长期不同施肥下黑土与灰漠土有机碳储量的变化

采用长期试验,研究了20年不同施肥下1 m深黑土与灰漠土有机碳含量与碳储量的剖面变化。结果表明,单施化肥和不施肥对黑土1 m土层有机碳储量没有显著影响,但灰漠土略有降低。有机肥配施化肥能显著提高土壤有机碳含量和储量。高量有机肥配施化肥（NPKM2）能提高020 cm和2040 cm土层土壤有机碳含量,黑土分别提高56.6%和49.6%、灰漠土提高143.1%和46.9%;常量有机无机配施（NPKM）效果较差,增幅分别为黑土35.1%和35.3%,灰漠土80.2%和4.1%。两种土壤1 m土体的有机碳储量,NPKM2处理分别提高了C 30.7 t/hm2与C 40.6 t/hm2。显然,有机无机肥配施可以显著提高1 m深土体中有机碳储量,主要是由于提高了040 cm土层土壤有机碳含量。

Changes of soil organic carbon storage under long-term fertilization in black and grey-desert soils

Long-term fertilization experiments were carried out to study variations of organic carbon contents and carbon storage in the profiles(0-100 cm) of black soil and grey desert soil.The results show that compared to the initial values of carbon contents,the contents of organic carbon in soil depths of 0-20 cm and 20-40 cm can be improved obviously by applying chemical fertilizers combined with manure(NPKM2),and increased continuously with the fertilization year by year.After 20-years’ application of NPKM2,the contents of organic carbon in soil depths of 0-20 cm and 20-40 cm are increased by 56.6% and 49.6% in black soil,and 143.1% and 46.9% in grey desert soil,respectively.The carbon contents in soil depths of 0-20 cm and 20-40 cm by applying NPKM increased are less than those of applying NPKM2,which are increased by 35.1% and 35.3% in black soil,and 143.1% and 46.9% in grey desert soil,respectively.The organic carbon contents in soil depth of 40-100 cm aren’t changed obviously under various fertilization conditions.The applications of chemical fertilizers and CK could keep the organic carbon contents in soil depth of 0-100 cm in black soil,while the organic carbon contents are slightly reduced in grey desert soil.Both applications of NPKM and NPKM2 can increase the organic carbon storages in soil depth of 0-100 cm obviously in black soil and grey desert soil,which are increased by C 30.7t/ha and 40.6 t/ha respectively,and the application of NPKM2 can improve the organic carbon storage more obviously.In conclusion,the applications of NPKM or NPKM2 can improve the contents of organic carbon in soil depth of 0-40 cm,and can also increase organic carbon storages in soil depth of 0-100 cm.