水田和旱地土壤交换性镁的特征差异

Differences in Soil Exchangeable Mg Characteristics between Paddy Soil and Upland Soil

明确水田和旱地土壤交换性镁的供应能力及影响因素,为科学施用镁肥提供依据。通过对福建省漳州市诏安县400组不同利用方式的典型耕地土壤进行分析,研究水田、旱地2种土壤交换性镁供应能力的差异性及其机理。结果表明,全县土壤交换性镁平均含量仅为46.9 mg/kg,各乡镇间存在较大差异,其中土壤交换性镁平均含量最高的乡镇是桥东,平均含量达91.3 mg/kg,最低的乡镇是白洋,平均含量仅为17.9 mg/kg;水田土壤为51.9 mg/kg,旱地土壤为32.5 mg/kg,水田土壤交换性镁的供应能力高于旱地;稻—稻—菜水旱轮作方式的土壤交换性镁含量平均为70.58 mg/kg,稻—稻轮作方式为47.85 mg/kg,大豆—甘薯旱地轮作方式为28.91 mg/kg,不同耕作方式对土壤交换性镁供应能力有较大影响。进一步分析土壤交换性镁与理化性状关系得出,土壤交换性镁与有机质、阳离子交换量、黏粒、粉粒等呈极显著正相关(P<0.01),与砂粒含量呈极显著负相关。综合得出,诏安县土壤交换性镁含量处于较低水平,各乡镇间分布不平衡,且供应能力较弱,可能会影响作物正常生长,因此,合理增施镁肥,特别是旱地土壤,可以有效降低缺镁造成的影响,对农业可持续发展具有重要意义。

The supply capacity and influencing factors of exchangeable magnesium in paddy and upland soil were definited,which provided basis for scientific application of magnesium fertilizer.Based on the analysis of 400 groups of typical cultivated soil samples in Zhaoan County,Zhangzhou City,Fujian Province and their different utilization patterns,the differences of physical and chemical properties of paddy and upland soils and the effects of different utilization modes on the supply capacity of exchangeable magnesium were studied.The results showed that the average content of exchangeable magnesium in the whole county was 46.9 mg/kg,there were great differences among towns,the highest average content was 91.3 mg/kg in Qiaodong,the lowest was 17.9 mg/kg in Baiyang;51.9 mg/kg in paddy soil and 32.5 mg/kg in upland soil.The average of exchangeable magnesium content in rice-rice-vegetable rotation was 70.58,47.85 mg/kg in rice-rice paddy field and 28.91 mg/kg in soybean-sweet potato upland soil.The supply capacity of exchangeable magnesium on different planting modes had significant influence.Further analysis of the relationship between exchangeable magnesium and physical and chemical properties of soil showed that the content of exchangeable magnesium in soil was positively correlated with,organic matter,cation exchange capacity,clay,silt,sand(P<0.01),and negatively correlated with the content of sand.Put it all together,the exchangeable magnesium content of soil in Zhaoan County was low,and its supply capacity was weak,which might affect the normal growth of crops.Therefore,reasonable application of magnesium fertilizer,especially dry land soil,could effectively reduce the impact of magnesium deficiency,which was of great significance to the sustainable development of agriculture.