Tackling the future challenges of Organic Animal Husbandry - vTI

! Agriculture and Forestry Research, Special Issue No 362 (Braunschweig, 2012) ISSN 0376-0723
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tember 2011. Thirty three samples were collected in total (Table 1). A higher number of samples
(13) was collected from the meadow plot, due to the periodical moving of pig grazing along the plot
area. Organic C and total N were selected as fertility indicators. Soil organic C (SOC; Walkley &
Black method) and total (Kjeldahl) N (Ntot) were measured in the top 0-20-cm soil layer according
to the Italian official methods of chemical analysis (MiPAAF 2000).
Table 1. Experiment details: date of soil sampling, crop sequence and other sources of variation
in the experimental device during the experiment period.
Plot no. Crop sequence Date of sampling
and code
1 Meadow 22/06/10 - 1
28/10/10 - 4
17/11/10 - 5
07/12/10 - 6
26/01/11 - 7
12/05/11 - 9
06/07/11 - 10
06/07/11.- 10
27/07/11 - 11
07/09/11 – 12
2 Barley 22/06/10 -1
28/10/10 - 4
17/11/10 - 5
07/12/10 - 6
Meadow 26/01/11 – 7
3 Sorghum 22/06/10 - 1
21/07/10 - 2
28/10/10 - 4
17/11/10 - 5
07/12/10 - 6
26/01/11 - 7
27/07/11 – 11
4 Vegetables 26/08/10 - 3
28/10/10 - 4
17/11/10 - 5
07/12/10 - 6
26/01/11 - 7
5 Old lucerne 26/01/11 - 7
21/04/11 – 8
304
Number of
samples
3
1
1
1
1
1
2
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
Crop cover Pig pasture 1
No
No
Yes 2
Yes 2
Yes 2
Yes
No
Yes
No
No
Yes
Yes 2
Yes 2
Yes 2
No
Yes
No
Yes 2
Yes 2
Yes 2
No
Yes
Yes
No
No
No
Yes
Yes
1 In parentheses, the actual number of days of grazing, at the soil sampling date
2 Crop re-growth
Results
Yes(21,38,56)
No
No
No
No
No
Yes (13, 50)
No
Yes (26)
No
No
Yes (28)
Yes (48)
Yes (68)
No
No
Yes (6)
Yes (28)
Yes (48)
Yes (68)
No
No
No
Yes (28)
Yes (48)
No
No
No
Yes (79)
Mean SOC and Ntot contents in soil were remarkably different depending on the plot (Table 2). In
particular, SOC and Ntot contents were on average higher in soil of the mixed grass and ex-lucerne
crops. For a given plot, the SOC and Ntot contents tended to increase or did not vary during the
sampling period, with exception of the sorghum plot, where a slight decrease in C content was observed
in the last sampling date. Pig grazing did not seem to influence the mean SOC content, during
the sampling period (Table 3).