Influence of Sand-Interlayer Position on the Free Infiltration Characteristics of Nitrogen Fertilization Through Film-Holes
In order to study the influence of the sand-interlayer position on the free infiltration characteristics of nitrogen fertilization through film holes in the layered soil,the silt loam and sandy loam were selected,and three different positions of the sand-interlayer were set for free infiltration tests.The results showed that for the three treatments with sand-interlayers located at 5 to10 cm,10 to 15 cm,and 15 to 20 cm from the soil surface,there were differences in the cumulative infiltration amount,wetting front migration patterns,the water content in the wetting body,and the distribution of ammonium nitrogen and nitrate nitrogen.The closer the sand-interlayer was to the surface,the greater the reduction in infiltration,the smaller the cumulative infiltration,and the greater the distance of the wetting front movement in the horizontal direction.The infiltration process could be divided into two stages:the first stage was before the water movement to the sand-soil interface,and the second stage was after the water movement to the sand-soil interface.The Philip and Kostiakov infiltration models were used to describe the relationship between the cumulative infiltration and the infiltration duration,with good model fitting result.The distribution of water content in layered soil was discontinuous,and the distribution of ammonium nitrogen and nitrate nitrogen was greatly affected by the position of the sand-interlayer.To sum up,the change of the sand-interlayer position has a significant impact on the free infiltration of nitrogen and fertilizer through film holes.
layered soilsand-interlayerfree infiltration through film holesammonium nitrogennitrate nitrogen
万方数据
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