CAJ | 학술논문

以浙江省永康市方山柿经济林坡地为试验区，依据不同地形条件及林下管理措施，设置7个径流小区和沉砂池，定期采集沉砂池水样，测定径流中不同形态氮素浓度。通过为期一年的监测分析，得到如下结论：（1）试验区氮素流失与水文年内降水具有明显的同步性，氮素流失多发生在降水集中的梅雨和台风季节。这两个季节的降水量占全年降水的66.2％，TN、NO-3-N和NH+4-N流失量分别占全年总流失量的80.3％、78.2％和83.0％。（2）坡顶、凸坡和凹坡径流小区的氮素流失符合养分流失的“临界坡度”规律，临界坡度在坡顶（10.22°）与凹坡（18.55°）之间。水文年内TN和NO-3-N流失量关系为坡顶﹥凹坡﹥凸坡，NH+4-N流失量关系为凹坡﹥坡顶﹥凸坡。三种地形径流小区的年内氮素累积流失量均呈幂函数型增加。（3）对照林下管理措施不同的6号（林下除草）和7号（林下不除草）径流小区，发现草被覆盖对减少经济林坡地氮素径流流失具有明显效果。保留草被覆盖的7号小区比除草的6号小区的TN、NO-3-N和NH+4-N径流流失分别减少了22.1％、36.2％和44.1％。
이절강성영강시방산시경제림파지위시험구，의거불동지형조건급림하관리조시，설치7개경류소구화침사지，정기채집침사지수양，측정경류중불동형태담소농도。통과위기일년적감측분석，득도여하결론：（1）시험구담소류실여수문년내강수구유명현적동보성，담소류실다발생재강수집중적매우화태풍계절。저량개계절적강수량점전년강수적66.2％，TN、NO-3-N화NH+4-N류실량분별점전년총류실량적80.3％、78.2％화83.0％。（2）파정、철파화요파경류소구적담소류실부합양분류실적“림계파도”규률，림계파도재파정（10.22°）여요파（18.55°）지간。수문년내TN화NO-3-N류실량관계위파정﹥요파﹥철파，NH+4-N류실량관계위요파﹥파정﹥철파。삼충지형경류소구적년내담소루적류실량균정멱함수형증가。（3）대조림하관리조시불동적6호（림하제초）화7호（림하불제초）경류소구，발현초피복개대감소경제림파지담소경류류실구유명현효과。보류초피복개적7호소구비제초적6호소구적TN、NO-3-N화NH+4-N경류류실분별감소료22.1％、36.2％화44.1％。
Nitrogen loss in sloping forest lands is not only an important source of non-point source pollution, but also reduces use efficiency of nitrogen fertilizer. An experiment was conducted to monitor nitrogen losses in persimmon economic forests in hilly red soil area in Yongkang, Zhejiang. Total 7 runoff plots were set up under different terrains and forest managements. Grit chambers were established to collect water samples monthly. Different forms of nitrogen in water samples were then measured. Nitrogen losses were obviously synchronous with precipitation in a hydrological year. Most of nitrogen losses occurred in rainy and typhoon seasons, which accounted for 66.2%of the annual precipitation. During these two seasons, TN, NO-3-N and NH+4-N losses were 80.3%, 78.2%and 83.0%of the annual total N loss, re-spectively. In the hydrological year, the rates of TN and NO-3-N losses were crest﹥concave slope﹥convex slope, while the rate of NH+4-N losses was concave slope﹥crest﹥convex slope. The cumulative nitrogen losses under three terrains had power function relationship with time. Grass coverage reduced runoff losses of TN, NO-3-N and NH+4-N by 22.1%, 36.2%and 44.1%, respectively.