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The effects of phosphorus (P) fertilizer on P loss potential, soil Olsen-P and neutral phosphatase activities in paddy soils fertilized with superphosphate or pig manure (PM) were evaluated in this paper. Data were collected from a field experiment in the Tai Lake Basin, China. Superphosphate rates were 0, 17.5, 26.7, and 35.0 kg P/ha, and PM rates were 0, 1.4, 2.1, and 2.8 t/ha for each crop, respectively. Soil Olsen-P in the plow layer increased to a greater extent with PM than with superphosphate. Pig manure increased neutral phosphatase activities in the plow layer compared with PM-free treatment. In contrast, superphosphate inhibited neutral phosphatase activities compared with superphosphate-free treatment. Spring application of P fertilizer markedly increased the total P of surface water in November (< 0.01 vs. 0.10 mg/L) compared with P-free treatment. The total P of shallow groundwater at a 75 cm depth was ~0.01 mg/L. Phosphorus fertilizer did not influence Olsen-P or neutral phosphatase activities under the plow layer. Downward movement of P did not occur. Appropriate rate of P application of 26.2 kg P/ha for each crop in this soil reduced the risk of P loss in the paddy wetland ecosystem.

Noccaea caerulescens (NC) and Arabidopsis halleri (AH) were studied to compare cadmiunm (Cd) accumulation and resistance. After 30, 60 and 90 days of plant cultivation in Cd contaminated soil (Cd1 = 30, Cd2 = 60 and Cd3 = 90 mg Cd/kg soil) amino acids were determined in plants. The comparison between both species showed that Cd stress resulted in different changes of amino acids levels playing a significant role in plant adaptation to Cd stress. Our analyses indicated higher accumulations of amino acids in the roots of NC compared to AH. Contrasting responses of plants to Cd contamination were confirmed in methionine metabolism. Methionine was determined only in roots of AH after 30 and 60 days of plant cultivation. Free methionine content decreased with increasing Cd contamination (Cd3 treatment - 40% decrease compared to the control treatment). Our results also showed that NC contains more than 10-fold higher content of histidine than AH. These observations indicated that this amino acid may be involved in Cd resistance and accumulation by reducing oxidative damage. Tryptophan plays a major role in the regulation of plant development and in defense responses. Its significant increase for NC treatments in contrast to AH treatments was determined.

Soil testing in the Czech Republic is based on the use of the Mehlich 3 method for determination of macronutrients and diethylentriaminepentaacetic acid (DTPA) and hot-water extraction for determination of micronutrients. Since inductively coupled plasma optical emission spectrometers have become commonly used in soil testing laboratories, Mehlich 3 extractant could be used very effectively also for a simultaneous micronutrient determination. To take full advantage of the universal Mehlich 3 extractant, new criteria for evaluation of the content of micronutrients in this extractant are needed. The criteria presented in this study were obtained by a simple calculation of criteria from the relationships between the Mehlich 3 extractant and the extraction methods for which the criteria were available (DTPA for copper, zinc, manganese, iron and hot-water extraction for boron). The first calculated estimates of the criteria were pre-validated and slightly adjusted to minimize the difference between the frequency of the samples in each category after determination and evaluation by the compared methods. Further adjustment of the presented critical values with respect to the field and pot experiments will be necessary in the future.

To investigate the effects of osmotic stress on plant growth, and ions and compatible solutes accumulations of sugar beet (Beta vulgaris L.), in the present study, two-month-old plants were subjected to different degrees of osmotic stress (-0.5, -1.0, and -1.5 MPa) induced by sorbitol for 7 days. The results showed that fresh weight and water content in both leaf blade and leaf petiole significantly decreased by osmotic stress. With the increase of osmotic stress, Na⁺ concentration in leaf blade showed the significantly increasing trend. However, osmotic stress significantly reduced K⁺ concentration in lateral root. It was observed that osmotic stress of -1.5 MPa remarkably increased sucrose accumulation in storage root compared to control. In addition, plants accumulated more sucrose and fructose in storage root than in other tissues. Proline concentrations in leaf blade, leaf petiole and storage root significantly increased by osmotic stress of -1.0 MPa and -1.5 MPa; in leaf blade it was to a higher degree than in leaf petiole and storage root. These results suggested that sugar beet plants can adapt to osmotic stress by accumulating more osmolytes, such as Na⁺, sucrose and proline.

Minituber production by traditional method is an expensive procedure due to limited productivity. In order to increase the multiplication rate of seed material in vitro, multiple techniques have been assayed in the last decades. The aeroponic system is a soilless culture system, where roots are kept in a dark environment saturated with aerosol of nutrient solution. Aeroponics technology is potentially efficient for specific potato cultivars. The aim of this study was to investigate the multiplication rate of microtubers of national cultivars in aeroponics while maintaining weekly intervals between harvests. The total number of harvests was 14 to 15 depending on year. The results of the experiments were analysed with ANOVA and means were separated with the Tukey's test at 5% P-value. The most important parameter of minituber production, their number, was on average 32.5-36.0 per plant and 1268-1396 per m² depending on cultivar. Number of minitubers was two to three times greater in the case of aeroponic production than by traditional method. A full economic analysis is necessary to prove that this production technique can be put into practice.

The effect of foliar application of selenium (Se) fertilizers (sodium selenite and selenate) in two different Se doses (10 and 20 g/ha) on grain yield, Se content and mechanical and technological parameters of winter wheat grain was investigated in the field fertilization experiment. Foliar spray application of Se was applied at the growth stage of the 2^nd node on the main stem (32 BBCH). Selenate foliar applications in dose 10 g Se per ha showed a significant increase of grain yield in comparison to control treatment without Se application. The mechanical and technological parameters of wheat grain were not significantly affected by both selenite and selenate foliar application. The average Se concentration was significantly lower in 2007/2008 (grain yield 8.72 t/ha) than 2006/2007 (yield 6.35 t/ha) growing season (0.133 versus 0.189 mg Se/kg dry matter). The grain Se absorption efficiency at foliar application of 10 and 20 g Se/ha of selenite and selenate were 1.35-1.45% and 13.24-15.14%, respectively.

Stable isotope ¹⁵N tracer technique was used in combination with artificial rainfall simulation to study the influence of interflow and surface-flow on nitrogen (N) migration loss of soil-plant systems on typical red soil sloping uplands. This study also investigated the utilization efficiency of fertilizer N during different peanut plant growth stages. The results indicated that soil N loss was predominantly via interflow and erosive sediment. Fertilizer N loss during the initial growth stage was mainly through surface runoff, while that occurred as interflow increased from less than 5% to around 16% during the middle and late growth stages. The loss of fertilizer N through surface runoff, erosive sediment and interflow accounted for over 18% of the total N application. The utilization rate of fertilizer N by peanut plants was around 45% through its life cycle, and that 70% of N absorbed by this plant derived from the soil. This highlighted the importance of adopting effective methods to reduce nutrient loss through interflow and surface-flow, the need to increase the utilization rate of fertilizers, and the importance to maintain soil fertility at a relatively high level.

Balancing the use of maize (Zea mays L.) residues for soil amendment and forage is an important strategy for agricultural sustainability. Therefore, the study assessed the impacts of four proportions of maize residues to soil retention (S) and forage (F) on soil total organic carbon (TOC); total nitrogen (TN); carbon/nitrogen ratio (C/N); grain yield, economic benefits and nutritional contents of removed residues. The concentrations of TOC and TN increased when more residue returned, while the C/N ratios were S₁₀₀ + F₀ > S₃₄ + F₆₆ > S₆₆ + F₃₄. Also, crude protein, crude fat, and crude starch in the removed residues were F₃₄ > F₆₆ > F₁₀₀, while the crude fiber and ash contents exhibited the opposite trend. The crop yield improved with residue retention increased, but there were no differences on the economic benefits of the four residue-use systems. The S₃₄ + F₆₆ system maintained a TOC ranging from 11.51 to 13.37 g/kg, a TN from 1.12 to 1.16 g/kg, 92.93% of the annual yields of the S₁₀₀ + F₀ system, and 6.2 t/ha/year of forage. Therefore, the S₃₄ + F₆₆ system can balance the use of maize residues for soil amendments and forage to sustainably develop a household crop-livestock system.

The leaf dehydration was accompanied by the highest increase in the content of cell wall-bound phenolics (CPh) during heading (148.3% C; % of control) and in course of drought applied twice during propagation and flowering (130.5% C) of triticale. A statistically significant correlations were obtained only for CPh and parameters of leaf water status and chlorophyll fluorescence. An increase in the content of free phenolics (FPh) under drought conditions was only noticed during the flowering (111.4% C) of plants. Drought application exhibited most spectacular decrease in the ratio of FPh to CPh during propagation (48.5% C) and heading (58.8% C). It was found that the cell wall increases at the expense of free phenolic compounds.

The present study was undertaken to quantify changes in the status of soil nutrients, their depletion and build-up after continuous long intensive cropping for last 36 years in a permanent manorial trial which has been in progress since 1972 in an alfisol of western Himalayas. The rotation was maize-wheat which included various combinations of N, P, K, Zn and FYM (farmyard manure). Continuous cultivation influenced pH, OC (organic carbon), available N (nitrogen), P (phosphorus) and K (potassium). An increase in the status of organic carbon was observed in 100% NPK + FYM treatments for more than three decades from initial value of 7.9 to 12.0 g/kg. The use of either FYM or lime alongwith 100% NPK sustained crop productivity or improved nutrient status. However, imbalanced use of nutrients i.e. NP or N alone is adversely affecting the fertility of soil by aggravating the problem of soil acidity. Application of S free P fertilizer DAP (diammonium phosphate) drastically reduced the yield of both the crops. Thus, continuous use of balanced fertilizers is necessary for sustaining soil fertility and productivity of crops.

Low application of fertilizer potassium (K) in intensive agriculture leads to a gradual decrease and, afterwards, to a steady state of soil K determined by tests which are based on soil exchangeable K (K_exch) extraction. In this situation, non-exchangeable K (K_non-exch) is being released and therefore real plant availability does not necessarily correspond to soil test K. This incoherency was investigated in 14 agricultural soils with low K as determined by the Mehlich 3 method. Plant-available K released by exhaustive cropping of perennial ryegrass and K determined by the Neubauer seedling test were compared with 8 soil K extraction methods, with the total K content and with the relative content of soil K-bearing minerals. K determined by the ryegrass test (314 mg/kg on average) was more than 3-times higher than K based on K_exch extraction methods, but was from 2 to 3 times lower than K determined by K_non-exch extracting methods. The relative content of mixed-layer phyllosilicates was significantly related to K extracted by soil tests. The relative content of orthoclase correlated only with total K and mica-group minerals with none of the extractions. The best prediction of plant-available K in investigated soils was obtained with sodium tetraphenylboron and StepK methods.

The aim of this study was to determine the effect of sulphur (S) fertilization on macronutrient concentrations in the roots, straw and oil cake of white mustard and Indian mustard. The experiment was conducted in northeastern Poland (2006-2008). The highest content of N, P, K, Mg and S was noted in the oil cake of both mustard species. Sulphur fertilization increased S concentrations and had no effect on Mg concentrations in the roots of white mustard and Indian mustard. Sulphur fertilizers applied to soil significantly increased the content of N, K and Ca in the roots of Indian mustard, whereas they had no significant effect on the content of N, P and Ca, and decreased K concentrations in the roots of white mustard. Sulphur fertilization led to a significant decrease in N content, and an increase in the content of K and Ca in the straw of both mustard species. Sulphur fertilization significantly decreased P concentrations and increased S concentrations in the oil cake of both mustard species. In response to S fertilization, the content of N and K decreased in the oil cake of Indian mustard, but did not change significantly in the oil cake of white mustard. Therefore, S fertilization significantly differentiated the fertilizing value of post-harvest residues and the feeding value of white mustard and Indian mustard seeds.

The availability of risk elements in soil can be possibly reduced by various soil additives. Among them, the attention has been recently focused on the research of unconventional soil additive - biochar. The aim of this study was (i) to observe the effect of biochar application on risk elements transport through the soil profile and (ii) to assess the availability of risk elements in biochar amended soil to willow growth. The experiment was established at greenhouse conditions and extremely contaminated soil, reaching 43 mg/kg cadmium (Cd) and 4340 mg/kg zinc (Zn), was used. To observe risk element content in leachate, the lysimeter cylinders were tested. The rates of biochar were 0 (control); 5, 10, and 15% per mass of soil. The results showed that biochar significantly increased biomass production whereas the plant Cd and Zn contents remained unchanged in most cases. In leachate, Cd and Zn content decreased by 99% at all the biochar treatments. We can summarize that biochar appears to be a very effective regulator of availability of observed risk elements and improver agent for biomass production of plants and remediation efficiency.

Based on a long-term fertilization experiment on a light soil, a study was conducted on the impact of varied fertilization on the levels of silicon forms available in the soil. It was shown that the exchangeable silicon content in the tested soil was very low, which can have a limiting effect on crop yields. Soil pH is a factor that significantly affects the exchangeable silicon content of the soil. Therefore, under the conditions of acidic soils, liming is a treatment that increases the level of silicon forms available to plants in the soil.

Thirty-day-old barley (Hordeum vulgare L. cv. Zafer-160) calli were treated with 0, 0.5, 1 µmol/L 22(S),23(S)-Homobrassinolide (HBL) for four weeks. Transfer of calli to hormone-free or HBL-supplemented medium caused an increase in total soluble protein and DNA contents and a decrease in superoxide dismutase (SOD; E.C. 1.15.1.1) activity. 0.5 µmol/L HBL caused the highest protein and DNA levels and the minimum decrease in fresh weight; while the lowest superoxide dismutase activity was recorded in 1 µmol/L HBL-treated group. Calli developed nodular structures and green cell clusters after transfer onto hormone-free or HBL-supplemented medium. Methylation-sensitive restriction fingerprinting (MSRF) analysis detected a few changes in methylation between control and 0.5 µmol/L groups. Combination of data led us to the conclusion that HBL favoured regeneration and shoot development and may ameliorate tissue culture stress in a mechanism, which is independent of cytosine methylation.

The large-diameter time-domain reflectometry soil water sensors placed horizontally in a structured loamy soil are very sensitive to rapid preferential percolation events. Their readings on these occasions rise considerably, often becoming higher than the native soil's porosity. The effect is caused by gaps between the native soil and the sensors. The geometry of the gaps, even if filled with soil slurry at installation, is not exactly reproducible, which leads to sensor-to-sensor variability of readings. Field calibration in percolation-free periods lead to non-unique trajectories rather than monotonous calibration curves, which can be commented in terms of soil heterogeneity and the dual porosity theory. Data of two typical percolation events are presented. Sensors of this type can be used for detection of preferential flux.

This study aims to reveal and to compare effect of two various systems of nitrogen nutrition, namely injection and sidedress application, on the levels of NO3- and phytohormones (cytokinins, abscisic acid (ABA), indole-3-acetic acid (IAA)) in Festulolium plants. Calcium nitrate (CN) or ammonium sulphate (AS) were used as N source in the pot experiment. The yield of Festulolium above and below ground biomass was more substantially enhanced after sidedress application of both AS or CN in comparison with injection application. The levels of endogenous cytokinins peaked 5 days after application regardless the form of N source and the method of application. The increased concentration of endogenous cytokinins as well as the enhanced content of selected free amino acid suggest that N applied sidedress can maintain better distribution patterns of nutrients and provide improved conditions for growth and nitrogen uptake. The nitrogen application affected ABA concentrations on all tested treatments. The correlation between NO3- and ABA concentrations ranged from 0.77 to 0.89. A significant IAA increase was recorded in plants after ammonium nitrogen sidedress application and it was confirmed that applications of nitrate reduced IAA concentration (correlation between NO3- and IAA for AS treatment R2 = 0.77-0.94).

In the paper, the results of the long-term field experiment on soil depletion from potassium on yields and selected indices of nitrogen use efficiency of maize and spring barley were presented. The factors of the experiment were potassium fertilization (K plus and K minus treatment) and increasing nitrogen rates. Maize responded for soil exhausting from K in yield reduction over all the range of nitrogen rates applied in the experiment, and spring barley only through the highest rates. The greater values of nitrogen use efficiency indices were proven for barley as compared with maize. Potassium fertilization slightly increased agronomic efficiency and physiological efficiency of barley.

Nitrogen plays a vital role in the growth, development and nutritional quality of Chinese chive, which is an important leafy vegetable. The effects of improved Hoagland nutrient solutions on the nutritional quality and physiological characteristics of three Chinese chive cultivars (Saisong, Pingjiu No. 4 and Pingjiu No. 8) were investigated by modulating the ratio of nitrite nitrogen (NO₃^--N) to ammonia nitrogen (NH₄⁺-N). Improved Hoagland nutrient solutions with NO₃^--N to NH₄⁺-N ratios of 50:50 and 75:25 could effectively promote the accumulation of soluble protein, soluble sugar, vitamin C and proline; decrease the malondialdehyde content; and induce the superoxide dismutase and peroxidase activities of the three cultivars. It is strongly suggested that NO₃^--N to NH₄⁺-N ratios of 50:50 and 75:25 improve nutritional quality and promote growth and are thus suitable for Chinese chive growth under hydroponic culture.

The objective of the present study was to evaluate the effect of P, Ca, S, and/or K and/or Mg application at different rates on the botanical composition, herbage yield and its nutritive value in dehesas developed on calcareous soils. In two growing seasons, 2009/10 and 2010/11, five surface-broadcast fertiliser treatments were applied once in autumn. Two grazing periods were simulated by cutting the pasture in mid-spring and late-spring. Treatment K1, with the highest amount of Ca and without K in its composition, provided higher crude protein values in the herbage than controls in 2009/10. When the effect of each nutrient was analysed separately, a strong and highly positive response of Mg application on herbage production was recorded. A surface application of fertilisers containing 25 kg Mg/ha in autumn could increase herbage yield by 40% under the studied conditions. However, Mg was not applied alone, and thus this increase could be due to an effect of Mg by itself or to a synergistic effect between Mg and other nutrients applied. The application of Ca, P and Mg may also favour the production of high-quality forage by yielding a greater cover of legumes and digestible protein.

In field experiments over three vegetation periods (2010-2012) we studied impact of the CULTAN (controlled uptake long term ammonium nutrition) method on yield and yield parameters of kernel maize. The field experiments were conducted at three sites with different soil-climatic conditions. CULTAN treatments were fertilized once with the total amount of nitrogen using an injection machine (at the canopy height of 20 cm) and compared to conventional fertilization with calcium ammonium nitrate application at pre-sowing preparations. In all treatments the amount of nitrogen was the same, 140 kg N/ha. In 2010 at Humpolec site, CULTAN urea ammonium nitrate + inhibitor of nitrification treatment gave by 20.5% higher number of ears compared to CULTAN urea ammonium nitrate treatment. In 2011 at Ivanovice all CULTAN treatments reached statistically significantly higher number of kernels per ear. The higher 1000 kernel weight at CULTAN treatments was observed in 2012 at the Ivanovice site; a statistically significant difference between conventional and CULTAN urea ammonium nitrate + inhibitor of nitrification treatment was observed. Fertilization of maize with nitrogen using the CULTAN method under the conditions of the Czech Republic provides the same yield certainty as the conventional surface application and the CULTAN method of fertilization increases the yield certainty at delayed sowing. Harvest index was statistically significantly influenced by year, fertilization treatment and site.

The aim of this work was to compare herbicide efficacy and reduction of weed reproduction after the application of three frequently used soil residual herbicides during pre-emergent (PRE) and early post-emergent (EPOST) application in maize. Plot field trials were carried out in Central Bohemia during two growing seasons (2010 and 2011). Good efficacy (88%, resp. 83%) was found in isoxaflutole + thiencarbazone (ISF + THC) and terbuthylazin + S-metolachlor (TBA + SMC) on Echinochloa crus-galli, especially in PRE application use. Efficacy on Amaranthus retroflexus was 91% at both tested application periods and there were no significant differences between experimental years. Significant differences in A. retroflexus control were recorded among all tested herbicides (ISF + THC > TBA + SMC > pendimethalin (PEM) + dimethenamid (DMA)). No significant differences between PRE and EPOST were recorded in efficacy on Chenopodium album. Significant differences in efficacy on C. album were recorded among all tested herbicides (ISF + THC > TBA + SMC > PEM + DMA). Mercurialis annua was the most tolerant tested weed, which was significantly better controlled at EPOST herbicide application (73%) compared to PRE application (32%). TBA + SMC showed a significantly higher efficacy on M. annua compared with other tested herbicides. Seed production of all tested weeds was strongly effected by weather conditions, which were significant during 2011, when there was higher than average precipitation during May and June. The most seeds were produced by A. retroflexus > C. album > E. crus-galli > M. annua. ISF + THC best reduced seed production of E. crus-galli, A. retroflexus and C. album, especially when applied at PRE. TBA + SMC best reduced seed production of M. annua. Weed competition on untreated control plots caused yield loss by 90%and 47% in 2011 and 2012, respectively, compared to treatments with the highest yield (ISF + THC).

This study aimed to separate the respective contributions of root and microbial respiration to soil respiration in a rape field in Southwest China. The soil respiration was measured with a closed chamber technique and a regression method was used to apportion root and microbial respiration. Microbial and root respiration ranged from 70.67 to 183.77 mg CO₂/m²/h and 21.99 to 193.09 mg CO₂/m²/h, averaged 127.16 and 116.66 mg CO₂/m²/h during the rape growing season, respectively. Root respiration coefficient ranged from 0.41 to 5.39 mg C-CO₂/g C/h and was negatively correlated with root/shoot ratio, aboveground and belowground biomass, but positively correlated with root N content. The contribution of root respiration to soil respiration averaged 44.2%, ranging from 14.5% to 62.62%.

The effect of various concentrations (3, 9, 27, 81, and 243 mg/kg) of tungsten (W) on growth performance, biochemical constituents and tungsten and molybdenum (Mo) contents in wheat was observed. Lower doses (up to 9 mg/kg) of tungsten showed promotory effects whereas higher doses retarded. An increment in growth, biomass, chlorophyll and carbohydrate contents was observed. Tungsten contents in root and shoot showed a very strong linear dependence on the soil applied W contents. Mo contents in plant tissue showed an increase with an increase in the W contents in plant tissue up to a threshold after which it showed an abrupt decrease. The activity of peroxidase enzyme decreased with lower application of W. Higher administration of tungsten (27-243 mg/kg) resulted in increased total phenol, free proline and activity of enzyme peroxidase.

Mixture of plants (Festulolium: Trifolium pretense L.) was grown in the pot experiment with different forms of nitrogen nutrition. The fertilizers (ammonium sulphate or calcium nitrate or ammonium nitrate) were applied conventionally or according to the CULTAN method (Controlled Uptake Long Term Ammonium Nutrition). The absolute growth rate (AGR) and contents of free asparagine and proline in the aboveground biomass were determined. Additional nitrogen increased the dry weight of biomass and AGR of the plants treated with sidedress application in comparison with plants treated with the CULTAN method. The results suggest increased levels of free proline in CULTAN-treated plants while those of asparagine did not increase. The significance of these observations to the loss of potential yield and the relationship between methods of application is considered.

The effects of land use practices on soil fauna, especially earthworms, are poorly known in coastal saline agricultural soils. Here we compare earthworm communities in six types of land use practice in the coastal region of China's Bohai Bay, namely uncultivated saline soil, two orchard (pear and winter jujube) lands, man-made forests (chinese ash), vegetable land and cropped land (maize). In addition, we recorded selected physicochemical properties of the soil. Soil organic matter content and total N were significantly higher under pear orchard and vegetable land than under the other land use practices, and their lowest values were observed from uncultivated saline soil. Vegetable land and pear orchard land showed a significantly higher abundance of earthworms than the other land use practices, whereas no earthworm was found in uncultivated saline soil. The sites under individual practices supported one to three earthworm species. Aporrectodea trapezoides species was present under four types of land use practice, and the biomass of this species accounted for more than 60% of the community. Vegetable land and pear orchard land supported richer earthworm community than the other land use practices, dominated by Aporrectodea trapezoides and Drawida japonica. These preliminary results indicated that land use practices have substantial effects on the abundance and composition of earthworm communities in saline soils.

Fertilization of crops with pig manure is a common practice throughout the world. Nevertheless, due to the relatively high copper (Cu) and zinc (Zn) contents in pig manure, continuous application of pig manure could have negative effects on soil and plant. The study aimed at the impacts of long-term applying different pig manure rates (equivalently 0, 100, 250 and 500 kg total N/ha/year from 2002 to 2008 and 0, 10, 25 and 50 t fresh weight/ha/year from 2009 to 2011, respectively) on Cu and Zn accumulation in soil and plant. During the 10 years of the experiment, a total of 2.04 to 10.20 kg/ha/year for Cu, 3.15 to 15.73 kg/ha/year for Zn were applied to the soil. Results from this study showed that long-term pig manure application resulted in serious accumulation of Cu and Zn in soil, total Cu and Zn concentrations increased by 204% and 107% at high application rates, respectively. Although topsoil Cu and Zn concentrations were below concentrations considered phytotoxic to crops, according to current Chinese legislation, it would take only less time than 16 and 27 years of high application rates to reach the allowable limits. Our result also suggested that Cu and Zn leaching occurred in the tested soil. The Cu and Zn concentrations in stalks and grains were not affected by the application of pig manure, and these values were lower than the threshold values for animal and human ingestion.

The aim was to compare the efficacy, selectivity to sunflower and dissipation of three chloracetamide herbicides (acetochlor, metolachlor and pethoxamid) in dependence on precipitation after application. A small plot field trial was carried out with sunflower in Central Bohemia in 2010 and 2011. The remaining concentration of active ingredient in the soil of all studied herbicides was lower in the year with a higher temperature and a low level of total natural precipitation at the beginning of the growing season. Higher leaching of metolachlor and pethoxamid was recorded in irrigated plots. No leaching was found in the case of acetochlor. The highest leaching was found for metolachlor (9.2-25.5% in soil layer 5-10 cm). The highest phytotoxicity was found for acetochlor (9.8%) > pethox-amid (4.6%) > metolachlor (1.8%). The mean phytotoxicity in the irrigated plots was 6.9%, compared with 3.9% in the non-irrigated plots. The efficacy of the tested herbicide was affected by wet conditions. The highest efficacy on Chenopodium album, Amaranthus retroflexus, Echinochloa crus-galli and Solanum physalifolium was recorded after application of acetochlor and irrigation.

MCPA sorption and desorption in five surface soils (denoted as A1-5), three bottom sediments (S1-3), two river sediments (L1-2) and one subsurface soil (SS) at two initial concentrations in aqueous solution - C₀ = 0.5 and 10 mg/l were studied. No significant effect of the initial concentration on MCPA equilibrium distribution between soil/sediment and aqueous solution was observed. The difference between distribution coefficient K_D at C₀ = 0.5 mg/l and K_D at C₀ = 10 mg/l was found only in the case of one bottom sediment (S2). A simple regression analysis between K_D at C₀ = 0.5 and 10 mg/l and soil/sediment properties indicated that the most important property which determined the variation in MCPA sorption is organic carbon (r = 0.886*** and r = 0.926***, respectively). Similarly, desorption of MCPA was inversely proportional to organic carbon content of the soils and sediments used (r = -0.862* and r = -0.842**). These observations showed that MCPA sorption and desorption in soils and sediments were primarily controlled by organic components of the geosorbents used. Overall, the percentage of MCPA sorption in soils and sediments was low (P_sorp ≈ 3-53%; K_D = 0.077-2.827 l/kg) and the percentage of MCPA desorbed was relatively high (P_des ≈ 11-70%), especially in the soils and sediments with lower organic carbon content. The experimental results and calculated values of groundwater ubiquity score GUS and relative leaching potential index RLPI imply that MCPA is very mobile in all the surface soils and has a potential to contaminate groundwater.