有机-无机复合改良剂对滨海盐碱地的改良效应研究

针对河北中捷农场滨海盐碱地所具有的盐碱化程度高、单盐毒害突出的特点,选取园林废弃物堆肥和惰化产品,并结合磷石膏对该地区的土壤进行改良研究.以大田条件下的实际应用为基础,设置不同处理,进行田间对比试验,定期取样,对土壤盐分指标进行测定分析.结果表明:1)施入有机改良剂和磷石膏,既能有效降低土壤pH值,又能避免单独施人磷石膏后,土壤pH值变化过大,对植物产生不利影响.2)从单因素试验分析,土壤的SAR随着有机改良剂和磷石膏施入量的提高而显著降低,磷石膏的改良效果优于有机改良剂;从2种改良剂的交互作用来看,有机-无机改良剂配施的效果优于改良剂的单施效果.3)随着有机-无机改良剂施人量的增加,土壤中的C1-质量分数呈显著降低,而SO42-质量分数呈显著增加趋势.4)根据试验结果,推荐施入1 kg/m2的磷石膏及5％的有机改良剂(体积比,约3.35 kg/m2),能够取得较好的改良效果,此时的改良成本约为6.70元/m2.研究结果以期为滨海盐碱地区城市绿化,提供理论依据.

Amelioration effects of organic-inorganic compound amendment on coastal saline-alkali soil

Background] The urbanization level in coastal areas are higher than other areas in China,and the coastal soils in these areas are threatened by salinization,which could cause negative effects on ornamental plants surviving and growing,thus the ornamental value and ecological functions of the urban green land was reduced.In this way,the improvement of saline-alkali soil should result in a significant impact upon construction of urban green space in coastal areas.Methods] The experiment was conducted in a greenbelt of Bohai district in Cangzhou City of Hebei Province,where is in high salinity.An organic modifier (Green waste compost:Pyrolysised garden wastes in 4:1 as 0,5％,10％,and 15％ of being-ameliorated soil volume) and phosphogypsum (0,1,2,and 3 kg/m2) were utilized for the soil amendments,totally 16 treatments by combining any 2 of them,and 0 of them as the control.Each treatment was laid in an experimental plot (12 m × 6 m) with 3 repeats of planting Sophora japonica.Soil samples were collected at 3 random sites of topsoil (0-20 cm) in each plot in July 2014,October 2014,March 2015 and July 2015.OHAUS Starter 3C was used for measuring pH,dual-indicator neutralization titration method for CO32-and HCO3-,silver nitrate titration method (Moore method) for C1-,EDTA titration method for Ca2+ and Mg2+,indirect EDTA complexometric titration for SO42-,flame photometry (FP6410,Shanghai) for K + and Na +,and total salt content was the sum of 8 ions' concentrations.The data were analyzed by Excel 2010 and SPSS 18 software,single factor analysis of variance (one-way ANOVA) was to compare the differences among different treatments,and the multiple comparisons were examined by Duncan method.Results] 1) The soil pH decreased obviously with the addition of organic modifier and phosphogypsum,and phosphogypsum played a leading role.To prevent the negative impacts to the plants from the drastic variations of pH caused by the application of phosphogypsum,organic modifier should be applied at the same time.2) Single-factor experiment showed that soil SAR (Sodium Absorption Ratio) significantly decreased when this 2 soil amendments were more used.Moreover,phosphogypsum showed better effects than organic modifier.Interaction experiments showed that combined application of phosphogypsum and organic modifier achieved better effect in decreasing SAR than single application.3) The content of C1-significantly decreased with the application of phosphogypsum and organic modifier,but SO42-was the opposite.4) The experimental results demonstrate that combined application of phosphogypsum and organic modifier was suggested to get the better effect,the recommended addition of phosphogypsum and organic modifier were 1 kg/m2 and 5％ (volume ratio,about 3.35 kg/m2),which improved the saline soil effectively.Conclusions] Due to the low cost,waste resource recovery and the solid environmental effects in treatment process,organic modifier is more practicable in the improvement of saline-alkali soil.Besides,this improvement method for saline soil provids a feasible plan for beneficial reuse of phosphogypsum and organic modifier.