볏짚거적과 토양개량제를 활용한 경사지 밭의 비점오염원 저감평가

초록

The objective of the research was to describe the effect of straw mat cover and soil amendments on the reduction of runoff andnon-point source load from steep sloped highland agricultural fields. Four 5×30 m plots on sandy loam soil with 28 % slope wereprepared. Experimental treatments were bare (control), rice straw mat cover (3,000 kg/ha) (S), PAM (5 kg/ha)＋Gypsum (1 ton/ha)(PG) and rice straw mat cover＋PAM＋Gypsum (SPG). A variety of lettuce was cultivated and runoff was monitored during agrowing season in 2011. Natural monitoring was conducted to three times. Runoff rate of S, PG and SPG plots were significantlylower than those of control plot. Especially, the runoff rate is zero in SPG plot at a first rainfall events. The reduction rate ofrunoff from the S, PG and SPG plots was 30.8 %, 29.0 % and 81.8 % compared to control plots, respectively. The reduction rateof NPS pollution load of S, PG and SPG was ranged of 50～90 %, 30～70 % and 90～100 %, respectively. Yield of lettuce fromS, PG and SPG plots was respectively 400 (567 kg/ha), 320 (453 kg/ha) and 760 (1,067 kg/ha) that of compared to control plotsgreater than that from control plots (140 kg/ha). We speculated that the experimental treated plots could hold more nutrients andmoisture than the control and helped the crop grow healthier. When analyzing the above results, in terms of reduction of runoff andNPS pollution load and crop yields, SPG experimental treatment had the best effect. It was concluded that the use of rice strawmats cover and soil amendments on soil surface could not only reduce the NPS pollution loads in receiving waters but also helpincrease the crop yield.

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