Soil nutrient availability and microbial properties of a potato field under ridge-furrow and plastic mulch

ABSTRACT

Ridge-furrow with plastic mulching (RFPM) has been commonly used in the production of field crops, but it is unknown whether this practice would affect soil quality attributes. Field experiments were conducted to determine the effects of RFPM on potato tuber yield and soil quality under semi-arid conditions. Six different planting patterns (i.e., various ridges and furrows were in combination with plastic mulching) were compared in randomized complete block with three replicates. It was consistent in the two years of study that the completely mulched with ridge planting significantly increased soil available N, available P, available K, and soil organic matter (SOM) content, and decreased the numbers of fungi in the 0-20cm soil, compared to the control (flat plots with no ridge and no mulching). Also, ridge planting increased the numbers of aerobic azotobacter, nitrifying bacteria and ammonifying bacteria and decreased anaerobic azotobacter and denitrifying bacteria compared to furrow planting. In addition, the completely mulched with ridge planting increased hydrogen peroxidase, alkaline phosphatase, and urease (UR) activities in the soil. The enhanced enzymatic activities in the soil were largely attributable to decreased soil evaporation and increased soil temperature due to the use of black plastic on the soil surface. Therefore, ridge planting with plastic mulching can be considered to be one of the best approaches in the improvement of potato productivity, whereas, at the same time, maintaining or enhancing soil health in semiarid areas.

KEYWORDS:

• planting patterns
• potato
• soil available nutrient
• soil enzyme activity
• soil microbial community

Acknowledgement

We sincerely thank all the students and staff in Dingxi Rainfed agricultural Research Institute for their assistance in field work. All authors are also grateful to Dr. Yantai Gan from Canada for their kind work in suggesting improvements to this paper.