유사한경향을보였으나, 15 N를표지한경우 10배이상의 15 N가식물체내로표지되었다. 콩과작물인헤어리베치와대두박은벼과작물인호밀보다 15 N 표지량이적었는데, 이는질소고정을하는콩과작물은대기중의질소를고정하기때문에호밀보다비료로투입한 15 N을조금이용하였기때문으로판단된다. 또한 5.37 atom% 15 N인호밀을이용하여표지한가축분퇴비는 1.05 atom% 15 N으로중질소함량이비교적낮았지만표지가된것을확인하였다.

The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System 63 배추수량및시험후토양분석수확기배추의수량은 Table 4과같다. 무처리대비 5개유기자원과화학비료처리에서배추수량이유의하게증가하였으며, 유기자원과화학비료처리는통계적으로유의한차이가없었다. 배추의 Total N 및 15 N 흡수량은유기자원및화학비료처리에유의한영향을받았으며, CF, GM, GM+LC, OC, LC, CON 순으로높았다. 시험후토양 ph는유기자원및화학비료처리에유의한영향을받았다 (p < 0.05). CON 대비 CF, GM, OC에서유의하게감소하였으며, LC와 GM+LC는무처리와차이가없었다. Total N (g kg -1 ) 및 Total C (g kg -1 ) 는 CON 대비 CF 및 OC는통계적으로유의한차이가없었으나 GM, LC, GM+LC는유의하게높았다 (Table 5). 질소동태조사 15 N을표지한유기자원을이용하여유기자원에서유래한질소의동태를조사한결과는 Table 6 과같다. 유기물형태로토양에투입된질소는무기화과정을거친후 1) 작물에이용되며, 작물에이용되지못한질소는토양미생물체로유기화되거나유기물형태로 2) 토양에잔존할수있다. 또한탈질, 휘산, 유거, 용탈등의과정을통해 3) 환경으로유실될수있다. 본연구에서는배추와토양에회수되지않은질소 (Unaccounted) 는유실된것으로계산하였으며, 끝이막혀있는포트에서수행하여유거나용탈이아닌휘산이나탈질을통해대기중으로유실된것으로판단하였다. 이에실제노지에서의질소유실량과는차이가있을것으로보인다. Table 3. atom % 15 N of organic materials used in the experiment. Organic materials Rye Hairy vetch Oil cake (soybean) livestock compost atom % 15 N 5.374.62 3.42 1.05 Table 4. Yields, N and 15 N uptakes of Chinese cabbages in treatments (Mg ha -1 ). Treatment Yields (Mg ha -1 ) N contents (kg ha -1 ) 15 N contents (kg ha -1 ) Control (CON) 86.3b 103d 0.4d Green manure (GM) 202.2a 270b 8.0b Livestock compost (LC) 163.1a 204c 1.2cd GM+LC 187.2a 268b 3.5c Oil cake (OC) 192.4a 233bc 2.7cd Chemical fertilizer (CF) 195.8a 569a 28.5a CON is control (non-application); GM is mixture of hairy vetch and rye; LC is livestock compost; GM+LC is mixture of GM and LC; OC is oil cake of soybean; CF is chemical fertilizer (ammonium sulfate) at the rate of 45.6 kg N ha -1. Table 5. Chemical properties of the soils after Chinese cabbages cultivation. Treatment ph T-N (g kg -1 ) T-C (g kg -1 ) Control (CON) 7.0a 0.36c 8.28c Green manure (GM) 6.7b 0.52ab 9.64b Livestock compost (LC) 7.0a 0.64a 11.56a GM+LC 6.9a 0.61a 10.79a Oil cake (OC) 6.7b 0.45bc 8.43c Chemical fertilizer (CF) 6.5b 0.38c 8.22c GM is mixed of hairy vetch and rye at the ratio of 6:4 and GM+LC is mixed of green manure mixture and livestock compost at the ratio of 3:7.

64 Korean Journal of Soil Science and Fertilizer Vol. 53, No. 1, 2020 Table 6. Distribution of 15 N derived from materials to Chinese cabbages-soil-environment system. Treatment 15 N distribution (%) Crop Soil Unaccounted Green manure (GM) 27 28 45 Livestock compost (LC) 8 47 45 GM+LC 25 50 25 Oil cake (OC) 25 23 51 Chemical fertilizer (CF) 50 6 44 is 15 N crop recovery of Chinese cabbages. is 15 N soil recovery in soil. is 15 N loss into environment (100-15 N total recovery). 1 작물 15 N회수율 ( 15 N crop recovery) 자재에서공급된 15 N이작물에이용된비율인 15 N crop recovery을조사한결과는다음과같다. CF는 50% 로가장회수율이높았고, 4개의유기자원처리는 CF보다낮고종류별로상이한경향을보여동일량의질소를투입하더라도자재에따라작물에이용되는비율이달랐다. Smith (2018) 이 15 N을표지한비료를사용한 100여개문헌을검토하여화학비료의 15 N crop recovery은 43% 로높고, 축분과유기물잔사는 17-18% 로낮다고보고한결과와같은경향을보였다. 유기자원중콩과작물이포함된 GM, OC, GM+LC처리는각각 27%, 25%, 25% 로높은회수율을보였는데, Vargas et al. (2017) 이콩과작물인 crotalaria를환원한후브로콜리의 15 N crop recovery가 29% 이었다고보고한결과와유사한경향을보였다. 작물이흡수하는질소는무기태질소로 (Lim, 2014), 유기자원이토양에투입되고난후무기화되어야작물이흡수할수있다. 자재처리후토양의무기태질소함량을경시적으로조사한결과 (Fig. 1), 초기 3 주동안질소무기화가가장활발하였으며화학비료의무기화량이가장많았고유기자원은 GM, OC, GM+LC 순으로높았다. 또한토양의무기태질소함량이높을수록배추의 15 N 흡수량이높은정의상관관계 (R 2 = 0.8776) 가있었다 (Fig. 2). Fig. 1. Changes of net mineral nitrogen in Chinese cabbages-cultivated soil over time.

The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System 65 LC는 15 N crop recovery이 8% 로가장낮았는데다수의문헌에서축분퇴비의 15 N crop recovery은 3-26% 수준으로낮다고보고하였으며 (Kirchamn, 1990; Jensen, 1999; Holbeck, 2013), 15 N crop recovery이적은것은질소유기화와관련있다고하였다. Dittert et al. (1998) 은가축분퇴비의암모니아가호기적조건에서토양미생물에빠르게이용된다고하였는데, 본연구에서 LC의토양질소순무기화가거의발생하지않은것 (Fig. 1) 으로보아 LC유래질소가토양미생물체내로많이이용되어 15 N crop recovery이낮은것으로판단된다. 2 토양 15 N회수율 ( 15 N soil recovery) 자재로투입된 15 N이배추수확후토양에얼마나남아있는지알아보기위하여토양 15 N회수율을분석한결과는다음과같다. CF는투입한 15 N의 6% 가토양에잔존하는것으로나타났는데, Bosshard (2009) 와 Smith (2018) 가화학비료의토양 15 N회수율이 22%, 20-30% 라고보고하였으며, Holbeck (2013) 가화학비료의토양 15 N회수율이 20% 미만이라고보고한것에비해낮은경향을보였다. 따라서화학비료는투입후 Fig. 2. Correlationship between mineral nitrogen in soil and 15 N uptakes by Chinese Cabbages (R 2 = 0.8776). Fig. 3. Microbial biomass nitrogen (MBN) in soil after harvest of Chinese cabbages.

66 Korean Journal of Soil Science and Fertilizer Vol. 53, No. 1, 2020 단기간에작물에이용되는양은많지만, 이용되지않은질소의대부분은토양에서제거되어다음작기에잔존효과를나타내기는어려울것으로판단된다. 유기자원의토양 15 N회수율은 23-50% 로, 1작기내에작물에이용되지않고토양에잔존하는 15 N의비율이화학비료에비해 3-6배높았으며, 유기자원중 GM+LC와 LC는 50%, 47% 로상대적으로높고 GM와 OC는 28%, 23% 로낮은경향을보였다. 배추수확후토양의 MBN함량을조사한결과 (Fig. 3), 토양 15 N회수율이높은유기자원처리에서화학비료보다높게나타났다. MBN은토양미생물체내에동화된 N량으로유기자원에서공급된 N가작물에이용되기보다토양미생물체내로이용되어토양 15 N회수율이증가하였음을나타낸다. 따라서유기자원은화학비료보다한작기내에작물에이용되는양은적지만, 토양에많이잔류하여토양지력증진에효과적일것으로보인다. Smith (2018) 역시유기자재는화학비료에비해토양 15 N회수율이높아토양유기물 pool에더기여한다고하였으며, 유기자재의토양 15 N회수율은 1년이내급격하게감소한다고하였다. 이러한결과로미루어볼때토양에잔류한유기자재유래질소는최소 1년까지는작물에잔존효과를보일것으로판단된다. 유기자원중 GM과 OC의토양 15 N회수율이상대적으로낮았던것은질소무기화량이상대적으로많았기때문으로보인다. Amato et al. (1987) 은밀짚과콩과작물의지상부및지하부를토양에투입한결과, 무기화량이가장많았던콩과작물의지상부가토양 15 N회수율이가장낮았다고하였다. LC와 GM+LC는투입한 15 N의약절반이토양에잔류하는것으로나타났으며, LC는초기 7일째이후거의질소순무기화가발생하지않았고, LC처리토양의 MBN이무처리에비해 2배이상증가한것으로보아 LC유래질소의상당부분이미생물체내로이용되어토양에잔류하고있음을알수있었다 (Fig. 3). 토양에투입된유기물의 C/N (Rowell, 2001; Qju, 2008) 과 lignin/n (Kumar, 2003) 은질소무기화에영향을준다. 가축분퇴비중우분은이분해성인헤미셀룰로스함량이돈분과계분에비해낮고난분해성인리그닌함량이높아 (Yun, 2007). C/N이낮아도질소무기화가거의발생하지않는다. 우리가실험에사용한퇴비는우분을주원료로제조하여낮은 C/N에도불구하고질소무기화가거의발생하지않은것으로판단된다. 3 15 N유실율 ( 15 N loss ) 투입된 15 N 중작물과토양에회수되지않고대기로유실된양 ( 15 N loss ) 을추정한결과, GM+LC를제외한유기자원 3종과화학비료는유사한경향을보였다. OC는 51% 로가장많은양이유실되었으며, GM, LC, CF는 44-45%, GM+LC는 25% 가유실된것으로나타났다. 유기자원중 GM과 OC의유실율이 CF와유사하게높았던것은배추의질소요구시기와자재의질소무기화특성이맞지않았기때문으로판단된다. GM과 OC의질소무기화량이활발했던초기 2-3주동안은배추의질소요구량은크지않은시기로, 무기화된질소의많은양이토양미생물에이용되거나탈질, 휘산등으로유실된것으로보인다. LC는토양중에서질소순무기화가거의발생하지않았음에도불구하고 45% 가환경으로유실된것을보아, 퇴비의암모늄태질소가휘산이나탈질을통해바로대기중으로제거된것으로보인다. GM+LC의유실율은 25% 로가장낮았으며총 15 N회수율 ( 작물 + 토양 ) 은 75% 로 GM을단독처리했을때보다토양회수율이증가하고, LC를단독으로처리했을때보다작물회수율이증가하여유실율이감소하였다. Conclusions 유기물형태로토양에투입된질소는무기화과정을거친후작물에이용되거나토양미생물체로유기화또는유기물형태로토양에잔존하거나탈질, 휘산등환경으로유실될수있다. 토양양분관리를위해사용하는녹비작물, 가축

The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System 67 분퇴비, 유박등의유기자원에포함된질소가작물, 토양, 환경으로이동하는특성을알아보기위하여 15 N를표지한유기자원을토양에투입한후배추및토양에대한 15 N회수율을조사한결과는다음과같다. 작물 15 N회수율은화학비료가 50% 로가장높았고, 유기자원은 8-27% 로화학비료보다낮았으며자재종류별로상이하였다. 토양 15 N회수율은화학비료가 6% 로가장낮았고유기자원은 23-50% 로화학비료보다 3-6배높았으며, 유기자원중에서도 GM+LC 와 LC는 47%, 50% 로높은경향을, GM과 OC는 28%, 23% 로낮은경향을보였다. 전체 15 N투입량에서총 15 N회수율 ( 작물 + 토양 ) 을뺀유실율은 GM+LC를제외하고는유기자원과화학비료간의뚜렷한차이가없었다. 위와같은결과로동일량의질소를기준으로자재를투입하더라도종류에따라작물에이용되고, 토양에잔존하고, 환경으로유실되는질소의비율이다른것을확인하였다. 화학비료는투입후단기간에작물에이용되는양은많지만이용되지않은질소의대부분이환경으로유실되어다음작기에잔존효과를나타내기는어려울것으로보인다. 반면, 유기자원은화학비료와유사한양이유실되지만한작기내에작물에이용되는질소가적고토양에잔류하는양이많아토양지력증진에효과적이며다음작기에잔존효과를나타낼것으로판단된다. 이에지속적으로유기자원을이용하여토양양분을관리하는유기농경지의경우유기자원의이러한특성을고려하여시비량을산정해야할것으로보이며, 동일자재의연용에의한누적 잔존효과에대한조사가필요할것으로보인다. Acknowledgement This study was conducted by the support of Research Program for Agricultural Science and Technology Development (Project No. PJ0134982018), National Academy of Agricultural Science, Rural Development Administration, Republic of Korea. References Amato, M., J. Ladd, A. Ellington, G. Ford, J. Mahoney, A. Taylor, and D. Walsgott, 1987. Decomposition of plant material in Australian soils. IV. Decomposition in situ of 14C labeled and 15 N labeled legume and wheat materials in a range of southern Australian soils. Soil Research. 25(1):95-105. Bosshard, C., P. Sorensen, E. Frossard, D. Dubois, P. Mader, S. Nanzer, and A. Oberson, 2009. Nitrogen use efficiency of 15 N-labelled sheep manure and mineral fertilizer applied to microplots in long-term organic and conventional cropping system. Nutr. Cycl. Agroecosyst. 83:271-287. Carpenter, S.R., N.F. Caraco, D.L. Correll, R.W. Howarth, A.N. Sharpley, and V.H. Smith, 1998. Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecological applications. 8(3):559-568. Cassman, K.G., A. Dobermann, and D.T. Walters, 2002. Agroecosystems, nitrogen-use efficiency, and nitrogen management. AMBIO: A Journal of the Human Environment. 31(2):132-141. Dittert, K., T. Goerges, and B. Sattelmacher, 1998. Nitrogen turnover in soil after application of animal manure and slurry as studied by the stable isotope 15 N: A review. Zeitschrift für Pflanzenernährung und Bodenkunde. 161(4): 453-463. Erisman, J.W., J.N. Galloway, S. Seitzinger, A. Bleeker, N.B. Dise, A.M.R. Petrescu, A.M. Leach, and W. de Vries, 2013. Consequences of human modification of the global nitrogen cycle. Philosophical Transactions of the Royal Society B: Biological Sciences. 368(1621):20130116. Galloway, J.N., E.B. Cowling, S.P. Seitzinger, and R.H. Socolow, 2002. Reactive Nitrogen: Too Much of a Good

68 Korean Journal of Soil Science and Fertilizer Vol. 53, No. 1, 2020 Thing? AMBIO: A Journal of the Human Environment. 31(2):60-63, 64. Gardner, J.B., and L.E. Drinkwater, 2009. The fate of nitrogen in grain cropping systems: a meta analysis of 15 N field experiments. Ecological applications. 19(8):2167-2184. Giambalvo, D., P. Ruisi, G.D. Miceli, A.S. Frenda, and G. Amato, 2010. Nitrogen Use Efficiency and Nitrogen Fertilizer Recovery of Durum Wheat Genotypes as Affected by Interspecific Competition. Agronomy Journal. 102(2):707-715. Hirel, B., P. Bertin, I. Quillere, W. Bourdoncle, C. Attagnant, C. Dellay, A. Gouy, S. Cadiou, C. Retailliau, M. Falque, and A. Gallais, 2001. Towards a better understanding of the genetic and physiological basis for nitrogen use efficiency in maize. Plant Physiol. 125:1258-1270. Holbeck, B., W. Amelung, A. Wolf, K.-H. Südekum, M. Schloter, and G. Welp, 2013. Recoveries of 15 N-labelled fertilizers (chicken manure, mushroom compost and potassium nitrate) in arable topsoil after autumn application to winter cover crops. Soil and Tillage Research. 130:120-127. Janzen, H., and S. McGinn, 1991. Volatile loss of nitrogen during decomposition of legume green manure. Soil Biology and Biochemistry. 23(3):291-297. Jensen, B., P. Sørensen, I.K. Thomsen, B.T. Christensen, and E.S. Jensen, 1999. Availability of Nitrogen in 15 N-Labeled Ruminant Manure Components to Successively Grown Crops. Soil Sci. Soc. Am. J. 63:416-423. Kim, S.T., C.H. Bae, B.U. Kim, and H.C. Kim, 2017. PM2.5 Simulations for the Seoul Metropolitan Area:(I) Contributions of Precursor Emissions in the 2013 CAPSS Emissions Inventory. Journal of Korean Society for Atmospheric Environment. 33(2):139-158. Kirchmann, H. 1990. Nitrogen interactions and crop uptake from fresh and composted 15 N labelled poultry manure. Journal of Soil Science. 41:379-385. Kumar, K., and K.M. Goh, 2003. Nitrogen release from crop residues and organic amendments as affected by biochemical composition. Comm. Soil Sci. Plant Anal. 34:2441-2460. Lee, J.H., Y.M. Kim, and Y.K. Kim, 2017. Spatial panel analysis for PM2.5 concentrations in Korea. Journal of the Korean Data & Information Science Society. 28(3):473-481. Lee, S.M. 2013. The study of nitrogen cycle in organic farming using stable isotope. Research program report. NAS. Lee, S.M., W.J. Choi, S.I. Yun, Y.D. Choi, H.M. Ro, and J.W. Park, 2002. Evaluation of Fate of NH + 4 of Condensed Molasses Solubles (CMS) in Soil Using by 15 N-Tracer Method. Korean journal of Soil Sci. Fert. 35(2):69-76. Lim, W.S., H.H. Lee, and C.O. Hong, 2014. Nitrogen Dynamics in the Soils Incorporated with Single and Mixture Application of hairy vetch and barley. Korean J Environ Agric. 33(4):298-305. McIsaac, G.F., M.B. David, G.Z. Gertner, and D.A. Goolsby, 2001. Eutrophication: nitrate flux in the Mississippi River. Nature. 414(6860):166. Muchecheti, F., and I.C. Madakadze, 2016. Yield and nitrogen recovery of rape (Brassica napus L.) in response to application of leguminous leaf litter and supplemental inorganic nitrogen. Experimental Agriculture. 52(4): 518-536. Poffenbarger, H.J., J.E. Sawyer, D.W. Barker, D.C. Olk, J. Six, and M.J. Castellano, 2018. Legacy effects of long-term nitrogen fertilizer application on the fate of nitrogen fertilizer inputs in continuous maize. Agriculture, Ecosystems & Environment. 265:544-555. Qiu, S., A.J. McComb, R.W. Bell, 2008. Ratios of C, N and P in soil water direct microbial immobilisation-mineralization and N availability in nutrient amended sandy soils in southwestern Australia. Agric. Ecosyst. Environ. 127:93-99 Ro, H.M., W.J. Choi, and S.I. Yun, 2003. Uptake and recovery of urea- 15 N blended with different rates of composted manure. Korean journal of Soil Sci. Fert. 36(6):376-383. Rowell, D.M., C.E. Prescott, and C.M. Preston, 2001. Decomposition and nitrogen mineralization from biosolids and other organic materials: relationship with initial chemistry. J. Environ. Qual. 30:1401-1410.

The Fate of 15 N-labeled Organic Materials Applied to Chinese Cabbages Cropping System 69 Samborski, S.M., N. Tremblay, and E. Fallon, 2009. Strategies to make use of plant sensors- based diagnostic information for nitrogen recommendations. Agronomy Journal. 101(4):800-816. Seo, J.H., S.H. Lee, Y.S. Cho, J.E. Lee, C.K. Lee, and Y.U. Kwon, 2008. Estimation of soybean N fraction derived from N sources by 15 N in soybean cultivation with rye as green manure. Korean journal of crop science. 53(1):50-57. Smith, C.J., and P.M. Chalk, 2018. The residual value of fertiliser N in crop sequences: An appraisal of 60 years of research using 15 N tracer. Field Crops Research. 217:66-74. Valkama, E., R. Lemola, H. Känkänen, and E. Turtola, 2015. Meta-analysis of the effects of undersown catch crops on nitrogen leaching loss and grain yields in the Nordic countries. Agriculture, Ecosystems & Environment. 203:93-101. Vargas, T.d.O., E.R. Diniz, A.L.V. Pacheco, R.H.S. Santos, and S. Urquiaga, 2017. Green manure- 15 N absorbed by broccoli and zucchini in sequential cropping. Scientia Horticulturae. 214:209-213. Yun, H.B., Y. Lee, C.Y. Yu, S.M. Lee, B.K. Hyun, and Y.B. Lee, 2007. Effect of Crude Carbohydrate Content in Livestock Manure Compost on Organic Matter Decomposition Rate in Upland Soil. Korean J. Soil Sci. Fert. 40(5):364-368.