施肥对土壤有机碳含量及碳库管理指数的影响

在华北夏玉米生产体系中，采用田间试验，研究了不同施肥措施下（不施肥、单施有机肥、推荐施肥、习惯施肥和单施化肥），土壤有机碳含量、活性有机碳含量和碳库管理指数的变化。结果表明:与不施肥相比，单施有机肥土壤有机碳和活性有机碳含量分别增加 11.68%，21.71%。推荐施肥和习惯施肥土壤有机碳含量分别增加 6.57%，7.58%，活性有机碳含量分别增加 8.53%，4.26%。单施化肥土壤有机碳与活性有机碳含量均没有显著增加；施有机肥和推荐施肥土壤碳库管理指数比不施肥分别高 31.79，13.01。单施化肥土壤碳库管理指数没有显著变化；土壤活性有机碳与总有机碳、碳库管理指数、玉米子粒产量均存在极显著相关关系。碳库管理指数与玉米子粒产量极显著相关，能够指示土壤生产力的变化。可见在当地土壤肥力条件下，施有机肥或有机无机适当配施能提高土壤有机碳含量和土壤碳库管理指数，有利于改善土壤质量，提高土壤肥力。

Effects of fertilization on soil organic carbon and carbon pool management index

As an essential indicator of soil quality,soil organic carbon(SOC) and its carbon pool management index(CPMI) had an important role in determining the reasonableness of fertilizer application scheme.The field experiment was conducted to study the influence of different fertilization system on SOC,active organic carbon(AOC) and CPMI under a summer maize cropping system in North China.The experiment included five treatments: 1) no fertilizer(CK);2) organic fertilizer only(OF);3) recommendation fertilizer(RF);4) conventional fertilizer(CF);5) chemical fertilizer only(NPK).The results showed that compared to CK treatment,SOC and AOC contents increased by 11.68% and 21.71% respectively under OF treatment.SOC contents increased by 6.57% and 7.58% respectively under RF and CF treatments,and AOC contents increased by 8.53% and 4.26%.However,SOC and AOC contents had no obvious enhancement under NPK treatment;OF and RF increased CPMI in comparison with CK by 31.79 and 13.01 respectively in soil,while CPMI had no evident change under NPK treatment;The content of AOC in soil were significantly positively correlated with the content of SOC,CPMI and corn grain yield.CPMI had significantly positive correlation with corn grain yield,and will be a good index to assess influence of fertilization practice on soil quality.It was concluded that under the condition of local soil fertility,application of organic fertilizer,combined application organic fertilizer and chemical fertilizer can both increase SOC contents and improve CPMI,favoring soil quality amelioration and soil fertility improvement.