Effect of mulches on bacterial populations and enzyme activity in soil and vegetable yields

• Published in: Plant and soil 1982-06, Vol.64 (2), p.193-201
• Main Authors: HANKIN, LESTER, HILL, DAVID E., STEPHENS, GEORGE R.
• Format: Article
• Language: English
• Subjects: Acid soils; Agricultural soils; Bacteria; Broccoli; Enzymes; Mulches; Plastic film mulches; Soil bacteria; Soil enzymes; Soil water
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/bf02184250

Mulches in five combinations of clear plastic, black plastic, and undecomposed leaves covered by or on top of black or clear plastic film to modify soil temperature, were used to study the enzyme activity of the soil and numbers of bacteria able to produce degradative enzymes. Yield of pepper and broccoli planted through the mulches was measured. The numbers of bacteria in the soil able to excrete protease, phosphatase, cellulase, and lipase were correlated with one another suggesting that the same group of organisms excreted the different enzymes. The activity of enzymes in the soil was similarly correlated. Bacterial urease-producers and the urease activity in the soil were not correlated with the number of other enzyme producers or activity of other enzymes in soil suggesting an independent population of urease producers degraded the urea fertilizer used. Temperature differences of 11-14°C provided by the various mulches appeared insufficient to create important differences in populations and biochemical activities of soil bacteria. Yield of broccoli was greatest early in the season in soil warmed under black polyethylene plastic and later in the season in the soil cooled with leaf mulch over black plastic. Yield of pepper was greatest in mid-to-late summer on soil warmed with black plastic, but the highest yield was obtained in early fall in soil with clear and black plastic over leaf mulch.