摘要
为了解从上世纪80年代以来广东省耕地土壤有效磷的演变规律,利用广东省1984以来的耕地长期定位监测网数据和重点监测点数据,对全省25年来的耕地土壤有效磷(AP)时空变化特征及影响因素进行了分析。结果表明:1984来以来全省耕地土壤有效磷含量总体水平增长了近3倍,年平均增加1.2 mg·kg-1;全省监测点有效磷含量处于中上水平(大于20 mg·kg-1)的频率由1986—1990年期间的10.8%上升至2006—2010年期间的66.6%,提高幅度超过50%,而处于低水平(小于10 mg·kg-1)的频率在相同时期内则由59.6%下降到10.4%,土壤有效磷含量由过去的亏缺状态已经转变到丰富水平。全省耕地有效磷时空变化整体特征表现为差异缩小再到差异扩大的演变趋势,不同区域的土壤有效磷变化速率存在差异,其中珠三角和粤西地区增加速度最快,其年平均增加值分别为1.72 mg·kg-1和<1.69 mg·kg-1;粤东和粤北相对较慢,其年平均增加值分别为1.08mg·kg-1和0.74 mg·kg-1。磷肥的广泛施用是全省土壤有效磷整体水平提高的主要原因,不同的施肥方法对土壤有效磷的累积效应存在显著差异,增城监测点连续10年配施磷肥与有机肥可以使土壤有效磷增加222%。由全省土壤有效磷平均含量与磷肥平均投入量的相关分析可知,25年来全省耕地每投入100 kg·hm-2磷养分平均累积有效磷0.8 mg·kg-1,而每盈余100kg·hm-2磷养分平均累积有效磷5.3 mg·kg-1。种植业结构调整和土壤自身性质对土壤有效磷的演变特征亦有重要影响。以土壤有效磷50 mg·kg-1为临界值进行估算,全省34.4%耕地由于磷累积而对周围环境构成了污染风险,今后应引起高度重视。
In order to investigate the evolution of farmland soil available phosphorus （AP） since the 1980s in Guangdong province, south China, the space-temporal variation of farmland soil AP was analyzed using long-term monitoring data and the main monitoring point data of farmland. The results showed that the overall level of farmland soil AP increased by nearly 4 times since 1984, with an increase of 1.2 mg·kg-1 annually. In all the monitoring points, AP content that higher than 20 mg·kg-1, increased from 10.8%in the period of 1986-1990 to 66.6%in the period of 2006-2010. However, AP content that lower than 10 mg·kg-1, reduced from59.6%to10.4%in the same period. AP content in the soil had changed from deficit to sufficient. The space-temporal variation of farmland soil AP indicated that the differences of AP among different regions decreased first and then increased. The variation rate of farmland soil AP is different among different regions. The fastest growth of soil AP was found in the Pearl River Delta and Western regions, with an average annual rate of 1.72 mg·kg-1 and〈1.69 mg·kg-1 respectively. Slower growth of soil AP was found in Northern and Eastern regions, with an average annual rate of 1.08 mg·kg-1 and 0.74 mg·kg-1 respectively. Extensive application of P fertilizer was the main reason for the overall level of soil AP in Guangdong province. The farmland soil AP content was affected by the fertilization methods significantly. In Zengcheng city, where organic-inorganic P fertilizer was used for 10 consecutive years, the soil AP content was increased by 222%. According to the correlation between the average content of soil AP and the average inputs of P nutrient, 0.8 mg·kg-1 of soil AP was accumulated when 100 kg·hm-2 P fertilizer was applied and 5.3 mg·kg-1 of soil AP was accumulated when a surplus of 100 kg·hm-2 P nutrient. The adjustment of planting structure and the physicochemical properties of soil also have important influences to the Space-temporal variation of farmland soil AP. There were 34.4%farmlands pose a serious threat to the surrounding environment because the accumulation of soil P.
出处
《生态环境学报》
CSCD
北大核心
2014年第3期444-451,共8页
Ecology and Environmental Sciences
基金
农业部耕地质量保护项目资金项目
广东省粮食专项资金项目(农财发[2013]45号)
关键词
广东
耕地土壤
有效磷
时空变化
影响因素
Guangdong
farmland soil
AP
space-temporal variation
influencing factors
作者简介
曾招兵（1982年生），男，硕士，助理研究员，主要从事农业面源污染与耕地质量监测工作。E-mail：zhaobingzeng@163．com
通讯作者：曾思坚。E-mail：Soil709@126．com
