Joint International Conference on Long-term Experiments ...

EFFECT OF FERTILIZATION SYSTEMS AND LIMING ON MOBILE
PHOSPHORUS CONTENT IN DIFFERENT SOIL TYPES
ABSTRACT
Augusta Olivia Lujerdean
University of Agriculture Science and Veterinary Medicine Cluj-Napoca,
Faculty of Animal Breeding and Biotechnology
3-5 Calea Manastur Street 400732, Romania
Liming and application on acidic soils of inorganic fertilizers or organic manure had the
considerable influence on the mobile phosphorus content and pH of soil. P(AL)
determinations suggest that differences in the soil physical-chemical properties and the
forming which P is applied influences the effectiveness of fertilization and P balance.
The phosphorus transformation process was changed under the influence of liming
intensity, soil liming changed phosphate forms and the ratio between mineral fractions
of phosphates.
The aim of this study was to establish the effect of liming and fertilization on the
amount of available soil phosphorus in different classes of North-Western Romanian
soils: albic luvisoil, clay illuvial brown, clay illuvial chernozem.
Observations showed a maximum effect of pH increase and P mobile content fertilising
inorganic NPK together with manure on albic luvisoil.
Keywords: soil liming, mobile phosphorus, inorganic fertilizer, farmyard manure
INTRODUCTION
Different classes of soils in North-West Romania present low productivity inadequate
soil management, irregular supply of nutrients, the acidity being pointed out as the
cause for declined yield.
Phosphorus availability in most soils is optimal at the soil pH of 6.5. Below this value
as in more the soils of this part of Romania phosphorus will react with iron (Fe)/
aluminium (Al) oxides and start forming precipitates which prohibit the plant from
being able to fixate phosphorus. Liming acidic soils will generally increase availability
of phosphorus to plant. Ideally a liming program should be planned so that the pH can
be kept between 5.5 and 6.8 if maximum benefit is to be derived from applied
phosphorus (Havlin et al.2005). Over liming can depress phosphorus solubility due to
the formation of insoluble precipitates with calcium. A decrease in phosphorus
availability because of this formation of Ca-P minerals also happen in an alkaline soil
with a pH value higher than 6.5. Several other characteristics affect the process and
availability of phosphorus fixation. The texture and type of soil strongly influences the
level of mobile phosphorus.
MATERIALS AND METHODS
Soil samples were obtained from long time experiments established in 1961 at Livada,
Satu Mare County. This experiment includes treatments with different levels of mineral
fertilizers, organic manure and lime inputs.
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