How the chemical composition and heterogeneity of crop residue mixtures decomposing at the soil surface affects C and N mineralization

Abstract

The effects of plant litter characteristics on its decomposition in soil or at the soil surface is of primary importance for adequate management of nutrients and carbon (C) in agro-ecosystems.

Sensitivity analysis of six soil organic matter models applied to the decomposition of animal manures and crop residues

“…Dynamics of simulated net CO2 emissions in amended treatments (Figures 2A, 3A, and 4A) were in general agreement with those observed in aerobic incubations experiments of soil amended with liquid animal manures (Sørensen and Fernández, 2003;Morvan et al, 2006;Bechini and Marino, 2009;Cavalli et al, 2014), solid animal manures (Thomsen and Olesen, 2000;Calderón et al, 2005;Morvan et al, 2006;Peters and Jensen, 2011) and low-N crop residues (Henriksen and Breland, 1999;Trinsoutrot et al, 2000;Nicolardot et al, 2001;Hadas et al, 2004;Jensen et al, 2005;Redin et al, 2014).…”

“…In our simulations, the application of exogenous organic matter to soil often induced temporary net immobilisation of N (up to several weeks) by soil microbial biomass, especially when the C to N ratio of the added organic input was far higher than that of the soil microbial biomass, as demonstrated experimentally for solid manures (Calderón et al, 2005;Morvan et al, 2006;Peters and Jensen, 2011) and low-N crop residues (Henriksen and Breland, 1999;Trinsoutrot et al, 2000;Nicolardot et al, 2001;Hadas et al, 2004;Jensen et al, 2005;Redin et al, 2014). This pattern was well represented by all o n l y models after application to soil of both SM ( Figure 3B) and CR ( Figure 4B).…”

Intercropping frost-sensitive legume crops with winter oilseed rape reduces weed competition, insect damage, and improves nitrogen use efficiency

“…However the mineralization of companion plant residues is not likely to be the only factor explaining the compensation in N acquisition in the WOR. Indeed, in the experiment of Redin et al (2014) the C mineralization was not complete after 120 days under subtropical conditions. Moreover, the aerial N content of the companion plants in our experiment was lower than 30 kg per hectare on average.…”

“…The first hypothesis explaining this effect is the mineralization of the companion plant residues, and the absorption of this N by the WOR. Indeed, Redin et al (2014) showed a fast mineralization of crop residues decomposing at the soil surface, in particular with Fabaceae crops. The absence of relationship between the deviation of the aerial N content from the sole WOR treatments and the companion plants characteristics (aerial dry weight, aerial N concentration and interaction between both variables) could be due to the importance of the multiple factors controlling the mineralization of mulches: biochemical residue quality, residue placement, soil water content (Coppens et al 2007), or climatic conditions during mineralization.…”

Advances and Perspectives to Improve the Phosphorus Availability in Cropping Systems for Agroecological Phosphorus Management

“…When P concentration and Pi released from crop residues is low, Pi of soil may be assimilated by the microbial biomass, and thus decrease P availability for plants (Damon et al, 2014). The decomposition of residue mixtures exhibits synergistic effects (i.e., faster rates of decomposition than expected), negative effects (i.e., slower rates than expected), or additive effects (i.e., rates equal to those expected) (Redin et al, 2014). Nonadditive effects of mixing residues would be assumed to be due to the transfer of P between P-rich and P-poor litter, as shown for N dynamics studies (Berglund et al, 2013).…”