摘要
以湖南省3个国家级稻田土壤肥力变化长期定位监测点(新化、宁乡和桃江)的土壤为对象,研究了20年不同土壤培肥方式(不施肥、单施化肥、化肥配施中量/高量猪粪和化肥配施秸秆)对土壤全氮、有机氮组分及氮素矿化的影响。结果显示,与不施肥相比,单施化肥对土壤全氮的影响在新化和宁乡点均不显著,但化肥配施猪粪或秸秆在三个试验点均显著提高了土壤全氮、碱解氮和微生物量氮的含量。总体来看,长期施肥能够提高土壤有机氮各组分的含量,并提高氨基糖氮和氨基酸氮在全氮中的占比,但不同类型肥料施入后对有机氮组分的影响因试验点的不同而异,这可能是不同试验点土壤理化性质差异导致的。相关分析显示土壤酸解有机氮组分与氮矿化势极显著相关,且在三个监测点,有机物配施化肥的处理土壤氮矿化势均高于单施化肥处理。研究表明,虽然土壤性质上的差异可能导致土壤氮组分对施肥措施的响应不同,但有机无机肥配施提高土壤供氮潜力的效果均优于单施化肥。
Applying fertilizers not only improves soil fertility, but may also influence nitrogen transformation in soil. Here the effects of long-term(20 years)different fertilization on total nitrogen(N), organic N components and organic N mineralization in paddy soils were studied at three experimental sites(Xinhua, Ningxiang and Taojiang)in Hunan Province. Fertilization included no fertilizer(CK), chemical fertil-izers(NPK), chemical fertilizers plus medium and high amounts of pig manure(MM+NPK and HM+NPK), and chemical fertilizers plus in-corporated straw(Str.+NPK). Compared with CK, chemical fertilizers alone did not consistently influence soil total N, alkali-hydrolyzable N and microbial biomass N, but chemical fertilizers plus organic materials(MM+NPK, HM+NPK and Str.+NPK)significantly increased these soil N content in all three experimental sites. In general, the proportions of amino acid N and amino sugar N to total N were improved by long-term fertilization. However, the responses of organic N fractions to fertilization varied in different experimental sites, which may be at-tributed to the differences in soil properties. Significant positive correlation was observed between hydrolyzable N content and potentially mineralizable N. In all three experiment sites, chemical fertilizer plus organic materials showed a higher potentially mineralizable N than chemical fertilizers alone. In conclusion, soil properties influence the responses of soil organic nitrogen fractions to fertilization, and com-bined applications of organic and chemical fertilizers show higher soil nitrogen supplying potential than chemical fertilizers alone.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2015年第10期1958-1964,共7页
Journal of Agro-Environment Science
基金
国家自然科学基金(41171212)
"十二五"国家科技支撑计划项目(2014BAK19B00)
关键词
水稻土
长期施肥
有机氮组分
土壤氮矿化
湖南
paddy soil
long-term fertilization experiment
organic nitrogen fraction
soil nitrogen mineralization
Hunan Province
