典型区域果园土壤有机质变化特征研究

在黄土高原、胶东半岛和北京郊区果园选择11个采样区,按照5～10年、10～15年和15年以上3个园龄段,利用GPS定位系统,共采集0～20 cm表层土壤样品99份,并在取样果园附近选择普通农田作为对照采集土壤样品33份,测定了果园与普通农田土壤的有机质含量,并从果园土壤有机质数量特征,果园与农田差异特征以及有机质随园龄段变化特征3个方面进行统计分析.研究结果表明:胶东半岛栖霞和北京郊区果园土壤有机质含量较高,黄土高原宝塔较低.与农田相比,60%多的果园土壤有机质未发生显著变化,明显提高的果园不到30%,明显降低的果园不到10%;土壤有机质发生变化的果园,平均提高0.62%,平均降低0.20%;随园龄增加,两个样点果园土壤有机质明显提高,其他果园变化不显著.在优质高产果园区,果园土壤有机质提高归因于施用有机肥、果园种草、青草或秸秆还田.总体上看,典型区域果园土壤有机质高低值差异较大,土壤有机质含量普遍不高,果业持续发展能力较低.

Variations of soil organic matter in typical orchard regions

Eleven sampling regions were selected in the Loess Plateau, Jiaodong Peninsular and Beijing suburbs, and based on orchard age, the orchards in each sampling region were devided into three groups of 5~10, 10~15 and >15 years. 99 soil samples in the 0~20 cm layer in orchards and 33 samples in the 0~20 cm layer in nearby croplands were collected. Quantitative attributes of topsoil organic matter in orchard fields, differences in soil organic matter property between the orchard and cropland, and variations in soil organic matter among different orchard age groups were statistically analyzed. The results show higher soil organic matter content in Xixia, Jiaodong Peninsular, and Beijing suburb; and lower in Baota in the Losse Plateau. Compared with croplands, over 60% orchards exhibit statistically insignificant variation in soil organic matter. In less than 30% orchard fields, soil organic matter significant increase, averagely by 0.62%; and significant decrease in less than 10% orchards, averagely by 0.20%. Significant changes in topsoil organic matter content with the orchard age are observed only in two sampling regions. In high yield and high quilty fruit-producing areas, soil organic matter is enhanced by organic fertilizer application, growing grass in orchard, returning grass or stalk into orchard soil. On the whole, soil organic matter in orchard field is not high and varies greatly. Sustainable development capacity of the fruit production is also weak.