In (a), rice yields are indicated by symbols and lines, and aquatic animal yields are indicated by bars. Values are means ± SE (n = 6).
Related to data in Figure 1a–c.
No herbicides were used in the experiment. Values are means ± SE (n = 6).
Related to data in Figure 2.
In each of the three plots in the figure, the white zone represents the proportion of food that aquatic animals (i.e. carp, crabs, or turtles) obtained from feed, and the grey zone represents the …
Related to data in Figure 3.
A higher percentage of 13C remaining indicates slower decomposition. Values are means ± SE (n = 6). An asterisk indicates a significant difference between RM (rice monoculture) and RA (rice-aquatic …
Related to data in Figure 4.
(a) Percentages of feed-N in rice plants, aquatic animals, and the environment (e.g., soil and water). (b) Total N in rice biomass at the end of the experiments. Values are means ± SE (n = 6).
Related to data in Figure 5a and b.
(a) δ15N value in soil at the beginning and end of the mesocosm experiments. (b) Total N in soil at the beginning and end of the mesocosm experiments. Values are means ± SE (n = 6). An asterisk …
Related to data in Figure 6a and b.
The rice plants and carp (A), crab (B), and turtle (C) were photographed in the corresponding experimental plots (D, E, and F), which were arranged in completely randomized blocks in three …
RM: rice monoculture; RA: rice coculture with an aquatic animal. Values are means ± SE (n = 6), ns indicates no significant difference between RM and RA (p > 0.05).
Related to data in Appendix 1—figure 1.
RM: rice monoculture; RA: rice coculture with an aquatic animal. Values are means ± SE (n = 6), * indicates a significant difference between RM and RA (p < 0.05).
Related to data in Appendix 1—figure 2.
RM: rice monoculture; RA: rice coculture with an aquatic animal. The P contents in soil were analyzed with a San++ Continuous Flow Analyzer (Skalar, Netherlands) after the air-dried soil samples …
Related to data in Appendix 1—figure 3.
System | Treatment | Nitrogen input (kg ha–1) | Phosphorus input (kg ha–1) | ||||||
---|---|---|---|---|---|---|---|---|---|
Feed | Fertilizer* | Feed | Fertilizer | ||||||
Base fertilizer | Top-dress fertilizer | Total | Base fertilizer | Top-dress fertilizer | Total | ||||
Rice-carp | RM | --- | 82.50 | 29.40 | 111.90 | --- | 36.02 | 5.31 | 41.33 |
RA | 78.41 | 82.50 | --- | 82.50 | 19.63 | 36.02 | --- | 36.02 | |
Rice-crab | RM | --- | 112.5 | 44.94 | 157.44 | --- | 49.12 | 11.79 | 60.91 |
RA | 80.46 | 112.5 | --- | 112.50 | 20.62 | 49.12 | --- | 49.12 | |
Rice-turtle | RM | --- | 82.5 | 44.94 | 127.44 | --- | 36.02 | 11.79 | 47.81 |
RA | 105.46 | 82.5 | --- | 82.50 | 36.61 | 36.02 | --- | 36.02 |
The total amount of feed-N and - P input were determined by multiplying the amount of feed by the percentage of N and P in feed that were analyzed with a San++ Continuous Flow Analyzer (Skalar, Netherlands) (Lu, 1999).
Values are means ± SE (n = 6)
System | Treatment | Rice grain*(kg ha–1) | Rice straw*(kg ha–1) | Aquatic animal*(kg ha–1) | Total(kg ha–1) | |
---|---|---|---|---|---|---|
Rice-carp | RM | 18.53 ± 0.92 | 5.49 ± 0.25 | --- | 24.02 ± 1.15 | |
RA | 21.68 ± 0.50 | 6.44 ± 0.32 | 7.45 ± 0.95 | 35.57 ± 0.96 | ||
Rice-crab | RM | 26.38 ± 1.53 | 8.60 ± 0.67 | --- | 34.98 ± 1.87 | |
RA | 34.74 ± 2.19 | 13.67 ± 1.04 | 1.07 ± 0.15 | 49.48 ± 2.79 | ||
Rice-turtle | RM | 19.57 ± 0.72 | 12.64 ± 0.44 | --- | 32.21 ± 0.42 | |
RA | 24.19 ± 1.17 | 17.19 ± 0.69 | 20.66 ± 1.47 | 62.04 ± 2.60 |
The total amount of P contained in the grain and straw of rice plants, and in the aquatic animals were determined by multiplying the biomass of rice (grain and straw) and aquatic animals by the percentage of P in rice and aquatic animals that were analyzed with a San++ Continuous Flow Analyzer (Skalar, Netherlands) (Lu, 1999).
The original feed (in which most N was supplied by soybean powder) was supplemented with 15N-labeled soybean powder to obtain 15N-labeled feed.
Experiment | Original feed | 15N-labeled soybean powder | 15N-labeled feed | % of labeled soybean powder in the 15N-labeled feed | |||
---|---|---|---|---|---|---|---|
N% | δ15N | N% | δ15N | N% | δ15N | ||
Rice-carp | 5.58 | 1.73 | 6.61 | 1,539 | 5.25 | 649 | 33 |
Rice-turtle | 8.21 | 8.41 | 6.98 | 445 | 7.54 | 128 | 30 |
Rice-crab | 5.94 | 1.19 | 6.98 | 445 | 7.27 | 145 | 33 |
Experiment | C (%) | δ13C | 13C (mg) |
---|---|---|---|
rice-carp | 0.41 | –16.21 | 2.18 |
rice-crab | 0.44 | –16.24 | 2.39 |
rice-turtle | 0.43 | –15.62 | 2.33 |
Related to data in Appendix 1—figure 1.
Related to data in Appendix 1—figure 2.
Related to data in Appendix 1—figure 3.