串叶松香草生物量和营养成分动态及其对土壤理化性质的影响

DYNAMIC OF BIOMASS AND NUTRIENT COMPONENTS AND INFLEUNCE OF SILPHIUM PERFOLIATUM ON SOIL PHYSICAL CHEMICAL PROPERTIES

田间试验和化学分析结果表明，串叶松香草两个品种４个生育期的茎、叶产量均以Ａ型＞Ｂ型，在３ａ内串叶松香草产量随生长年限增加，且以Ａ型品种产量高．串叶松香草３个生育期叶片氨基酸和蛋白质含量高于茎，并以Ａ型品种现蕾期为最高；两个品种氨基酸组分以Ａｓｐ、Ｇｌｕ、Ｌｅｕ和Ｌｙｓ含量高，各生育期氨基酸组分含量变化规律不同．串叶松香草的粗脂肪、Ｃａ、Ｐ和灰分含量以叶＞茎，而粗纤维和可溶性糖含量却以茎中较高．除粗纤维外，其余饲用成分含量均随生育期的出现而呈递降之趋势．串叶松香草现蕾期Ｎ、Ｋ含量和莲座期Ｐ含量达最高．种植３ａ后串叶松香草明显改善土壤物理性质，提高土壤酶活性，明显降低土壤有效Ｎ。

Field experiment and chemical analysis were conducted to evaluate the latent use value of Siphium perfoliatum as a forage and green manure crop. Yields of stem and leaf in two variants were in the order of model A>model B at four growth stages.All plant yields were increased significantly with years . Contents of amino acid and protein in leaf were higher than those in stem at three growth stages ,and appeared the highest value in model A at bud stage.Among the amino acid components of two variants ,Asp ,Glu ,Leu and Lys had higher proportion,and the change of amino acid component was different at three growth stages.Contents of crude fat , Ca , P and ash in Silphium perfoliatum plant were in the following sequence:leaf>stem ,but higher crude fibre and soluble sugar existed in stem. Excepting crude fibre,other feeding components decreased with appearence of growth period. Contents of N and K in plant at bud stage and P content at rosette stage came up to the maximum value.After growing three years, Silphium perfoliatum could obviously improve soil physical properties,inherence activities of soil enzymes and reduce distinctly contents of soil available N, P and K.