Fundamento normativo del acceso a la salud

As expected, the arable soil functioned as CH4 sink during the whole season 2004/2005 in winter wheat 5 and prior intercrops with only three excepted sampling dates (figure 3.1). CH4 oxidation rates ranged between 0 and 15 µg C m-2 _h-1 _{in w/o L-M and between 0 and 19 µg} C m-2 _h-1 _{in w/o L-FC. Highest CH4 uptake rates of the soil occurred in May, June, and July} 2005. CH4 emissions were observed in w/o L-FC on February 1 (2.9 µg C m-2 h-1) and February 24, 2005 (4.7 µg C m-2 _h-1_{), i.e. one and two days after application of liquid fermented fertilizer,} which derived from CH4 dissolved in the fertilizer. However, two days after manuring end of January, no CH4 emissions could be measured anymore but CH4 uptake. The only efflux of CH4 in w/o L-M was detected in winter wheat 5 on December 22, 2004 (2.6 µg C m-2 h-1), that differed significantly from CH4 uptake in w/o L-FC. Further significant differences were determined in intercrops on September 15, 2004 and in winter wheat 5 on March 15, 2005. CH4 fluxes integrated over 365 days resulted in similar carbon uptakes of 479 g C ha-1 in w/o L-M and 478 g C ha-1 _{in w/o L-FC, respectively (table 3.7). Generally, emissions derived} from CH4 outgassing of the fertilizer (here on February 1 and 24, 2005) were included into the integration for the day of measurement and into the calculation of the coefficients of variation. Mean spatial variabilities of CH4 fluxes of 256% and exceedingly high 905% were assessed in w/o L-M and in w/o L-FC, respectively (table 3.8). The CV values for temporal variability of the CH4 fluxes amounted to 85% in w/o L-M and 131% in w/o L-FC (table 3.8). Coefficients of correlation (r²) between CH4 fluxes in winter wheat 5 and air temperature and between CH4 fluxes and temperature in 5 cm soil depths accounted for 0.37 and 0.51, respectively (table 3.9).

CH4 fluxes measured in 2003/2004 in winter wheat 5 and prior intercrops similarily showed a continuous CH4 uptake of the soil with rates between 2.6 and 22 µg C m-2 h-1 in w/o L-M and between 1.1 and 23 µg C m-2 _h-1 _{in w/o L-FC (figure 3.2). High CH4 oxidation rates were} observed in June and July 2004. A single CH4 emission peak occurred a few hours after application of liquid fermented fertilizer on February 27, 2004 in w/o L-FC, when 153 µg C m-2 _h-1 _{(CH4 dissolved in the fertilizer) were evolved. However, this efflux event was not} significant. Manuring on March 25 and April 7, 2004 did not result in CH4 emissions at the investigated dates. The only significantly decreased CH4 oxidation rates in w/o L-FC were found on March 11 and April 15, 2004. Integration of CH4 fluxes over 365 days led to amounts of carbon uptake of 663 g C ha-1 _{in w/o L-M and 546 g C ha}-1 _{in w/o L-FC, thus a reduction of}

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18% in w/o L-FC (table 3.7). The spatial variability of CH4 fluxes averaged 37% in w/o L-M and 42% in w/o L-FC (table 3.8). The CV value for the temporal variability of CH4 fluxes accounted for 71% in w/o L-M and for exceedingly high 1592% in w/o L-FC (table 3.8). Coefficients of correlation of 0.37 and 0.51 between CH4 fluxes and air and soil temperature in 5 cm soil depth, respectively, were calculated (table 3.9).

During season 2002/2003, CH4 oxidation rates in winter wheat 5 accounted for 0 to 36 µg C m-2 _h-1 _{in w/o L-M and for 0 to 22 µg C m}-2 _h-1 _{in w/o L-FC (figure 3.3). The large CH4 influxes} occurred in June and July 2003. Due to manuring of liquid fermented fertilizer in w/o L-FC on February 19, 2003, a very high CH4 emission peak of 175 µg C m-2 h-1 was observed approximately six hours after application (significant), whereas determination of a CH4 flux directly after fertilizing was not possible. However, manuring on March 13, 2003 did not result in CH4 efflux. A single observation of a non-significant CH4 emission in w/o L-M was made on May 22, 2003 when 10 µg C m-2 _h-1 _{evolved. No CH4 fluxes could be observed on October 16,} November 6, 2002, and January 7, 2003 in both treatments, on February 19 and May 7, 2003 in w/o L-FC, and on March 13, 2003 in w/o L-M. Integration of CH4 fluxes over 365 days showed a carbon uptake of 855 g C ha-1 _{in w/o L-M and 476 g C ha}-1 _{in w/o L-FC, representing a} decrease of 44% in w/o L-FC (table 3.7). CH4 emission on May 22, 2003 in w/o L-M was included in integration for one day. Mean spatial variabilities of CH4 fluxes of 84% and 45% were assessed in w/o L-M and in w/o L-FC, respectively (table 3.8). The CV values for temporal variability of the CH4 fluxes amounted to 163% in w/o L-M and 661% in w/o L-FC (table 3.8). Correlation coefficients (r²) between CH4 fluxes in winter wheat 5 and air temperature and between CH4 fluxes and temperature in 5 cm soil depths accounted for 0.34 and 0.31, respectively (table 3.9).

Table 3.7: Integrated CH4 fluxes over 365 days in winter wheat 5 and spring wheat in the cropping

system without livestock in w/o L-M and w/o L-FC, respectively.

Manuring Treatments w/o L-M w/o L-FC Season Crops % of w/o L-M g C ha-1 % of w/o L-M g C ha-1 Winter Wheat 5 100 -855 56 -476 2002/2003 Spring Wheat 100 -585 90 -529 Winter Wheat 5 100 -663 82 -546 2003/2004 Spring Wheat 100 -502 109 -547 Winter Wheat 5 100 -479 100 -478 2004/2005 Spring Wheat 100 -714 90 -644

Table 3.8: Coefficients of variation (CV) for temporal and mean spatial variability of the CH4 fluxes in

winter wheat 5 and spring wheat in the cropping system without livestock in w/o L-M and w/o L-FC, respectively. Manuring Treatments w/o L-M w/o L-FC Season Crops CV % time Ø CV % space CV % time Ø CV % space Winter Wheat 5 163 84 661 45 2002/2003 Spring Wheat 121 38 110 73 Winter Wheat 5 71 37 1592 42 2003/2004 Spring Wheat 68 56 77 47 Winter Wheat 5 85 256 131 905 2004/2005 Spring Wheat 159 47 205 76

Table 3.9: Correlation coefficients (r²) between CH4 fluxes and air temperature as well as between CH4

fluxes and soil temperature in 5 cm depth. CH4 emissions resulting from fertilizer application were

excluded for correlation analysis.

Season Crops CH4 Fluxes – Air Temp. CH4 Fluxes – Soil Temp. Winter Wheat 5 0.34 0.31 Spring Wheat 0.47 0.50 Spelt 0.57 0.58 2002/2003 Potatoes 0.48 0.44 Winter Wheat 5 0.37 0.51 Spring Wheat 0.46 0.44 Spelt 0.57 0.64 2003/2004 Potatoes 0.29 0.27 Winter Wheat 5 0.37 0.51 Spring Wheat 0.42 0.51 2004/2005 Spelt 0.28 0.46

Comparing results of annual CH4 fluxes in winter wheat 5 and prior intercrops during the seasons 2002/2003, 2003/2004, and 2004/2005, the arable soil acted continuously as CH4 sink. Oxidation rates in intercrops slightly decreased from first to third sampling in 2004/2005 and 2003/2004. Highest CH4 uptake rates were always observed at the end of the investigation periods, thus in summer. Manuring of liquid fermented fertilizer in w/o L-FC mostly entailed CH4 emissions of CH4 dissolved in the fertilizer with different duration. Except 2004/2005 with similar amounts of carbon uptake, less CH4 was oxidized in w/o L-FC compared to w/o L-M, but in

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different proportions. The level of uptake rates in w/o L-M decreased from 2002/2003 to 2004/2005, whereas the level in w/o L-FC was higher in 2003/2004 than in the other two seasons.