有机物料对两种紫色土氮素矿化的影响

以猪粪沼渣(PM)、牛粪沼渣(CM)、污泥堆肥(SC)、农村生活垃圾堆肥(RWC1)、农村生活垃圾与污泥的堆肥产物(堆肥过程中添加20%的污泥,RWC2)为材料,采用室内恒温好气培养试验研究了不同有机物料施入酸性紫色土和石灰性紫色土后土壤氮矿化的差异.结果表明,不同有机物料有机氮组分含量及其占全氮比例的基本顺序为:氨基酸态氮酸解未知氮酸解铵态氮非酸解氮氨基糖态氮.添加有机物料显著提高了酸性紫色土的NH~+_4-N和NO~-_3-N含量,而石灰性紫色土中猪粪沼渣和污泥堆肥显著提高了NH~+_4-N的含量,牛粪沼渣却使其NO~-_3-N含量降低.牛粪沼渣对酸性紫色土氮矿化量的影响不显著,使石灰性紫色土的氮矿化量降低,其余4种有机物料均明显提高两种土壤的氮矿化量.相关分析表明土壤氮矿化量与有机物料中的氨基酸态氮和酸解铵态氮呈显著正相关,与有机物料的有机质含量和C/N呈显著负相关.上述结果说明有机物料对土壤氮素矿化的效应因土壤和有机物料的性质不同而异,特别是有机物料中的有机质含量、C/N以及有机氮组分.

Effect of Different Organic Materials on Nitrogen Mineralization in Two Purple Soils

An aerobic incubation experiment was conducted at a constant temperature to investigate the differences in nitrogen mineralization between an acid purple soil and a calcareous purple soil amended with five organic materials including biogas residues of pig manure(PM), cow manure(CW), sewage sludge compost(SC), rural waste compost(RWC1)and the compost of rural waste plus 20% of sewage sludge(RWC2). The results showed that the organic nitrogen forms in these materials followed the order of amino acid N> hydrolysable unidentified N> ammonium N> non-hydrolysable N> amino sugar N. Application of organic materials could significantly improve the contents of NH₄⁺-N and NO₃^--N in acid purple soil, PM and SC could significantly improve the content of NH₄⁺-N, but CM reduced the content of NO₃^--N in calcareous purple soil. Except for CM, which had no significant effect on the quantity of nitrogen mineralization in acid purple soil, but decreased the quantity of nitrogen mineralization in calcareous purple soil, applying the organic materials could significantly increase the quantity of nitrogen mineralization in both soils. Correlation analysis showed that the quantity of nitrogen mineralization was significantly and positively correlated with the contents of amino acid N and ammonium N, but were significantly and negatively correlated with the content of organic matter and the C/N of organic materials. Overall, the results illustrated that the effect of organic materials on the mineralization of nitrogen varied with soil types and the characteristics of organic materials, especially the content of organic matter, C/N and the fractions of organic nitrogen in organic materials.