人工草地绵羊系统优化研究Ⅲ几种冬春青绿饲料作物的引种栽培

用新西兰引进的波纳、威诺阿、帕斯加、艾品、巴堪特和当地长期种植的芜菁6种冬春青绿饲料作物在云南省种羊场2个气候带种植,对各品种生物量及干鲜比进行比较分析.结果为芜菁生物量及含水量均较引进品种高;在引进品种中,高海拔山区威诺阿表现最佳,中海拔地区艾品较好.     

Differential Competitive Ability and Growth Habit of Pearl Millet and Clusterbean Cultivars in a Mixed Cropping System in the Arid Zone of India

Dryland sustainable agriculture in the arid zone of India depends upon the choice of suitable cultivars for pure and mixed crop stands. Field experiments were conducted for two years to examine the response of two contrasting cultivars each of pearl millet (Pennisetum glaucum) and clusterbean (Cyamopsis tetragonoloba) in pure stands and in mixed pearl millet‐clusterbean stands. The differential response of cultivars of both crops to pure and mixed stands resulted in a significant genotype × cropping system interaction. Reduction in seed yield of both clusterbean cultivars was greater in mixed stands with tall and long duration pearl millet MH 179 than with medium statured and early maturing HHB 67. The degree of reduction was greater in Naveen, the branched clusterbean cultivar, than in RGC 197, the single stemmed cultivar. Mixing of pearl millet HHB 67 with medium duration clusterbean cultivar Naveen produced maximum pearl millet equivalent total yield. Higher land equivalent ratios (LERs) were also observed when clusterbean cultivars were mixed with early maturing and short statured pearl millet HHB 67.     

除草剂残留对亚麻的影响及预防措施

长残效除草剂大面积施用及超量施用,对后茬作物亚麻造成严重危害,已成为影响我国北方亚麻主产区产业发展的重要因素。本文阐述了亚麻受药害原因及症状表现,列举了对后茬亚麻有影响的除草剂种类并提出了预防措施。     

茭白新品种"金茭2号"的选育及其栽培技术

介绍了金茭2号的选育背景、选育过程、产量表现及其特征特性和主要栽培技术。     

农机技术推广要围绕农业产业化发展做好工作

农机技术推广是农机化工作的重心。当前围绕农业产业化发展做好农机技术推广工作,是推进农业现代化和新农村建设的需要。根据池州市贵池区农业产业化发展实况,在水稻生产机械化取得一定成果和经验的基础上,应将油菜、茶叶、棉花等优势经济作物产业化发展与农机化技术发展同步推进。同时对农机技术推广还须建立强有力的配套措施予以支持：充分发挥基层农机推广机构的作用,以农机大户及产业基地为依托,强化农机与农艺结合,农机购置补贴等惠农政策要向重点对象倾斜。     

Performance of Agricultural Systems under Contrasting Growing Season Conditions in South-western Quebec

Climate change will alter temperature and rainfall patterns over North American agricultural regions and there will be a need to adapt crop production systems to the altered conditions. A set of field experiments were conducted in south-western Quebec, Canada, with soybean ( Glycine max L.), corn ( Zea mays L.), sorghum ( Sorghum bicolor L.) × sudangrass ( Sorghum sudanense Piper) hybrid and switchgrass ( Panicum virgatum L.) under two tillage and three nitrogen fertility regimes, to study their performance in three successive growing seasons (2001–2003), two of them with unusually warm and dry conditions. The annual crops were established in two tillage systems: conventional and no-till (NT). All crops except soybean were fertilized with three levels of nitrogen: corn – 0, 90 and 180 kg N ha⁻¹, sorghum-sudangrass – 0, 75 and 150 kg N ha⁻¹, switchgrass – 0, 30 and 60 kg N ha⁻¹. The 2001 and 2002 seasons were hotter and drier than the 2003 season, which was the most favourable for crop growth. The capacity of the crops to yield in dry seasons was as follow: switchgrass > sorghum-sudangrass > corn > soybean. The corn and sorghum-sudangrass responses to nitrogen fertilizer were low in 2001 due to the combined effect of dry growing season and coarse soil texture. Soybean did not perform well under NT. Corn yielded better at the highest nitrogen fertilizer rate under NT when the early season was warmer than the normal. Our results show that switchgrass and sorghum-sudangrass could be an option in south-western Quebec if the frequency of hot and dry seasons increase in the future, because of climate change.     

Potential allelopathic influence of certain pasture weeds

Laboratory and growth chamber research was conducted to determine the potential allelopathy of tissue harvested from certain weeds commonly found in pastures. Results of bioassays indicated that the weeds dogfennel and mayweed chamomile are potentially allelopathic to alfalfa and Italian ryegrass seedlings. Leaf-tissue extracts from the two weed species reduced seedling growth more than stem and root extracts. In most experiments alfalfa seedlings were influenced more than Italian ryegrass seedlings and seedling growth was influenced more than seed germination. Leaf tissue from the weed species mixed into potting soil at a concentration as low as 0.25% (w/w) significantly reduced alfalfa and Italian ryegrass plant development and foliage production. Extract and tissue concentration used in this research were estimated to be similar to concentrations expected to occur within the pasture ecosystem and below concentrations that would result in hypertonicity in the bioassays.     

“黑麦草—水稻”草田轮作系统应用效益初探（案例研究）

“黑麦草—水稻”草田轮作系统（简称ＩＲＲ系统）在广东省产生了显著的效益。黑麦草作为饲料的应用范围包括了奶牛、奶水牛、肉牛、奶山羊、肉（毛）用兔、实验用兔、猪、鸵鸟、鹅、草鱼等，目前最常见的系统有“稻—草—牛”、“稻—草—鱼”和“稻—草—鹅”。因此，ＩＲＲ系统为发展大农业多种经营提供了重要的物质基础，改善了区域农业生产结构，促进了“三元结构农业”和节粮型畜牧业的发展。ＩＲＲ系统的应用，提高了土地的利用率以及土地单位面积的产出，其经济效益因不同的应用系统而异，一般情况下一个冬季的产出在１．５万元／ｈｍ２以上。     

农机技术推广要围绕农业产业化发展做好工作

农机技术推广是农机化工作的重心。当前围绕农业产业化发展做好农机技术推广工作,是推进农业现代化和新农村建设的需要。根据池州市贵池区农业产业化发展实况,在水稻生产机械化取得一定成果和经验的基础上,应将油菜、茶叶、棉花等优势经济作物产业化发展与农机化技术发展同步推进。同时对农机技术推广还须建立强有力的配套措施予以支持:充分发挥基层农机推广机构的作用,以农机大户及产业基地为依托,强化农机与农艺结合,农机购置补贴等惠农政策要向重点对象倾斜。