CAJ | 학술논문

基于27年长期试验，采集0~20 cm和20~40 cm两土层原状土样，研究施氮磷钾化肥及配施有机肥对洞庭湖区典型水稻土物理性状及团聚体中有机碳积累的影响。结果表明：与不施肥相比，长期施肥后两土层内土壤总孔隙度、田间持水量分别提高2.6％~8.3％、-3.0％~23.5％，土壤容重则降低3.0％~11.6％，其影响效应随土层加深而减弱，在0~20 cm土层均达显著水平（P﹤0.05）。长期施肥后粒径﹥5 mm具不良孔性的团块结构数量明显减少，两土层中0.5~2 mm和2~5 mm大团粒结构体比例则较不施肥处理分别显著提高57.3％~94.3％和25.8％~103.8％（P﹤0.05），土壤物理结构得以改善。随粒径减小，团聚体中有机碳含量和储量分别呈现逐渐增加和降低的变化趋势，长期施肥均显著提高两土层特别是0~20 cm层土壤及各级团聚体中有机碳含量（P﹤0.05）。施肥主要影响且显著提升粒径﹤5 mm特别是0.5~2 mm和2~5 mm团聚体中有机碳储量。研究表明，氮磷钾化肥配施有机肥改善土壤物理性状和增强团聚体固碳能力的效应较氮磷钾化肥单施更为突出，且随有机肥施用比例增加，其效应愈趋明显。
기우27년장기시험，채집0~20 cm화20~40 cm량토층원상토양，연구시담린갑화비급배시유궤비대동정호구전형수도토물이성상급단취체중유궤탄적루적영향。결과표명：여불시비상비，장기시비후량토층내토양총공극도、전간지수량분별제고2.6％~8.3％、-3.0％~23.5％，토양용중칙강저3.0％~11.6％，기영향효응수토층가심이감약，재0~20 cm토층균체현저수평（P﹤0.05）。장기시비후립경﹥5 mm구불량공성적단괴결구수량명현감소，량토층중0.5~2 mm화2~5 mm대단립결구체비례칙교불시비처리분별현저제고57.3％~94.3％화25.8％~103.8％（P﹤0.05），토양물리결구득이개선。수립경감소，단취체중유궤탄함량화저량분별정현축점증가화강저적변화추세，장기시비균현저제고량토층특별시0~20 cm층토양급각급단취체중유궤탄함량（P﹤0.05）。시비주요영향차현저제승립경﹤5 mm특별시0.5~2 mm화2~5 mm단취체중유궤탄저량。연구표명，담린갑화비배시유궤비개선토양물이성상화증강단취체고탄능력적효응교담린갑화비단시경위돌출，차수유궤비시용비례증가，기효응유추명현。
Soil physical properties and organic carbon are important indexes of soil quality, which are sensitive to fertilization practices. Based on a 27-year fertilization experiment on paddy field in Dongting Lake region, China, the responses of soil physical properties and dry sieved aggregate-associated organic carbon to applications of nitrogen(N), phosphorus(P)and potassium(K)mineral fertilizers with or without organic manure were studied at 0~20 cm and 20~40 cm soil layers. Compared to long-term unfertilized treatments, the soil total porosity and field moisture capacity in the two soil layers under fertilizer application increased by 2.6%~8.3%and-3.0%~23.5%, respec-tively, while the soil bulk density decreased by 3.0%~11.6%,which were significant(P﹤0.05)at 0~20 cm layer but not at 20~40 cm layer. The amount of soil aggregates in the﹥5 mm group decreased after long-term fertilization, while the proportions of aggregates in 2~5 mm and 0.5~2 mm groups increased significantly(P﹤0.05)by 57.3%~94.3%and 25.8%~103.8%, respectively, in two soil layers. These meant that the physical structure of paddy soil was improved by long-term fertilization. Along with aggregates size decreasing, the contents of aggre-gates-associated organic carbon increased, but storages presented an opposite trend. Both mineral and organic fertilizers applications signif-icantly(P﹤0.05)increased the organic carbon contents in various size classes of aggregates, but such effects decreased with increasing soil depths. Organic carbon storages in the﹤5 mm aggregates in two soil layers were significantly higher in all fertilization treatments(P﹤0.05) than those of no fertilizer treatment, but the storages of aggregates-associated organic carbon in the 2~5 mm and 0.5~2 mm aggregates were more sensitive to long-term fertilization than in others. It can be concluded that the improvements of soil quality varied with different fertil-ization modes. Combined application of N, P, K fertilizers and organic manure was better than balanced application of N, P, K fertilizers in improving soil physical properties and enhancing carbon sequestration in aggregates. With increasing rates of manure applications, the im-provement of soil quality would become more distinct.