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The results achieved in (long-term) field fertilization experiments can be extended or generalized within certain limits with the help of soil and diagnostic plant analysis. In addition, it was reasonable to determine the readily available nutrient contents in soil samples taken from the Hungarian National Fertilization Long-term Trials, particularly that of P, not only using the AL (ammonium lactate) method officially recognized in Hungary, but also with the P tests applied in the European Union and North America (including the CaCl2, H2O, Olsen, Bray 1, LE and Mehlich3 methods). The major differences in the soil properties of the experimental sites made it possible to investigate these soil P tests, together with plant P uptake, in various characteristic Hungarian soils, often with extreme values of soil parameters. Averaged over 28 years, there was a difference of around 50 kg P2O5•ha-1 between the actual P levels. The P contents at the P0 level gave a good indication of the diverse P supplies in the soils of the experimental locations and, indirectly, of the differences in soil texture, pH and CaCO3 status. At the P 2 level the new AL-P limit values, established for crops having higher P requirements grown on Hungarian soils on the basis of correlations detected by analysing the data from long-term field P fertilization experiments, resulted in an improvement in P supply level to at least the "good" category in all soils except a chernozem brown forest soil in Bicsérd. The analyses confirmed the dependence of the AL method on the soil CaCO 3 content: in comparison with the Mehlich3 method, non-calcareous and calcareous soils were separated into two distinct groups. The use of the AL-P correction, i.e. the conversion of AL-P values to standard soil property values (KA: 36; pH(KCl): 6.8; CaCO3: 0.1%) greatly reduced the dependence of the AL method on the CaCO3 content of the soil. Nevertheless, this correlation was not observed when comparing AL-P and Olsen-P contents and corrected AL-P and Olsen-P contents, suggesting that the Olsen method may also depend on the pH and CaCO3 status to some extent. The results confirmed the correctness of the Sarkadi AL-P correction model. However, this needs to be backed up by correlations with plant P contents. This will require the comparison of soil analysis results with plant analysis and yield data. The soils of long-term experiments can be used to evaluate P analysis for environment protection purposes and to estimate the environmental risks of soil P saturation. These issues will be discussed in other papers in this series.


Csorba S.,Szent Istvan University | Farkas C.,MTA Talajtani Es Agrokemiai Kutatointezet | Birkas M.,Szent Istvan University
Agrokemia es Talajtan | Year: 2011

The effect of different soil tillage systems on soil physical properties, especially the water retention functions (pF curves) decisive for the soil moisture regime, was studied in a split-plot field experiment set up on pseudomyceliar calcareous chernozem soil (Calcic Cernic Chernozem, WRB) formed on loess at the Józsefmajor Experimental Station of Szent István University. The experiment was carried out in a single-factor strip design on plots measuring 13 m × 150 m in three replications. The following soil tillage systems and tilling depths were applied: ploughing (SZ, 26-30 cm); disking (TÁ, 16-20 cm), disking combined with deep loosening (LT, L: 40-45 cm, T: 16-20 cm), shallow cultivation (SK, 12-16 cm); cultivation (K, 16-20 cm), and no tillage (DV). All the six treatments were investigated. The crop sequence was sunflower, winter wheat and maize between 2008 and 2010, with mustard as an intercrop in 2009. In the year analyzed, maize was sown on 4 May 2010. On all the plots basic tillage was carried out in autumn 2009. The soil structure in the various tillage treatments was characterized on the basis of pore size distribution. For this purpose single and dual porosity pF curves were fitted to the water retention values recorded for the soil layers in the individual tillage treatments. The dual porosity pF curve was found to give a better fit to the measured values than the single porosity curve for all the treatments. The soil macro- and micropore domains were used to evaluate the effect of different tillage systems on soil structure, as they strongly influence the soil moisture regime. These two domains could be clearly distinguished using the dual porosity pF curve. Studies were also made on the effect of direct drilling (without soil disturbance), ploughing, disking and the other agronomic measures on soil water retention characteristics. The no-tillage technology resulted in an almost constant macropore domain at various soil depths, while in the ploughed treatment the tillage depth could be clearly identified as changes in the pore domain. Differences could be observed between the tillage treatments both in pore size distribution and in the measured soil moisture content. In the complex function applied, the w value expressing the ratio of pore domains gave the best reflection of the individual effects of the tillage treatments on soil structure. It was found that under the given conditions, tillage using deep cultivation resulted in the most stable soil structure, most favourable for the water and air regimes.


Kodobocz L.,MTA Talajtani Es Agrokemiai Kutatointezet | Zsiros L.R.,MTA Novenyvedelmi Kutatointezet | Muranyi A.,MTA Talajtani Es Agrokemiai Kutatointezet
Agrokemia es Talajtan | Year: 2011

The efficiency of inoculating soybean and the host plant specificity of the inoculant strains was examined on chernozem soil under field conditions. The soybean (Glycine max L., Kurca) was inoculated at a rate of 80 kg seed/5×1011 CFU. In the course of the vegetation period, inoculation was supplemented by the application of a trace element solution. The results were evaluated by analysing plant and soil samples taken from 5×1 m for each treatment (uninoculated control; inoculated; inoculated + microelements). The comparative analysis of the microsymbiotic bacterium strains was carried out using the BOX-PCR method. No nodule formation was observed on the control plants. The inoculation of the soybean seed proved to be successful. The infection and N-fixing activity of the inoculant strains was satisfactory, resulting in an average of 6-7 composite, active nodules per plant. The dry mass of the plants increased by 25% in response to inoculation. The supplementary microelement solution did not lead to a significant increase in the dry mass of the plants or in the number of flowers. Only one of the strains used as inoculant was able to form efficient symbiosis with soybean, indicating that the host plant-microsymbiont relationship is extremely specific. This was confirmed by the PCR analysis.


Interactions between potassium and boron were investigated in 1988 on a pseudomyceliar (calcareous) chernozem soil at the Experimental Station of RISSAC in Nagyhörcsök, using sunflower as indicator plant. Basic fertilization was applied at a rate of 100 kg each of N and P2O 5 per hectare. K2O rates of 0, 1000 and 2000 kg•ha-1 and B rates of 0, 20, 40 and 60 kg•ha-1 were applied in autumn 1987, after alfalfa as forecrop. The fertilizers were applied in the form of calcium ammonium nitrate, superphosphate, 60% KCl and 11% borax. The three K rates formed the main plots and the four B rates the subplots. Each of the 12 treatments was tested in three replications on a total of 36 plots arranged in a split-plot design. The ploughed layer contained around 5% CaCO3, 3% humus and 20-22% clay. The soil originally had good supplies of N, Ca, Mg and Mn, moderately good supplies of K and relatively poor supplies of P and Zn. The groundwater was located at a depth of 13-15 m and the area was prone to drought. During the growing period of sunflower there was 290 mm rainfall (close to the long-term mean), but May and July were extremely dry. The main conclusions were as follows: - The number of plants per hectare at harvest dropped significantly from 34,000 to 23,000 on the K control plots in response to B application. However, the lower plant density resulted in the production of larger flower heads, and greater thousand-seed mass and seed mass per flower head, thus preventing a loss of yield. On plots replenished with potassium, this negative effect of boron was not observed. The distribution of the total air-dry aboveground biomass (5.5 t•ha-1) was 2.1 for seeds, 2.1 for stems and 1.3 t•ha-1 for the flower heads. - The B content of sunflower organs was significantly increased by B fertilization, while K fertilization led to a significant or insignificant decrease. The largest quantity of boron (averaging 69 mg•kg- 1) was accumulated in the flower heads at harvest. This was around three times the mean B content of the stem and seeds. The K content of the plants was not modified significantly by K fertilization. - Na and Fe were mainly accumulated in the roots of 4-6-leaf plants, N, K, Ca and Mg in the shoots, Ca and Cu, as well as B, in the flower heads at harvest, and N, P, Zn and Cu in the seeds. There was a reduction in the N, P, Zn and Cu contents of the stem, while these elements accumulated in the seeds. - The element content of 1 t seed yield + the corresponding stem and flower head by-products amounted to approximately 46 kg N, 40 kg K (47 kg K2O), 27 kg Ca (38 kg CaO), 7 kg P (16 kg P2O5) and 7 kg Mg (11 kg MgO). These data could be used as guidelines for the estimation of the nutrient requirements of sunflower by the extension service. - The fertilizer requirements of sunflower, generally considered to exhaust the soil and have a high demand for nutrients, declined drastically in the case of combine harvesting, since most of the K, Ca and Mg was found in the by-products, which were not removed from the field.


The effect of microelement pollution at rates of 0, 30, 90 and 270 kg•ha-1 on winter barley was examined on calcareous sandy soil in the region between the rivers Danube and Tisza. The microelement salts were applied on a single occasion at the start of the experiment in spring 1995 in the form of Cr2(SO4)3, K 2Cr2O7, CuSO4, Pb(NO 3)2, Na2SeO3 and ZnSO4. The 24 treatments (6 elements×4 pollution rates) were each applied in three replications, giving a total of 72 plots, each measuring 7×5 = 35 m2. As generally observed on sandy soils, the growing site had a poor water regime, was prone to drought and was poorly supplied with macronutrients (NPK). The ploughed layer contained 0.7-1.0% humus and 2-3% CaCO3, and the groundwater was at a depth of 5-10 m. The whole experiment was treated each year with 100 kg•ha-1 each of N, P2O 5 and K2O active agents as basic fertilizer. The main results were as follows: - Due to the very dry weather in May and June the yields were very low. On uncontaminated soil the grain yield of winter barley was around 1.8 t•ha-1, while the total air-dry aboveground biomass only just exceeded 3 t•ha-1. In the 6th year of the experiment the carry-over effects of the 270 kg•ha-1 rates of Se and Zn proved to be toxic. This effect was felt mainly in the generative phase, with a 60-70% loss of grain yield. - In the Cr(III) treatment, the Cr content of the straw and grain did not rise significantly with the contamination rate, but in the Cr(VI) treatment the moderate accumulation was significant. Lead accumulation was only significant in the straw, remaining below the 0.1 mg•kg-1 detection limit in the grain even on contaminated soil. Compared with the control, there was a 2-2.5 times increase in Cu accumulation on average. The Zn content was 6-times higher in the straw and 3-times higher in the grain, while hyperaccumulation was recorded for Se in both plant organs (with a 470× increase in the concentration). The grain became unfit for human consumption in the Se treatment and at higher rates of Zn, and the straw for feeding purposes on soil treated with selenium. - On contaminated soil the maximum element uptake (g•ha-1) at harvest was as follows: Se 243, Zn 81, Cu 10, Cr and Pb 6. Assuming constant conditions, the phytoremediation of the soil would require 1111 years for Se, 3300 for Zn, 27,000 for Cu and 45,000 for Cr and Pb. - The specific element content of winter barley (1 t grain + the corresponding by-products) was found to be 28, 13, 28, 9 and 7 kg•t-1 for N, P2O5, K 2O, CaO and MgO, respectively. These data could be used as guidelines for the estimation of the nutrient requirements of winter barley by the extension service. - Soil analysis indicated that the NH4- acetate+EDTA-soluble Cr content increased in the 0-30 cm topsoil in the Cr(III) treatment, while in the Cr(VI) treatment the Cr maximum was detected below a depth of 260 cm and the whole soil profile was contaminated. Cu, Pb and Zn also accumulated in the topsoil, remaining at the application site even after the 6th year of the experiment. Like Cr(VI), the water-soluble Se could be detected throughout the 0-290 cm profile examined, so the total extent of the leaching zone could not be determined.


Szecsy O.,MTA Talajtani Es Agrokemiai Kutatointezet | Uzinger N.,MTA Talajtani Es Agrokemiai Kutatointezet | Villanyi I.,MTA Talajtani Es Agrokemiai Kutatointezet | Szili-Kovacs T.,MTA Talajtani Es Agrokemiai Kutatointezet | Anton A.,MTA Talajtani Es Agrokemiai Kutatointezet
Agrokemia es Talajtan | Year: 2011

The effect of chromium, lead and zinc (all common heavy metal pollutants in Hungary) was studied on various soil microbiological and biochemical parameters, and on how these biological parameters are correlated with the fractions of the heavy metals dissolvable with various extracting agents. Lignite was used as a stabilising agent. The upper 0-25 cm layer of an acidic sandy soil from Nyírlugos was used for the 8-week incubation experiment set up in 2006, as this soil has very low metal-binding capacity (low organic matter content, CaCO3 deficiency). The soil had the following chemical properties: pH(H2O): 5; pH(KCl): 3.9; KA: 27; humus: 0.92%; CaCO3: traces; salt content: <0.02%; "total" element content soluble in aqua regia (mg•kg -1): As: 1.20; Ba: 31.9; Co: 1.35; Cr: 7.54; Cu: 3.51; Mn: 144; Ni: 5.31; Pb: 8.02; Sr: 7.63; Zn: 41.6; the Cd, Hg, Mo, Se and Sn contents were below the detection limit (0.02; 0.12; 0.04; 0.6; 0.25, respectively). The experiment was set up using the DISITOBI experimental design and evaluation model, which allowed linear, quadratic and pair-wise interactions to be calculated for the variables. The heavy metals were applied at concentrations of 0, 375, 750, 1125 and 1500 mg•kg-1 in the form of Cr(NO 3)3•9H2O, Pb(NO3)2 and ZnSO4•7H2O, while the lignite was added to the pots at rates of 0, 2.5, 5, 7.5 and 10 m/m%. The lignite did not contain any heavy metals at concentrations above the limit values laid down by the Ministry of Agriculture and Rural Development. Further parameters: pH(H2O): 4.2; organic C: 34.5%; element contents (mg•kg-1) Ca: 570; Mg: 115; SO4: 15 058; S: 14 273. The air-dry soil and the lignite were homogenized (<2 mm). Then 1 kg quantities of soil were placed in unperforated plastic pots and covered. The metal salts were added in solution, simultaneously with the lignite. During the incubation period the values of soil moisture content (65% of field water capacity) and temperature (25°C) were kept constant. Samples were taken after 8 weeks. Cellulose powder was added to the model soil at a rate of 1 m/m% to increase the magnitude and activity of the soil microflora, in the interests of easier detection. The "total" Cr, Pb and Zn contents soluble in aqua regia, distilled water, acetate buffer and Lakanen-Erviö extractant were recorded. Changes in the soil microflora were estimated by determining the invertase enzyme activity, the fluorescein diacetate (FDA) hydrolytic activity, the microbial biomass-C (CFE) and the "total" phospholipid-fatty acid content (PLFA analysis). In addition to the DISITOBI model, the variables were evaluated by means of principal component analysis and linear correlation analysis (using StatSoft Statistica, version 9). Although correlations were detected between the metal contents dissolved by the four extractants and the soil microbiological and biochemical parameters, none of these were close. Neither principal component analysis nor correlation analysis demonstrated correlations between the Cr, Pb and Zn contents soluble in aqua regia, distilled water, acetate buffer and Lakanen-Erviö extractant and changes in the soil microbiological and biochemical parameters, suggesting that these extractants were unable to indicate the fraction available to soil microbes. The clearly negative effect of chromium on the soil microflora was detected in the form of moderate and loose correlations, irrespective of the extractant. The negative effect of lead proved to be significant for some of the soil microbiological and biochemical parameters. No negative effect could be demonstrated in the case of zinc. This could probably be attributed to the fact that, as an essential element, Zn plays a positive role in the activity of the soil microflora.


Kadar I.,MTA Talajtani Es Agrokemiai Kutatointezet | Csatho P.,MTA Talajtani Es Agrokemiai Kutatointezet
Agrokemia es Talajtan | Year: 2011

Interactions between potassium and boron were investigated on a pseudomyceliar (calcareous) chernozem soil at the Experimental Station of RISSAC in Nagyhörcsök in 1990, in the 3rd year of an experiment involving spring rape. Basic fertilization was applied at rates of 100 kg each of N and P2O5 per hectare. The K levels were 0, 1000 and 2000 kg•ha-1 K2O and the B levels 0, 20, 40 and 60 kg•ha-1, applied in autumn 1987 after the forecrop, alfalfa. The fertilizers were applied in the form of calcium ammonium nitrate, superphosphate, 60% KCl and 11% Na2B4O7× 10H2O (borax). The three K levels formed the main plots and the four B levels the sub-plots, giving a total of 12 treatments in 3 replications on a total of 36 plots, arranged in a split-plot design. The ploughed layer contained around 5% CaCO3, 3% humus and 20-22% clay. The soil was originally satisfactorily supplied with N, Ca, Mg, Mn and B, with moderate supplies of K but only relatively poor supplies of P and Zn. The groundwater was located at a depth of 13-15 m and the area was prone to drought. During the 130-day vegetation period, the spring rape received 244 mm rainfall, in addition to which the top 1 m of soil contained an estimated 126 mm of water when the crop was sown. This total of 370 mm water was sufficient to supply the water demands of a good to moderate yield. However, the drought during ripening in August hindered seed formation. The main conclusions were as follows: - The K and B treatments had no influence on the development or yield of rape. The stem, pod and seed yields at harvest amounted to 7.6, 1.9 and 1.0 t•ha-1. On the untreated soil the N, P, K, Ca, Mg, Mn, B and Cu concentrations in the shoot at the rosette stage were in or close to the optimum range given in the literature. - After fertilization with borax the B content of the vegetative organs of spring rape doubled on averaged by the third year of the experiment. K fertilization increased the K content of the vegetative organs, while lowering the concentrations of Ca, Mg and B due to ion antagonism. The K-Mg antagonism was especially pronounced. The K/Mg ratio rose from 8 on the K control soil to around 14 in the roots, from 10 to 17 in the shoots and from 16 to 28 in the stem. - The total 10.6 t•ha-1 aboveground biomass at harvest accumulated 245 kg K, 236 kg N, 121 kg Ca, 35 kg Na, 26 kg P and 19 kg Mg. These data could be utilized by the extension service when estimating the nutrient requirements of spring rape.


The effect of 0, 30, 90 and 270 kg•ha-1 microelement loads on rape was investigated on a calcareous sandy soil in the region between the Danube and Tisza rivers. The salts of the microelements, in the form of Cr 2(SO4)3, K2Cr2O 7, CuSO4, Pb(NO3)2, Na 2SeO3 and ZnSO4, were applied on a single occasion at the start of the experiment in spring 1995. The four rates of six elements in three replications gave a total of 72 plots, each measuring 7×5 m = 35 m2. The growing site, which had the poor moisture regime characteristic of sandy soils, was prone to drought and poorly supplied with macroelements (NPK). The ploughed layer contained 0.7-1.0% humus and 2-3% CaCO3. The groundwater was located at a depth of 5-10 m. Basic fertilization with 100 kg each of N, P2O5 and K 2O per hectare was applied to the whole experiment every year. The main results were as follows: - In the course of the 10-month vegetation period, the winter rape crop received a total of 545 mm precipitation. Due to the dry weather in autumn and winter, the seed yield hardly reached 1 t•ha -1 and the by-product yield was 5 t•ha-1 on the untreated soil. In response to rising rates of Se the seed yield dropped significantly by 45% and the by-product yield by 22% compared with the control, when the carry-over effect was examined in the 7th year. The carry-over effect of the other elements was not significant. - On contaminated soil the maximum Cr concentration in the straw at harvest was 0.4 and 1.6 mg•kg-1 in the Cr(III) and Cr(VI) treatments, respectively. There was no significant Cr accumulation in the seed in either treatment. The Pb content reached 0.6 mg•kg-1 on soil severely loaded with lead, but in all cases the content in the seed was below the detection limit. The Cu content, too, increased hardly perceptibly in the seed, and the Zn content did not change as the Zn rate increased. In the by-products, however, the Cu and Zn contents both doubled. Selenium exhibited hyperaccumulation in both plant organs, with a concentration increase of two orders of magnitude, making the rape seed and the by-products unsuitable for human and animal consumption, respectively. - The quantity of Cr incorporated into the aboveground yield of rape at harvest amounted to 2.8 and 10 g•ha-1 in the Cr(III) and Cr(VI) treatments, respectively. The maximum uptake of Pb, Cu, Zn and Se was 3.6, 30, 109 and 1660 g•ha-1, respectively. Some 93% of the Se absorbed was accumulated in the by-products. The time required for the complete phytoremediation of soil contaminated with the 270 kg•ha-1 rate would be 163 years for Se, 2477 years for zinc, 9000 years for copper, 27,000 years for chromium Cr(VI) and 75,000 years for lead, assuming the same farming conditions. - On the untreated control soil the specific element content of 1 t seed + the associated by-products (kg•t-1) was 78 for N, 46 for P2O5, 96 for K2O, 158 for CaO and 27 for MgO. This is around twice the specific contents recommended by the Hungarian extension service for K2O and three times as high for CaO and MgO, partly due to the very wide by-product/main product ratio and partly as a consequence of the calcareous soil.

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