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Change of soil nitrogen content in a long term fertilization experiment
39-44Views:164The most important aim of sustainable agriculture is to ensure our natural resources – such as soils – protection, which includes fertility preservation and the use of appropriate methods of cultivation.
If we want to get accurate information about the occurred 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 and it is present in the soil mainly in organic form. In general only a low percentage of the total nitrogen content can be used directly by plants in the soil. The mineral nitrogen is incorporate by plants into our bodies. This inorganic nitrogen is produced by the transformation of organic contents through mineralization processes and it gets into the soil by fertilization. This is how nitrogen turnover occurs when mineral forms become organic and organic forms become mineral.
The objective of this publication was to introduce – through some element s of nitrogen turnover- how changing the properties of soil in a long term fertilization experiment.
We established that the fertilization is influenced the soil pH. With the increase of fertilization levels increased the acidity of the soil, maybe it is related with the number of nitrification bacteria. The fertilization and the rotation affected to the quantity of nitrate.
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Change of mineral and organic nitrogen forms in a long term fertilization experiment (literature)
43-47Views:129The 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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The effect of crop rotation and fertilization on wheat and maize in the pedoclimatic conditions of the Banat Plain
14-18Views:87The simplification of the plant cultures range and the yields in the last 10-15 years brings into the actuality the role of crop rotation and
of fertilization on the yield level and stability for wheat and maize even on the soils with a high natural fertility. The results of the researches
performed between the years 2006 – 2009 on a cambic low gleyed chernozem from the Banat Plain showed that the wheat cultivated in
monoculture gives productions with 59-81% lower than that cultivated in crop rotation with other plants during 2-4 years. In maize, the yield
obtained in monoculture is situated behind that obtained in crop rotation with 11-21%. The most favorable crop rotations for wheat were
rape-wheat in a 4 years rotation and soybean-wheat in simple rotation of 2 years. In maize, the most favorable was the 2 years rotation
(wheat-maize). The mineral fertilization was very efficient both in wheat (11-36%) and maize (9-31%). The organic fertilization with manure
was very efficient for maize, the yields being superior with a mean value by 34% for a 60 t/ha dose and with 16% for 30t/ha. The fertilization
compensates the negative effect expressed by the monocultivation only in a small measure -
Different soil fertility conditions depending on different land use methods
169-172Views:103In precision nutrient management the most important aspect is adaptation but we should consider the possibility of the long-term improvement of soil fertility within the less fertile landscape zones. This possibility can be evaluated principally by long-term field experiments, which are running on similar soil types. The results of these field experiments can indicate that which soil fertility status should be attained. Some more important soil fertility data, (such as pH, P-, K- and soil organic matter (SOM) content) of a long-term field experiment with increasing farmyard manure(FYM) doses or equivalent NPK fertilizers, set up on an Eutric cambisol, are presented. The yieldincreasing capacity of FYM doses was only 82%, as compared to the equivalent amount of mineral NPK, but long-term FYM treatments resulted in 10% higher SOM content than that of equivalent NPK
fertilizer doses. The studies indicate that SOM content is a function of local climate and clay content of the soil, and neither long-term high FYM doses can increase SOM content steadily above a supposed steady-state value. However we have to make efforts to keep the optimum level. The lowest soil reactions developed both with the highest NPK doses and without any fertilization. AL-P2O5 content of soil was increased more by mineral fertilization than by FYM treatments, but in case of AL-K2O content there was no difference between the fertilization variants. However the highest doses of both fertilization variants increased soil nutrient content to an excessive degree. Wecould get very valuable data from the unfertilized control plots as well, where long-term yield data suppose 48 kg ha-1 year-1 air-borne N-input. -
Researches regarding the influence of the some technological elements on water use efficiency in maize from Crisurilor Plain
5-9Views:155Plain and the influence of the hybrid, plant density, crop rotation, nutrient supply, weeds and irrigation on water use efficiency were studied.
Choosing of the hybrid with the best water use efficiency is very important because a hybrid from 500–600 FAO group (Fundulea 376) in unirrigated conditions and a hybrid from FAO group over 600 (Fundulea 365) obtained the biggest water use efficiency; the hybrid Fundulea 365 obtained the highest irrigation water use efficiency, 20.1 kg yield gain 1 mm-1 irrigation water.
One of the most known hybrid in the area is Turda super and the highest water use efficiency was obtained using the plant density of 55 000 plants/ha in unirrigated variant and 70 000 plants/ha in irrigated variant. The highest irrigation water use efficiency, 20.7 kg yield gain 1 mm-1, was obtained at 70 000 plants ha-1.
In maize monoculture was obtained the lowest values of the water use efficiency in unirrigated and irrigated variant: in the wheat-maize crop rotation the values were higher than in maize monoculture and in the wheat-maize-soybean were registered the highest values. The same situation was registered regarding the irrigation water use efficiency.
Farm manure (30 t ha-1) and especially manure (30 t ha-1) +chemical fertilizers (N90P45) determined a higher values of the water use efficiency in comparison with the control. In the variant with organic + mineral fertilization was registered the higher value (19.4 kg yield gain mm-1) of the irrigation water use efficiency.
Water use efficiency was much lower in the variant with weeds in comparison with the variant without the weeds; the differences were of 69% in unirrigated variant and of 64% in irrigated variant, very significant statistically. Irrigation water use efficiency from variant with weeds was lower than the value registered in the variant without weeds; the difference (68%) was very significant statistically.
In average in period 1976–2012, the irrigation determined the increasing in water use efficiency with 22%, 19.4 kg mm-1 vs. 15.8 kg mm-1, but not in all the years caused the irrigation increasing in water use efficiency in comparison with unirrigated maize.
The results research emphasized the need of the optimization for technology elements studied and a better water use efficiency will be obtained.
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The influence of the fertilizing system on the petroleum residues biodegradation on a preluvosoil under control polluted
251-254Views:101The paper presents the partial results of researches regarding the agrochemical melioration of soils under control polluted by petroleum residues that took place at the Agricultural and Research and Development Station in Oradea, Bihor County.
The experimental device was made out of 1 m2 microparcels, spread out in subdivided parcels, in four repetitions, having tree factors: A - the pollution by crude oil from Suplacu de Barcău, B – the mineral fertilization, and C – the organic fertilization.
The experience was set out on a preluvosoil în the year 1993 and the soil was cultivated with millet in the first 3 years and with spring wheat in the last 7 years of research.
The researches carried out in Oradea had the objective of establishing the effects of the fertilizing system on the petroleum residue biodegradation on a preluvosoil under control polluted with crude oil from Suplacu de Barcău, Bihor County. -
The possibility of use of the 0,01 M CaCl2 and Baker- Amacher extractants for the determination of plantavailable potassium
7-15Views:89The Hungarian fertilizing recommendation systems use AL soil test for the evaluation of potassium supply. The 0.01 M CaCl2 is a definitely milder extractant, it extracts the easily soluble and exchangeable potassium amount. Its European introduction was already taken into consideration in 1994. The research project on this topic is started in several european countries, also in Hungary at the Department of Agricultural Chemisty of Agricultural University of Debrecen. Another advantage this multielement method is that the different element-ratios can also be calculated.
The Baker-Amacher extractant’s principle is that it contains a known amount of K, P, Mg in the CaCl2 solution. During the soil extraction adsorption and desorption process take place, so the adsorption or desorption can be calculated from the original and the final concentrations.
In this paper we introduce the results of comparing analysis of the samples (n=630) from Soil Information and Monitoring System. Our aim was to measure the use of new extractants beside conventional extractant (AL) for the evaluation of K-supply would be reasonable.
It can be stated that there is a medium close relationship (r=0.75) between AL-K and 0.01 M CaCl2-K. My calculations confirmed the results of former examinations, and proved that the two extractants don’t extract and change the same rate of K-fractions. We found that regression between 0.01 M CaCl2 and AL depend on texture classes, pH classes, amount of lime, and organic matter content of soils.
Comparing the relations between AL and Baker-Amacher we find relatively loose correlation (r=0.45). We stated that there are K-fixing soils among soils considered to be well supplied with potassium by AL. This might be caused by the high amount of mineral clay and the quality of mineral clay. We stated that the dK averages show that the Hungarian nutrient-supply categories characterize generally well K-supplement of soil.
It can be stated that it would be necessary to use new extractants to specify evaluation of plant available K. We found that the 0.01 M CaCl2 and Baker-Amacher extractants could complete usefully the AL procedure and could help effective potassium fertilization. -
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:200The 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.