Influence of the degree of soil organic matter lability on the calcium carbonate equilibrium of soil water
2010
Kuzel, S.,Jihoceska Univ., Ceske Budejovice (Czech Republic). Zemedelska Fakulta | Kolar, L.,Jihoceska Univ., Ceske Budejovice (Czech Republic). Zemedelska Fakulta | Gergel, J.,Jihoceska Univ., Ceske Budejovice (Czech Republic). Zemedelska Fakulta | Peterka, J.,Jihoceska Univ., Ceske Budejovice (Czech Republic). Zemedelska Fakulta | Borova-Batt, J.,Jihoceska Univ., Ceske Budejovice (Czech Republic). Zemedelska Fakulta
In average samples of three sandy-loamy acid Cambisols from a South Bohemian area, labile organic matters were determined by the permangate method modified by the dichromate method and the rate constant of their biochemical oxidation was determined in hot water extracts of the samples. The need of liming was determined by means of 2 methods. In soil solutions of these samples, all values necessary to evaluate their calcium carbonate equilibriums were determined. The soil samples were enriched with 3% of dry matter of farmyard manure and meadow clover meal, and were incubated at 25 deg C for 180 days under wetting above 50% of their retention water capacity. Both methods were found to increase the need of liming in all three soils: the more labile the organic matter in 3% addition, the higher the need. The meadow clover matter was more labile than the farmyard manure matter. All three methods yielded similar results, the potassium permanganate method was more sensitive than the dichromate one. Increases were observed in equilibrium [Cr(H2CO3*)] and in Langelier saturation index Is. In our experiment, about 220 kg CaCO3 per hectare of land were consumed on condition that it was not necessary to re-establish it. The process of Ca-compound consumption to establish the calcium carbonate equilibrium is controlled exclusively by the degree of mineralising organic matters lability while the influence of soil properties is only marginal. The same results were provided by the comparison of calcium carbonate equilibriums in nine Sumava brooks of the total watershed area 78,564 square km. A reduction in the intensity of agricultural production in 1986-2004 resulted in an increase in the stability of organic matters in the sediments, in a decrease in Is, and in a lower corrosivity of brooks water towards CaCO3. However, the quality of soils and their potential soil fertility decreased due to the loss of labile organic matters.
显示更多 [+] 显示较少 [-]