In this paper, the effect of different land-use types on soil organic carbon (SOC) and Particulate Organic Carbon(POC) was studied by analyzing the soils in the meadow and conversing land of grassland to cropland in ecotones of agriculture and animal husbandry. It is shown t㏊t, compared with meadow, rotations of P/O and P/Cwill reduce SOC in 0-30㎝ soil layers by 47.54%-65.11% and 34.16-64.26% and POC by 16.90%-24.48% and 11.94%-20.29%, respectively. And SOC in meadow is more t㏊n in conversing land of grassland to cropland (P＜0.05). Conversing grassland to cropland in ecotones of agriculture and animal husbandry will decrease the contents of SOC and POC.

We have studied the catalytic combustion of soot particulates over perovskite-type oxides prepared by malic acid method. The catalysts were modified to enhance the activity by substitution of metal into A or B site of perovskite oxide. In addition, the reaction conditions such as temperature and O2 concentration were investigated. The partial substitution of alkali metals into A site in the LaMnO3 catalyst, enhanced the catalytic activity in the combustion of carbon particulate and the activity was shown in the order: Cs＞K＞Na. For the La1-xCsxMnO3 catalysts, the catalytic activity showed the maximum value with x=0.3 but no more increase on the catalytic activity was shown with x＞0.3. For the La0.8Cs0.2MnO3 catalyst, the substitution of Fe or Ni increased the ignition temperature. The ignition temperature decreased with an increase of O2 concentration, however, no more increase in the catalytic activity was shown with O2 concentration＞0.2. The introduction of NO into reactants showed no effect on the catalytic activity.