蚯蚓粪施用对土壤氮含量及形态的影响

采用盆栽试验,研究蚯蚓粪施用量为0 t/hm²(CK)、15 t/hm²(A1)、30 t/hm²(A2)、45 t/hm²(A3)、60 t/hm²(A4)五种处理对土壤氮含量及形态的影响。结果表明,与CK相比,施用蚯蚓粪后土壤有机质、电导率增加,土壤全氮(TN)含量也显著增加,TN含量在2.06~2.56 g/kg之间,平均含量为2.23 g/kg。A2的TN含量(2.56 g/kg)比CK(1.75 g/kg)提高了46.28%。非可转化态氮(NTF-N)含量较高,占TN的89.43%~91.46%,可转化态氮(TF-N)占TN的10.57%~13.54%。不同形态氮含量依次为:有机态及硫化物结合态氮(OSF-N)>铁锰氧化态氮(IMOF-N)>碳酸盐结合态氮(CF-N)>离子交换态氮(IEF-N)。随着蚯蚓粪用量的增加,OSF-N含量呈逐渐增加的趋势,IEF-N、CF-N含量呈先降低后增加的趋势,IMOF-N含量呈先增加后降低的趋势。OSF-N在TF-N中含量最高,是主要的赋存形态,说明可转化态氮的活性比较稳定,不易流失造成土壤-水体体系污染。TN和NTF-N含量之间呈显著正相关,说明NTF-N是TN的主要组成部分,NTF-N对TN贡献较大。本研究表明蚯蚓粪施用对土壤氮含量及形态影响较大。

Effects of Vermicompost Application on the Content and Forms of Soil Nitrogen

A pot experiment was conducted, which includes five treatments of 0 t/hm² (CK), 15 t/hm² (A1), 30 t/hm² (A2), 45 t/hm² (A3) and 60 t/hm² (A4), to study the effects of different treatments on soil nitrogen content and form.Resultsindicated that in comparison with CK, vermicompost application significantly increased the content of organic matter, the conductivity and the total nitrogen (TN). The TN content in soil ranged from 2.06 to 2.56 g/kg, with an average of 2.23 g/kg. Compared with CK (1.75 g/kg), the TN content of A2 (2.56 g/kg) increased by 46.28%. The content of non-transferable nitrogen (NTF-N) was relatively high, accounting for 89.43% to 91.46% of TN, while, transferable nitrogen (TF-N) accounted for 10.58% to 13.54% of TN. Nitrogen content of transformable nitrogen decreased in the order of organic matter-sulfide form nitrogen (OSF-N)> iron-manganese oxides form nitrogen (IMOF-N) > carbonate-bound form nitrogen (CF-N) > ion-extractable form nitrogen (IEF-N). With the dosage increased, OSF-N was increased gradually, while IEF-N and CF-N decreased first and then increased, IMOF-N increased first and then decreased. The content of OSF-N was highest of TF-N, which was the main occurrence form, and this indicated that the activity of transformable nitrogen forms was relatively stable, and was not easy to induce the soil-water pollution. There was a significant positive correlation between TN and NTF-N, indicating that NTF-N was the main component of TN, and NTF-N had greater contribution to TN. The study showed that the application of vermicompost had great effect on the soil nitrogen content and form.