10:45 〜 12:15
[AGE27-P04] Can fine soil particle application improve the aggregation stability and physical properties in degraded sandy soil?
キーワード：fine particles application, bentonite, paddy soil, soil aggregation
Soil aggregation stability, represented by the mean weight diameter (MWD) index, is a fundamental parameter of soil that expresses soil resistance to erosion. Thus, maintenance or enhancement of high aggregate stability in soils is a priority for sustainable land use because of its impacts on the preservation of agricultural production, minimizing soil erosion and degradation, and mitigating environmental pollution. Soil erosion is a process in which fine soil particles and organic matter are detached and removed from surface soil due to weathering conditions. Therefore, this study examined whether the application of fine soil particles might enhance the soil aggregation stability in degraded soil, how it impacts the soil's physical properties, and the soil benefit for agricultural production.
Decomposed granite soil (Masa soil) was used in the preliminary experiment with and without compost amendment. Three treatments were implemented, which were bare masa soil (control), 5% bentonite, and 5% fine paddy soil (sieved through 0.053-mm mesh) application. Mean weight diameter (MWD), water retention curves, saturated hydraulic conductivity, soil porosity, and soil bulk density were monitored after the experiment. To evaluate soil's ability for agricultural production, pot experiments using the examined soils were set up to observe the development traits of Vigna unguiculata (cowpea pea or sasage), including plant height, number of leaves, root length, and biomass of stems.
Some primary results were revealed as follows: (1) The MWD results showed an increasing trend of erosion resistance for soil treatment with 5% bentonite and 5% paddy soil after 7-day incubation. (2) The water holding in the soil samples was increased when applied the fine particles (bentonite or paddy soil sized < 0.053mm). (3) The high saturated hydraulic conductivity of Masa soil was maintained when applying fine paddy soil. In contrast, it was reduced when applying bentonite due to the high concentration of clay. (4) The plants grown in the soil incorporated 5% fine paddy showed high values of height, number of leaves, taproot length, and stem biomass, particularly when the soil amended compost. In contrast, soil with bentonite showed low values of the parameters.
Consequently, fine soil particle application might promote the particle aggregation process of degraded soil, which implies a higher resistance to soil erosion. However, fine paddy soil application could be favorable for agricultural production.
Decomposed granite soil (Masa soil) was used in the preliminary experiment with and without compost amendment. Three treatments were implemented, which were bare masa soil (control), 5% bentonite, and 5% fine paddy soil (sieved through 0.053-mm mesh) application. Mean weight diameter (MWD), water retention curves, saturated hydraulic conductivity, soil porosity, and soil bulk density were monitored after the experiment. To evaluate soil's ability for agricultural production, pot experiments using the examined soils were set up to observe the development traits of Vigna unguiculata (cowpea pea or sasage), including plant height, number of leaves, root length, and biomass of stems.
Some primary results were revealed as follows: (1) The MWD results showed an increasing trend of erosion resistance for soil treatment with 5% bentonite and 5% paddy soil after 7-day incubation. (2) The water holding in the soil samples was increased when applied the fine particles (bentonite or paddy soil sized < 0.053mm). (3) The high saturated hydraulic conductivity of Masa soil was maintained when applying fine paddy soil. In contrast, it was reduced when applying bentonite due to the high concentration of clay. (4) The plants grown in the soil incorporated 5% fine paddy showed high values of height, number of leaves, taproot length, and stem biomass, particularly when the soil amended compost. In contrast, soil with bentonite showed low values of the parameters.
Consequently, fine soil particle application might promote the particle aggregation process of degraded soil, which implies a higher resistance to soil erosion. However, fine paddy soil application could be favorable for agricultural production.