武汉市郊区蔬菜地土壤磷素释放的主要影响因素研究

以武汉市城乡结合部蔬菜地土壤为研究对象,通过室内模拟实验,分析施磷水平、土壤含水率、淹水深度、淹水时间等对土壤磷素释放的影响。研究结果表明:①高水平施磷易导致磷素在土壤中的积累,当积累量超过土壤吸磷极限时,在雨水、浇灌水等的作用下磷素易进入水体;②土壤含水率对Olsen-P影响不显著;③淹水深度对土壤释磷量有着很大影响,在淹水初期,随着淹水深度提高,土壤释磷量增加;④在3 cm和6 cm淹水深度下,在0~3 d时间里,样品土壤释磷量占到整个淹水期总释磷量的80%~95%以上,随后急剧减小日趋缓和,直至达到一个相对稳定水平。

Study on Main Influencing Factors of Soil Phosphorus Release in Wuhan Suburbs Vegetable Field

The paper takes the vegetable soil of Wuhan urban-rural marginal area as the research object to study that the phosphorus application,soil moisture content,flooding depths and flooding duration has impact on soil phosphorus release in laboratory by simulation experiment.The result shows that:①Excessive manure phosphorus input to soils elevated P in soil solution and P can be easily transported to surface water under the action of rain and irrigation when soil phosphorous accumulation should excess the phosphorus sorption maximum;② in the same test segment,there is no significant difference in Olsen-P of every soil sample that had different moisture content;③the depth of overlying water greatly affects soil phosphorus release.In the initial stage of overlying water,solution concentration of phosphorus increases with the increase of overlying water depth;④in the different experimental flooding depth(3 cm and 6 cm),from the initial day to the third day,the quantity of soil samples phosphorus released occupies 80%-95% of the total released quantity,then dramatically decreases,but gently in later period,until it reaches a relatively stable level and drops no longer.