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Plant growth analysis of wheat populations in a long-term field-experiment
147-151Views:344The experiments were conducted as part of the long-term trial adjusted, in triculture (pea-wheat-corn) and biculture (wheat-corn), at three nutrition levels, with the use of one crop protection technologie (conventional) at the Látókép Research Site of the Centre of Agricultural Scienses, University of Debrecen, on a chernozem soil. The wheat variety used in the long-term trial was GK Csillag, which was sown at 5,8 million germs/ha.
The effect of pre-crops and nutrient-supply levels on some growth-parameters (LAI, HI, LAD), just as SPAD-values and yield amounts of winter wheat has been investigated in this experiment. We tried to find out the extent of relationship between the different parameters, so we determined the relationships between different nutrient-supply levels, yield amounts, LAI- SPAD- and LAD-values – measured in the crop-year of 2010–2011 in different crop rotation systems – by using correlation analysis. It has been stated both in case of bi- and tri-culture crop-rotation systems that different fertilizer dosages had significantly affected the leaf area index dynamics and its maximal value, and that increasing N+PK fertilization has
significantly increased the duration of leaves, as well. The highest SPAD-values were measured during the flowering and grain filling stages. However, we haven’t revealed significant differences between all fertilizer treatments. In case of the bi-culture crop-rotation system harvest index values showed an increasing tendency parallel to the increasing nutrient-supply levels, while in case of the tri-culture system this tendency was rather decreasing. However, these differences were
not significant. Parallel to the increasing fertilizer dosages yield results were increased in a significant extent. At the same nutrient supply-levels 2088–4615 kg ha-1 higher yields were measured in the tri-culture than in the bi-culture system. The correlation analyses have confirmed that all of the investigated parameters (yield amount, LAI, SPAD, LAD) had almost in all cases close positive correlation to the nutrient-supply level and the yield amount in both crop-rotation systems. These results have confirmed that the leaf area, the leaf duration, the SPAD-values and the fertilization have altogether resulted in the production of maximum grain yields. -
The Role and Significance of Soil Analyses in Plant Nutrition and Environmental Protection
3-8Views:237Hungary has a rich history of soil analyses and soil mapping. Our main tasks today are the preservation of soil fertility as well as balancing the goals of production and environmental protection. The main requirement of agricultural production is to adapt to ecological and economic conditions.
In a series of consultative meetings in the past seven years, representatives from Central and Eastern Europe have analyzed nutrient management practices in their respective countries. According to a joint memorandum agreed upon in 2000, in the countries awaiting accession, the quantity of nutrients used per hectare is considerably smaller than the Western-European usage targeted through special subsidies. The current low nutrient usage contradicts the principles of sustainability and that of the efficient use of resources, jeopardizing soil fertility.
In Hungary, the use of inorganic fertilizers underwent a dynamic development, which manifested itself in an almost tenfold usage growth between 1960 and 1985. This growth slowed down somewhat between 1985 and 1990 and then reduced dramatically after 1990, reaching record lows at the usage levels of the 60s. The nutrient supply has had a negative balance for the last 15 years.
The increasing and then decreasing usage trends can equally be detected in the domestic yield averages of wheat and corn as well as in the nutrient supply of soils. Yields were the largest when usage levels were the highest, and decreased thereafter. Draughts have also contributed to smaller yields. The dramatic decrease in the use of inorganic fertilizers when adequate organic fertilizers are lacking endangers our soils’ fertility.
About 50% of soils in Hungary are acidic. Acidity is mostly determined by soil formation, but especially on soils with a low buffering capacity, this acidity may intensify due to inorganic fertilizers. Sustainable agriculture requires the chemical improvement of acidic soils. According to their y1 values, the majority of our acidic soils need to be improved. This chemical soil remediation is required in 15% of the acidic soils, while it’s recommended for another 20% of these soils.
Results of the analyses conducted in the framework of the soil-monitoring system set up in Hungary in 1992 show that in 95% of the analyzed samples, the toxic element content is below the allowable limit. Cultivated areas are not contaminated; toxicity above the legal level was found only in specific high-risk sampling areas: in the vicinity of industry, due to local overload. The basic principle of sustainable agriculture is to preserve soil fertility without undue strain on the environment. The intensity of the production needs to be considered according to the conditions of the site; i.e.; nutrient management needs to be site-specific. It is recommended to differentiate three types of cultivated land in terms of environmental sensitivity: areas with favorable conditions, endangered areas, and protected areas, and then to adopt nutrient management practices accordingly. To meet all the above-mentioned goals is impossible without systematic soil analysis. Tests conducted by the national monitoring system cannot replace regular field measurements. -
Spectral analysis of stress symptoms caused by apple powdery mildew (Podosphaera leucotricha
83-88Views:394An orchard can be examined on the basis of spectral data, using methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Calculated on the basis of such hyperspectral data from different index numbers the water supply of foliage conditions can be well characterized.
The research site is an intensive apple orchard, which located in University of Debrecen, Agricultural Sciences Centre, Farm and Regional Research Institute at Pallag. During my experiments the preliminary evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by Podosphaera leucotricha.
Based on the results narrow band greenness indices (NDVI705, mNDVI705, mSR705 and REP) can be used for determination of diseased canopy and for the detection of stress symptoms of Podosphaera leucotricha,. These statements can be utilized in precision plant protection systems, since it can be a basis for such integrated active sensors with LED or laser light source, measuring reflectance at the certain spectral range, which can facilitate real time status assessment of orchards and can control precision fungicide utilization.
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Evaluation of long term experiments from a new aspect
55-60Views:322During our work, we developed a new, simple method to show the effects of fertilization on yield, which can both be applied over the long term as well as in series of independent experiments.
During the testing of this method, at the experimental farm of the Debrecen University Center for Agricultural Sciences at Látókép on a chernozem soil with lime deposits, we examined the fertilizer reaction of maize hybrids between 1989 and 1994. The treatments were: winter tillage, plant density of 70-80 thousand, unfertilized, N 120, N 240 kg/ha fertilized treatments, long term experiments using Dekalb 524 and Volga SC hybrids in long term experiments.
Four parameters are shown in the model. In the examined period TRmax represents the greatest yield in the fertilized treatments, NT the yield in unfertilized treatment, k the „efficiency of fertilizer” to NT and b the depression-coefficient, where the expected value is zero. The expected grain yield of the fertilized treatments (Y), in the function of the unfertilized grain yield (x) is the following:
The parameters were determined using the Monte Carlo method, in the optimizing process the sum of deviation square was minimized. The correct conformation of the functions was determined by the greatness of the R-value and the standard error. We found that during six years of testing, the tendency of fertilization efficiency was similar in the case of both hybrids. There was an unfavorable weather interval and, in these years, the yields were low, fertilization did not have an effect and moreover, in extremely bad conditions resulted in an obvious yield decrease. With the improvement of conditions, which in the case of our country means an increase in precipitation, the efficiency of fertilization increases and reaches its peak at 13-14 t/ha. At this point, the yield increasing effect of fertilization is 4-4,5 t/ha. If the yield of the unfertilized treatments increases from 8-9 t/ha, then the efficiency of the applied fertilizer decreases.
Most likely, the k and b parameters depend on the soil of the experimental location (nutrient and water management) and on the amount of pplied fertilizer and the characteristics of the hybrid. With the increase of fertilizer dosage the k-parameter also increases. The greater value though does not obviously mean a more favorable situation. It is true that in medium and good years this means great fertilizer efficiency, but in low or extreme precipitation conditions it also means greater risk. With the increase of the k-parameter, the yield deviation also increases which, from a cultivation point of view, is quite unfavorable. If the value of the b-parameter is other than, zero then the effect is clearly unfavorable, because with the increase of this value, the yield decrease is also greater. The fertilizer reaction of the two examined hybrids can be well characterized by these two hybrids.
Examining the six years, our created model estimated the effect of fertilization on the yield accurately and with a high degree of safety. Both in highly unfavorable and extremely good years, it gave an exact estimate. In our opinion, it can be used well to evaluate the effects of fertilization on yield in the future. -
Nest-site selection of Hooded Crow (Corvus cornix) in urban environment
35-39Views:340In the past decade Hooded Crows showed a significant growth in Debrecen. The aim of this study was to become acquainted with Hooded Crows nest-site selection in urban circumstances. The research revealed that Hooded Crows are not choosy when it comes to selecting the species of the trees, but we noticed differences regarding nesting height - Hooded Crows living in the city build their nests in higher regions than those living in places outside Debrecen. We discovered a significant difference between nesting heights and the tree species, which is probably due to the different characteristics shown by the given tree species. As for nesting heights, we found that in typical urban habitats there were no relevant differences shown. Samet the situation, when we compared these habitats in pairs, it came to light that nesting heights - when comparing lonely trees - wood segments and tree raws – wood segments - did not show significant differences too, which can be explained by the various conditions provided by the habitats mentioned.
To sum up, during our research the following results emerged:
1. Hooded Crows prefer approximately the same nesting heights in all kinds of habitats, urban environment and tree species.
2. Nesting height depends on the tree species but independent from habitat.