Soil potassium forms and availability under different land use patterns:Taking the southern margin of Horqin Sandy Land as an example
[Background]The northeast region has the highest potassium supply level,but the potassium supply potential of sandy soil in Horqin Sandy Land is extremely low.Clarifying the effects of different land use patterns on the content and availability of various forms of potassium in soil can optimize land use and is of great significance for improving soil fertility in Horqin sandy land.[Methods]Soil samples were collected from 0-20 and 20-40 cm soil layers under seven land use types(paddy field,dry field,natural grassland,shrub,coniferous forest,broad-leaved forest,mixed coniferous and broad-leaved forest)in the southern margin of the Horqin Sandy Land.The contents of 8 forms of potassium in soil was detected by chemical analysis method.Non-exchangeable potassium conversion and conversion rate was calculated.Analysis of variance,correlation analysis(Pearson coefficient)and factor analysis were performed on the detected and calculated data.[Results]1)The overall potassium content of the soil in the study area was 16.41-20.75 g/kg,but the content of available potassium was only 0.76％-2.62％,which was seriously lack of available potassium.2)Different land use patterns significantly increased the soil potassium pool reserve(P＜0.05),and the effectiveness was enhanced.The proportion of effective parts of various forms of potassium increased by 0.46％-1.86％,and the content showed surface accumulation characteristics,but it was affected by the soil texture in the study area.3)Long-term stable land use increased the amount of non-exchangeable potassium in soil by 23 mg/kg on average,and there was a significant positive correlation between available potassium,which promoted the balanced transformation of various forms of potassium.4)The order of soil potassium fertility evaluation was broad-leaved forest＞dry field＞mixed coniferous and broad-leaved forest＞paddy field＞coniferous forest＞shrub＞natural grassland.[Conclusions]The study area needs to apply potassium fertilizer regularly to ensure crop growth.In the absence of potassium,having broad-leaved forest or mixed coniferous and broad-leaved forest is a better way to maintain and improve the fertility level of the aeolian sandy soil potassium.
soil fertilitysoil potassiumland use patternHorqin Sandy Land
国家科技期刊平台
NSTL
万方数据
