农业工程学报
農業工程學報
농업공정학보
2015年
3期
137-145
,共9页
灌溉%排水%节水%农业面源污染%四道防线%总氮%总磷
灌溉%排水%節水%農業麵源汙染%四道防線%總氮%總燐
관개%배수%절수%농업면원오염%사도방선%총담%총린
irrigation%drainage%water-saving%nonpoint source pollution%four lines of defense%total nitrogen%total phosphorus
不合理的农田水肥管理是造成农业面源污染的主要原因之一。为了探寻灌区水稻节水、增产和减污相统一的措施，提出运用由田间、草沟、塘堰湿地和骨干沟“四道防线”组成的系统净化农田排水，并在广西桂林市青狮潭灌区及广西灌溉试验中心站开展了系统的试验研究。通过站内不同水肥处理下对田间节水、水稻增产、氮磷流失减少指标的分析，优选水稻田间最优水肥管理模式，即采用间歇灌溉模式、施氮肥总量不变、适当减少氮肥基肥增加追肥用量；在站外根据现有的水系分布构建“四道防线”系统，分析了各道防线对农田排水的净化效果以及提高净化效果的主要措施。由“四道防线”构成的节水防污型农田水利系统对农田氮磷排放具有良好的净化效果，实现了减少农田面源污染和修复农田水环境的目的。
不閤理的農田水肥管理是造成農業麵源汙染的主要原因之一。為瞭探尋灌區水稻節水、增產和減汙相統一的措施，提齣運用由田間、草溝、塘堰濕地和骨榦溝“四道防線”組成的繫統淨化農田排水，併在廣西桂林市青獅潭灌區及廣西灌溉試驗中心站開展瞭繫統的試驗研究。通過站內不同水肥處理下對田間節水、水稻增產、氮燐流失減少指標的分析，優選水稻田間最優水肥管理模式，即採用間歇灌溉模式、施氮肥總量不變、適噹減少氮肥基肥增加追肥用量；在站外根據現有的水繫分佈構建“四道防線”繫統，分析瞭各道防線對農田排水的淨化效果以及提高淨化效果的主要措施。由“四道防線”構成的節水防汙型農田水利繫統對農田氮燐排放具有良好的淨化效果，實現瞭減少農田麵源汙染和脩複農田水環境的目的。
불합리적농전수비관리시조성농업면원오염적주요원인지일。위료탐심관구수도절수、증산화감오상통일적조시，제출운용유전간、초구、당언습지화골간구“사도방선”조성적계통정화농전배수，병재엄서계림시청사담관구급엄서관개시험중심참개전료계통적시험연구。통과참내불동수비처리하대전간절수、수도증산、담린류실감소지표적분석，우선수도전간최우수비관리모식，즉채용간헐관개모식、시담비총량불변、괄당감소담비기비증가추비용량；재참외근거현유적수계분포구건“사도방선”계통，분석료각도방선대농전배수적정화효과이급제고정화효과적주요조시。유“사도방선”구성적절수방오형농전수리계통대농전담린배방구유량호적정화효과，실현료감소농전면원오염화수복농전수배경적목적。
Unreasonable farmland irrigation and fertilizer management practice results in the huge loss of nutrients in the field, which is one of the main factors of agricultural non-point source pollution. In order to find out compatible measures of saving water, increasing production and reducing pollution in the paddy fields, a “four lines of defense” system was proposed in this paper, which was composed of field, grass ditch, pond wetland and main ditch. For the purpose of analyzing integrated purification effect, experimental research was systemically conducted in Qingshitan reservoir irrigation area in Guilin, Guangxi and Guangxi Center Station of Irrigation Experiment. Through optimizing the management of irrigation and fertilizer mode, it was expected to find the optimal management pattern of water and fertilizer. This was mainly done by analyzing field yield, irrigation amount, water drainage and discharge loads of total nitrogen (TN) and total phosphorus (TP) under the situation of different irrigation systems, nitrogen fertilizer application frequencies and distributions. Representative demonstration area was built in situ condition. Measuring weirs were installed respectively at the inlets and outlets of grass ditch, pond wetland and main ditch, and water samples were tested to obtain the TN and TP concentrations. Based on these data, the emission laws of TN and TP load were analyzed. The results showed that optimal management pattern was the practice of intermittent irrigation, fertilizer application four times at a ratio of 3:3:3:1 keeping the total amount constant. Compared with traditional practice, it could save 36.5% of irrigation water, reduce 20.2% of drainage water, and reduction rates of TN and TP loads reached to 24.0% and 19.8% respectively, while its effect on rice yield was not significant. It achieved the prevention and control of agricultural non-point source pollution from the source. The other three components of “four lines of defense”, namely grass ditch, pond wetland and main ditch, also reflected the purification effect; and the purification rates of TN and TP loads of grass ditch were 21.8% and 25.9%, pond wetland were 21.7% and 20.9%, and main ditch were 16.3% and 14.4%, respectively. This article gave some suggestions on optimization design of each component of “four lines of defense”. The research displayed that TN and TP loads in drainage were reduced by 61% and 60% respectively after the purification of the “four lines of defense” system. There is a great purification effect to reduce nitrogen and phosphorus loads from farmland discharged by the “four lines of defense” system, realizing the goals of reducing farmland nonpoint source pollution and recovering its water environment.
