The study analysed the relationship between the granulometric composition of grassland soils as determined by laser diffraction and their content of mineral forms of nitrogen and organic carbon. The content of mineral forms of nitrogen (NO3-N and NH4-N) in soil samples - after their extraction with 1% solution K2SO4 , was determined by flow colourimetry. Soil organic carbon content was determined using the Tyurin method. The study examined soil samples collected from 169 control and measurement sites located in different regions of Poland in terms of conditions for agricultural production. Statistical analyses of the research results showed that the grain size of grassland soils had a significant effect on their ammonium nitrogen content but not on their nitrate nitrogen and organic carbon content. In this respect, it was found that there was a positive correlation between the share of the sand fraction and the content of ammonium nitrogen in soils and an opposite relation between the share of coarse silt, fine silt and clay and the content of the aforementioned component. Results of the analyses differ considerably from the results of studies by other authors on the influence of soil grain size distribution on the content of mineral nitrogen and organic carbon in soils based on classical methods of measurements of soil particle size distribution. There is a need to develop solutions to convert and compare results obtained by laser diffraction and standard methods.
The aim of the study was to recognise the accumulation of organic carbon (SOC) in the soils of Polish grasslands (GL) and to consider the possibility of increasing its sequestration in these soils. The Tiurin method (mineral soils) and the mass loss method (soil of organic origin) were used. It was found that: (i) the average SOC content of mineral soils is 2.44% and of organic soils - 10.42%; (ii) according to the Polish criteria, approximately 84% of GL mineral soils are classified as classes with high and very high SOC content, and over 15% and 1% - in classes with medium and low SOC content, respectively; more than 99% of organic soils belong to two classes with the highest SOC content and less than 1% to the class with an average content; (iii) according to the European Soil Bureau, the share of GL mineral soils with a high SOC content is slightly over 4%, medium - slightly over 47%, and low and very low - around 50%; for organic soils they are 67, 29, and 4%, respectively; (iv) the reserves of organic carbon in the 0-30 cm layer on the entire surface of GL soils amount to 412.7 Tg of SOC. There is considerable scope for increasing the SOC stock in meadow-pasture soils.
3
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Zaprezentowano wyniki badań oddziaływania aplikacji do gleby różnych substancji: azotu (mocznik), kompostu, bentonitu i zeolitu oraz tlenku wapnia na zawartość węgla organicznego (Corg) w glebach zanieczyszczonych wzrastającymi dawkami oleju opałowego (5-20 g/kg gleby). Stosowano je w ilościach: mocznik 200 mg/kg w przeliczeniu na N, kompost, bentonit i zeolit, odpowiednio 3%, 2% i 2% w stosunku do masy gleby, oraz tlenek wapnia 50% (dawka odpowiadająca 1 pełnej kwasowości hydrolitycznej). Wpływ oleju opałowego na zawartość Corg był uzależniony od dawki zanieczyszczeń oraz gatunku uprawianej rośliny. W serii kontrolnej (bez dodatków) wykazano wpływ oleju opałowego na wzrost zawartości Corg w glebie, szczególnie w wyniku oddziaływania niewielkich jego dawek. Aplikacja CaO, mocznika i zeolitu spowodowała zmniejszenie zawartości Corg w glebach po zbiorze wszystkich roślin, w porównaniu z glebą bez dodatków. Bentonit miał odwrotny wpływ na zawartość Corg w glebach po zbiorze kukurydzy oraz jęczmienia jarego/gorczycy białej. Dodatek kompostu wywołał zwiększenie zawartości Corg w glebach po zbiorze kukurydzy oraz zmniejszenie jego zawartości w glebach po uprawie pozostałych roślin.
EN
Soils contaminated with the oil (5-20 g/kg of soil) were purified by addn. of urea (N content 200 mg/kg soil) as well as of compost, bentonite, zeolite (concns. 3%, 2% and 2% by mass, resp.) and CaO (dose equiv. to 1 full hydrolytic acidity). Soils with or without the additives were used for cultivation of maize, spring barley/white mustard and oats to test the effect of oil pollution and used additives on the content of org. C in soils after crops. The type of the crop and content of oil contamination had a significant impact on the content of org. C in unmodified as well as modified soil samples. The contamination with the oil resulted in an increase in org. C content in soils, esp. in soils with small doses of heating oil. The addn. of CaO, urea and zeolite resulted in decrease in org. C content in soils after crops of all tested plants compared to their content in original soils with comparable oil content. The addn. of bentonite resulted in the opposite effect for soils after maize and spring barley/white mustard crops. The addn. of compost resulted in an increase in the org. C content in soils after cultivation of maize and a decrease in its content in soils after cultivation of other plants.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.