不同种植时间脐橙园土壤理化特性研究

Effects of different planting years on soil physical and chemical properties in navel orange orchard

【目的】通过研究不同种植年限脐橙园土壤理化特性,为脐橙园施肥管理提供理论依据。【方法】以未种植地(对照)、2年生、4年生、9年生、15年生、23年生6个脐橙园为研究对象,采集样点0~20 cm,≥20~40 cm,≥40~60 cm土层土壤,分别测定土样的物理性黏粒含量、容重、20 cm蓄水量、有机质、速效氮、速效磷、速效钾、全氮、全磷含量和p H等土壤理化性质。【结果】脐橙种植年限对土壤容重和蓄水量影响不显著。土层对土壤容重、蓄水量在土层之间存在极显著的影响(P<0.001),随着土层加深,土壤容重和蓄水量逐渐升高。脐橙种植年限、土层及其交互作用对土壤物理性黏粒均存在极显著影响(P<0.001),2年生及4年生果园上层土壤物理性黏粒显著低于未种植对照地(P<0.05),而23年生林地则显著高于未种植对照地(P<0.05),下层土壤物理性黏粒变化无显著规律。脐橙种植年限、土层深度及其交互作用对各土壤化学性质的影响均达到极显著水平(P<0.001),脐橙园中层土壤的p H均显著低于未种植对照地,下层土壤的p H则是随着种植年限的增加而逐渐降低。15年生脐橙园土壤各土层的有机质、速效磷、全氮、全磷含量均显著高于其他年限(P<0.05),上层土壤的速效氮含量在23年生果园达到最高值。土壤有机质、速效氮、速效磷、速效钾、全氮、全磷与土壤物理性黏粒呈正相关关系,而与p H、土壤容重、蓄水量呈负相关关系。【结论】脐橙种植年限对土壤理化特性存在显著影响,随着脐橙种植年限延长,土壤逐渐酸化,表层土壤物理性黏粒含量呈先降低后升高的趋势;15年生果园土壤总体肥力显著高于其他种植年限。

【Objective】The present study investigated the physical and chemical properties of soil in a navel orange orchard from different planting years. This was done to obtain data to form a theoretical basis for making informed fertilization management decisions. 【Method】Six treatments were examined： control plantation（ unplanted）,and land 2 years,4 years,9 years,15 years and 23 years after planting. Soil samples were collected in each plot at three depths（ 0-20 cm,≥20-40 cm and ≥40-60 cm）,which were then used for analyses of soil physical and chemical characteristics,including physical clay content,bulk density,20 cm soil water storage capacity,content of soil organic matter,available nitrogen,available phosphorus,available potassium,total nitrogen as well as total phosphorus,and p H. 【Result】The influence of navel orange planting years on soil volume and water storage was not significant. The soil layer exerted significant effects on soil bulk density and water storage capacity（ P 0. 001）,both of which increased with the soil layer depth. The navel orange planting years,soil layers and their interactions exerted significant influences on soil physical clay content（ P〈0.001）. The soil physical clay content of top soil from 2-and 4-year plantations was significantly lower than that of control plantations（ P〈0. 05）. However,the soil physical clay content from 23-year plantations was significantly higher than that of control plantations（ P〈0. 05）. In addition,no obvious trends in differences in subsoil physi-cal clay content among different plantations were found in this study. The navel orange planting years,soil layers,and their interactions had significant influences on soil chemical properties（ P〈0.001）. The middle layer soil pH in navel orange plantations was significantly lower than that in control plantations,and the subsoil pH decreased as the depth of the soil layer. The content of soil organic matter,available phosphorus,total nitrogen and total phosphorus in 15-year plantations were significantly higher than those in all other plantations（ P〈0. 05）,and the content of available nitrogen was the highest in 23-year plantations. The content of soil organic matter,available nitrogen,available phosphorus,available potassium,total nitrogen,and total phosphorus were positively correlated with physical clay content,and negatively correlated with bulk density,water storage capacity and pH. 【Conclusion】Navel orange plantation age had a profound impact on soil physicochemical properties. Soil pH decreased,and physical clay content of the surface soil first decreased and then increased,with increasing years of planting. Soil fertility of 15-year plantations was significantly higher than that in all other plantations.