摘要
【目的】设施土壤次生盐渍化主要是由于氮肥施用过多造成的硝酸盐在表土中的累积。本研究根据碳/氮互作原理,向次生盐渍化土壤中添加碳调节剂(秸秆+腐解菌),探讨其降低土壤可溶性盐含量的可行性。【方法】碳调节剂主要以小麦成熟期秸秆磨成粉加入快腐菌剂制成。采用盆钵试验方法,土壤盐分动态试验在每盆2.5 kg土壤中添加150 g碳调节剂,调节剂用量试验在每盆中添加0(CK)、30(T1)、60(T2)、90(T3)、120(T4)、150(T5)和180 g/pot(T6)碳调节剂,进行短期(7 d)和长期(90 d)培养,并在培养过程中测定土壤溶液的电导率、可溶性盐含量及离子组成。【结果】盐分动态试验监测结果表明,土壤中加入碳调节剂后,明显增加了起始电导值,随培养进行,电导值不断下降,呈二项式关系(y=0.0138x2-0.2681x+3.7768,r=0.9966**),7 d以后基本趋于稳定。碳调节剂用量试验结果表明,培养7 d后,添加碳调节剂的所有处理其水溶性盐含量均较对照有极显著下降,下降幅度随调节剂用量的增加而增加。培养90 d后,添加碳调节剂的各处理土壤水溶性盐呈现进一步下降趋势。与培养7d时相比,T3和T4处理降幅最为明显,其中T4处理在培养7 d已降低23.82%的基础上又降低了9.14%,总降幅达到32.96%,该结果说明碳调节剂的加入,其长期效应也是不可忽视的。无论是短期培养还是长期培养,只要加入碳调节剂,土壤溶液中的硝酸根浓度均明显下降,最多可使硝酸根浓度降低97.10%,这些结果说明,通过向次生盐渍化土壤中加入碳调节剂来降低硝酸根含量的方法是可行的。碳调节剂还可大幅增加土壤速效钾的含量,其中T6处理使土壤水溶性钾浓度提高了近10倍,但对速效磷的补充有限。长期培养90 d,速效氮、磷、钾养分的变化与短期培养7 d相似,只是铵态氮和硝态氮进一步明显减少。【结论】综合考虑经济效益,理论上碳调节剂用
【Objectives】Over application of nitrogen fertilizer leads to high level nitrate accumulation in the top layer,which has been considered as the main cause of secondary salinization in greenhouse soils. Based on the principle of carbon / nitrogen interactions, a carbon regulator, composed of crop straw and fast decomposing microbial strains,was developed and added to a salinized greenhouse soil to investigate the effect of the regulator on reducing soil soluble salt content. 【Methods】Two pot experiments were carried out and 2. 5 kg of satirized soil from a greenhouse was added to each pot. In the salt monitoring experiment,150 g of carbon regulator was added to each pot and the electro-conductivity（ EC） of soil was measured during the 10 days incubation. In the saltregulator dosage experiment,six rates of the regulator,0（ CK）,30（ T1）,60（ T2）,90（ T3）,120（ T4）,150（ T5） and 180（ T6） g /pot were added and the composition and concentration of soluble salts,the EC of soil solution were determined after short term（ 7 d） and longer term（ 90 d） incubation. 【Results】The soil EC was elevated by the addition of carbon regulator at the beginning of the experiment,then declined with the incubation continuing. The dynamic of soil EC with the incubation time fitted with a quadratic curve： y = 3. 7768-0. 2681 x ＋0. 0138x2（ r = 0. 9966＊＊） and the EC was stable after 7 d incubation. In the dosage experiment,the salt contents at the 7thday of incubation in all treatments significantly declined,compared with that in CK,and the salt content declined more in the treatments with higher rates of regulator addition. After 90 days＇ incubation,the salt content was observed further declined in all treatments with regulator addition,especially in T3 and T4. In T4,the salt content deceased by 23. 8% after 7 day＇s incubation and further reduced by 9. 14% at the end of incubation. The total salt content in T4 reduced by 32. 96%. These data indicated the long term and apparent effe
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2016年第1期192-200,共9页
Journal of Plant Nutrition and Fertilizers
基金
江苏省农业科技自主创新资金[CX(12)3021]
国家重点基础研究发展计划(2013CB127404)
江苏省科技支撑计划(BE2014345
BE2013360)资助
关键词
土壤
次生盐渍化
硝酸根
碳/氮互作
碳调节剂
soil
secondary salinization
NO-3
carbon /nitrogen interactions
carbon regulator
