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Accueil du site → Doctorat → Chine → 2016 → Effect of Switchgrass and Energy Sorghum on Main Physical and Chemical Properties of Soil in Marginal Land, Inner Mongolia

Université de l’agriculture de Chine (2016)

Effect of Switchgrass and Energy Sorghum on Main Physical and Chemical Properties of Soil in Marginal Land, Inner Mongolia

Raisibe Lucy Molatudi

Titre : Effect of Switchgrass and Energy Sorghum on Main Physical and Chemical Properties of Soil in Marginal Land, Inner Mongolia

Auteur : Raisibe Lucy Molatudi

Grade : Doctoral Dissertation 2016

Université : Université de l’agriculture de Chine

Résumé
The use of biomass which will be grown in marginal lands for biofuel production has been regarded as a potential approach to meet certain needs of petroleum consumption sustainability. The main aim of the study is to determine the effect on switchgrass and energy sorghum plantations on soil moisture, nutrients and organic carbon in marginal land in a semiarid region. A two year field experiment was conducted in a sandy wasteland, Ganqika, Inner Mongolian. At the study site, the switchgrass stands that were established in 2006,2008 and 2009 were arranged as treatments. A plot of native grasses in the adjacent field was set up as a control. Five plots, each with an area of 6 x 6 m, were randomly placed in each treatment as replicates. Energy sorghum (sweet sorghum and biomass sorghum) were also laid out in RCBD in a neighbouring field as treatments with five replicates. Soil samples were collected from different soil layers (0-15,15-30,30-45,45-60,60-75 and 75-90 cm) under different switchgrass plantations (which were established in 2006,2008 and 2009), energy sorghum (sweet sorghum and biomass sorghum) and a control (native grasses). Soil samples were collected before switchgrass regrowth and sorghum plantation and at 40-d intervals until harvesting. Soil pH and electric conductivity (EC) were higher in native grasses recording 9.07 and 184.3 μS cm-1 respectively than energy sorghum which recorded 9.00 and 196.1 μS cm-1, respectively, in average and all switchgrass plantations which recorded an average of 8.6 and 132.6 μS cm-1, respectively. Soil pH and EC were also higher in energy sorghum than in all switchgrass plantations. Soil moisture was significantly higher in native grass than in switchgrass plantations and energy sorghum. Soil organic carbon (SOC), microbial biomass carbon (MBC) and total nitrogen (TN) were significantly higher in native grass than switchgrass plantations. Olsen phosphorus (Olsen P), available potassium (AK), ammonium-nitrogen (NH4+-N) and nitrate-nitrogen (NO3-N) values were significantly higher in all switchgrass plantations than in energy sorghum. These nutrients were also significantly higher in the upper soil layers and decreased with an increase in soil layer under all treatments. Our study attributed that switchgrass decrease soil moisture and salinity in marginal land. An increase in switchgrass plantation age increased SOC, MBC and TN. There were no significant difference in soil moisture, pH, EC, SOC, TN and MBC between energy sorghum and native grass in this study. Switchgrass and energy sorghum were significantly higher in Olsen P, AK, NH4+-N and MO3—N than native grass. These nutrients also increased with an increase in switchgrass plantation age. The two years energy sorghum cultivation in this experiment was not enough to determine the change of SOC and TN in this study. Therefore, long term cultivation of energy sorghum in marginal land is recommended for further studies to assess the response of soil moisture, nutrients and organic carbon under these plantations

Mots clés : Sorghum; switchgrass; soil nutrients; organic carbon; marginal land;

Présentation (CNKI)

Page publiée le 6 février 2017, mise à jour le 20 septembre 2017