1. Vertical distribution of soil organic matter in different cropping systems Zoltan Toth Univ. of Veszprem, Georgikon Faculty of Agriculture Dept. of Soil Management and Land Use Keszthely, Hungary

2. Aim: Long-term effect of different cropping systems and fertilization on soil organic matter content

3. Cropping systems Crop rotations Maize continuous cropping

4. Soil Ramann-type brown forest soil (Eutric Cambisol) Texture: sandy loam Humus content: 1,6-1,7% (C org : 9.28-9.86 gkg -1 ) AL-P 2 O 5 : 60-80 mgkg -1 AL-K 2 O: 140-160 mgkg -1 pH KCl : 7.3

6. Climate Long-term annual mean precipitation: 650 mm Mean annual temperature: 10.8 o C (january: -0,8 o C; july: 21,5 o C) Average number of sunny hours: 1962 Average number of rainy days: 161

7. Crop rotation long-term field experiment Set up: 1963 Design: striped block 2 factors: - fertilizer rates (“A”) - crop rotations (“B”) Replications: 4 Number of plots: 160 Gross area of the plots: 129,2 m 2

8. Crop rotations (“B”): winter wheat alfalfa winter wheat maize sorghum winter wheat oats and vetch winter wheat maize

9. Fertilizer rates (“A”): a 1 : 0 kg NPK/ha/5 years a 2 : 520 kg NPK/ha/5 years a 3 : 2080 kg NPK/ha/5 years a 4 : 2080 kg NPK + 35t #/ha/5 years)

10. Continuous maize cropping long-term field experiment Set up: 1969 Design: split-plot 2 factors: - fertilizer rates (“A”) - timing of N application (“B”) Replications: 4 Number of plots: 48 Gross area of the plots: 88.8 m 2

11. Fertilizer rates (“A”): - a 1 : 0 kg NPK/ha/year - a 2 : 300 kg NPK/ha/ year - a 3 : 600 kg NPK/ha/ year - a 4 : 900 kg NPK/ha/ year Timing of N application (“B”): - b 1 : N in 1 dose in spring - b 2 : N in 1 dose in autumn - b 3 : N in 2 doses in spring

12. Studied parameters: Organic matter contenet of soil (by Tyurin’s method) NO 3 - -N content of soil

19. Conclusions In the crop rotations the soil organic matter content was greater than in continuous maize cropping. The highest organic matter content was registered in the crop rotation including alfalfa

20. Soil organic matter content decreased gradually with a rise in the depth of soil layers until the depth of 100-120 cm either in each of the crop rotations or in the maize monoculture, but the depth of the effect of the experimental treatments was different

21. Fertilization as well as complementary FYM application resulted in higher soil organic matter content

22. Thank you for your attention!