摘要
在水稻生长季节设置不同施磷水平 (0、30、70、15 0、30 0 kg P/hm2 )田间小区试验 ,研究施磷对环境及水稻产量的影响。结果表明 ,施磷量与土壤速效磷含量、土表径流磷含量均呈极显著正相关 ,随施磷量提高 ,表层土壤速效磷含量明显增加 ,径流磷含量也随之增加。早期径流液中的磷以颗粒磷为主 ,而后期可溶性磷的比例加大。一般施磷水平下径流液的可溶性磷中有机磷占的比例较大 ,而大施磷量时无机磷占的比例较大。虽然通过径流损失的磷占总施磷量的 0 .2 %以下 ,但径流液中可溶性磷的浓度和总磷浓度均已超过水体富营养化磷浓度的临界值 。
Continuous application of large amount of P fertilizer in Taihu Region in recent years has rapidly increased plant available phosphorus in the topsoil. Accumulation of P in an appropriate amount can lead to beneficial effects, while in an excessive amount could cause water pollution. Aimed at the realistic problem on environment protection, this study was carried out field plot experiments in a leaky paddy soil (in Zhangjiagang, Jiangsu province) with different levels of P application rates (0, 30, 70, 150, 300 kgP·hm^2). Twenty plots (5m×6m) were distributed along both sides of an irrigation ditch and with a randomized block design. Plots were separated from each other with ridges between them and a cement cistern on one side of the plot was used to collect run-off after rain. Runoff was analyzed for total phosphorus (TP), particulate phosphorus (PP), total dissolved phosphorus (TDP), dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP). Topsoil of each plot was also sampled and analyzed for rapidly available P. The results from this study clearly indicated that the amount of P application had significant positive correspondence with the content of rapidly available P and P loss in runoff. The content of available P in the surface soil and the runoff loss of P increased as P application rates increased. The dominant form of P in the runoff was particulate P at first, and then the proportion of dissolved P went up. The leading form of dissolved P was organic P for most levels of P application, while was inorganic P at the highest level. Though the runoff loss of P was even below 0.2 % total P, the concentration of both dissolved P and the total P in the runoff were all above the P threshold of the eutrophication. This suggests that long term field drainage from P applied fields can negatively impact water quality.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第12期2837-2840,共4页
Acta Ecologica Sinica
基金
国家科技部重大基础研究资助项目 ( G19990 1180 6)~~
关键词
磷
径流
水稻
phosphorus
runoff
rice
