曲靖市耕地土壤有机质状况

2006—2011年,采集曲靖市耕地12个土类13 171个土壤样品,进行有机质测定,了解曲靖市耕地土壤有机质状况。结果表明,与第二次土壤普查结果相比,曲靖市耕地不同土类土壤有机质有升有降。其中,赤红壤、水稻土、紫色土、冲积土和燥红土有机质平均含量分别升高13.0%、16.8%、19.5%、52.5%和222.4%;而草甸土、黄壤、红壤、石灰(岩)土、黄棕壤、棕壤和沼泽土平均含量则分别降低了6.2%、17.7%、19.6%、32.3%、36.0%、42.9%和74.1%。从面积上来看,80.8%的旱作耕地土壤有机质平均含量低于第二次土壤普查结果,这意味着曲靖市旱作耕地土壤质量有所退化。耕地土壤管理中需加强绿肥生产利用、秸秆还田,提升土壤有机质。

Contents of Soil Organic Matter of Cultivated Soils in Qujing

In order to investigate the contents and changes of cultivated soil organic matter (SOM) of different soil groups since the 2nd national soil survey (1980s) in Qujing, 13 171 samples of plough layers covering 12 soil groups of cultivated soils were collected from 2006 to 2011 and SOM contents were analyzed. The results showed that SOM content of 5 soil groups was increased and 7 soil groups decreased, in which the average SOM contents of Latosolic red soils, Paddy soils, Purplish soils, Alluvial soils and Torrid red soils increased by 13.0%, 16.8%, 19.5%, 52.5% and 222.4%, respectively; while those of Subalpine meadow soils, Yellow soils, Red soils, Limestone soils, Yellow-brown soils, Brown soils and Bog soils reduced by 6.2%, 17.7%, 19.6%, 32.3%, 36.0%, 42.9% and 74.1%, respectively. SOM content in 80.8% area of dry farming land decreased, suggesting soil quality of dry farming land was degraded in Qujing, so green manure plant and straw turnover should be applied in order to increase SOM and to improve soil quality.