几种改良剂对酸性紫色土氮组分及酶活性的影响

Exploring the Effects of Several Amendments on the Nitrogen Components and Enzyme Activities of Acidic Purple Soil

活性氮组分对农业生态系统的生产力、稳定性及其环境效益至关重要.土壤中的胞外酶(纤维素酶、乙酰氨基肽酶和过氧化物酶)对外源氮的输入反应强烈且迅速,通过测定土壤胞外酶活性,可以了解土壤氮素变化.为探究几种改良剂施用对酸化花椒园土壤活性氮组分特征及相关胞外酶活性的影响,厘清改良剂与土壤活性氮组分及酶活性之间的关系,为紫色土酸化治理及养分管理提供科学依据.采用田间试验,设置不施肥(CK)、单施化肥(F)、石灰+化肥(SF)、有机肥+化肥(OM)、生物炭+化肥(BF)及酒糟灰渣+化肥(JZ)6个处理,研究不同处理土壤pH值和全氮、活性氮组分及土壤纤维素酶(S-CL)、过氧化物酶(S-POD)和乙酰氨基肽酶(S-NAG)活性,阐明其相互关系.结果表明:(1) JZ和SF两个处理均显著提高土壤pH值(p<0.05),分别比对照提高了3.39和2.25;与对照处理相比,OM处理土壤全氮质量分数提高了61.45%,显著增加了土壤氮库存量(p<0.05);(2) JZ和OM处理土壤PON质量分数较对照处理分别提高了102.20%和101.45%;F和OM处理土壤MBN较对照处理分别提高了44.28%和19.08%,土壤DON分别提高了72.35%和57.61%;截至2022年6月,JZ处理土壤矿质氮质量分数提高最为显著(p<0.05),硝态氮和铵态氮质量分数较对照处理分别提高了1.63倍和5.43倍;(3)施用了改良剂的4个处理均显著提高了土壤胞外酶活性(p<0.05),其中JZ处理S-CL和S-POD活性最高,较对照处理分别提高了134.72%和96.27%,F和OM处理S-NAG活性提高较显著,较对照处理分别提高了190.63%和75.59%.综上所述,酸性紫色土壤施用石灰、酒糟灰渣及有机肥中和土壤酸度效果最显著,同时提高土壤胞外酶活性,有利于土壤氮库积累和活性氮组分转化.

The bioactive nitrogen components play a crucial role in the productivity,stability,and environmental benefits of agroecosystems.Extracellular enzymes in the soil exhibit a strong and rapid response to exogenous nitrogen inputs.By assessing soil extracellular enzyme activities,insights can be gained into soil nitrogen dynamics.This experiment sought to define the relationship between amendments and soil active nitrogen components and enzyme activities,as well as to provide a scientific foundation for treating acidification and managing nutrients in purple soil.It also aimed to find out how different amendments affect the extracellular enzyme activities associated with these components in an acidified Sichuan pepper orchard.Field experiments were carried out,and six treatments were set up:no fertilization(CK),fertilizer only(F),lime + fertilizer(SF),organic manure + fertilizer(OM),biochar + fertilizer(BF) and Vinasse biomass ash + fertilizer(JZ).The soil pH,total nitrogen(TN),labile nitrogen components and the activities of cellulase(S-CL),peroxidase(S-POD) and N-acetyl-β-D-glucosidases(S-NAG) under different treatments were studied to clarify the relationship between them.The results showed that:(1) Soil pH was significantly increased under the two treatments of vinasse biomass ash + fertilizer and lime + fertilizer by 3.39 and 2.25 units,respectively,compared with the control(p<0.05).(2) Compared with the control,the content of PON in soil treated with vinasse biomass ash + fertilizer and organic manure + fertilizer increased by 102.20% and 101.45%,respectively.Compared with the control,the MBN of soil treated with chemical fertilizer alone and organic manure + fertilizer increased by 44.28% and 19.08%,and the DON of soil increased by 72.35% and 57.61%,respectively.Up to June 2022,the JZ treatment exhibited the most significant increase in soil mineral nitrogen content(p<0.05),with nitrate nitrogen and ammonium nitrogen levels being enhanced by 1.63 fold and 5.43 fold,respectively,compared to the control.(3) The extracellular enzyme activities were significantly increased in the four treatments with the amendments(p<0.05),among which the activities of S-CL enzyme and S-POD enzyme were the highest in the treatment of vinasse biomass ash + fertilizer,which were increased by 134.72% and 96.27% compared with the control,respectively,while the S-NAG enzyme activity of single fertilizer treatment and organic manure + fertilizer treatment was significantly increased by 190.63% and 75.59% compared with the control,respectively.The application of lime,vinasse biomass ash and organic fertilizer to acidic purple soil had the most significant effect on neutralizing soil acidity,and at the same time increased the activity of soil extracellular enzymes and promoted the accumulation of nitrogen as well as mineralization of soil nitrogen fractions.