坡度和耕作措施对土壤侵蚀及大豆产量的影响

Effect of Slope and Tillage Measures on Soil Erosion and Yield of Soybean

采用径流小区试验,在克山县粮食沟小流域定位试验站不同坡度(3°和5°)下研究横坡垄作和顺坡垄作两种耕作措施对地表径流、土壤侵蚀及大豆产量的影响,寻求最优推荐措施。结果表明:以克山县近30年降雨数据发生频率为依据,2012年为湿润年型,全年降雨量578.6 mm,有效降雨(产生地表径流的降雨)次数为18次,有效降雨量为399.6 mm,占全年降雨量的69.1%;3°顺坡垄作和5°顺坡垄作发生径流的临界雨量分别为13.1和11.1 mm,有效降雨与3°顺坡垄作和5°顺坡垄作产生径流量的相关系数分别为0.765和0.805,而与3°横坡垄作和5°地埂植物带产生的径流量相关性较弱,相关系数分别为0.109和0.112。与顺坡垄作相比,3°横坡垄作和5°地埂植物带阻水抗蚀效果明显,两处理年径流量分别减少94.3%和95.9%,侵蚀模数降低99.9%和99.8%,3°横坡垄作和5°地埂植物带大豆百粒重分别增加9.3%和21.4%,产量分别增加8.2%和13.4%。

Using runoff plot experiments, the effect of cross ridge and downslope ridge （3°and 5° ） on runoff, soil erosion and soybean yield was studied in the experimental station, which located in grain gully watershed in Keshan county. The results showed that three rainfall year types were classified according to local 30-year rainfall data of Keshan County ,2012 was charac- terized as a wet-year with 578. 6 mm annual rainfall. Eighteen times of effective rainfall （ start producing surface runoff） sur- face runoff happened with 399. 6 mm precipitation, accounted for 69. 1% of annual rainfall. The amount of critical rainfall, a- bove which could make surface runoff happen, were of 13. 1 mm and 11.1 mm for vertical ridge tillage land with slope of 3°/ 5° degree respectively. Correlation coefficients between the amount of effective rainfall and 30/5° vertical ridge tillage land were 0. 765/0. 805 respectively and meanwhile these between the effective precipitation and 3° cross ridge tillage/5° contour hedgerow 0. 109/0. 112 respectively. Cmpared with vertical ridge tillage, the conservation effects of cross ridge tillage with slope of 3 degree and contour hedgerow with slope of 5 degree were significant by reducing runoff 94. 3% and 95.9% respec- tively and reducing erosion mode by 99. 9% and 99. 8% , meanwhile 100 - seed weight of those two treatments increased by 9. 3% and 21.4% and the percentage of soybean yield increasing were up to 8. 2% and 13.4%. The results could provide in- tegrated evaluation for comprehensive soil fertility improvement measures.