Effects of Tillage and Nitrogen Fertilizers on CH4 and CO2 Emissions and Soil Organic Carbon in Paddy Fields of Central China

Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT) and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha−1) on fluxes of CH4 and CO2, and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH4 emissions by 13%–66% and SOC by 21%–94% irrespective of soil sampling depths, but had no effect on CO2 emissions in either year. Tillage significantly affected CH4 and CO2 emissions, where NT significantly decreased CH4 emissions by 10%–36% but increased CO2 emissions by 22%–40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%–48% in the 0–5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0–20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered

Changes in CH₄ emission fluxes from paddy fields under different management practices during the 2009 and 2010 rice growing seasons.

<p>The vertical bars are standard deviations of the mean, n = 3.</p

Changes in CO₂ emission fluxes from paddy fields under different management practices during the 2009 and 2010 rice growing seasons.

<p>The vertical bars are standard deviations of the mean, n = 3.</p

SOC contents (g kg⁻¹) and bulk density (g cm⁻³) before tillage and at harvesting, and SOC sequestration (kg C ha⁻¹) based on soil sampling depths from different tillage treatments in the 2009 and 2010 rice growing seasons, n = 3.

<p>T, tillage; F, application of N fertilizer;</p>*<p>, significant at the 0.05 probability level;</p>**<p>, significant at the 0.01 probability level; NS, not significant; SOC, soil organic C.</p><p>Different letters in a year at different depths mean significant differences at the 5% level.</p><p>The values in brackets are standard deviations of the mean.</p

Cumulative CH₄ and CO₂ emissions (g m⁻²) from different tillage treatments in the 2009 and 2010 rice growing seasons, n = 3.

<p>T, tillage;</p><p>F, application of N fertilizer;</p>*<p>, significant at the 0.05 probability level;</p>**<p>, significant at the 0.01 probability level;</p><p>NS, not significant;</p><p>The values in brackets are standard deviations of the mean.</p

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present