Tuesday, February 2, 2016

Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils.

The tillage is a common agricultural practice that consist in draw furrows variable depth in the ground with a hand tool or a plow before to cultivate, this technique has been used by centuries, but some investigation say that tillage practice has a negative effect in soil bacterial populations, for that reason was necessary to evaluate the different effect of tillage practice on soil autotrophic bacterial populations and their CO2 assimilation rates at varying soil depths.
Autotrophic bacteria can fix CO2 and are widely distributed in agricultural soils. We know six pathway to fix CO2 but the most common is the Calvin-Benson cycle. To know the effect of tillage on soil, in this study two samples were from paddy soil and two from upland from different region of China (Table 1.). Two sets were taken from each site of soil, in one group tillage was simulated (CT) and in the other one the analysis of soil was direct, without tillage (NT). The samples of soil were incubated and the CO2 were labelled with 14C. The Result of this experiment showed that the amount of CO2 was higher in the tillage treatment, also the samples of all soil was taken from different depth and independently whether tillage was practiced or not, in both cases the CO2 fixed was to more depth, the lees CO2 fixed.

Table1. Basic study site information and corresponding soil physicochemical characteristics. CEC, cation exchange capacity; SOC, soil organic carbon

Figure 1. The 14C-SOC, 14C-MBC and 14C-DOC concentrations recovered at different depths (0–1 cm, 1–5 cm, and 5–17 cm) in conventional tillage (CT) and no-till (NT) soils after 110 days of incubation. Error bars indicate the standard error of the mean (n =4). *indicates significant differences between CT and NT soils at P < 0.05; nd, not detectable. DOC, dissolved organic carbon; MBC, microbial biomass carbon; SOC, soil organic carbon.

The effect of tillage on soil microbial CO2 fixation, can be positive on agricultural practice, if you are interest, you can read more here:

Ge, T., Wu, X., Liu, Q., Zhu, Z., Yuan, H., Wang, W., Whiteley, A.S., and Wu, J. 2016. Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils. Scientific Reports.

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