[Change in soil enzymes activities after adding biochar or straw by fluorescent microplate method]

Area of Science:

• Soil Science
• Enzymology
• Biogeochemistry

Background:

• Soil enzymes like alpha-glucosidase and beta-glucosidase are key indicators of soil health and carbon cycling.
• Understanding how soil amendments affect enzyme activity is crucial for sustainable land management.

Purpose of the Study:

• To investigate the impact of biochar and straw amendments on soil alpha-glucosidase and beta-glucosidase activities.
• To evaluate the effectiveness of a fluorescence microplate method for measuring soil enzyme activities.

Main Methods:

• Soil samples (and red soils) were amended with biochar or straw (2.5 g/50g soil).
• Enzyme activities were measured using a fluorescence detection method with a 96-microplate reader under controlled conditions (25°C, 20% moisture).
• Comparison with conventional spectrophotometric methods was performed.

Main Results:

• Straw amendment significantly increased both alpha-glucosidase and beta-glucosidase activities.
• Rice straw showed a greater stimulatory effect on beta-glucosidase activity than corn straw.
• Enzyme activity remained high for at least 40 days after straw application.
• Biochar amendment had a negligible effect on the measured enzyme activities.
• The fluorescence microplate method proved more sensitive and efficient than spectrophotometry.

Conclusions:

• Straw addition enhances soil enzyme activities, promoting soil carbon transformation and potentially increasing microbial activity.
• Biochar's limited impact is attributed to lower nutrient content and resistance to degradation.
• The fluorescence microplate method is a rapid, accurate, and simple technique for high-throughput soil enzyme analysis.