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The effect of NPK fertilisation on mineral phosphorus fraction content in soil

100%

Acta Agrophysica

2017

tom 24

nr 2

A field experiment, conducted on loess-derived gray-brown podzolic soil, evaluated the effect of different levels of intensive fertilization with nitrogen, phosphorus and potassium on the soil content of mineral phosphorus fractions which are the major but varying source of this nutrient for crop plants. Before the establishment of the experiment, the soil contained 77.2 mg P kg–1, 187 mg K kg–1, 44 mg Mg kg–1, and 1.18% of humus, whereas pHKCl was 4.9. The experiment consisted of twenty seven fertilization treatments – nine nitrogen and potassium fertilization treatment combinations, each in four replicates, were carried out in relation to three increasing levels of phosphorus fertilization. Phosphorus fraction was indicated with the modified Chang-Jackson method. Mineral nitrogen, phosphorus and potassium fertilization after timothy grass harvest significantly affected the easily soluble phosphate fraction content in soil. Phosphorus fertilization caused the highest increase, while this increase was lower in the case of potassium and nitrogen fertilization. Mineral fertilization (with nitrogen, phosphorus, and potassium) used in the experiment caused a significant increase of the content of aluminium phosphate fractions in soil. Evaluating iron phosphate fraction content in soil, it can be concluded that it was the most stable fraction and that mineral fertilization at increasing NPK rates essentially did not have any statistically proven effect on its occurrence. Among the three fertilizer nutrients applied (NPK), phosphorus and potassium fertilization caused a significant increase in calcium phosphate fraction content in soil. The application of nitrogen was not found to have such an effect. Mineral NPK fertilization significantly affected the total mineral phosphorus fraction content in soil. A systematic increase in the total fraction analysed was found primarily under the influence of phosphorus and potassium fertilization. Phosphorus applied as granulated triple superphosphate was primarily transformed in the soil into fractions of iron and aluminium phosphates, to lower extent into calcium phosphate fraction, and – to the lowest extent – into easily soluble phosphates fraction.

Preliminary characterization of the trophic state of Maly Kopik Lake near Olsztyn and its drainage basin as a supplier of biogenic substances

88%

Grochowska J., Tandyrak R.

Journal of Elementology

2008

tom 13

nr 1

The study was carried out on a small (7.8 ha) and shallow (9.0 m) lake Mały Kopik, situated 9 km on south western from Olsztyn, drainage basin of Giłwa and Pasłęka rivers. The catchment area of the lake is 194.7 ha. Forests cover the most of the drainage basin area (64.2%), agriculture land comprises 28.7% (21% grass land and 7.7% arable land) and urban land - 7.1%. Lake Mały Kopik is not susceptible to degradation (III category), and drainage basin having a great potential for supplying matter to the reservoir, was included in basin category 4. The lake with its drainage basin belong to the 4th type of lake-drainage basin ecosystems. In such a system the natural eutrophication of the lake is expected to proceed at a fast rate. As evidenced in the study, lake Mały Kopik is highly eutrophic reservoir. The lake waters were characterized by a high content of nutrients, up to 0.673 mg P·dm-3 and 10.61 mg N·dm-3. The high fertility of the lake was exhibited also by the values of BOD5 reaching 7.5 mg O2·dm-3, chlorophyll a content - 50 µg·m-3, and low water transparency - 2 m.

Ograniczanie wyników

1 Acta Agrophysica

1 Journal of Elementology

1 Grochowska J.

1 Tandyrak R.

1 2017

1 2008

Wyniki wyszukiwania

The effect of NPK fertilisation on mineral phosphorus fraction content in soil

Preliminary characterization of the trophic state of Maly Kopik Lake near Olsztyn and its drainage basin as a supplier of biogenic substances