为研究保定东部平原区夏玉米种植农田农业面源污染情况,于2016年夏玉米种植期分别在定位试验场及保定东部平原区进行了取土试验,探索了2 m土层内土壤氮磷含量及时空分布规律。结果 表明:农民传统田间管理下,土壤硝态氮垂直方向上随土层深度呈“S”型分布,空间上表土层硝态氮东部低西部高,南部低北部高,心土层与底土层硝态氮在研究区中部出现局部高点,底土层硝态氮东部低西部高; 土壤铵态氮垂直方向上分布均匀,大致都稳定在0.6 mg/kg左右,空间上表土层铵态氮变化较为明显,心土层及底土层变化幅度较小,极差小于3 mg/kg。同时,心土层与底土层铵态氮均呈现东部高西部低,南部高北部低的趋势; 土壤有效磷垂直方向上随深度的增加先减小再增加最后减小,空间上表土层有效磷含量降幅最大且变化较为明显,极差为32.66 mg/kg,表土层有效磷南部低北部高,心土层与底土层均呈现东部高西部低的趋势,而南北部具有差异性。因此,根据该区域农业面源的时空动态变化,统筹考虑夏玉米生育期各土层氮磷含量合理施肥,将对该区域减少面源污染以及生态建设具有重要现实意义。
In order to study the agricultural non-point source pollution of summer maize farmland in Eastern Plain of Baoding City, soil sampling were taken in the positioning test site and Eastern Plain of Baoding City in 2016, respectively, and the temporal and spatial distribution of soil nitrogen and phosphorus contents in 2 m soil layer were investigated. The results showed that under the traditional field management, the vertical distribution of soil nitrate nitrogen presented as the S-shape along soil depth; spatially, nitrate nitrogen of surface soil was lower in the east and higher in the west, lower in the south and higher in the north; there were a local high values of nitrate nitrogen in subsoil and deep soil in the middle part of the study area, and the content of nitrate nitrogen in deep soil was lower in the east and higher in the west of the study area; the vertical distribution of ammonium nitrogen was uniform, and content was almost stable with the value of about 0.6 mg/kg; ammonium nitrogen in surface soil layer changed obviously on the spatial scale, while the range of ammonium nitrogen content in subsoil layer and deep soil layer changed slightly, and the range was less than 3 mg/kg; at the same time, contents of ammonium nitrogen in the subsoil and deep soil layer were high in the east and low in the west, high in the south and low in the north; the vertical distribution of available phosphorus decreased at first, then increased, and finally decreased with the increase of soil depth, and the content of available phosphorus in the surface soil layer decreased the most and changed obviously in space, the range was 32.66 mg/kg; the available phosphorus of the surface soil layer was low in the south and high in the north, and the those of the subsoil and deep soil layer were high in the east; There was the low trend in the west, but there was a difference between the contents in the north and the south. Therefore, according to the spatial and temporal changes of agricultural non-point sources in this region, it is of great practical significance to reduction of non-point source pollution and ecological construction in this region through considering the reasonable fertilization based on nitrogen and phosphorus contents in different soil layers during the growing period of summer maize.
