Ridge-furrow with film mulching practice ameliorates soil microbial metabolic activity and carbon utilization in rhizosphere soil of rapeseed ( Brassica napus L.)

Abstract

Purpose

The farming practices of ridge-furrow with film mulching (RFFM) have been extensively reported as a valuable technique for improving crop productivity and enhancing water-use efficiency. However, research on the high-yield mechanism of RFFM measures under drought stress from the perspective of microbial diversity has been scared.

Materials and methods

Field experiments were conducted to analyze the effects of conventional flat planting (FP), no film mulching (NR), white polyethylene film mulching (WR), black polyethylene film mulching (BR), and biodegradable film mulching (BDR) with 40 and 80 cm furrow width levels on soil temperature, soil water storage (SWS), microbial carbon utilization, and yield of winter oilseed rape.

Results and discussion

The RFFM significantly increased the SWS as well as rapeseed yield and yield components. However, these treatments did not cause obvious differences in soil temperature. A relative high value of average color change rate (AWCD) was observed during the incubation time of 24–216 h, and it reached the peak value at 240 h. The AWCD in the furrow with 80 cm width was greater than that of 40 cm. The RFFM also could improve the utilization intensities of soil microorganism on the carbon sources of carbohydrates, amino acids, and miscellaneous in rapeseed rhizosphere. This result was consistent with that of the principal component analysis. The Shannon–Wiener diversity index, Simpson's diversity index, and Shannon–Wiener evenness in BDR₄₀, BR₄₀, and BR₈₀ were significantly higher than other treatments, respectively. In addition, correlation analysis results suggested that the indicator of affecting the diversity of carbon source was mainly due to the water storage capacity.

Conclusions

The methods of film mulching have a remarkable effect on microbial diversity. The yield of BR and BDR were significantly higher than other treatments. Compared with FP, RFFM increased rapeseed yield by 9.61–86.10%. In the year of less rainfall, production has decreased in comparison with the first season, while BDR₈₀ guarantees continuous high yield and substantially promoted carbon utilization and soil microbial diversity. Soil microbial diversity is positively correlated with soil water content, which is beneficial to increase production. Wider furrow (80 cm) is recommended a sustainable high-yield method due to convenient labor in the region in Southwest China.

from Energy Ecology Environment Ambio via Terpsi Hori on Inoreader http://bit.ly/2NgJ076