Impacts of tillage treatments on rhizosphere soil N transformation rates in double-cropping rice field.
Items | Treatments | |||
---|---|---|---|---|
CT | RT | NT | RTO | |
GMR (mg N kg-1 d-1) | 1.81 ± 0.05a | 1.67 ± 0.05b | 1.55 ± 0.05b | 1.32 ± 0.03c |
GACR (mg N kg-1 d-1) | 2.62 ± 0.07a | 2.44 ± 0.07b | 2.23 ± 0.06c | 2.02 ± 0.06d |
GNR (mg N kg-1 d-1) | 0.82 ± 0.02a | 0.63 ± 0.02b | 0.43 ± 0.02c | 0.24 ± 0.01d |
GNCR (mg N kg-1 d-1) | 0.57 ± 0.02a | 0.44 ± 0.01b | 0.32 ± 0.01c | 0.21 ± 0.01d |
NMR (mg N kg-1 d-1) | 0.58 ± 0.02a | 0.47 ± 0.02b | 0.30 ± 0.01c | 0.12 ± 0.01d |
NNR (mg N kg-1 d-1) | 0.62 ± 0.02a | 0.52 ± 0.02b | 0.35 ± 0.01c | 0.15 ± 0.01d |
RR (mg N kg-1 d-1) | 7.17 ± 0.18a | 7.02 ± 0.20a | 6.34 ± 0.21b | 4.17 ± 0.12c |
RT: rotary tillage with crop straw input; CT: conventional tillage with crop straw input; NT: no-tillage with crop straw returning;
RTO: rotary tillage with all crop straw removed as a control.
GACR: gross ammonium consumption rate; GMR: gross N mineralization rate; GNCR: gross nitrate consumption rate; GNR: gross nitrification rate; NNR: net nitrification rate; NMR: net mineralization rate; RR: respiration rate.
Values were presented as mean ± SE.
Different lowercase letters among different tillage treatments indicated significant difference at 0.05 levels.
The same as below.