Response of Soil Microbial Biomass and Enzyme Activity to Soil Fertilization in an Eroded Farmland of Chinese Mollisols

Abstract

The aims of this study were to examine interrelationships between microbial biomass and enzyme activities of soil quality and to determine their suitability for differentiating areas. The study included five simulated erosion soil depths (0, 5, 10, 20, and 30 cm), which had received contrasting fertilizer treatments over a 5-year period in an eroded black soil of northeastern China. Our results indicated that soil microbial carbon, nitrogen, urease, phosphatase, and invertase activities declined as the erosion depth increased. On the five erosion depths, soil microbial carbon, phosphatase, and invertase variation ranged as follows: 35.4–53.3, 39.8–45.2, and 55.9–67.1%, respectively. In the fertilizer + manure treatment, soil microbial carbon, nitrogen, urease, phosphatase, and invertase activities were significantly greater (P < 0.05) than those of fertilizer treatment in all five different erosion depths. Overall, this study may be considered as the foundation for soil quality evaluation and fertility restoration in northeastern China and similar regions.

Keywords:

• Microbial biomass
• soil erosion
• soil enzyme activities
• soil fertilization
• soil organic carbon

Acknowledgments

This study is partially supported by the Harbin Bureau of Science and Technology for Outstanding Scientist (2010RFXYN044) and National Natural Science Foundation of China (41071171, 41171229, and 41271313). It was also partially supported by the South Dakota Governor's 2010 Individual Research Seed Grant (SDBOR/NSU(a) 2010-08-01).