CAJ | 학술논문

基于为期30年的红壤性水稻土长期定位试验，选用不施肥（CK）、化肥氮磷钾配施（NPK）、NPK配施低量有机肥（NPKM7/3）、NPK配施中量有机肥（NPKM5/5）、NPK配施高量有机肥（NPKM3/7）五个处理，通过物理-化学联合分组方法，分析土壤有机碳在不同施肥处理下的非保护、物理、化学、生化、物理-化学及物理-生化保护组分的碳含量特征及其与土壤总有机碳之间的关系，并探讨稻田土壤有机碳的固持机制。结果表明，除了非保护的轻组和微团聚体内闭蓄态的粘粉粒组分外，其他组分的质量比例在各施肥处理间均有显著性差异。有机无机配施（NPKM7/3、NPKM5/5、NPKM3/7）下，总有机碳含量（19.1~25.0 g·kg-1）、非保护的粗颗粒有机碳（cPOM）含量（8.41~12.7 g·kg-1）及物理保护的微团聚体有机碳（6.41~6.62 g·kg-1）含量均显著高于CK处理（P﹤0.05）。对化学、生化、物理-化学及物理-生化保护态的有机碳含量无显著性影响，表明非保护的cPOM及物理保护的微团聚体（μagg）对施肥的响应最敏感。相关分析表明，cPOM、物理保护的μagg及其闭蓄的细颗粒有机碳（iPOM）与土壤总有机碳含量之间呈显著正相关关系（P﹤0.05），相关方程的斜率表明有机碳变化引起了组分变化，其中：土壤总有机碳变化引起的cPOM变化率最高（50％）；土壤总有机碳积累引起物理保护的μagg及其闭蓄的iPOM碳组分变化率为12％；生化保护的非酸解粘粒和物理-化学保护的酸解的粉粒虽与土壤总有机碳显著相关，其变化率仅为2％~3％；其他各保护机制下的组分与土壤总有机碳含量均无显著相关关系。这表明在现行种植和管理制度下，供试红壤性水稻土有机碳主要以cPOM及μagg有机碳的形式积累，土壤化学、生化、物理-化学及物理-生化保护碳组分可能已经达到平衡。基于為期30年的紅壤性水稻土長期定位試驗，選用不施肥（CK）、化肥氮燐鉀配施（NPK）、NPK配施低量有機肥（NPKM7/3）、NPK配施中量有機肥（NPKM5/5）、NPK配施高量有機肥（NPKM3/7）五箇處理，通過物理-化學聯閤分組方法，分析土壤有機碳在不同施肥處理下的非保護、物理、化學、生化、物理-化學及物理-生化保護組分的碳含量特徵及其與土壤總有機碳之間的關繫，併探討稻田土壤有機碳的固持機製。結果錶明，除瞭非保護的輕組和微糰聚體內閉蓄態的粘粉粒組分外，其他組分的質量比例在各施肥處理間均有顯著性差異。有機無機配施（NPKM7/3、NPKM5/5、NPKM3/7）下，總有機碳含量（19.1~25.0 g·kg-1）、非保護的粗顆粒有機碳（cPOM）含量（8.41~12.7 g·kg-1）及物理保護的微糰聚體有機碳（6.41~6.62 g·kg-1）含量均顯著高于CK處理（P﹤0.05）。對化學、生化、物理-化學及物理-生化保護態的有機碳含量無顯著性影響，錶明非保護的cPOM及物理保護的微糰聚體（μagg）對施肥的響應最敏感。相關分析錶明，cPOM、物理保護的μagg及其閉蓄的細顆粒有機碳（iPOM）與土壤總有機碳含量之間呈顯著正相關關繫（P﹤0.05），相關方程的斜率錶明有機碳變化引起瞭組分變化，其中：土壤總有機碳變化引起的cPOM變化率最高（50％）；土壤總有機碳積纍引起物理保護的μagg及其閉蓄的iPOM碳組分變化率為12％；生化保護的非痠解粘粒和物理-化學保護的痠解的粉粒雖與土壤總有機碳顯著相關，其變化率僅為2％~3％；其他各保護機製下的組分與土壤總有機碳含量均無顯著相關關繫。這錶明在現行種植和管理製度下，供試紅壤性水稻土有機碳主要以cPOM及μagg有機碳的形式積纍，土壤化學、生化、物理-化學及物理-生化保護碳組分可能已經達到平衡。
기우위기30년적홍양성수도토장기정위시험，선용불시비（CK）、화비담린갑배시（NPK）、NPK배시저량유궤비（NPKM7/3）、NPK배시중량유궤비（NPKM5/5）、NPK배시고량유궤비（NPKM3/7）오개처리，통과물리-화학연합분조방법，분석토양유궤탄재불동시비처리하적비보호、물리、화학、생화、물리-화학급물리-생화보호조분적탄함량특정급기여토양총유궤탄지간적관계，병탐토도전토양유궤탄적고지궤제。결과표명，제료비보호적경조화미단취체내폐축태적점분립조분외，기타조분적질량비례재각시비처리간균유현저성차이。유궤무궤배시（NPKM7/3、NPKM5/5、NPKM3/7）하，총유궤탄함량（19.1~25.0 g·kg-1）、비보호적조과립유궤탄（cPOM）함량（8.41~12.7 g·kg-1）급물리보호적미단취체유궤탄（6.41~6.62 g·kg-1）함량균현저고우CK처리（P﹤0.05）。대화학、생화、물리-화학급물리-생화보호태적유궤탄함량무현저성영향，표명비보호적cPOM급물리보호적미단취체（μagg）대시비적향응최민감。상관분석표명，cPOM、물리보호적μagg급기폐축적세과립유궤탄（iPOM）여토양총유궤탄함량지간정현저정상관관계（P﹤0.05），상관방정적사솔표명유궤탄변화인기료조분변화，기중：토양총유궤탄변화인기적cPOM변화솔최고（50％）；토양총유궤탄적루인기물리보호적μagg급기폐축적iPOM탄조분변화솔위12％；생화보호적비산해점립화물리-화학보호적산해적분립수여토양총유궤탄현저상관，기변화솔부위2％~3％；기타각보호궤제하적조분여토양총유궤탄함량균무현저상관관계。저표명재현행충식화관리제도하，공시홍양성수도토유궤탄주요이cPOM급μagg유궤탄적형식적루，토양화학、생화、물리-화학급물리-생화보호탄조분가능이경체도평형。
Understanding the mechanisms of soil organic carbon(SOC)stabilization would help improve soil carbon sequestration in paddy soil. In this paper, we obtained paddy soils from a 30 year experimental field under five different fertilization, including no fertilizer(con-trol), mineral nitrogen(N)-phosphorus(P)-potassium(K)fertilizers(NPK), 70%mineral N+30%organic N plus PK(NPKM7/3), 50%mineral N+50%organic N plus PK(NPKM5/5), and 30%mineral N+70%organic N plus PK(NPKM3/7). Organic N was provided from green manure and pig manure. The soils were subjected to separating unprotected, and physically, chemically, bio-chemically, physical-chemically, and physical-biochemically protected SOC fractions by a physical-chemical combined fractionation method. Except the unpro-tected light fraction and the occluded silt and clay-sized fraction, the mass proportion of all other SOC factions was significantly different be-tween the treatments. Compared with non-fertilization(CK)treatment, chemical fertilizers mixed with organic manure(NPKM7/3、NPKM5/5 and NPKM3/7)significantly increased the content of total SOC(19.1~25.0 g·kg-1), unprotected coarse particulate organic carbon(cPOM) (8.41~12.7 g·kg-1), and physically protected aggregate(μagg)organic carbon(6.41~6.62 g·kg-1)in red paddy soil(P﹤0.05). There were no significant differences for the chemically, biochemically, physical-chemically and physical-biochemically protected fractions between the five treatments. These results indicated that the unprotected cPOM and the physically protected μagg fractions were the most sensitive ones in long-term fertilization. There was a linear positive correlation between total SOC and tcPOM, physically protected μagg, and oc-cluded POM inside theμagg(iPOM)fraction(P﹤0.05), and their response efficiency to total SOC accumulation(the slope of the regression) was 0.5, 0.12, and 0.12 respectively. However, the response efficiency of non-hydrolysis clay and physic-chemically protected silt fraction to total SOC accumulation was only 0.02 to 0.03, even though they had significant responses. There was no significant relationship of the rest fractions with total SOC. Under the present cropping and management practices, cPOM and micro-aggregates were the main stabilization mechanisms for soil carbon sequestration. Soil physically, chemically, biological-chemically and physical-biochemically protected SOC fractions might have reached the maximum capacity in this paddy soil.