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  • The effect of fertilization on the mineral contant of artificial grasslands 3.
    57-66
    Imre Kadar
    Views:
    83

    The effects of different N, P and K supply levels and their combinations were examined on the mineral element content of an established all-grass sward with seed mixture of eight grass species in the 28th year of a long term fertilization field experiment set up on a calcareous chernozem loamy soil. The lay-out and method of the trial as well as the fertilizer responses on the hay yield were published elsewhere (Kádár 2004). The effect of fertilization on the nutritional values and nutrient yield also described earlier (Kádár and Győri, 2005). The soil of the growing site contained around 3% humus, 5% CaCO3, 20-22% clay in the ploughed layer and was originally, moderately well supplied with available K, Mg, Mn and Cu and poorly supplied with P and Zn. The trial included 4Nx4Px4K=64 treatments in 2 replications, giving a total of 128 plots. The fertilizers applied were Ca-ammonium nitrate, superphosphate and potassium chloride. The groundwater table was at a depth of 13-15 m, the area was prone to drought. In 2001, however the area had a satisfactory amount of 621mm precipitation with a fairly good distribution. The grass was established on 21. September 2000. The main results and conclusions can be summarised as follows:
         1. As a function of N-fertilization the element content of the 1st cut hay usually increased, except for Al and Mo, which showed dilution effects. The concentration of K, Ca, Mg, Mn, P, Sr, B, Ni enhanced with 25-50%, S and Co with 60-70%, N and Cu 2-times, NO3-N and Na about 5-times compared to the N-control. The P-fertilization stimulated uptake of Mn and Mg for 10-20%; S, NO3-N and Co for 40-50%, Na and for Sr 60-70%, P for 90%, however, inhibited the uptake of Zn and Co for 20-40%, Al and Fe for 50-60%, Mo for 70% compared to the P-control.
         2. The P/Zn ratio showed on P-control soil optimal values of 118, while on highly P-supplied soil 278 P/Zn ratio, so indicating Zn-deficiency. As a function of PxK negative interactions, concentration of Fe dropped from 307 to 105 Al from 206 to 60, Mo from 0.44 to 0.05, Cr from 0.33 to 0.12 mg/kg in air-dry hay. The Cu/Mo ration on N-control soil showed the optimal value of approx. 10, while on heavily fertilized with N soil that of 40-80, indicating extreme Mo-deficiency.
         3. The 2nd cut hay contained about 20% more N, K, Ca, Mg, Na, 40% more Cu, 70-80% more S and Mn, 90% more Fe and P, 140% more Al and nearly 5-times more Mo. The content of B did not changed, while NO3-N dropped about 40% . The Cu/Mo ratio showed value of 2.6 on N-control soil, while on heavily fertilized with N soil ratio of 7.8. The P/Zn ratio indicated on P-control soil optimal value of 150, while on overfertilized with P soil value of 269. So, the P-induced Zn-deficiency could also be proven in the 2nd cut hay, while the Cu-induced Mo-deficiency disappered.
         4. The N-fertilization stimulated in the 2nd cut hay also the accumulation of elements N, K, Mg, P, Mn, Cu and Ni with 20-50% compared to the N-control. The NO3-N increased 4-times, while Na content 10-times. However the elements Fe, Al, B, Mo and Cr showed a dilution effect with 20-60%. The P-fertilization increased the concentration of Mn, Sr, Cd, Co, S and P, while decreased the content of Na, NO3-N, Cu and Zn. As a general rule, the K-fertilization hindered the accumulation of metal cations. The P-induced Cd accumulation was fully counterbalanced by increasing K-supply of soil.
         5. Summarizing above we can state that the long-term fertilization can drastically (in some cases with an order of magnitude) change the concentrations and ratios of elements built in hay through synergetic or antagonistic effects. In the 1st cut hay, for example, the minima-maxima contents of measured elements varied in air-dry hay as follows: N 0.90-3.02, Ca 0.4-0.7, S 0.14-0.32, P 0.12-0.30, Mg 0.10-0.24%; Na 70-700, Fe 100-288, Al 45-250, Mn 71-130, Sr 10-22, Zn 7-14, Ba 6-11, B 3.6-8.1, Ni 0.3-1.6, Cr 0.1-0.4, Mo 0.04-0.44, Co 0.04-0.12 mg/kg.

  • The effects of fertilization on a 6 years old established grassland
    19-30
    Imre Kadar
    Imre Vinczeffy
    Peter Ragalyi
    Views:
    67

    The effect of different N, P and K supply levels and their combinations were examined in the 33rd year of a long-term fertilization experiment on the yield and mineral element content of a 6 years old established all-grass sward in 2006, with seed mixture of eight grass species. The trial was established on a calcareous chernozem soil. The soil of the growing site contained around 3% humus, 5% CaCO3, 20-22% clay in the ploughed layer and was originally moderately well supplied with available K, Mg, Mn and Cu and poorly supplied with P and Zn. The trial included 4N×4P×4K=64 treatments in 2 replications, giving a total of 128 plots. The fertilizers applied were Ca-ammonium nitrate, super phosphate and potassium chloride. The groundwater table was at a depth of 13-15 m and the area was prone to drought. The 1st cut was made on 08th June, the 2nd one on 11th September. During the vegetation period of 8.5 months in 2006, the site had a total of 397 mm precipitation. The lay-out, method and main results of the trial were published earlier (Kádár, 2004, 2008; Kádár és Győri, 2004, 2005). Main conclusions of this study are as follows:

    1. The 1st cut hay yield gave the ¾ of the total yield. Highest yields were reached with the 200 kg/ha/year N-fertilization on soil well supplied with P (Ammonium-lactate soluble P2O5: 214 mg/kg). The yield of NP control plots increased from 1.5 t/ha to about 7.5 t/ha as a function of the N×P positive interaction. The rising P supply alone was not able to enhance the yield, however the N fertilization gave 3.5 t/ha hay surplus even in the P-control treatments. N and P fertilization together resulted in 6.0-6.5 t/ha yield surpluses. The effect of K fertilization also reached 1 t/ha on the NP levels where the ammonium-lactate soluble K2O content fell below 150 mg/kg.
    2. The 2nd cut hay gave 0.5 t/ha on the NP-control plots unfertilized for 33 years, and 2.5 t/ha on the 300 kg/ha/year N treatment with well P-supply. The two cuts together resulted in yield levels between 2-10 t/ha according to the extreme NPK supply. In this year, with relatively good amount of precipitation, the hay yield surpluses for 1 kg N were 47-33-23 kg for the 100-200-300 kg/ha treatments.
    3. The C/N ratio of the 1st cut was narrowed (from 52 to 24) with N-supply and the concentration of N as well as most of the cations increased with the rising N fertilization. In the low yield of the 2nd cut the elements, metals were accumulated. The P, S and Sr were enriched in hay as a result of rising P supply, as superphosphate contains these elements. Antagonistic effect of P predominated in the uptake of other elements, metals (Na, Zn, Cu, Mo, Cr, Co). K content of the hay was lifting while other elements were dropping with the increasing K fertilization partly as a result of dilution effect (N, P, S) and mainly because of cation antagonism (Ca, Mg, Na, Sr). K-B antagonism also appeared.
    4. The N×K interactions resulted in 2-fold Sr and 18-22 fold Na content changes while N×P caused 18-22 fold changes in Mo contents, especially at the 2nd cut. As it can be seen, fertilization can have drastical effects on soil and crops. The induced element deficiencies or oversupplies can lead to diseases, disturbances in the metabolism of animals, so the soil and fodder analyses are necessary.
    5. Considering the leaf diagnostical data, the satisfactory level will be at 200 kg/ha/year N supply and 150 mg/kg ammonium-lactate soluble P2O5 and K2O level or above. The S, Ca, Mg, Fe, Mn supply were satisfactory even at the control plots, while the Zn, Cu and B levels showed deficiency. The P/Zn and K/B ratios became adversely wider in some treatments, as well as the narrowing of the Cu/Mo ratio denotes Cu deficiency and Mo oversupply.
    6. The amount of elements uptaken by hay as a sum of the two cuts and as a function of the supply/yield varied between the following values in kg/ha: 17-163 N; 36-122 K; 9-48 Ca; 6-17 P; 4-15 S; 3-14 Mg; 0,3-8,0 Na; 0,2-1,4 Fe; 0,2-0,9 Al and Mn. The other elements showed the following uptake: Zn 33-194, Sr 28-141, Ba 5-46, Cu 5-39, B 5-26, Mo 3-6 g/ha.
    7. The botanical composition was drastically modified by the aging of the grass and the nutrient supply. Only three species remained out of the eight sown species and one immigrated. Coverage of the tall fescue was between 21-70% according to the N×P supply and 44% as average; coverage of cocksfoot varied between 4-24% depending on the treatment and 18% as an average; coverage of crested wheatgrass was between 0-28% and 9% as an average; the immigrant smooth brome covered 0-24% and 9% as an average; Weed cover was 3-4% as an average at the 1st cut. Weeds thrived mainly on those areas where the grass thinned away (extreme NP-deficiency or oversupply). The total plant coverage on NP-deficient soil was about 50%, while on treatments well supplied with NP it amounted 95-97%.
  • Effect of NPK fertilization and manure load on the grazed natural permanent grassland
    16-25
    Imre Kadar
    Petr Ragalyi
    Laszlo Szeman
    Laszlo Marton
    Sandor Nagy
    Views:
    77
    1. The 2nd year effects of fertilization at Cserkeszőlő site were not proven statistically in hay yield. However, the NP-fertilization and the sheep manure gave 1-1.5 t/ha hay surpluses at Bakonszeg farm. The mineral composition of the hay did not change significantly as a function of treatment neither at Cserkeszőlő, nor at Bakonszeg site.
    2. Elevated, in some cases extreme high K, N, Ca, P, Mg, S and partly Sr, Cd, B concentrations were found in the above ground plant tissue on the resting hump; as well as Fe, Na, Al, Cr and Co concentrations on the driveway. Plant samples were not cleaned or washed so surface pollution could also contribute to the abnormal composition.
    3. According to soil analyses the organic matter content increased in the 0-40 cm layer at watering-place and screen wall. The NO3-N content can reach 250-300 kg/ha level in the 0-1 m soil layer under the watering-place. The potassium rose more fold in the 0-40 cm layer at passageway, watering-place and near to screen wall. The NH4-acetate+EDTA-soluble P content of the whole 0-1 m layer showed 2-fold excess at driveway, 4-fold at resting hump, watering-place and screen wall, as well as 23-fold at passageway.
    4. The resting hump and passageway showed Zn pollution/accumulation. This phenomenon needs to be cleared by more examination. The soluble Fe increased in the topsoil near to screen wall, while soluble S in the topsoil of the watering place and around screen wall. The 0-20 cm soil layer had 72 mg/kg NH4-N and 25 mg/kg NO3-N, so N load can reach 300 kg/ha. The rear, suffering grass stand on this place can not use this N-pool, so here point pollution can be significant.

     

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