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  • The effects of fertilization on 2 year old established swards. Yield and mineral content 6.
    94-106
    Views:
    58

    The effects of different N, P and K supply levels and their combinations were examined on the hay yield and mineral element content of an established 2 year old all-grass sward in the 29th year of a long-term fertilization field experiment set up on a calcareous chernozem soil. The soil of the growing site contained around 3% humus, 3-5% CaCO3, 20-22% clay in the ploughed layer and was originally moderately well supplied with available N, 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, superphosphate and potassium chloride. The groundwater table was at a depth of 13-15 m and the area was prone to drought. In 2002, the area had 401 mm precipitation and gave 2 cuts of grass. The 1st year results of the trial were published earlier (Kádár, 2005a, b). The main conclusions can be summarised as follows:
    1. As a function of N×P fertilization the two cuts of the hay yield made up 1.4-8.0 t/ha while the green herbage 5.0-24.0 t/ha. The N-fertilization was of vital importance, which increased the hay mass 5 times. The P-response was moderate in the 1st, cut while there were no K-responses at all on this soil with 135 mg/kg ammoniumlactate (AL) soluble K2O values in plough layer.
    2. On those plots well supplied with PK the 100 kg/ha/yr N-treatment gave a total of 48 kg surplus hay/kg N applied. The 200 kg/ha/yr N-treatment yielded 11 kg, while the 300 kg/ha/yr N-treatment yielded 4 kg surplus hay/kg N applied. The NO3-N content of the 1st cut hay increased over permitted 0.25% level when using the maximum N-rate and made up this NO3-N form 26% of the total-N pool. The optimum PK-supplies in this site seems to be about 130-150 mg/kg AL-P2O5 and AL-K2O in plow layer with 200 kg/ha/yr N applied.
    3. N-fertilization enhanced the content of N, K, Mg, Na, Mn, Cu and NO3-N, while the concentration of S, P, Al, Fe, B and Mo dropped in the primary hay. The increasing P-supply stimulated the uptake of P, Ca, Mn, Sr and Ba, while hinderned the uptake of S and Mo. The K-fertilization rose the content of K and Ba and diminished the concentration of Mo and the antagonistic metal cations like Ca, Mg and Na.
    4. The NPK fertilization-induced Mo-deficiency can first of all jeopardized the fodder quality in this site. On the unfertilized plots the hay showed around 1.0 mg Mo /kg D.M., while on the N3P3K3 plots 0.1-0.2 mg/kg D.M. The P/Mo ratio lifted from 2-4 thousand up to 20 thousand. In the 2nd cut this phenomena partly disappeared, while developed the P-Zn antagonism. On P-control plots measured 15 mg/kg Zn
    94
    GYEPGAZDÁLKODÁSI KÖZLEMÉNYEK, 2006/4.
    dropped to 10 mg/kg while the P/Zn ratio rose from 167 up to 364.
    5. The 2nd cut hay had a little yield, yet was rich in minerals having 30-50% higher average element content compared with the primary hay. However the N, Al, Fe and Mo showed 2-times higher concentrations in the 2nd cut hay. There were found extra large, 25-fold differences in hay Na content as a function of N×K supply levels under synergetic effect of N and antagonistic effect of K treatment.
    6. Summarizing the above we can state that the long-term fertilization may drastically change the content and ratios of elements built in hay through synergetic or antagonistic effects. In the air-dried 1st cut hay for example, the minima-maxima concentrations of measured elements varied as follows: N 0.7-3.0%, K 1.3-3.0%, Ca 0.3-0.5%, Mg 0.13-0.21%, S 0.15-0.32%, P 0.10-0.32%; Na 50-1400, Mn 60-120, Al 50-120, Fe 70-140, Sr 8-170, Zn 6-40, Ba and B 3-6, Cu 2.5-5.5, Ni 0.4-1.4, Mo 0.1-1.0 mg/kg.

  • The effect of fertilization on the mineral contant of artificial grasslands 3.
    57-66
    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
    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%.
  • Comparing of soil and rhizoplane of grasses
    13-17
    Views:
    61

     The aims of this paper were to determine and compare the most important physical, chemical and microbial characteristics of seven grassland areas near Debrecen.
         Physical properties: moisture content (t%), clay and silt contents (Li%), soil plasticity according to Arany (KA), were measured.  

    As were the chemical characteristics: pH, salt content (%). lime content (it depends on pH), humus content, organic nitrogen and mineral materials (nitrate nitrogen, ammonium lactate soluble phosphorous and potassium).
         The total viable number of bacteria, the amount of cellulose decomposing and nitrifying bacteria and the quantity of microscopic fungi were studied. Additionally, some soil enzyme activities, such as phosphatase and catalase as well as carbon-dioxide production were determined.
         The number of microbes and the microbiological activity of the soils were higher in autumn than in summer. The lowest number of bacteria was determined in solonchak-solonetz soil. The phosphatase enzyme activity and the CO2 production are connected with the higher organic matter content of the soils. The increasing sodification decreased the phosphatase activity and the intensity of CO2 production. Meadow soil type led to an increase in catalase activity.
    During the examination zhe rhizoplane of two test plants per grassland was also studied. The umber of microorganisms in the rhizoplane of test plants was usually higher than the values obtained in soil samples.
         Within one soil types there were differences between two test plants including the same or different family.
         There were no considerable differences among the number of fungi genera isolated from the soil samples and the rhizoplane or among the results obtained in summer and autumn. Independent of the soil types and plant species, Fusarium, Mucor and Penicillium genera were found in large percentages promoted by the rainy summer and autumn season. 

  • Effect of NPK fertilization and manure load on the grazed natural permanent grassland
    16-25
    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.

     

  • Effect of fertilization on the mineral element uptake of an established all-grass sward 4.
    3-10
    Views:
    57

    The effects of different N, P and K supply levels and their combinations were examined on the mineral element uptake 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, nutritional values and element content were published elsewhere (Kádár, 2005, 2005a; Kádár és 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 satisfactory amount of 621 mm 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 NxP positive interactions the element uptake of the 1st cut hay expressed as mean of K treatments increased between the N0P0 control and the maximum N3P3 levels as follows: K 62-190, N 45-218, Ca 16-51, S 5-24, P 4-24, Mg 4-16, Na 0.5-5.0 kg/ha; Mn 282-968, Sr 35-170, Zn 32-73, Ba 29-55, B 18-44, Cu 8-40 g/ha. The uptake of Ba increased from 23 to 62 g/ha, that of Ni from 1.5 to 8.9 g/ha as a result of KxP positive interactions. Uptake of Mo measure on K0P0 soil, however, dropped from 1.6 g/ha to 0.4 g/ha on the K3P3 soil as a function of negative KxP interactions.
         2. The 2nd cut hay harvested on 9th October 2001 showed only N-effects. The hay yield measured on N-control soil was 1.0 t/ha while on 300 kg/ha/yr N-treatment 3.9 t/ha. The uptake of Fe, Ba and Mo increased 2-fold; uptake of Ca, S, P, Sr, Zn and Co 3-4-fold, uptake of K, N, Mg, Mn, Ba and Cu 5-6-fold, while uptake of Na 33-fold with the maximum N-rate, compared to the N-control and as means of PK treatments.
         3. The 2 cuts together gave on the unfertilised control 3 t/ha, while on the N3P3K3 maximum supply level 13 t/ha hay yield. The uptake of Fe, Cr, B, Ni, Mo and Co increased 2-3 times, uptake of Ca, Mg, Mn, K, Zn, Ba and Cu 5-6 times, uptake of S, Sr and P 7-8 times, uptake of N 10 times, while uptake of Na 16 times on the maximum N3P3K3 supply levels, compared to the unfertilised control. The maximal mass of uptaken K and N made up 388 kg/ha, Ca 80 kg/ha, S 49 kg/ha, P 42 kg/ha (96 kg/ha P2O5), Mg 24 kg/ha in 2001.
         4. To have 1 t of air-dry hay it was used by grasses as a mean of 25 kg K (30 kg K2O), 20 kg N, 6 kg Ca (8-9 kg CaO), 2-3 kg S, 2 kg P (5 kg P2O5) and 2 kg Mg (3-4 kg MgO). For microelements: 300 g Na, 200 g Fe, 120 g Mn, 100 g Al, 16 g Sr, 13 g Zn, 8 g Ba, 5 g B, 5 g Cu, 1-2 g Ni, 1 g Mo, 0.2 g Cr and 0.1 g Co. The As, Hg Cd, Pb and Se were under detection limit of 1 g. Data may serve for assessing the nutrient demand of all-grass sward.

  • The effects of fertilization on 2 year old established swards. Mineral uptake 7.
    107-118
    Views:
    52

    The effects of different N, P and K supply levels and their combinations were examined on the mineral element uptake of an established 2 year old all-grass sward in the 29th year of a long-term fertilization field experiment set up on a calcareous chernozem soil. The soil of the growing site contained around 3% humus, 3-5% CaCO3, 20-22% clay in the ploughed layer and was originally moderately well supplied with available N, 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, superphosphate and potassium chloride. The groundwater table was at a depth of 13-15 m and the area was prone to drought. In 2002 the area had 401 mm precipitation and gave 2 cuts of grass. The lay-out and method of the trial as well as the fertilizer responses on the hay yield and element content were published earlier (Kádár 2006). The main conclusions drawn as follows:
    1. While the hay yield was basically determined by N-fertilization which lifted the hay mass 5 times compared to the N-control, the uptake of elements was drastically modified through the N×K and N×P synergistic and antagonistic interactions.
    2. As a function of N×K treatments the uptake K changed for example at the 1st cut between 23-198 kg/ha, at the 2nd cut between 9-80 kg/ha. At the same time the uptake of Na fluctuated between 0.05-7.15 kg and 0.4-4.4 kg/ha, that of Mo 0.4-3.2 g/ha and 0.2-2.3 g/ha resp. As a function of N×P treatments the uptake of P changed at the 1st cut between 3-14 kg/ha, Sr between 12-388 g/ha, Mo between 0.5-4.5 g/ha. The nutrient accumulation at the 2nd cut showed an analogical picture.
    3. The K-fertilization stimulated accumulation of K and Ba, while inhibited the antagonistic metal cations’ uptake of Ca, Mg and Na. The increased P-supply rose the absorption of P, S, Sr and Ba while diminished the extracted amount of Mo, which dropped down by 1/3rd compared with the control. The liberal N-supply stimulated the incorporation of N, K, Mn, Sr and Cu resulting an increase of an order of magnitude.
    4. Between the two extreme supply levels (N0P0K0 and N3P3K3) there were found extreme differences in element uptake in 2002 as follows: 34-302 kg/ha K, 15-168 kg/ha N, 8-35 kg/ha Ca, 5-22 kg/ha S, 4-22 kg/ha P (9-51 kg/ha P2O5) and 3-14 kg/ha Mg. The incorporated Mn, Sr, Zn and Cu enhanced an order of magnitude on N3P3K3 plots compared to the N0P0K0 absolute control. Uptake of As, Cd, Co, Cr, Hg, Pb and Se left behind the detection limit of 1 g/ha.
    5. To have 1 t air-dry hay it was used by grasses 17-35 kg K, 9-19 kg N, 3-5 kg Ca, 2.0-2.5 kg S, 1.3-2.5 kg P (3.0-5.7 kg P2O5), 1.4-1.9 kg Mg, 170-980 g Na, 90-170 g Fe, 60-120 g Mn and Al, 10-50 g Sr, 7-25 g Zn, 3-6 g Ba, B and Cu, 0.3-1.3 g Mo and 0.4-0.9 g Ni. Data illustrate the nutrient turnover of a grassland and may be used for assessing the nutrient demand of all-grass sward.

  • Mineral content of floodplain meadows in the upper Tisza region
    32-34
    Views:
    73

    Az állatok zavarlalan életműködéséhez a táplálékuknak megfelelő mennyiségben és arányban kell ásványi anyagokal tartalmaznia. A gyepek növényzelének elemtartalmát igen sok tényező befolyásolja. Többek között a hő, a csapadék, az öntözés, a talaj típusa és tápanyag-ellátottsága, a gyeptípusok, a fajösszetétel. a tenyészidőszak aspektusai, a növények fenofázisa, a gyephasználat módja.
         A folyók árterében gyakran találunk extenzív hasznosítású legelőket, illetve természetes, nem telepített kaszálókat. Mivel ezen területeken kemikáliákat nem lehet alkalmazni, és a fajgazdagság nagy,  igen alkalmasak arra, hogy a különböző növények elemtartalmát meghatározzuk. 2001-es évben négy ártéri legelőről, illetve kaszálóról készítettünk cönológiai felvételezést és mértük meg az ott található növényfajok elemtartalmát.
         Azok a növények, amelyeket nem vonnak be szándékosan a termelésbe, vagyis tágabb értelemben használva gyomnövények, igen értékes elemei a legelők növényzetének, mert az állatok számára értékes mikroelemekben gazdagabbá teszik a legelőt.
         Az általunk vizsgált területeken, az ideálisnak tartott 2/3 rész egyszíkű, 1/3 rész kétszikű aránytól eltérő arányokat kaptunk, de ez nem eredményezett Mn-hiányt. 

  • The effect of magnesium application on the yield and mineral content of grass species
    29-31
    Views:
    63

    A füvek jól reagálnak a tápanyag-ellátásra, a fűhozam és ásványianyag tartalom jelentősen növelhető trágyázással. A növények Mg-tartalmát elsősorban a talaj Mg-tartalma határozza meg. A füvek Mg tartalma 0,1-0,3% között változik, esetenkélll ennél nagyobb is lehet. Az állatok ásványianyag-ellátása szempontjából 0.20-0.25% Mg tekinthető kritikus értéknek. Amennyiben a szárazanyag Mg-tartalma 0.2%-nál kisebb, a legelőn tartott teheneknél fűtetánia léphet fel.
         Tenyészedény-kísérleteink alapján megállapítható, hogy magnéziumszegény, savanyú homoktalajokon a szálkásperje, az angolperje hozama és Mg-tartalma egyaránt növelhető megfelelő NPK- és Mg-trágyázással. A nagyobb hozam és a jó minőség elérésére a K-, Ca- és Mg-ellátást össze kell hangolni. Az egyoldalú beavatkozások torzulásokhoz vezetnek a talajoldat összetételében. melyek a termés mennyiségét és minőségét is kedvezőtlenül befolyásolhatják.
         A Box-Wilson módszerrel tervezeti többtényezős kísérletek alkalmasak a magnézium érvényesülését befolyásoló tényezők vizsgálatára. A tényezők együttes változtatásával sokkal kevesebb kezeléskombinációval határozhatók meg a közvetlen hatások és kölcsönhatások, mint a hagyományos kísérletezési módszerekkel.
         Kísérleteink igazolták, hogy Biczók és Tolner-Kafarov munkáján alapuló - számítógépes programjai alkalmasak a többtényezős kísérletek tervezésére és értékelésére. A regressziós egyenlet hűen írja le a mért paraméter és a kezelések kapcsolatát. A felület egyes szegmensei síkban ábrázolhatók.
         Az értékelés módszerét kiegészítettük a hatásfelületek térbeli ábrázolásával, a maxumum-számítással, továbbá az optimális adagok és arányok számításával. A továbbfejlesztett értékelési módszerrel megállapítottuk, hogy a K-, Ca- és Mg-ionok antagonizmusa a termésképzésben csak szélsőséges esetekben érvényesül. A vizsgált elemek bizonyos határok között segítik egymás hatását.