A Study Of Soil Enzyme Activity On Soil And Water Conservation In Typical Black Soil

In order to explain the characteristics of forest soil enzyme activities in black soil area, Soil enzyme activities of different soil layers soils from natural secondary forest in tipical black soil region were studied by measuring and analyzing the soil enzyme activities and soil nutrients. Based on this experiment, soil enzyme activities of soils from soil from different land use, in typical black soil region were studied by measuring and analyzing soil enzyme activities and nutrients. We also studied the soil enzyme activities and nutrients of soils from the different forest types and different ages of Larch (Larix gmelini) in typical black soil region, revealing the black soil region variation in recovery mode different soil enzyme activities and nutrients. Evaluation findings can restore vegetation to provide reference black soil area.The results showed that:Soil organic matter, hydrolytic nitrogen, nitrate nitrogen, ammonium nitrogen, and phosphorus content were showed the trend of decreased in the soil depth of0-200cm, in undisturbed black soil. Soil polyphenol oxidase, alkaline phosphatase activities varied from3.08-3.63ml/(g·24h),3.66-9.77mg/(g·24h), and decreased with increasing soil depth; Soil catalase, dehydrogenase, sucrase ctivities varied from6.88-10.71ml/(g·24h),7.38-45.93μg/g·24h),0.29-2.29mg/(g·24h), they showed the trend of decrease of0-60cm, after an increasing at60-80cm, then decreased after increased in the range of60-200cm, and those in the soil depth of0-20cm were significantly higher than other layers; The total enzyme activity of soil showed a similar trend; The soil enzyme activities were highter during soil degth of0-20cm, and the metabolic of soil wal strong, soil material transformation was fast, but those of the soil depth of160-200cm were weak. It was believed that soil enzyme activities and soil nutrients from natural secondary forest during soil depth of0-20cm were the highest, and decreased with the increase of soil depth.In the layer of0-20cm, Soil organic matter, hydrolytic nitrogen, ammonium nitrogen of Manchurian Ash(Fraxinus mandshurica) and Poplar(Populus nigra var.italica×P.cathayan) forest were significantly higher than that of natural forests, abandoned land and arable land, and arable land had the highest contents of phosphorus, nitrate; Soil catalase, dehydrogenase, urease and alkaline phosphatase activityies of Manchurian Ash(Fraxinus mandshurica) and Poplar(Populus nigra var.italica×P.cathayan) forest were the highest, arable land the second, followed by natural forests, abandoned land; and the polyphenol oxidase activity of arable land was higher than forests and abandoned land. The relationships analysis showed that soil nutrients had higher correlation with enzyme activities. It is believed that Manchurian Ash (Fraxinus mandshurica) forests, Poplar(Populus nigra var.italica×P.cathayan) is more conducive to the accumulation and release of soil nutrients, and soil enzyme activity increased. The soil nutrients and soil enzyme activities showed the trend of decreased significant in black forests upon the depth of0-40cm. The organic matter and nitrogen showed that, Manchurian Ash (Fraxinus mandshurica), Poplar (Populus nigra var.italica×P.cathayan) highter than other plots, abandoned land and Scots Pine(Pinus sylvestris var.mongolica) the second followed by Larch (Larix gmelini). Soil catalase, dehydrogenase, invertase, urease and alkaline phosphatase activities showed that forests were higher than abandoned land, but there was no significant difference between the soil polyphenol oxidase activities. Soil and water conservation plantations, especially Manchurian Manchurian Ash (Fraxinus mandshurica), could significantly improve the soil fertility, the soil biochemical processes, and also could provide favorable environmental conditions for plants and animals.Soil organic matter, nitrogen and phosphorus hydrolysis were increased with the increasing forest ages during soil depth of0-20cm, and the main nutrients on28years old Larch (Larix gmelini) was significant highter than abandoned land(p<0.05). The invertase activity was higher than abandoned land in the age of36. While the other enzyme activities were showed that forests were highter than abandoned land after28years. Soil catalase, dehydrogenase, sucrose, urease, alkaline phosphatase, and total enzyme activities were first increased with the increasing age. Then decreased, and polyphenol oxidase was showed the trend of increasing with the age. The relationships analysis showed that there were significant relationship between catalase, dehydrogenase, urease, alkaline phosphatase activities and soil nutrients, except the polyphenol oxidase. Summing it that Larch (Larix gmelini) soil nutrients and soil enzyme activities were highter than the abandoned land after the age of36. Total enzyme activity index could reflect the characteristics of soil enzymes with the evolution of vegetation recovery, could be used as a soil quality evaluation method.