摘要
【目的】揭示长期施肥对中性紫色水稻土生态系统氮素内循环矿化及硝化特征的影响,探索维持紫色水稻土长期供氮潜力的途径。【方法】利用重庆市北碚区21年的中性紫色水稻土长期定位试验,通过淹水密闭培养-间歇淋洗法研究长期施肥对土壤氮素矿化特性的影响,并测定了不同施肥措施下土壤硝化细菌数量、氨氧化潜势及硝化强度的变化。【结果】与长期不施肥对照相比,单施化肥(除单施氮肥)、有机肥或有机无机配施显著提高了土壤累积矿化氮量和氮素矿化势(N0),氮磷钾肥配施有机肥处理累积矿化氮量最高达164.43 mg.kg-1,氮素矿化势相比CK处理增加了59.29%,而含氯氮磷钾肥配施有机肥增加累积矿化氮量和氮素矿化势幅度显著低于氮磷钾肥配施有机肥处理;不同施肥(除氮磷钾肥与单施有机肥)显著提高了氮素矿化速率常数(k)。施用氮肥处理显著提高了土壤硝化细菌数量,尤其是氮磷钾肥配施有机肥处理最高为CK处理的74.25倍;土壤氨氧化潜势和硝化强度表现出一致的趋势,均是氮磷钾肥配施有机肥处理最高而含氯氮磷钾肥配施有机肥显著低于不施肥对照处理。相关分析表明,土壤氨氧化潜势和硝化强度与土壤pH呈显著正相关关系(P<0.05)。【结论】氮磷钾肥配施有机肥是提高紫色水稻土供氮潜力及改善有机氮品质的有效手段,含氯化肥抑制了硝化过程,可充当硝化抑制剂使用。
【Objective】The objective of the experiment is to reveal the effects of long-term fertilization on nitrogen internal cycle of neutral purple paddy soil ecosystem and the ways maintaining soil nitrogen supplying potentials.【Method】 A long-term fertilization experiment lasted for 21 years was carried out in Beibei District,Chongqing City.Waterlogging incubation method proposed by Warning was used to investigate N mineralization characteristics.The total number of soil nitrobacteria,the potential nitrification rate and the intensity of soil nitrification were studied.【Result】Nitrogen accumulations and nitrogen mineralization potential（N0） were significantly improved under the chemical fertilizer（except N） or organic fertilizer or combined application of organic manure and inorganic NPK,and combined application of organic manure and inorganic NPK was the highest（164.43 mg.kg-1）,nitrogen mineralization potential（N0） improved by 59.29%,as compared to CK.But the increasing extent of combined chloride-containing fertilizer and organic manure was much lower than the fertilization of organic manure and inorganic NPK.Different fertilization in all treatments（except NPK or M） increased the rate of mineralization（k）.Compared to CK,the total number of soil nitrobacteria was significantly improved under fertilizers N,especially organic manure and inorganic NPK fertilizer combined application,which was about 74.25 times of CK.The potential nitrification rate and the intensity of soil nitrification showed a consistent trend,which applied the organic manure and inorganic NPK fertilizer had the best effect,and combined chloride-containing fertilizer and organic fertilizer was significantly lower than CK.Soil pH affected significantly the potential nitrification rate and the intensity of soil nitrification,with a correlation coefficient of r =0.925（P＆lt;0.01） and r =0.773（P＆lt;0.05）.【Conclusion】 Long-term combined application of organic manure and inorganic NPK is considered the best way for maintaining the soil fertility,chloride-containing fertilizer inhibits nitrification process and it can be used as nitrification inhibitor.
出处
《中国农业科学》
CAS
CSCD
北大核心
2013年第16期3392-3400,共9页
Scientia Agricultura Sinica
基金
农业部公益性行业科研专项(201203030)
中央高校基本科研业务费专项资金资助(XDJK2010B012)
关键词
长期施肥
氮素
矿化作用
硝化作用
含氯化肥
水稻土
long-term fertilization
nitrogen
mineralization
nitrification
chloride-containing fertilizer
paddy soil
