Severe drought rather than cropping system determines litter decomposition in arable systems


Loading...

Date

2022-10-15

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

Litter decomposition is a fundamental process in soil carbon dynamics and nutrient turnover. However, litter decomposition in arable systems remains poorly explored, and it is unclear whether different management practices, such as organic farming, conservation agriculture can mitigate drought effects on litter decomposition. Thus, we examined the effects of a severe experimental drought on litter decomposition in four cropping systems, i.e., organic vs. conventional farming, each with two levels of tillage (intensive vs. conservation tillage) in Switzerland. We incubated two types of standard litter (tea bags), i.e., high-quality green tea with a low C:N ratio and low-quality rooibos tea with a high C:N ratio. We assessed litter decomposition during the simulated drought and in the post-drought period during three years in three different crops, i.e., pea-barley, maize, and winter wheat. Subsequently, we assessed whether decomposition in the four cropping systems differed in its resistance and resilience to drought. Drought had a major impact on litter decomposition and suppressed decomposition to a similar extent in all cropping systems. Both drought resistance and resilience of decomposition were largely independent of cropping systems. Drought more strongly reduced decomposition of the high-quality litter compared to the low-quality litter during drought conditions regarding the absolute change in mass remaining (12.3% vs. 6.5 %, respectively). However, the decomposition of high-quality litter showed a higher resilience, i.e., high-quality approached undisturbed decomposition levels faster than low-quality litter after drought. Soil nitrate availability was also strongly reduced by drought (by 32–86 %), indicating the strong reduction in nutrient availability and, most likely, microbial activity due to water shortage. In summary, our study suggests that severe drought has a much stronger impact on decomposition than cropping system indicating that it might not be possible to maintain decomposition under drought by the cropping system approaches we studied. Nevertheless, management options that improve litter quality, such as the use of legume crops with high N concentrations, may help to enhance the resilience of litter decomposition in drought-stressed crop fields.

Publication status

published

Editor

Book title

Volume

338

Pages / Article No.

108078

Publisher

Elsevier

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Climate change; Drought; Resistance; Resilience; Organic farming; Conservation tillage

Organisational unit

03648 - Buchmann, Nina / Buchmann, Nina check_circle

Notes

Funding

Related publications and datasets