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Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

Schmidt A, John K, Arida G, Auge H, Brandl R, Horgan FG, Hotes S, Marquez L, Radermacher N, Settele J, Wolters V, Schädler M - PLoS ONE (2015)

Bottom Line: Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season.We found no significant responses in microbial decomposition rates to management practices.However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates.

View Article: PubMed Central - PubMed

Affiliation: Department of Community Ecology, Helmholtz-Centre for Environmental Research-UFZ, Halle/Saale, Germany.

ABSTRACT
Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

No MeSH data available.


Related in: MedlinePlus

Litter mass loss, C content, N content: mesh size × treatment.Percent litter mass loss (A), N content (B) and C content (C) (means + standard error SE) of rice straw retrieved after the five treatments in coarse-meshed (decomposition by invertebrates and microorganisms) and fine-meshed (decomposition by microorganisms) litterbags. Different letters above the bars indicate significant differences between means (Tukey’s HSD, P ≤ 0.05). Values of the original straw (= time 0d): N = 0.6%, C = 36.8%. Treatment abbreviations: ‘Asc’—ash of burned rice straw scattered on the field, ‘Ami’—ash of burned rice straw mixed into the soil, ‘Ssc’—rice straw scattered on the field, ‘Smi’—rice straw mixed into the soil, ‘Ctr’—control (no ash or straw added).
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pone.0134402.g001: Litter mass loss, C content, N content: mesh size × treatment.Percent litter mass loss (A), N content (B) and C content (C) (means + standard error SE) of rice straw retrieved after the five treatments in coarse-meshed (decomposition by invertebrates and microorganisms) and fine-meshed (decomposition by microorganisms) litterbags. Different letters above the bars indicate significant differences between means (Tukey’s HSD, P ≤ 0.05). Values of the original straw (= time 0d): N = 0.6%, C = 36.8%. Treatment abbreviations: ‘Asc’—ash of burned rice straw scattered on the field, ‘Ami’—ash of burned rice straw mixed into the soil, ‘Ssc’—rice straw scattered on the field, ‘Smi’—rice straw mixed into the soil, ‘Ctr’—control (no ash or straw added).

Mentions: The mean loss of litter mass in coarse-meshed litterbags was higher than in the fine-meshed bags (84 ± 0.8% vs. 75 ± 0.8% (overall mean across all treatments and retrieval times ± SE) respectively; Table 1). All tested factors as well as their two-way interactions showed highly significant effects on litter mass loss (Table 1). Mesh size had a significant effect on litter mass loss on all retrieval dates (Table 1, S3A Fig). The mean percent litter mass loss was lower from the coarse-meshed bags (Fig 1A) retrieved after 25 days (Fig 2A) in plots with straw scattered on the surface of the field (treatment Ssc) compared to the other treatments. In both the fine- and coarse-meshed bags, retrieved later in the rice cycle, the mass loss of rice straw litter was similar across all five treatments (Fig 2A).


Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

Schmidt A, John K, Arida G, Auge H, Brandl R, Horgan FG, Hotes S, Marquez L, Radermacher N, Settele J, Wolters V, Schädler M - PLoS ONE (2015)

Litter mass loss, C content, N content: mesh size × treatment.Percent litter mass loss (A), N content (B) and C content (C) (means + standard error SE) of rice straw retrieved after the five treatments in coarse-meshed (decomposition by invertebrates and microorganisms) and fine-meshed (decomposition by microorganisms) litterbags. Different letters above the bars indicate significant differences between means (Tukey’s HSD, P ≤ 0.05). Values of the original straw (= time 0d): N = 0.6%, C = 36.8%. Treatment abbreviations: ‘Asc’—ash of burned rice straw scattered on the field, ‘Ami’—ash of burned rice straw mixed into the soil, ‘Ssc’—rice straw scattered on the field, ‘Smi’—rice straw mixed into the soil, ‘Ctr’—control (no ash or straw added).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520592&req=5

pone.0134402.g001: Litter mass loss, C content, N content: mesh size × treatment.Percent litter mass loss (A), N content (B) and C content (C) (means + standard error SE) of rice straw retrieved after the five treatments in coarse-meshed (decomposition by invertebrates and microorganisms) and fine-meshed (decomposition by microorganisms) litterbags. Different letters above the bars indicate significant differences between means (Tukey’s HSD, P ≤ 0.05). Values of the original straw (= time 0d): N = 0.6%, C = 36.8%. Treatment abbreviations: ‘Asc’—ash of burned rice straw scattered on the field, ‘Ami’—ash of burned rice straw mixed into the soil, ‘Ssc’—rice straw scattered on the field, ‘Smi’—rice straw mixed into the soil, ‘Ctr’—control (no ash or straw added).
Mentions: The mean loss of litter mass in coarse-meshed litterbags was higher than in the fine-meshed bags (84 ± 0.8% vs. 75 ± 0.8% (overall mean across all treatments and retrieval times ± SE) respectively; Table 1). All tested factors as well as their two-way interactions showed highly significant effects on litter mass loss (Table 1). Mesh size had a significant effect on litter mass loss on all retrieval dates (Table 1, S3A Fig). The mean percent litter mass loss was lower from the coarse-meshed bags (Fig 1A) retrieved after 25 days (Fig 2A) in plots with straw scattered on the surface of the field (treatment Ssc) compared to the other treatments. In both the fine- and coarse-meshed bags, retrieved later in the rice cycle, the mass loss of rice straw litter was similar across all five treatments (Fig 2A).

Bottom Line: Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season.We found no significant responses in microbial decomposition rates to management practices.However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates.

View Article: PubMed Central - PubMed

Affiliation: Department of Community Ecology, Helmholtz-Centre for Environmental Research-UFZ, Halle/Saale, Germany.

ABSTRACT
Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

No MeSH data available.


Related in: MedlinePlus