沼液对狼尾草产量和土壤无机氮素及酶活性的影响

摘要

To explore the potential of utilizing slurry from biogas-producing fermentation beds for fertilization,‘Fujian 6’grass (Pennisetum americanum P .purpureum CV.Minmu 6)was used in a turf experiment.Varied quantities of slurry application (i.e.,N1 as control,and N2 through N5 as treatments)on the grass were executed. The plant height and yield of the grass,as well as the ammonium nitrogen,nitrate nitrogen and the activities of urease,protease, glutaminase and asparaginase in the soil, were determined. The results showed that the applications improved the plant height over N1 ,but no significant differences among the treatments (P >0.05).The grass yield was also significantly increased (P <0.05)reaching 1 74 754 kg·hm-2 ,a level 1 1 9.0% higher than that of N1 .In the 0-20 cm or 20-40 cm soil layers,there was no significant change on the ammonium nitrogen content (P > 0.05 ),but the nitrate nitrogen increased with increasing slurry application.Compared to N1 ,N4 and N5 significantly increased the nitrate nitrogen content in the 0-20 cm soil (P <0.05).The effects of biogas slurry on the activities of urease,protease,glutaminase and Asparaginase were not significant during T1 (May,7,201 5 ) period (P >0.05).A correlation analysis on the data re-confirmed a significant correlation between the biogas slurry applications and the plant height of the grass (P < 0.05 ),and an extremely significant correlation between the applications and the nitrate nitrogen in 0 - 20 cm layer of soil and the yield of the grass (P < 0.01 )at all time periods,but none on the enzymatic activities during T1 period.%通过沼液浇灌人工草地定位试验,以‘闽牧6号’狼尾草 P.americanum × P.purpureum CV .Minmu 6为供试植物,研究不同沼液浇灌量(N1~N5)对狼尾草株高、产量以及土壤铵态氮、硝态氮、脲酶、蛋白酶、谷氨酰胺酶和天冬酰胺酶活性的影响。结果表明：与对照(N1)相比,施沼液可显著提高狼尾草株高,但 N2~N5之间没有显著差异(P >0.05)。施沼液还能显著提高狼尾草产量(P <0.05),全年最高可增产119.0%,增产量为174754 kg·hm-2。施沼液对0~20 cm 和20~40 cm 土层土壤铵态氮含量影响不显著(P >0.05)。0~20 cm 和20~40 cm 土层土壤硝态氮含量随沼液浇灌量的增加呈上升趋势,且0~20 cm 土层,N4和 N5处理较 N1处理土壤硝态氮含量显著增加(P <0.05)。T1时期,施沼液对脲酶、蛋白酶、谷氨酰胺酶和天冬酰胺酶活性无显著影响(P >0.05)。相关性分析表明,施沼量与株高在各个时期都达到显著性相关(P <0.05),与0~20 cm 土层土壤硝态氮含量及产量达到极显著相关(P <0.01),T1时期,与4种酶活性没有显著相关性(P >0.05)。