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The effect of water supply and crop year on the yield potential of sweet maize (Zea mays L. convar. saccharata Koern.) hybrids with different genotypes
203-210Views:384The successfulness of crop production is significantly affected by not only the the average yields that provide cost effectiveness, but also the success of striving for yield safety, therefore, varieties and hybrids tolerant to environmental stress factors are worth being included into the sowing structure. Our aim was to further the decision making of producers in prepaering the right sowing structure by the evaluation of sweet maize hybrids’ tolerance to excess rainfall.
We performed our examinations in an extremely wet year (2010) on chernozem soil on three sweet maize hybrids (GSS 8529, GSS 1477, Overland) in 12 replications. Comparing the yields of 2010 with those that can be expected under optimal rainfall conditions, we showed that the examined hybrids react to the amount of rainfall higher than their needs with yield depression. The excess rainfall tolerance of the examined hybrids is different in the case of each hybrid. -
Production of corn in Serbia in the light of climate change
305-322Views:346This paper presents the basic elements of maize production technology in Serbia. For their good knowledge, it is necessary to be familiar with the basic biological requirements of the species, phenology and its particular requirements for water, heat, soil conditions and mineral nutrition. A special emphasis in this paper is given to recent research by the author regarding the correction of production technology (selection of hybrids, time and density of sowing, etc.) from the aspect of knowing the weather conditions of the year to the moment of sowing and the amount and position of available nitrogen in the soil profile during the spring before sowing. In the light of predicted climate change conditions for the Republic of Serbia, the authors of this paper have proposed and appropriated adaptation measures. The general conclusion is that there are no general recipes for the correct production technology of this plant species, but should be adapted to each specific year, field and hybrid.
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Long term researches regarding the irrigation influence on sugarbeet crop inthe Crisurilor Plain
11-15Views:307The paper is based on the researches carried out in the long term trial placed on the preluvosoil from Agricultural Research and Development Station Oradea, Crisurilor Plain in during 1976–2012.
The soil water reserve in 0–75 cm depth decreased bellow easily available water content every year and in 32% of years the soil water reserve decreased bellow wilting point. For optimum water supply an irrigation rate of 2665 m3 ha-1 (variation interval 500–5090 m3 ha-1) was needed.
The irrigation determined improving of water/temperature + light report (Domuta climate index) with 47.4% in average in the period May–September. A statistically very significant connection was quantified between this indicator and the yield.
Daily water consumption increased in the irrigated variant, the biggest difference in comparison with unirrigated variant was registered in August, 86% in comparison with unirrigated variant. As consequence, the value of the total water consumption increased with 50%, variation interval was 11–154%. The irrigation covered 37.8% of total water consumption, the variation interval was 8.3%–67.9%.
The yield level of the sugarbeet increased in average with 61%, the variation interval was 9–227%. Standard deviation was lower in the irrigated variant and this emphasizes an improve of the yield stability with 25.1%. The sugar content of the sugarbeet roots from irrigated variant increased statistically very significantly in the droughty years and differs significantly in the rainy years.
Water use efficiency increased in the irrigated variant with 7% and irrigation water use efficiency was between 7.9 kg yield gain 1 m-3 irrigation water and 17.4 kg yield gain 1 m-3 irrigation water.
The positive influence of the irrigation on microclimate, water consumption, yield level, stability and quality and on water use efficiency sustain the need of the irrigation in sugarbeet from Crisurilor Plain.
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Development of technology elements for growing of perennial sorghum
15-17Views:225Optimal sowing time for perennial sorghum under irrigation is when soil temperature at the depth of sowing reaches up to 10–11 °С, harvesting for the green mass has to be done when panicle is situated on the stem in 10 sm from the flag leaf and hight of cut must be 11 sm.
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Seed treatment with Bacillus bacteria improves maize production: a narrative review
105-111Views:1046Maize (Zea mays L.) is an important crop in relation to its production and consumption. Production of maize is constrained by soil infertility and poor quality seed. Microbial technologies like seed treatment with Bacillus bacteria improves the productivity of maize on infertile soil. However, due to variations in maize growth environments and Bacillus species, this review was conducted to identify the common species of Bacillus species used for seed treatment, and provide an overview of the effect of seed treatment with Bacillus on maize growth and yield. Results show that Bacillus subtilis, Bacillus pumilus and Bacillus amyloliquefaciens were the dominant species used for seed treatment. Bacillus was used as both a biofertiliser and biopesticide. The conspicuous positive effects of Bacillus were in plant height, shoot and root length, and shoot dry matter depending on the species. In terms of grain yield, Bacillus subtilis (8502 kg ha-1), Bacillus amyloliquefaciens (6822 kg ha-1) and Bacillus safensis (5562 kg ha-1) were the bacterial species that had an overall pronounced effect. The highest increase in grain yield was in the interactive effect of Bacillus megaterium + Bacillus licheniformis (18.1%) and sole Bacillus subtilis (15.6%), while Bacillus pumilus reduced grain yield by 4.8%. This shows that the improvement of maize productivity using Bacillus bacteria requires careful selection of the species for seed treatment.
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Status of soil quality in south-west of Romania and its role in sustainable development of the rural space
273-278Views:192Being aware of lands ecological resources’ natural conditions and particularities for different uses and crops is of great importance
for the big and small producers.
In this paper we present the main aspects regarding the quality of the ecopedological conditions. Here there are briefly presented the
physico-geographic conditions and the telluric-edaphic configuration of the area. Also, the structure of the main categories of agricultural
activities in the physical geographical areas (mountains, hills and plateaus, high and low plains and meadows) and main soils’ types and
associations are presented. Lands vocation for different use (arable, lawns, hay, orchard, vineyard
The paper ends with highlighting the necessary measures for a lasting administration of ecopedological resources in the studied area. -
Investigations on Mud on Heavy Metal Contaminated Flood-Plain of Tisza
96-101Views:791At the beginning of the year 2000 subsequently to a mine accident high heavy metal content mud entered the catchment area of the Tisza and was transported through the whole Hungarian section of the river. The majority of the heavy metals had been bounded to the floating sediment that was deposited on the flood-plain soil during flood forming a new, 5-10 cm thick layer. In the mud samples collected after the flood there was a clearly visible dark grey layer with significantly higher heavy metal content that was formed by the pollution wave and it was sorruonded by a light layer. The upper layer of flood-plain soils are formed from this mud layer during the soil development process, so the amount of Lakanen-Erviö soluble heavy metals that correlate with bioavailable heavy metal content was examined as well. In this case only the lead content was significantly higher in the dark layer.
New mud samples were collected after the 2001 flood. Separate layers could not have been identified, their colour was similar to those of the previous year’s light layers’. Comparing to this light layer the total Zn and Lakanen-Erivö soluble metal content was significantly lower in the mud samples of the year 2001. While the proportions of total and Lakanen-Erviö soluble metal concentrations were equal in both of the layers regarding the elements, these ratios have significantly changed next year regarding Pb and Zn: the amount of Lakanen-Erviö soluble metals considerably decreased.
As a result of sequential extraction the heavy metal content was rather low in the water soluble and exchangeable and NaOH-soluble fractions, so heavy metals found in the mud could be released in greater amount only in case of a heavy acidification. -
Agronomical and Economic Evaluation of Different Soil Cultivation Systems
255-258Views:186In the interest of profitable plant production and environmental protection we have to make an effort to protect and improve the productivity of our soils while moderating production limiting factors. Due to different soil cultivation methods, the quantity of yield and required expenses also differ.
We examined the production costs in four different production technology systems. Overall, it can be said that farming standards are good, since cost prices were low (2001: 14-15 HUF/kg, 2002: 15-21 HUF/kg, 2003: 39-49 HUF/kg) in the case of all main products per 1 kg. Cost prices were lowest in the case of direct sowing, probably due to low machinery costs.
All economic indicators have to be compared when choosing the most suitable production technology in a specific farming environment. -
The role and impact of N-Lock (N-stabilizer) to the utilization of N in the main arable crops
51-55Views:364The nitrogen stabilizer called N-Lock can be used primarily with solid and liquid urea, UAN and other liquid nitrogen, slurry and manure. In corn it can be applied incorporated before sowing or with row-cultivator or applied with postemergent timing in tank-mix. In postemergent timing need precipitation for long effect. In oil seed rape and autumn cereals the N-Lock should be applied with liquid nitrogen in tank mix late winter or early spring (February-March). The dose rate is 2.5 l/ha. N-Lock increases the yield of maize, winter oil seed rape, winter wheat and winter barley 5-20 %. The yield increasing can be given the thousand grain weight. In case of high doses of nitrogen it can be observed higher yield. The quality parameter also improved, especially the oil content of winter oil seed rape and protein and gluten contents of winter wheat. The use of N-Lock increases the nitrogen retention of soil and reduces nitrate leaching towards the groundwater and the greenhouse effect gas emissions into the atmosphere. The degradation of the applied nitrogen is slowing down and the plant can uptake more nitrogen in long period. The effect of N-Lock the nitrogen is located in the upper soil layer of 0-30 cm and increasing the ammonium nitrogen form. The product can be mixed with herbicide products in main arable crops.
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Evaluation of chickpea (Cicer arietinum L.) in response to salinity stress
105-110Views:813Soil salinity is a severe and expanding soil degradation problem that affects 80 million ha of arable lands globally. Chickpea (Cicer arietinum L.) is very sensitive to saline conditions; the most susceptible genotypes may die in just 25 mM NaCl in hydroponics. Approximately 8–10% yield loss in chickpea production is estimated due to salinity stress. However, it is still not established why chickpea is so susceptible to salt affection. Salinity (NaCl) impedes germination of seeds, though chickpea varieties considerably differ from one another in this respect. Some chickpea genotypes are more tolerant in the stage of germination, tolerating even 320 mM NaCl. The reasons of this variation are unrevealed; there is a shortage of knowledge about the germination abilities of chickpea genotypes in saline conditions. Nevertheless, the effect of salt stress on vegetative growth can be analysed in hydroponics, in pot or field conditions, regardless the experimental environment, the ranking of genotypes regarding salt resistance is coherent. Chickpea genotypes can be different in their ability to retain water, maybe under salt affection; the more salt tolerant lines can maintain higher water content in the shoots, while the more sensitive ones cannot. The identification of salt tolerant chickpea landraces based on developing genetic variability is a suitable strategy to combat against salinity problems arising in arid and semi-arid areas.
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Examination of drought stress of two genotype maize hybrids with different fertilization
53-57Views:337In the growing season of 2019, we analysed stress resulting from climatic factors on maize hybrids of different genotypes, with the aim of gaining a better understanding of the physiological responses of each hybrid, which might support the elaboration of a cost-effective irrigation plan.
Our experiments were carried out at the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil in a small-plot long-term field trial with strip plot design. In the scope of the experiment, N-fertilizer doses were applied as basic fertilizer and top-dressing in addition to the non-fertilized (control) treatment. The 60 and 120 kg N/ha doses applied as basic fertilizers in the spring were followed by top-dressing in the V6 phenophase with a +30 kg N/ha dose. Measurements were carried out with the involvement of the Renfor early (FAO 320) and Fornad (FAO 420) late maturity hybrids-
The stomata of the plants became more and more closed with the progression of the phenological phases; their stomatal conductance decreased. However, the hybrids responded differently to environmental stress. In the case of the Renfor hybrid, the highest conductance (669 mmol/m2-s) was recorded in the V12 phenophase with the 150 kg N/ha treatment. The stomata were more open due to the high turgor pressure, allowing plants to evaporate properly. The plant was in its worst physiological condition on 2nd July, at the time of the appearance of the last leaf in the case of the 120 kg N dose (224 mmol/m2-s). The value measured in the V12 phenophase has already shown that the stomata were closing due to the self-regulating system of the plant. It would have been necessary to dispense irrigation water following the measurement. This confirms the finding that water stress can be prevented by measuring stomatal conductance.
In the case of the Fornad hybrid, stomatal conductance was the highest on 12th June (630 mmol/m2-s) in the 90 kg N/ha treatment and it was the lowest (183 mmol/m2-s) in VT (emergence of the last leaf) phenophase in the 60 kg N/ha treatment. In this case, the appropriate time for applying irrigation water would have been early July, when the conditions for the plants were still adequate. Subsequently, the stomata began to close due to a reduction of the water resources available to them.
There was a significant correlation between soil moisture and stomatal conductance, as well as between temperature and stomatal conductance.
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The Effect of Grazing Intensities on Magnesium Contents
8-13Views:795Research was carried out on two areas of grassland in Hortobágy National Park, Hungary. Two herds of Hungarian Grey Cattle were kept in free range grazing and the effects of grazing pressure on the magnesium content of soil and ryegrass (Lolium perenne L) were determined.
Changes of plant available and total soil magnesium content under different grazing intensities did not show any evident tendency on the investigated grasslands. Different amounts of cattle faeces, urine and trampling had no effect on the magnesium concentration of ryegrass. We conclude that the magnesium content of ryegrass on both grassland sites as moderate grazing and overgrazing matches the requirements of cattle. Symptoms of magnesium deficiency of cattle will likely not appear. -
Agronomical and Economic Evaluation of Different Soil Cultivation Systems
17-22Views:219In the interest of profitable plant production and environmental protection we have to make an effort to protect and improve the productivity of our soils while moderating production limiting factors. Due to different soil cultivation methods, the quantity of yield and required expenses also differ.
We examined the production costs in four different production technology systems. Overall, it can be said that farming standards are good, since cost prices were low (2001: 14-15 HUF/kg, 2002: 15-21 HUF/kg, 2003: 39-49 HUF/kg) in the case of all main products per 1 kg. Cost prices were lowest in the case of direct sowing, probably due to low machinery costs.
All economic indicators have to be compared when choosing the most suitable production technology in a specific farming environment. -
Activity of some enzymes, participating in nitrogen compounds transformation in chernozem, polluted by fluorine compounds
99-104Views:227Contamination of chernozem by fluorine compounds variously affects those enzymes (urease, asparaginase, glutaminase, arginase, amidase), which takes part in the metabolism of nitrogen-bearing organic compounds. In broken soils the inhibited desaminisations is stronger, than enzymatic hydrolysis of asparagine and arginine. The features of seasonal dynamics of change activity of urease and correlation dependence of its activity from some physical and chemical soils properties are described. These tendencies well comport with the results of model experiments. At minimum HF influence there is inhibition of processes of monohydrocarboxylic acids desaminisation, hydrolytic breaking up of arginine and glutamine. By a side with this there is activating of urea and asparagine breaking up processes on the initial stages of toxicant influence. The study of kinetics of process of urea enzymatic hydrolysis in chernozem at the different level of HF influence showed changes of initial and maximal velocity of enzymatic reaction, and also Michaelis-Menten constant.
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Combined traffic control of irrigation on heterogeneous field
187-190Views:744In arid areas, such as Hungary, most climate models forecast a rise in water scarcity. Irrigated land accounts for 2% of agricultural land in Hungary, with most irrigation technology being relatively outdated. The aim of this research was to lay the foundation for a combined traffic management system for a water-saving precision irrigation system on an 85-ha field in the Tisza River basin's reference region. High-precision soil maps were created to support the water-efficient variable-rate irrigation system by selecting and selecting areas for different agrotechnical implementations and precision farming zones.
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The examination of flesh firmness in different apple varieties
103-107Views:358Of the different physical features of fruits, one important quality feature is flesh hardness. This is an important parameter to be considered when selling fresh apples, for the manufacturing industry and when entering into storage. In our research, we examined 7 apple varieties, in 2016 and 2017, from the establishment of KITE Zrt. in Derecske and the Horticultural Experimentation Site of Pallag (Pallagi Kertészeti Kísérleti Telep). The plantations took place in accordance with intensive apple production. In both years, samples were collected at the time ripening of the given apple variety. Of the examined apple varieties, 5 of them are resistant to scab (Gaia, Isaaq, Modí, Smeralda, Fujion), 1 is not resistant (Golden Reinders) and 1 (Pinova) is moderately susceptible to scab. The scab resistant apple varieties were correlated to the non-resistant Golden Reinders. Flesh firmness was measured with a fruit penetrometer in each of the seven apple varieties. In the first year a two-month storage experiment was carried out, where the flash firmness after harvest, and after one-month and two-month storage was measured. The results were assessed with the help of the IBM SPSS Statistics 20 program. The goal is to compare the apple varieties based on their flesh firmness, in particular with regard to the resistant varieties.
The Isaaq 8.81–8.82 N/cm2 , the Modí 9.18–9.59 N/cm2 and the Fujion 8.66–9.13 N/cm2 , all of which are scab resistant apple varieties, showed a significant initial flesh firmness. During storage, the Pinova apple variety flesh firmness changed the most favourably.
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What does precision crop production hold for the future of soil science and plant nutrition?
411-421Views:324The concept of precision agriculture is straightforward at the scientific level but even basic goals are blurred at the level of everyday practice in the Hungarian crop production despite the fact that several elements of the new technology have already been applied. The industrial and the service sectors offer many products and services to the farmers but crop producers do not get enough support to choose between different alternatives. Agricultural higher education must deliver this support directly to the farmers and via the released young graduates. The price of agricultural land must be higher if well-organized data underpin the production potential of the fields. Accumulated database is a form of capital. It must be owned by the farmers but in a data-driven economy its sharing will generate value for both farmers and the society as a whole.
We present a methodological approach in which simple models were applied to predict yield by using only those yield data which spatially coincide with the soil data and the remaining yield data and the models were used to test different sampling and interpolation approaches commonly applied in precision agriculture. Three strategies for composite sample collection and three interpolation methods were compared. Multiple regression models were developed to predict yields. R2 values were used to select among the applied methods.
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Impact of fertilization on production capacity and reaction to fertilization in maize hybrids
42-46Views:157New varieties and fertilization have significantly increased yields of maize in recent decades. It has to be taken into account however that the interactions and the balanced combination of cropping factors (ecological, biological and agrotechnical) are the main factors which determine yields. Weather conditions were rather unfavourable during the last decade. Extreme weather conditions occurred due to global warming; 6 of 10 years were plagued by drought. Consequently yields increased from 10-20% to 30-50%. In view of varieties the situation is advantageous, maybe the supply of hybrids is too high, nevertheless those hybrids need to be selected which are particularly well adjusted to the ecological conditions. Many technologies can be applied which vary according to intensity, but the balanced combination of cropping factors should be secured on the basis of the hybrid’s intensity. Among agrotechnical factors the compensation of nutrients and technological conditions were inadequate. These days farmers only use nitrogenous fertilizers consequently they significantly decrease the easily available P and K content of the soil which in long term leads to the deterioration of the soil’s productivity. The technological background is therefore important, because sufficient yields can only be expected if agrotechnical operations are carried out in the right time and quality.
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Current Conditions and Opportunities of Biofarming in Hungary
150-156Views:233The aim of organic farming is not to maximize income, but to achieve optimal product quality. It is completed by the tightest possible material, and energy flow within the farm. Organic agriculture significantly reduces external inputs by avoiding the use of chemo-synthetic fertilizers, pesticides and pharmaceuticals. Instead it works with nature to increase both agricultural yields and disease resistance. Total independence of external resources can not be achieved in Hungary due to the small-scale of organic animal husbandry. Some materials in limited quantities can be purchased from external resources, though the group of these materials is strictly regulated. Organic farming harmonizes with the concept of European multifunctional agriculture, because besides farming, it includes social considerations, as it helps to maintain natural resources and the relationship between people and their environment, and provides a living for those living in the region.
As regards organic farming the fertility of the soil and the health of vegetation can be influenced in various ways. Farmers have to be highly skilled and able to manage a farm with great expertise. Generally it can be stated that as the use of non-organically produced products is limited, the opportunities to correct failures made by the farmer are minimal, contrary to conventional farming. Farmers must be intent on developing the tightest material- and energy flow. This means that organic farms ideally have both animal husbandry and crop production. This energy and skill demanding system of farming is compensated by state subsidies, growing market share and relatively high prices for organic products. -
Examination of the possible role of biofertilizers and wood ash in the nutrient supply of plants
87-95Views:236Some physiological effects of bacteria containing fertilizer and some wood ash were examined in the experiments. The minimization of the use of chemicals in agriculture has been an ongoing challenge. One option lies in the intenzification of soil life. The release of organic matters by the roots and bacteria play a significant role in the uptake of minerals. The main problem to usilize wood ash in agriculture is its heavy metal contents. The solubility of heavy metals is very low, therefore there is no risk to use the wood ash in the agriculture and in the horticulture according to our experiments. The wood ash and biofertilizer contains several micronutrients in an optimum composition for forestry and agricultural plants.
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Using research findings in precision maize production
227-231Views:642The effect of crop production factors on maize yield are examined on chernozem soil in a more than 30 year old long-term experiment on the Látókép Experiment Site of the Centre for Agricultural and Applied Economic Sciences of the University of Debrecen. The aim of research is to evaluate the effect of fertilisation, cultivation, plant number, genorype and irrigation. The analysis of the data in the database of the examined period makes it possible to evaluate the effect of maize yield, as well as that of the crop production factors and the crop year, while the correlations and interactions between these factors were also examined. During the examination of the cultivation treatments, it was concluded that the highest yield was obtained as a result of autumn ploughing, but its effect largely differs in the irrigated and the nonirrigated treatments. Based on our examinations, strip cultivation should be applied periodically (e.g. strip – strip – ploughing – loosening) in areas with favourable soil conditions free from compacted layers.
In years with smaller, average precipitation supply or when the precipitation was higher than average, higher plant numbers were more favourable. Under drier conditions, but especially in several consecutively dry years, a lower plant number can be recommended which is not higher than 60 thousand per hectare. In the case of favourable water supply, 70-80 thousand plants per hectare can be used. The yield increasing effect of fertilisation was significant in the case of both non-irrigated and irrigated conditions, but it was much more moderate in the non-irrigated treatment. The extent of weed coverage was significantly affected by the previous crop. In the case of a favourable previous crop (wheat), the weed coverage was significantly lower than after an unfavourable previous crop (maize). In the case of the same previous crop (maize), the extent of weed coverage was mostly determined by the crop year and the extent of precipitation supply. Irrigation is not enough in itself, because if it was not accompanied by intensive nutrient management, yields started to decline.
The results of researhc, development and innovation contributed to the technological method which makes it possible to apply locally adjusted sowing seed, fertiliser and pesticide in a differentiated way, as well as to change the method of operations within the given plot. -
From Organic to Precision Farming (Contemporary Publication)
81-86Views:167The paper presents a short review of the different types of farming systems:
Biofarming, Organic farming, Alternatíve farming, Biodynamic farming, Low input sustainable agriculture (LISA)
Mid-tech farming, Sustainable agriculture, Soil conservation farming, No till farming, Environmentally sound, Environmentally friendly, Diversity farming
Crop production system, Integrated pest management (IPM), Integrated farming, High-tech farming
Site specific production (SSP), Site specific technology (SST), Spatial variable technology, Satellite farming.
Precision farming
It concludes that the various systems are applicable in different ratios and combinations depending on the natural and economic conditions.
The author predicts an increase in precision technologies , the first step being the construction of yield maps compared with soil maps and their agronomic analysis. Based on this information, it will be necessary to elaborate the variable technology within the field, especially for plant density, fertilization and weed control.
The changes in weed flora during the past fifty years based on 10.000 samples within the same fields using the weed cover method are presented. -
Environmental inspection agro tech – guarantee sustainable development agricultural systems
41-42Views:235Shown the expediency of the environmental expertise technologies of growing crops in terms of impact on soil fertility, crop phytosanitary status, quality, chemicals migration, biological soil activity, crop productivity, which ensure avoidance of adverse impact on the environment and human health.
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Changes in the Sulphur Content of Winter Wheat in a Field Experiment
85-88Views:201The use of superphosphate as P-containing fertiliser decreased in the last years in many countries in accordance with strict air pollution laws, and the S-deposition decreased from the atmosphere to the soil as well.
Winter wheat is the one of the S-demanding plants. Recently, the gradually increasing S absence endanger the formation of required average yield of winter wheat, and has bad effect on its quality.
We examined the effect of treatments on the sulphur-, nitrogen content and the N/S ratio of winter wheat in the whole upperground plant and in the grain and straw at harvest in a arable land sulphur fertilization experiment on brown forest soil (Agricultural Company of Felsőzsolca).
We analysed the samples from spring to harvesting, in the critical phenophases. In this study we discuss only the values from the stooling and stalking and the results of analysis of grain and straw in the harvest.
We experienced that the concentration of sulphur in the whole upperground parts of winter wheat showed increase to the end of vegetation independently of fertilization. The N/S ratio was between 8% and 12% in the beginning of the growth period in the whole upperground plant, while the ratio in the grain at harvest was between 13 and 14%. When we examined the whole upperground plant, stalk and leaf at stalking, we got the highest sulphur content in the leaf. Mostly the middle level sulphur fertilization dose (4 l/ha) increased the sulphur accumulation in the green plant. At total maturing, the greatest part of accumulated sulphur is in the grain, but then the effect of fertilization is less glaring. -
GC-MS studies to map mechanistic aspects of photolytic decomposition of pesticides
11-16Views:214Transformation of pesticides in the environment is a highly complex process affected by different factors. Both biological and physical-chemical factors may play a role in the degradation, whose ratio depends on the actual environmental conditions.
Our study aims to reveal specific details of photolytic degradation of pesticides as important soil contaminants. Significance of these studies is enhanced by the fact that pesticide decomposition may contribute to soil degradation, and have harmful biological effects by degrading to toxic products. The toxicity of the examined pesticides is well known, however very little information is available regarding their natural degradation processes, the quality, structure and biological impact of the degradation products.
The photolytic degradation of frequently applied pesticides of distinctive types (acetochlor – acetanilide, simazine – triazine, chlorpyrifos – organophosphate, carbendazim – benzimidazole) was investigated. A special, immerseable UV-light source was applied in order to carry out photodegradation. The degradation processes were followed by thin layer chromatography (TLC) and mass spectrometry coupled with gas chromatography (GC/MS). EI mass spectrometry was used to identify the degradation species.
Each of the studied pesticides underwent photolytic decomposition, and the detailed mechanism of photolytic transformation was established. At least four degradation species were detected and identified in each case. Loss of alkyl, alkyloxy, amino-alkyl and chloro groups might be regarded as typical decomposition patterns. Deamination occurred at the last stage of decomposition.