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Evaluation of long term experiments from a new aspect
55-60Views:112During 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. -
Effect of fertilization on the potentially mineralize N forms of soil of long term field experiment was set in an acidic sandy soil
20-24Views:120The aim of this paper was to provide further information about the nitrogen mineralization processes of soil. A modified incubation technique was applied to establish the amount of easily soluble mineral and organic N forms during the incubation period. An acidic sandy soil was used for incubation, which was sampled from the „Westsik” long-term field experiment. The incubation was carried out on fifteen selected soil samples which were received different treatments since the experiment was set up.
From the obtained results, the amount of potentially mineralizable N and the mineralization rate constant were determined. Results of chemical analysis and biological interpretation of results are discussed. -
Study regarding the influence of the nPK fertilizers use in long term trial on heavy metals concentration in wheat grains
107-109Views:107The paper presents research results obtained in stationary experiments, carried out at Agricultural Research and Development Station Oradea, regarding the influence of nitrogen, phosphorus and potassium fertilizers, on Cd, Pb, Cu, Zn and Ni concentration on wheat grains.
The minimum concentration of cadmium in wheat grains was recorded in the case of the unfertilized plot N0P0K0, 0.12 mg kg-1, and maximum value 0.22 mg kg-1, was registered at the fertilized plot with N160P80K120, relative difference relative to control was 84.2%.
Lead concentration had the lowest value in the unfertilized plot, the value (0.4 mg kg-1) being under the maximum allowed (1.0 mg kg-1). In case of the fertilized plot with N160P80K120, the lead concentration had the highest value, 0.47 mg kg-1, but even in this case it was located beneath the maximum limit allowed.
In all four systems of fertilization, copper has not exceeded the maximum allowed limit (5 mg kg-1), the values have been comprised between 1.68 mg kg-1 at the unfertilized plot and 2.81 mg kg-1 at the fertilized plot with N160P80K120. In other plots of fertilization copper had concentrations of 1.97 mg kg-1, at the fertilized plot with N80P40K40, and 2.78 at the fertilized plot with N80P80K80.
The lowest concentration of zinc, 26.47 mg kg-1, has been registered in the control N0P0K0. In the other fertilization plots studied, the zinc concentrations had the following values: 27.66 mg kg-1 (N80P40K40), (N80P80K80) 29.87 mg kg-1 and 33.62 mg kg-1 (N160P80K120).
Nickel has registered the lowest value in the unfertilized plot, 3.47 mg kg-1. The fertilized plot with N160P80K120 had the highest value 4.94 mg kg-1, with 42.39% higher compared to the control N0P0K0.
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Correlations of the growth indexes and yield of winter wheat in a long-term experiment
139-144Views:135The experiments were carried out at the Látókép experimental station of the Centre for Agricultural Sciences of University of Debrecen on chernozem soil in a long term winter wheat experiment. As forecrop rotation, we set up two models: a biculture (wheat and corn) and a triculture (pea, wheat and corn). We applied three levels of nutrients during the fertilization process (control, N50P35K40 and N150P105K120). The third variable studied was irrigation in case of which we tested non-irrigated variables (Ö1) and irrigation variables complemented up to the optimum (Ö3).
The effect of pre-crops, irrigation and nutrient-supply levels on some growth-parameters (LAI, LAD), weight of dry matter, just as SPADvalues 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, and we used the correlation analysis. The correlation analyses have confirmed that all of the investigated parameters had almost in all cases close positive correlation to the yield amount. These results have confirmed that the leaf area, the leaf duration, the SPADvalues, the fertilization and the forecrop have altogether resulted in the production of maximum grain yields.
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Effects of Tillage Systems on Physical Status and Organic Matter Turnover of the Soil
42-45Views:154The cultivation technology for those plant, that play a key role in arable land production need to be renewed in order to reduce production costs and to protect arable land. The modernisation of technologies can only be achieved by applying appropriate tillage systems. Our measurements were carried out on chernozem soil with lime deposits at the Látókép Experimental Station of the Center for Agricultural Sciences, Debrecen University, in long term tillage experiments set up in 1989. We examined the typical physical parameters, the albedo, field capacity, the bulk density of the soil, organic carbon content (humus %) and the measured pH-values in the water solution within the two tillage variations. We have also modelled nitrogen cycle formation in different treatments.
A significant difference occured between the albedos of the two soils, which may be the result of significant amounts of stem remaining on the surface in the case of the reduced tillage method. The yellow, waxy stem of maize reflects 21% of the sun’s rays, especially at the beginning of the vegetation period, when its decomposition has only just started. This delys the warming up in early spring, which delays the sowing time of maize and reduces evaporation. In the two tillage variations, the water management characteristics do not differ practically, the wilting point field capacity are in accordance. In reduced tillage methods, the so-called „plough-pan” can be well measured at 15-20 cm, while in winter ploughing it is at 30 cm. The humus % of the soil does not differ in the two tillage variations, but due to the difference in bulk density this means a different humus and organic nitrogen content. The organic nitrogen content is greater in the reduced tillage method. On the basis of pH value evaluations, we could not detect significant differences in the two tillage variations. The organic nitrogen content of areas where reduced tillage method was applied is higher than in areas where conventional winter ploughing was applied. -
Change of mineral and organic nitrogen forms in a long term fertilization experiment (literature)
43-47Views:112The research topic has timeliness, since the rational utilization and protection of the soil, besides the conservation of its diverse functions is part of the sustainable development. Research of the long-term experiments is esentially important, because it can model the term effects in the same place, under the same conditions. If we want to get accurate informations about the occured changes, way and danger of changes, we should track the resupply and effect of the mineral nutrients and the removed quantity of nutrients with the harvest. Nitrogen is an essential element for living organisms, it is present in the soil mainly in organic form. In general only only a low percentage of the total nitrogent content can be used directly by plants in the soil. This inorganic nitrogen is produced by the transformation of organic contents through mineralization processes and it get into the soil by the fertilization. The plants incorporote the mineral nitrogen into our bodies. This is how nitrogen turnover is realized when mineral forms become organic and organic forms become mineral.
The purpose of our paper is to make a literature before our research.
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Long-term field experiments in the crop production and agroecology
267-272Views:145In Hungary, there are 57 LTFEs included 13360 plots of them 51 trials elder than 20 years, more than 50 years are 32 trials and 6 less than 20 years old. Compared to the 2003 statistical data, some 26 LTFEs ceased to operate in the course of the last 15 years. All research workers and scientist have to do the best to preserve the recently still existing LTFE’s. This paper presents the list of the currently active LTFEs with some comments including the locations, year of setting and the number of plots.
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Growth and clorophyll content dynamics of winter wheat (Triticum aestivum L.) in different cropyear
101-105Views:107The experiments were carried out at the Látókép experimental station of the University of Debrecen on chernozem soil in a long term winter wheat experiment in the season of 2011 and 2012 in triculture (pea-wheat-maize) and biculture (wheat-maize) at three fertilisation levels (control, N50+P35K40, N150+P105K120). Two different cropyears were compared (2011 and 2012).
The research focused on the effects of forecrop and fertilisation on the Leaf Area Index, SPAD values and the amount of yield in two different cropyears. We wanted to find out how the examined parameters were affected by the cropyear and what the relationship was between these two parameters and the changes of the amount of yield.
Examining the effects of growing doses of fertilizers applied, results showed that yields increased significantly in both rotations until the N150+PK level in 2011 and 2012. By comparing the two years, results show that in 2011 there was a greater difference in yields between the rotations (7742 kg ha-1 at N150+PK in the biculture and 9830 kg ha-1 at N150+PK in the triculture). Though wheat yields following peas were greater in 2012, results equalized later on at N150+PK levels (8109–8203 kg ha-1).
Due to the favorable agrotechnical factors, the leaf and the effects of the treatments grown to a great extent in 2011, while in 2012 the differences between treatments were moderate. Until the N150+PK level, nitrogen fertilisation had a notable effect on the maximum amount of SPAD values (59.1 in the case of the biculture and 54.0 in the triculture). The highest SPAD values were measured at the end of May (during the time of flowering and grain filling) in the biculture. In the triculture, showed high SPAD values from the beginning. The same tendency could be observed in the 2012 cropyear, although increasing doses of fertilizers resulted in higher SPAD values until N150+PK level only from the second measurement. Maximum SPAD values were reached at the end of May in both crop rotation system
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The effect of long-term fertilization on phosphorus content determined in different soil extractants on meadow chernozem soil
7-11Views:66The 0.01 M CaCl2 universal extractant is known all over Europe since the 90’s. During my research, I exam the phosphorus content determined in 0.01 M CaCl2 of the samples originated from the B 17 National Uniformed Long Term Fertilisation Trials in the experimental site Karcag, in the 40th year of the experiment. Relationships between the CaCl2-P and the AL-P content of the soil, the average yields, and the phosphorus balance of the
2006/2007 year were studied. From the results of the study it was concluded as follows:
– Correlation was close (r=0.68-0.7) between the AL-P and CaCl2-P. This is in accordance with the results of previous experiments in Hungary and other countries.
– My studies confirmed that the calcium-chloride method indicates well the deficiency and the surplus of plant available phosphorus. In case of different degrees of negative balance, the amount of CaCl2 extractable phosphorus showed no changes, or decreased, and in case of positive balance it increased exponentially by the long-term effect of P rates.
– The 120 and 180 kg ha-1 rates resulted in significant increases in the amount of CaCl2-P according to the control and treatments that are not fertilized with phosphorus. The 60 kg ha-1 rate didn’t result any increase as it didn’t meet the phosphorus requirement of winter wheat, and presumably the P-balance was negative in the earlier years as well.
– It can be stated that the 0.01 M CaCl2 was able to assess the deficiency and the excess of phosphorus causing negative impacts on environment as well.