Contrasting microbial mechanisms of soil priming effects induced by crop residues depend on nitrogen availability and temperature

2021 ◽  
Vol 168 ◽  
pp. 104186
Author(s):  
Xiaohong Wang ◽  
Jiayu Lu ◽  
Xiuwei Zhang ◽  
Peng Wang
Keyword(s):  
Nitrogen Availability ◽  
Crop Residues ◽  
Priming Effects

scholarly journals Evaluation of the Agronomic Performance of Organic Processing Tomato as Affected by Different Cover Crop Residues Management

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 504 ◽  
Author(s):  
Abou Chehade ◽  
Antichi ◽  
Martelloni ◽  
Frasconi ◽  
Sbrana ◽  
...  
Keyword(s):  
Plant Growth ◽  
Cover Crop ◽  
Nitrogen Availability ◽  
Crop Residues ◽  
N Uptake ◽  
Total Yield ◽  
Soluble Solids ◽  
Plastic Mulch ◽  
Processing Tomato ◽  
No Till

No-till practices reduce soil erosion, conserve soil organic carbon, and enhance soil fertility. Yet, many factors could limit their adoption in organic farming. The present study investigated the effects of tillage and cover cropping on weed biomass, plant growth, yield, and fruit quality of an organic processing tomato (Solanum lycopersicon L. var. Elba F1) over two seasons (2015–2017). We compared systems where processing tomato was transplanted on i) tilled soil following or not a winter cover crop (Trifolium squarrosum L.) and with/without a biodegradable plastic mulch; and ii) no-till where clover was used, after rolling and flaming, as dead mulch. Tomato in no-till suffered from high weed competition and low soil nitrogen availability leading to lower plant growth, N uptake, and yield components with respect to tilled systems. The total yield in no-till declined to 6.8 and 18.3 t ha−1 in 2016 and 2017, respectively, with at least a 65% decrease compared to tilled clover-based systems. No evidence of growth-limiting soil compaction was noticed but a slightly higher soil resistance was in the no-till topsoil. Tillage and cover crop residues did not significantly change tomato quality (pH, total soluble solids, firmness). The incorporation of clover as green manure was generally more advantageous over no-till. This was partly due to the low performance of the cover crop where improvement may limit the obstacles (i.e., N supply and weed infestation) and enable the implementation of no-till in organic vegetable systems.

scholarly journals Effect of organic carbon addition on paddy soil organic carbon decomposition under different irrigation regimes

2021 ◽  
Vol 18 (18) ◽  
pp. 5035-5051
Author(s):  
Heleen Deroo ◽  
Masuda Akter ◽  
Samuel Bodé ◽  
Orly Mendoza ◽  
Haichao Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Crop Residues ◽  
Irrigation Management ◽  
Reductive Dissolution ◽  
Priming Effects ◽  
Organic C ◽  
Carbon Decomposition ◽  
Enhanced Dissolution ◽  
The Impact

Abstract. Anaerobic decomposition of organic carbon (OC) in submerged rice paddies is coupled to the reduction of alternative soil electron acceptors, primarily Fe3+. During reductive dissolution of Fe3+ from pedogenic oxides, previously adsorbed native soil organic carbon (SOC) could be co-released into solution. Incorporation of crop residues could hence indirectly, i.e. through the stimulation of microbially mediated Fe3+ reduction, promote the loss of native SOC via enhanced dissolution and subsequent mineralisation to CO2 and CH4. Our aim was to estimate the relevance of such a positive feedback during the degradation of added OC, and to investigate the impact of irrigation management on this mechanism and on priming effects on native SOC decomposition in general. In a six-week pot experiment with rice plants, two Bangladeshi soils with contrasting SOC to oxalate-extractable Fe (SOC : Feox) ratios were kept under a regime of alternate wetting and drying (AWD) or continuous flooding (CF), and were either amended with maize shoots or not. The δ13C signatures of dissolved organic C and emitted CH4 and CO2 were used to infer the decomposition of added maize shoots (δ13C = −13.0 ‰) versus native SOC (δ13C = −25.4 ‰ and −22.7 ‰). Addition of maize residues stimulated the reduction of Fe as well as the dissolution of native SOC, and the latter to a larger extent under CF, especially for the soil with the highest SOC : Feox ratio. Estimated Fe-bound SOC contents denote that stimulated SOC co-release during Fe reduction could explain this positive priming effect on SOC dissolution after the addition of maize. However, priming effects on SOC mineralisation to CO2 and CH4 were lower than for SOC dissolution, and were even negative under AWD for one soil. Enhanced reductive dissolution of Fe-bound SOC upon exogenous OC addition therefore does not necessarily lead to stimulated SOC mineralisation. In addition, AWD irrigation was found to decrease the above-mentioned priming effects.

scholarly journals Effect of organic carbon addition on paddy soil organic carbon decomposition under different irrigation regimes

2021 ◽  
Author(s):  
Heleen Deroo ◽  
Masuda Akter ◽  
Samuel Bodé ◽  
Orly Mendoza ◽  
Haichao Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Crop Residues ◽  
Irrigation Management ◽  
Reductive Dissolution ◽  
Priming Effects ◽  
Organic C ◽  
Carbon Decomposition ◽  
Enhanced Dissolution ◽  
The Impact

Abstract. Anaerobic decomposition of organic carbon (OC) in submerged rice paddies is coupled to the reduction of alternative soil electron acceptors, primarily Fe3+. During reductive dissolution of Fe3+ from pedogenic oxides, previously adsorbed native soil organic carbon (SOC) could be co-released into solution. Incorporation of crop residues could hence indirectly, i.e. through the stimulation of microbially mediated Fe3+ reduction, promote the loss of native SOC via enhanced dissolution and subsequent mineralisation to CO2 and CH4. Our aim was to estimate the relevance of such a positive feedback during the degradation of added OC, and to investigate the impact of irrigation management on this mechanism and on priming effects on native SOC decomposition in general. In a six-week pot experiment with rice plants, two Bangladeshi soils with contrasting SOC-to-reducible-Fe (SOC : Feox) ratios were kept under a regime of alternate wetting and drying (AWD) or continuous flooding (CF), and were either amended with maize shoots or not. The δ13C signatures of dissolved organic C and emitted CH4 and CO2 were used to infer the decomposition of added maize shoots (δ13C = −13.0 ‰) versus native SOC (δ13C = −25.4 ‰ and −22.7 ‰). Addition of maize residues stimulated the reduction of Fe as well as the dissolution of native SOC, and the latter to a larger extent under CF, especially for the soil with the highest SOC : Feox ratio. Estimated Fe-bound SOC contents denote that stimulated SOC co-release during Fe reduction could explain this positive priming effect on SOC dissolution after the addition of maize. However, priming effects on SOC mineralisation to CO2 and CH4 were lower than for SOC dissolution, and were even negative under AWD for one soil. Enhanced reductive dissolution of Fe-bound SOC upon exogenous OC addition therefore does not necessarily lead to stimulated SOC mineralisation. In addition, AWD irrigation was found to decrease abovementioned priming effects.

scholarly journals Soil nitrogen availability in olive orchards after mulching legume cover crop residues

2013 ◽  
Vol 158 ◽  
pp. 45-51 ◽  
Author(s):  
M. Ângelo Rodrigues ◽  
Carlos M. Correia ◽  
Ana Marília Claro ◽  
Isabel Q. Ferreira ◽  
José C. Barbosa ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
Cover Crop ◽  
Nitrogen Availability ◽  
Crop Residues ◽  
Soil Nitrogen Availability ◽  
Legume Cover Crop

The Direction of Affective Priming as a Function of Trait Anxiety When Naming Target Words With Regular and Irregular Pronunciation

2004 ◽  
Vol 51 (3) ◽  
pp. 180-190 ◽  
Author(s):  
Michael P. Berner ◽  
Markus A. Maier
Keyword(s):  
Trait Anxiety ◽  
Reading Aloud ◽  
Naming Task ◽  
Affective Priming ◽  
Priming Effects ◽  
Expected Effect ◽  
Negative Affective Priming ◽  
Whole Word ◽  
German Data ◽  
Target Words

Abstract. Results from an affective priming experiment confirm the previously reported influence of trait anxiety on the direction of affective priming in the naming task ( Maier, Berner, & Pekrun, 2003 ): On trials in which extremely valenced primes appeared, positive affective priming reversed into negative affective priming with increasing levels of trait anxiety. Using valenced target words with irregular pronunciation did not have the expected effect of increasing the extent to which semantic processes play a role in naming, as affective priming effects were not stronger for irregular targets than for regular targets. This suggests the predominant operation of a whole-word nonsemantic pathway in reading aloud in German. Data from neutral priming trials hint at the possibility that negative affective priming in participants high in trait anxiety is due to inhibition of congruent targets.

Combining the Post-Cue Task and the Perceptual Identification Task to Assess Parallel Activation and Mutual Facilitation of Related Primes and Targets

2018 ◽  
Vol 65 (2) ◽  
pp. 84-97 ◽  
Author(s):  
Demian Scherer ◽  
Dirk Wentura
Keyword(s):  
Semantic Priming ◽  
Stimulus Onset ◽  
The Other ◽  
Perceptual Identification ◽  
Identification Task ◽  
Priming Effects ◽  
Priming Paradigm ◽  
Parallel Activation ◽  
Prime Target

Abstract. Recent theories assume a mutual facilitation in case of semantic overlap for concepts being activated simultaneously. We provide evidence for this claim using a semantic priming paradigm. To test for mutual facilitation of related concepts, a perceptual identification task was employed, presenting prime-target pairs briefly and masked, with an SOA of 0 ms (i.e., prime and target were presented concurrently, one above the other). Participants were instructed to identify the target. In Experiment 1, a cue defining the target was presented at stimulus onset, whereas in Experiment 2 the cue was not presented before the offset of stimuli. Accordingly, in Experiment 2, a post-cue task was merged with the perceptual identification task. We obtained significant semantic priming effects in both experiments. This result is compatible with the view that two concepts can both be activated in parallel and can mutually facilitate each other if they are related.

Do I Shoot Faster Because I Am Thinking about an Outgroup or a Threatening Outgroup?

2016 ◽  
Vol 47 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Jessica Mange ◽  
Keren Sharvit ◽  
Nicolas Margas ◽  
Cécile Sénémeaud
Keyword(s):  
Pilot Study ◽  
Target Group ◽  
Main Study ◽  
Priming Effects ◽  
Males And Females

Abstract. This research examines if aggressive responses through a shooter bias are systematically generated by priming outgroups or if a threat stereotypically associated with the primed outgroup is required. First, a pilot study identified outgroups stereotypically associated and not associated with threat. Afterwards, the main study included a manipulation of target group accessibility – ingroup versus nonthreatening outgroup versus threatening outgroup. Following exposure to primes of the group categories, the participants in all conditions played a shooter game in which the targets were males and females with ambiguous ethnicity and religion. Results demonstrated that while only priming of an outgroup stereotypically associated with threat elicits aggressive responses, priming of both nonthreatening and threatening outgroups leads to an increase in the ability to distinguish between stimuli compared to ingroup priming. These effects are discussed in terms of priming effects, dimensions of threat, and possible interpretations of this ability increase.

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