绿肥-沼液-水稻体系对江苏沿海盐土理化性质的影响

Effects of Green Manure Combined with Biogas Slurry and Rice on Physical and Chemical Properties of Saline Soils in Jiangsu Coastal Area

为促进江苏沿海盐土的快速改良与修复,构建了绿肥-沼液-水稻农业改良技术体系。通过选择种植紫云英、毛叶苕子和油菜作为绿肥,施入2个沼液量(17000和34000 L/667 m^(2)),并种植水稻,进行旱作与水作结合处理,定期测定土壤盐分、p H值及有机质、全氮、有效磷、速效钾含量(质量分数)。结果表明,3种绿肥-沼液(17000 L/667 m^(2))-水稻体系(体系A)与3种绿肥-沼液(34000 L/667 m^(2))-水稻体系(体系B)对江苏沿海盐土理化性质的影响存在一定差异:1)体系B最终的土壤盐分低于体系A;2)体系A与B土壤的p H值变化趋势基本相同,以油菜处理组合对盐土p H值降低效果明显;3)体系A与B对土壤有机质含量增加有一定效果,但毛叶苕子处理组合显示较大差异;4)体系A与B对土壤有效磷影响有类似趋势,但只有体系A中毛叶苕子与油菜组合处理下土壤的最终有效磷含量明显高于原始值,体系B中这2个却相反;5)体系A与B土壤中速效钾含量主要呈现降-升-降趋势,但紫云英组合处理有所不同;6)体系A与B最终均增加了土壤全氮的含量,其中以体系A中的紫云英处理组合增加较多。因此,绿肥-沼液-水稻体系对江苏沿海盐土理化性质的影响具有一定复杂性,相对而言,以油菜-沼液(34000 L/667 m^(2))-水稻组合作为综合性农业改良技术措施,具明显降低土壤的盐分、稳定土壤p H值及提高土壤有机质含量的效果。

To accelerate the amelioration and restoration of saline soils in Jiangsu coastal area,we assessed effects of a treatment system comprising a green manure,biogas slurry,and rice on the physical and chemical properties of coastal saline soils.Chinese milky vetch(Astragalus sinicus),hairy vetch(Vicia villosa)and rape(Brassica campestris)were planted as green manures,each of which was then applied in combination with biogas slurry and rice planted.The properties of coastal saline soil were measured periodically,comprising soil salinity;pH value;and contents of organic matter,total nitrogen,available phosphorus,and available potassium.Two groups of treatments were set as follows:a green manure(Chinese milky vetch,hairy vetch,or rape)combined with biogas slurry(17000 and34000 L/667 m^(2)in groups A and B,respectively)and rice.They produced effects on the soil properties with both differences and similarities.First,Group B led to a lower soil salinity than Group A.Second,the two groups showed similar pH variation trends over the time course,in both of which the treatment involving rape had an obvious effect of decreasing soil pH.Third,both groups increased the organic matter content,whose dynamics,however,differed in the rape-containing treatments of groups A and B.Fourth,the two groups revealed overall similar dynamics of available phosphorus content;however,in Group A,the ultimate available phosphorus content was substantially higher than the original value in the two treatments with hairy vetch and rape as manures,while in Group B,its content in the corresponding two treatments was lower than the original value.In conclusion,a green manure co-applied with biogas slurry and rice can improve the physical and chemical properties of coastal saline soil,which is more effective with biogas slurry applied at 34000 L/667 m^(2)than the lower rate;moreover,application of rape as a green manure can significantly improve the physical and chemical properties of coastal saline soil by decreasing salinity,stabilizing pH,and increasing organic matter content.