黄土高原沟壑区种植植物和施肥对土壤矿质氮的影响

Effect of Different Plant Species and Fertilization Conditions on Mineral Nitrogen in Gully Region of Loess Plateau

[目的]筛选能快速提升黄土高原沟壑区矿山废弃地土壤肥力的适宜恢复植物种类和种植模式,为该区实现资源的优化配置和促进农业的可持续发展提供科学依据。[方法]选取白三叶、草木樨、紫穗槐、柠条、黑麦草5种植物试材,在中国科学院长武农业生态试验站的模拟弃土场上做长期连续定位监测试验,监测不同速效氮处理下各植物小区0—10cm,10—20cm土层的养分含量变化。设3种施肥处理:A:设施有机肥(羊粪),施肥量为30 000kg/hm^2;B:施秸秆,施肥量为9 000kg/hm^2;C:不施肥,作为对照。[结果]与对照相比,单播模式土壤平均硝态氮含量为9.05mg/kg,比对照提高0.44mg/kg;混播模式土壤平均硝态氮含量为9.02mg/kg,比对照提高0.41mg/kg。单播模式土壤铵态氮平均含量为4.49mg/kg,比对照减少了2.06mg/kg;混播模式土壤铵态氮平均含量为7.06 mg/kg,比对照增加了0.51 mg/kg。[结论]不施肥和施秸秆条件下,单播模式对土壤改良效果优于混播模式;而在施有机肥条件下,混播模式对土壤改良效果优于单播模式。

[Objective]Effective improves the soil fertility of abandoned lands of mines in gully region of the Loess Plateau,suitable plant species and cropping pattern selection were researched in order to provide a scientific basis for optimizing allocation of resources and promoting the sustainable development of agriculture in this area.[Methods]The experiments were conducted at the Changwu agro-ecological experimental station of the Chinese Academy of Sciences on the Loess Plateau.In order to explore the soil nutrient content under different available nitrogen condition in the 0—10 cm and 10—20 cm,five species plants were choosed（Trifolium repens,Melilotus suaveolens,Amorpha fruticosa,Caragana korshinskii and Lolium perenne）.The treatments included three fertilization conditions﹝ Organic manure（sheep manure）was used with the amount of 30 000 kg/hm^2 as the treatment of A.Straw was used with the amount of 9 000 kg/hm^2 as thetreatment of B.No fertilization was used as a control group﹞,to explore the effect of soil available nitrogen under the different cropping pattern of single and mixed condition.[Results]The content of the average nitrate nitrogen was 9.05 mg/kg in the soil under the cropping pattern of single,which was more than 0.44 mg/kg compared with cotrol.The content of average nitrate nitrogen was 9.02 mg/kg in the soil under the cropping pattern of mixed,which was 0.41 mg/kg more than the cotrol.Under the condition of non-fertilization,the effect of cropping pattern on soil improvement was the single better than the mixed.The content of average ammonium nitrogen was 4.49 mg/kg in the soil under the cropping pattern of single,which was 2.06 mg/kg less than the control.The content of average ammonium nitrogen was 7.06 mg/kg in the soil under the cropping pattern of mixed,which was 0.51 mg/kg more than the cotrol.The effect of cropping pattern on soil improvement was the single better than the mixed.[Conclusion]The effect of cropping pattern on soil improvement was the single better than the mixed under the condition of non-fertilization and strawfertilization.The effect of cropping pattern on soil improvement was the mixed better than the single under the condition of organic-fertilization.