基于较高收割机生产率的东北地区适宜水田规格阈值分析

农业规模化机械化是东北地区农业产业发展的必然趋势,规模化水田布局除了考虑灌溉效率问题,还需要协同农机作业性能等目标来满足当前农业生产的需求。本文将田间试验与数值模拟相结合,田间试验测量了庆安国家灌溉试验重点站内22块水田的收割机生产率,数值模拟选取了收割机机型、田块面积、田块长宽比共计210组方案,利用收割机生产率模型开展数值模拟,分析了水田不同形状、面积和长宽比对收割机生产率的影响,探究了基于较高收割机生产率前提下东北地区适宜水田规格阈值。研究结果表明,具有较大面积、较大长宽比的矩形水田规格有较高的收割机生产率,适宜东北地区水田长度和宽度的阈值分别为[160 m,200 m]和[40 m,200 m],该结果可为水田优化布局提供技术参考。     

水稻除草返青专用肥的生产与应用

用除草剂36%(苯噻 苄)与氯化铵制成水稻除草返青药肥,介绍该药肥配方、挤压造粒制造工艺、田间试验情况及经济效益,比肥料、除草剂分别施用增产8.3%;水稻杂草基本被封杀;药、肥配伍混合增效明显;每667m2可少投入1.4元,并可减轻农户耕作负担。     

Methane emission from rice paddy fields in all of Japanese prefecture

Field measurements of CH₄ emission from rice paddy field during cultivation periods were performed at all of 47 Japanese prefectures under the project of ‘Research for evaluation of CH₄ and N₂O emissions from agricultural land, and improvement methods of soil, water and fertilizer management’ conducted by Agricultural Production Bureau, the Ministry of Agriculture, Forestry and Fisheries. Although this project was carried out at 159 fields, the data of 132 fields were used for this report because other 27 fields had not enough data to be suitable for the statistics analyses. The measurements at rice paddy fields in various locations in Japan showed that there were large temporal variations of CH₄ flux and that the fluxes differed markedly with climate, characteristics of soil and paddy, application of organic matter and mineral fertilizer, and agricultural management practices. These data mainly indicated that CH₄ emission from Gley soils was greater than those from other soil types such as Andosols, Upland soils, fine-textured Lowland soils, medium and coarse-textured Lowlands soils and gravelly Lowland soils, and that water and organic matter managements influenced CH₄ emission. It is suggested that midsummer drainage treatment suppressed while the application of fresh organic matter such as rice straw and wheat straw enhanced CH₄ emission, respectively. This revised version was published online in August 2006 with corrections to the Cover Date.     

5种水田除草剂对稻稗和稗草的生物活性研究

室内生测结果表明,供试的5种水田除草剂中,丙草胺对稗草的活性最高,苯噻草胺对稗草的活性最低,莎稗磷、二甲戊灵和丁草胺居中,且三者对稗草的活性相当;二甲戊灵对稻稗的活性最高,丁草胺对稻稗的活性最低,莎稗磷、苯噻草胺和丙草胺对稻稗有较好的防除效果。     

Nitrogen fertilization and nitrate pollution in groundwater in Japan: Present status and measures for sustainable agriculture

During the last two decades, nitrate nitrogen (NO₃-N) concentrations in groundwater in Japan have increased steadily due to the development of intensive agriculture. In some areas, they have reached or even exceeded the unacceptable level for drinking water, 10 mg l^–1. In 2000, the Environment Agency showed that 5.6% (173 of 3,374) tested wells and 4.7% (64 of 1,362) wells used for drinking water exceeded the standard level in 1999. The highest value of NO₃-N in the wells was 100 mg l^–1. Many researches have shown that NO₃-N pollution of groundwater was widely observed in Japan, except the paddy field regions. Farming practices in Kagamigahara city of Gifu prefecture have been typical ones for reducing NO₃-N pollution in groundwater. In the east district of the city, NO₃-N concentration was low in 1966, but reached 27.5 mg l^–1 in June, 1974. The farmers in this district began to reduce the nitrogen fertilizers in carrot cultivation, going from 256 kg N ha^–1 in 1970 to 153 kg N ha^–1 in 1991. The use of controlled release fertilizer increased fertilizer-nitrogen efficiency compared with common compound fertilizer and NO₃-N concentration in the groundwater began to decrease steadily. It was discussed that in order to decrease the NO₃-N pollution of groundwater, it is necessary to refocus not only agricultural technology but also agricultural policy, toward sustainable agriculture and rural development.     

稻谷中镉的石墨炉原子吸收测定方法优化及其分布

对GB/T 5009.15-2003中石墨炉原子吸收光谱测定法进行了优化,并对稻谷中镉的分布进行了初步分析.结果显示:石墨炉最佳升温程序为:干燥温度110℃,27 s;灰化温度300℃,20 s;原子化温度1 700℃,2 s;除残温度2 100℃,2 s.稻谷中,糙米皮层镉含量最高,糙米次之,标一米略低于糙米,稻壳最低.     

淹水条件下不同渗漏强度对稻田地表水NH+-N影响研究

基于蒸渗仪中淹水稻田不同渗漏强度控制试验,研究了稻田施肥后和各生育阶段不同渗漏强度条件下地表水中NH+-N浓度变化.结果表明:分蘖肥施用后,稻田地表水NH+-N浓度大幅升高,并随时间上升;稻田补水会扰动土壤,使吸附在土壤表层的NH+-N重新溶于水中,导致稻田地表水中NH+-N浓度升高;高温和淹水会加速稻田土壤中NH+-N的释放;水稻各生育期,不同渗漏强度对地表水中NH+-N浓度影响不显著.这些研究为制定稻田控制排水策略提供了科学依据.     

人工湿地对稻田氮磷污染的去除试验

为研究人工湿地对稻田氮磷污染的去除效应和规律,在广西青狮潭灌区选取农田洼地、废弃耕地改造为人工湿地,分别于2008、2009年水稻生育期在人工湿地进出水口采集水样进行氮磷浓度化验并分析.结果表明:2008年人工湿地对早稻和晚稻排水中TN、TP的去除率分别达到约26.5%、8.1%和53.0%、58.2%;2009年人工湿地对早稻和晚稻排水中TN、TP的去除率分别达到约56.0%、17.2%和64.1%、76.7%,能明显地改善农田排水水质.由此可见,选用人工湿地处理农田排水是合理可行的.     

生态塘对稻田降雨径流中氮磷的拦截效应研究

农田养分的大量流失已成为农业面源污染的主要来源之一,生态塘兼具排水和生态湿地双重功效,研究其对稻田排水氮磷的拦截效应对于防治农业非点源污染具有重要意义。针对降雨径流条件下生态塘对降雨径流中氮磷的动态拦截效应以及降雨径流结束后氮磷在静水中的去除效应有待明了的需求,本文选取太湖西岸何家浜流域典型农田作为研究对象,并将该区域的塘堰改造为生态塘,研究了生态塘对水稻生长期内的三场降雨径流氮磷的拦截去除效果及降雨径流结束后氮磷在静水中的去除效应。研究结果表明:(1)在三场降雨过程中,生态塘对总氮(TN)的平均去除率为34.7%,总磷(TP)的平均去除率为34.8%;(2)生态塘对降雨径流中不同形态氮磷的去除率大小排序为氨氮(NH_4~+-N)颗粒态氮(PN)硝态氮(NO_3~--N),颗粒态磷(PP)溶解态磷(DP),且径流状态下水体垂向分层氮磷浓度分布随降雨进行而变化,总体分布规律为底层氮磷浓度大于表层氮磷浓度;(3)降雨径流结束后,TN在生态塘中的去除率为50.4%,TP在生态塘中的去除率为52.3%,塘2对TN、TP的去除率大于塘1与塘3,生态塘表现了较强的抗冲击自修复性。     

啤酒厂废渣制有机-无机复混肥在水稻上的应用

利用啤酒厂废渣开发出 1种水稻专用有机无机复混肥 ,并将其对水稻的增产效果做了田间试验。试验结果表明 ,本肥施用效果明显优于当地习惯施肥和无机复混肥 ,主要通过促进植株分蘖提高成穗率而增产 ,增产幅度达 14 %。