1. EFFECT OF ORGANIC AND INORGANIC FERTILIZATION ON YIELD AND C(ORG) CONTENT OF SOIL IN LONG-TERM FIELD EXPERIMENTS Tamás Kismányoky University of Veszprém Georgikon Faculty of Agriculture Festetics Str. 7., H-8360 Keszthely E-mail: kis5556@ella.hu

2. Introduction In the frame of the Internationalen Arbeitsgemeinschaft für Bodenfruchtbarkeit under Prof. Dr. Drs. h.c. Boguslawski leadership the IOSDV network with participation of 10 European countrys were established in 1984. Most of the above mentioned field trials are carried out recently and hopefully in the future, too. In Keszthely (Hungary) the initiation date of IOSDV was 1983 autumn, and the investigations are running now as well. The recent publication wanted to give a short information about the main important results of the past 20 years. Till now 7 rotations of the three field rotation went through. At the biometrical evaluation the first rotation (1984-1986) is left out because of the accuracy and the last rotation (2002-2004) is omitted than it is not evaluated now. In this material the conclusions have been drawn from the 5 rotations results.

3. Methods The experimental site (univ. exp. station) is situated int he west part of Hungary at the Longit East 17 o 14’ Latit North 46 o 46’. The soil is Ramann- type brown forest soil (Eutric Cambisol) above 112 m see-level. Water table 3 m deep. This area has moderate rainfall and mild temperature copnditions. The amount of ranfall 683 mm/year, mean temperature is 10.5 o C (1901- 2000). Soil characteristics Volume weight1530 mg/cm 3 Fractions< 0.2 µm26.8% 6.3-2.010.8 20-6.310.8 63-2054.6 Corg0.812 % Norg0.08 % pH7.1 P2.2 mg/100 gr K5.7 mg/100 gr Mg9.0 mg/100 gr Cation exchange capacity 13.9 mval/100 gr.

4. Experimental design and treatments Split-plots, 3 replications Size of plots 48 m 2 (6x8) Factors: Anutrients (organic, inorganic) a 1 (I)NPK a 2 (II)NPK+35 t/ha FYM a 3 (III) NPK+straw+green manure+N BN fertilizers N 0 – N 4 P 2 O 5 100, K 2 O100 in all treatments Crop rotation: Maize-Winter Wheat-Winter Barley (M) – (WW) – (WB) FYM plowed in maize (35 t/ha) Green manure (GM): Raphanus sativus var. Oleiformis 2nd crop sowing on barley stubble Straw (stalk) incorporated into the soil (+1kg N/100 kg DM) in the A III at every crops int he rotation Factor B: N fertilizer kg/ha MWW WB N 0 - - - N 1 70 50 40 N 2 140100 (50+50) 80 N 3 210150 (50+50+50) 120 (80+40) N 4 280200 (100+50+50) 160 (80+40+40)

8. Table 1 C org g/kg 2003 Wheat N0N0 N 50 N 100 N 150 N 200 Average I19.7320.8019.4318.7318.9619.53 II24.9623.9323.5323.4025.3624.23 III22.3023.4322.0320.9320.4021.81 A LSD5% 1.68B LSD5% N.S Table 2 C org g/kg 2003 Maize N0N0 N 70 N 140 N 210 N 280 Average I21.2319.8320.9319.2020.5620.35 II24.8024.4625.1023.6025.3624.66 III24.0626.2025.3325.9625.9325.49 A LSD5% 0.93B LSD5% N.S Table 3 C org g/kg 2003 Barley N0N0 N 40 N 80 N 120 N 160 Average I16.7618.6318.8017.9017.2617.87 II19.8621.7023.0322.8322.5321.99 III16.9317.4019.4620.0319.0018.56 A LSD5% 2.01B LSD5% N.S

9. Table 4 N g/kg 2003 Wheat N0N0 N 50 N 100 N 150 N 200 Average I1.141.181.161.141.101.14 II1.341.391.471.371.361.39 III1.241.27 1.291.181.25 A LSD5% 0.062B LSD5% N.S Table 5 N g/kg 2003 Maize N0N0 N 70 N 140 N 210 N 280 Average I1.191.111.321.131.101.17 II1.361.301.361.311.281.32 III1.251.341.291.321.351.31 A LSD5% 0.10B LSD5% N.S Table 6 N g/kg 2003 Barley N0N0 N 40 N 80 N 120 N 160 Average I1.231.281.261.271.251.26 II1.451.421.471.491.521.47 III1.301.331.361.351.251.32 A LSD5% 0.071B LSD5% N.S

10. Conclusion The IOSDV field experiment testing mineral nitrogen fertilizer in combination with differnet forms of organic manure over period of 20 years (7 crop rotation cycles) has provided specific results concerning the interaction of the manures. Int he crop rotation the yield of winter-wheat in the average of years varied in 2-5.5 t/ha interval. With the organic manuring at the N0 plots yielded 1000 kg/ha grain more compare to the absolute N0 and have positive effect on yield at the lower N fertilizer level, as well. Depending ont he amount of N fertilizer the yield of maize were between 6-8 t/ha and the winter barley 2.8-4.8 t/ha. Int he crop rotation the FYM, straw and the green manure +N increased the yield significantly. The Corg and the Nt values int he soil were significantly influenced by the FYM and the other organic fertilizers.