中国农业科学
中國農業科學
중국농업과학
SCIENTIA AGRICULTURA SINICA
2015年
9期
1764-1773
,共10页
贾淑霞%孙冰洁%梁爱珍%陈学文%张士秀%魏守才%刘四义%陈升龙%张晓平
賈淑霞%孫冰潔%樑愛珍%陳學文%張士秀%魏守纔%劉四義%陳升龍%張曉平
가숙하%손빙길%량애진%진학문%장사수%위수재%류사의%진승룡%장효평
土壤微生物呼吸%土壤微生物数量%免耕%黑土
土壤微生物呼吸%土壤微生物數量%免耕%黑土
토양미생물호흡%토양미생물수량%면경%흑토
soil microbial respiration%soil microbial quantity%no-tillage%black soil
【目的】利用东北黑土13年保护性耕作定位试验，研究耕作措施（免耕和秋翻处理）对土壤微生物的影响，从土壤微生物角度分析免耕是否有利于土壤有机碳（SOC）的固定，为合理评价农田黑土碳“源”与“汇”功能提供科学依据。【方法】以连作玉米为研究对象，采用单因素随机区组设计，耕作处理包括免耕和秋翻。免耕除播种外不扰动土壤，秸秆覆盖地表。秋翻处理的田间管理包括人工除草、中耕起垄和秋翻，秋翻时将秸秆翻于地表之下。土壤微生物呼吸速率通过PVC环在野外采用动态气室法（Li-Cor8100）直接测定（去除植物根系），定期监测土壤微生物呼吸速率的季节变化，并在土壤微生物呼吸速率最高的季节取样分析不同处理土壤微生物量碳和数量特征。【结果】生长季节内免耕和秋翻处理下土壤微生物呼吸速率分别为0.42—3.35和0.48—3.24μmolCO2·m-2·s-1，两处理平均值差异不显著（8.8%），但土壤累积CO2-C释放量免耕比秋翻高10.0%（2012）和4.3%（2013）（P＜0.05）。免耕显著地增加0—5 cm表层土壤细菌、真菌和放线菌的数量，分别比秋翻高125.7%、112.4%和53.3%；还显著地增加了其他土层的真菌数量，分别为105.3%（5—10 cm），159.4%（10—20 cm）和114.7%（20—30 cm）。耕作处理影响土壤温度，主要体现在春季，秋翻（0—5 cm，5—10 cm）春季（6月）土壤温度比免耕分别高2.8%和5.8%。土壤微生物呼吸速率表现出显著的季节变化规律，与土壤温度具有相似的动态变化，夏季（7、8月份）最高，秋季较低。尽管耕作处理没有明显地影响土壤微生物呼吸速率的季节动态格局，但秋翻的土壤微生物呼吸最高值比免耕晚半个月。土壤微生物呼吸速率随土壤温度（5 cm和10 cm）呈指数型增长，10 cm处的回归模型明显好于5 cm。耕作处理只改变了5 cm的Q10值，免耕比秋翻高10.8%。土壤微生物呼吸速率与土壤温度、水分混合回归模型能更好地反应其变化规律，解释土壤微生物呼吸速率变异的65%（秋翻）和81%（免耕）。【结论】免耕增加了表层（0—5 cm）的SOC含量，从而使得该土层的土壤微生物量碳和活性增加，但是由于免耕处理增加0—30 cm 土层SOC含量的加权平均值，因此相对于传统的耕作措施（秋翻），免耕有利于SOC含量的增加。
【目的】利用東北黑土13年保護性耕作定位試驗，研究耕作措施（免耕和鞦翻處理）對土壤微生物的影響，從土壤微生物角度分析免耕是否有利于土壤有機碳（SOC）的固定，為閤理評價農田黑土碳“源”與“彙”功能提供科學依據。【方法】以連作玉米為研究對象，採用單因素隨機區組設計，耕作處理包括免耕和鞦翻。免耕除播種外不擾動土壤，秸稈覆蓋地錶。鞦翻處理的田間管理包括人工除草、中耕起壟和鞦翻，鞦翻時將秸稈翻于地錶之下。土壤微生物呼吸速率通過PVC環在野外採用動態氣室法（Li-Cor8100）直接測定（去除植物根繫），定期鑑測土壤微生物呼吸速率的季節變化，併在土壤微生物呼吸速率最高的季節取樣分析不同處理土壤微生物量碳和數量特徵。【結果】生長季節內免耕和鞦翻處理下土壤微生物呼吸速率分彆為0.42—3.35和0.48—3.24μmolCO2·m-2·s-1，兩處理平均值差異不顯著（8.8%），但土壤纍積CO2-C釋放量免耕比鞦翻高10.0%（2012）和4.3%（2013）（P＜0.05）。免耕顯著地增加0—5 cm錶層土壤細菌、真菌和放線菌的數量，分彆比鞦翻高125.7%、112.4%和53.3%；還顯著地增加瞭其他土層的真菌數量，分彆為105.3%（5—10 cm），159.4%（10—20 cm）和114.7%（20—30 cm）。耕作處理影響土壤溫度，主要體現在春季，鞦翻（0—5 cm，5—10 cm）春季（6月）土壤溫度比免耕分彆高2.8%和5.8%。土壤微生物呼吸速率錶現齣顯著的季節變化規律，與土壤溫度具有相似的動態變化，夏季（7、8月份）最高，鞦季較低。儘管耕作處理沒有明顯地影響土壤微生物呼吸速率的季節動態格跼，但鞦翻的土壤微生物呼吸最高值比免耕晚半箇月。土壤微生物呼吸速率隨土壤溫度（5 cm和10 cm）呈指數型增長，10 cm處的迴歸模型明顯好于5 cm。耕作處理隻改變瞭5 cm的Q10值，免耕比鞦翻高10.8%。土壤微生物呼吸速率與土壤溫度、水分混閤迴歸模型能更好地反應其變化規律，解釋土壤微生物呼吸速率變異的65%（鞦翻）和81%（免耕）。【結論】免耕增加瞭錶層（0—5 cm）的SOC含量，從而使得該土層的土壤微生物量碳和活性增加，但是由于免耕處理增加0—30 cm 土層SOC含量的加權平均值，因此相對于傳統的耕作措施（鞦翻），免耕有利于SOC含量的增加。
【목적】이용동북흑토13년보호성경작정위시험，연구경작조시（면경화추번처리）대토양미생물적영향，종토양미생물각도분석면경시부유리우토양유궤탄（SOC）적고정，위합리평개농전흑토탄“원”여“회”공능제공과학의거。【방법】이련작옥미위연구대상，채용단인소수궤구조설계，경작처리포괄면경화추번。면경제파충외불우동토양，갈간복개지표。추번처리적전간관리포괄인공제초、중경기롱화추번，추번시장갈간번우지표지하。토양미생물호흡속솔통과PVC배재야외채용동태기실법（Li-Cor8100）직접측정（거제식물근계），정기감측토양미생물호흡속솔적계절변화，병재토양미생물호흡속솔최고적계절취양분석불동처리토양미생물량탄화수량특정。【결과】생장계절내면경화추번처리하토양미생물호흡속솔분별위0.42—3.35화0.48—3.24μmolCO2·m-2·s-1，량처리평균치차이불현저（8.8%），단토양루적CO2-C석방량면경비추번고10.0%（2012）화4.3%（2013）（P＜0.05）。면경현저지증가0—5 cm표층토양세균、진균화방선균적수량，분별비추번고125.7%、112.4%화53.3%；환현저지증가료기타토층적진균수량，분별위105.3%（5—10 cm），159.4%（10—20 cm）화114.7%（20—30 cm）。경작처리영향토양온도，주요체현재춘계，추번（0—5 cm，5—10 cm）춘계（6월）토양온도비면경분별고2.8%화5.8%。토양미생물호흡속솔표현출현저적계절변화규률，여토양온도구유상사적동태변화，하계（7、8월빈）최고，추계교저。진관경작처리몰유명현지영향토양미생물호흡속솔적계절동태격국，단추번적토양미생물호흡최고치비면경만반개월。토양미생물호흡속솔수토양온도（5 cm화10 cm）정지수형증장，10 cm처적회귀모형명현호우5 cm。경작처리지개변료5 cm적Q10치，면경비추번고10.8%。토양미생물호흡속솔여토양온도、수분혼합회귀모형능경호지반응기변화규률，해석토양미생물호흡속솔변이적65%（추번）화81%（면경）。【결론】면경증가료표층（0—5 cm）적SOC함량，종이사득해토층적토양미생물량탄화활성증가，단시유우면경처리증가0—30 cm 토층SOC함량적가권평균치，인차상대우전통적경작조시（추번），면경유리우SOC함량적증가。
Objective] In this study, soil microbial activity and biomass carbon under 13-year conservation tillage (no-till) were assessed in a black soil agro-ecosystem in northeast China in order to determine the effect of tillage treatment on soil organic carbon and soil microbial biomass, which would provide a theoretical basis for valuing the ‘sink’ or ‘source’ function of soil carbon pool.[Method] The present study was conducted as part of a long term tillage experiment on the continuous maize (Zea mays L.), tillage treatments consisted of no-tillage (NT), and mouldboard plough (MP). The NT treatment had no soil disturbance except planting, crop residues were left on soil surface after harvest. The MP treatment included one fall mouldboard plough (about 15 cm in depth) after maize harvest, one disking (7.5 to 10 cm in depth) in spring and field cultivation (ridging in June). Soil respiration without roots represented soil microbial respiration, which was measured biweekly from 14 June 2012 to 25 September 2013 using LI-8100 automated soil CO2 flux system (LI-COR Inc., Lincoln, NE, USA), soil microbial biomass and the number of colony forming units of bacteria (cfub), fungi (cfuf), and actinomyces (cfua) were measured during the soil microbial respiration was the highest.[Result] It was found that the range of soil microbial respiration was 0.42-3.35μmolCO2·m-2·s-1under NT and 0.48-3.24μmolCO2·m-2·s-1under MP during growing season, the average soil microbial respiration was similar between NT and MP (8.8%), while the total soil CO2 emission during the growing season under NT was 10.0% (2012) and 4.3% (2013) higher than MP (P<0.05). The cfub, cfuf and cfua at 0-5 cm under NT were significantly higher by 125.7%, 112.4%, and 53.3% than MP, respectively, and cfuf at 5-10 cm, 10-20 cm and 20-30 cm under NT was 105.3%, 159.4% and 114.7% higher than MP, and. Soil temperature at 0-5 cm and 5-10 cm under NT were 2.8% and 5.8% higher than MP in June, respectively. Soil microbial respiration showed a significant seasonal pattern similar to soil temperature, the highest rate occurred in summer (July or August), followed by spring and fall. Although tillage treatment did not influence the seasonal dynamic of soil microbial respiration, the highest rate of soil microbial respiration under MP was a half-month behind the NT. There was a significant exponential relationship between soil microbial respiration and soil temperature at 5 cm and 10 cm soil depth, exponential model at 10 cm produced better fitness than 5 cm, the temperature sensitivity (Q10) at 5 cm under NT was 10.8% higher than MP. The combined exponential model indicated that soil temperature and water content (SWC) could jointly explain 65% (MP) and 81% (NT) of variation in soil microbial respiration.[Conclusion]The results suggested that the soil microbial activity at surface soil (0-5 cm) under NT was higher than MP, which is contributed to the higher SOC content under NT, the increase of the weighted average of SOC at 0-30 cm suggested that NT appears to be a better tillage practice to SOC sequestration in Northeast China.
