Joint International Conference on Long-term Experiments ...

MATERIALS AND METHODS
The experiment was carried out in the Nyírség region, the NE Hungary. The biogas
plant is a part of a big agricultural system with crop production, livestock (beef and
diary cattle), slaughterhouse and processing plant. The biogas plant works with
mesophylic and thermophylic systems, the basic materials are livestock manure, plant
crop and offal. The total capacity of thermophylic and mesophylic digesters are 7,600
m 3 and 9,400 m 3 , respectively. The remaining digestate after anaerobic digestion can be
utilized in crop production as a nutrient supply.
No. of
treatment
Table 1: Applied treatments in the experiments with digestate.
Phenological stage at the time
of treatment
Proportion
Quantity of
digestate
Quantity of water
1. Control 0 0 0
2. after sowing 100% mean 0
3. after sowing 100% +30% 0
4.
5.
6.
7.
after sowing
plants with 6-7 leafs
after sowing
plants with 6-7 leafs
after sowing
plants with 3-4 leafs
plants with 6-7 leafs
after sowing
plants with 3-4 leafs
plants with 6-7 leafs
50%
50%
50%
50%
25%
50%
25%
25%
50%
25%
mean 0
+30% 0
mean 0
+30% 0
8. after sowing 100% 0 +30%
9. after sowing 100% 0 mean
10.
after sowing
plants with 6-7 leafs
50%
50%
0 mean
11.
after sowing
plants with 6-7 leafs
50%
50%
0 +30%
after sowing
25%
12.
plants with 3-4 leafs
50%
0 +30%
plants with 6-7 leafs
25%
after sowing
25%
13.
plants with 3-4 leafs
50%
0 mean
plants with 6-7 leafs
25%
The rates of the digestate to be applied was determined by its actual N-content, because
N is one of the main macronutrients for plants, but it could be a serious environmental
pollution if leached to the soil water and accumulates in it. The main parameters of the
digestate are the followings: pH 8.025, density 1025.75 kg m 3 , dry matter content
1.1824 m/m% (row matter), total-N 0.376 m/m% (row matter), Mg 32.7 mg kg -1 (r.m.),
Na 272.5 mg kg -1 (r.m.).
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