Practical Allelopathic Effect Of The Humus Soil From Broad-leaved Forest On Shrub And Grass In The Loess Plateau

There are many problems exist in the natural or artificial pure forest, such as singlenessof species, simple structure, and low stability. To resolve these problems, planting leguminousshrubs and grasses may be the most convenient and effective way, for these plants usuallyshow obvious improved effects on soil properties. Humus soil from pure forests may haveallelopathic effects on the growth of leguminous shrubs and grasses, thus we need toinvestigate these effects during the reforming of pure forest.For doing this, based on the survey of common pure forests, taking4kinds of forest asobjects, collecting the humus soil from forests of broad leaf species and wasted land (CK), inplastic greenhouse for planting shrub-herb Leapedeza bicolor, Astragalus adsurgens,coronilla varia, Medicago sativa, Melilotus officinalis, Vicia villosa, Hippophae rhamnoides,Caragana korshinskii, Amorpha fraticosa pot experiment. Then we studied the allelopathiceffects of humus horizon soil on shrubs and grasses understory the forests. The mainconclusions are as follows:Comprehensive analysis indicated that: Populus simonii woodland (hilly area of LoessPlateau) humus horizon soil showed obvious inhibition effects on Medicago sativa, Melilotusofficinalis, Coronilla varia and Amorpha fruticosa. So, Medicago sativa, Melilotus officinalis,Coronilla varia and Amorpha fruticosa should avoid to be planted with Populus simonii andLespedeza davurica, Caragana korshinskii are suitable to be planted with Populus simonii.Specific performance: Humus soil of Populus simonii woodland significantly inhibited theseed germination of Medicago sativa, Melilotus officinalis, and Hippophae rhamnoides, italso inhibited the biomass growth and reduced activity of catalase(CAT) and chlorophyllcontent of Medicago sativa, Melilotus officinalis, Coronilla varia and Vicia villosa.Comprehensive analysis indicated that: Quercus liaotungensis woodland (hilly area ofLoess Plateau) humus horizon soil showed obvious inhibition effects on Medicago sativa,Astragalus adsurgens and Amorpha fruticosa. So, Medicago sativa, Astragalus adsurgens andAmorpha fruticosa should avoid to be planted with Quercus liaotungensis and Coronilla variaand Caragana korshinskii are suitable to be planted with Quercus liaotungensis. Specificperformance: Humus soil of Quercus liaotungensis woodland significantly inhibited the seed germination of Medicago sativa, it also inhibited the biomass growth of Medicago sativa,Melilotus officinalis, Vicia villosa and Hippophae rhamnoides, and reduced activity ofcatalase(CAT) and chlorophyll content of Amorpha fruticosa.Comprehensive analysis indicated that: Betula platyphylla woodland (hilly area of LoessPlateau) humus horizon soil showed obvious inhibition effects on Medicago sativa, Melilotusofficinalis and Amorpha fruticosa. So, Medicago sativa, Melilotus officinalis and Amorphafruticosa should avoid to be planted with Betula platyphylla and Vicia villosa, Caraganakorshinskii are suitable to be planted with Betula platyphylla. Specific performance: Humussoil of Betula platyphylla woodland significantly inhibited the seed germination of Medicagosativa and Melilotus officinalis, it also inhibited the biomass growth of Medicago sativa andMelilotus officinalis, and reduced activity of catalase(CAT) of Coronilla varia.Comprehensive analysis indicated that: Robinia pseudoacacia woodland (hilly area ofLoess Plateau) humus horizon soil showed obvious inhibition effects on Melilotus officinalisCoronilla varia and Amorpha fruticosa. So, Melilotus officinalis Coronilla varia andAmorpha fruticosa should avoid to be planted with Robinia pseudoacacia. Specificperformance: Humus soil of Robinia pseudoacacia woodland significantly inhibited the seedgermination of Medicago sativa and Astragalus adsurgens, it also inhibited the biomassgrowth of Coronilla varia and Melilotus officinalis.Comprehensive analysis indicated that: Robinia pseudoacacia woodland (gully area ofLoess Plateau) humus horizon soil showed obvious inhibition effects on Melilotus officinalisCoronilla varia and Amorpha fruticosa. So, Melilotus officinalis Coronilla varia andAmorpha fruticosa should avoid to be planted with Robinia pseudoacacia. Specificperformance: Humus soil of Robinia pseudoacacia woodland significantly inhibited the seedgermination and biomass growth of Coronilla varia.