不同利用方式及施肥对黑土地表磷素养分流失的影响

本文针对黑土利用现状,在吉林农业大学教学试验场黑土区选择不同利用方式的玉米地、休闲地、果园、草地,并在玉米区进行了不同数量的施肥。通过野外试验,采集2002年度5~10月历次自然降雨(共7次)产流及泥沙样品,同时采集降雨前后的耕层土壤样品,研究了黑土区地表径流对磷素养分特征及肥力退化的影响。结果表明:径流TP流失比和DP流失比随覆盖度都表现为先增加后逐渐降低;不同利用方式表层土壤的TP和DP相差很大,就全磷富积表现为果园>草地>玉米地>休闲地,可溶性磷的富积却表现为:休闲地>玉米>果园>草地;随P肥用量的增加而径流磷素(TP、DP)浓度及径流磷素流失量也增加;流失泥沙TP浓度随着磷素施入的增加而增加;泥沙磷素浓度、泥沙磷素流失量均比CK大,但泥沙流失量均比CK小;增施氮磷虽能增加作物的产量,但N、P施用量必须适度,从试验期间径流、泥沙的TP、DP流失量观测,可以初步得出黑土氮磷配合施肥的宜于选配的方案是B5区N98P44N570。

Effect of P Application and Land Use Manners on P Loss from Surface Soil of Phaeoz

This research made corn land,fallow land,orchard,grass land as experimental field in Jilin Agricultural University black soil region,in which the experiment was carried out by applying different amounts of N and P fertilization in corn field.By means of collecting the samples of rainfall runoff,erosion silt and surface layer soil before and after rainfall for one year nature precipitation in field,we studied the effect of surface runoff on P nutrient and fertility degeneration.The results showed that total phosphorus(TP) and dissolved phosphorus(DP) loss rate in runoff display increased first and decreased afterwards with cover level increasing.TP and DP concentration of top layer soil showed great divergence with different use patterns.As far as Enrichment Ratio was concerned,TP showed as orchard > Meadow >Maize ground > Fallow land.While soluble phosphorus showed as Fallow land > Maize > Orchard > Meadow.Runoff Phosphorus(TP,DP) density and flow dropouts of surface runoff phosphorus increased with the increase of P fertile consumption,meanwhile TP density of loss silt also increased with the increase of P fertile consumption.The density of silt phosphorus and dropouts of silt phosphorus were bigger than CK,but the number of dropouts of silt was smaller than CK.Although nitrogen and phosphorus nutrient can increase output of crop,N and P nutrient application amount must be appropriate again.According to TP and DP of loss amount in surface flow and erosion silt during while testing,can preliminarily draw a conclusion that N and P fertilizer cooperating application scheme was N98P44N570 in black soil field of B5.