从世界粮食市场变化趋势看中国粮食安全

过去20年,世界粮食生产和贸易呈增加趋势,其中三大主粮的结构、地区分布也在逐步发生变化。今后一段时期世界粮食生产有望继续增长,南美、独联体国家、东欧等地区将是重要的潜在增产区域。中国粮食生产已实现10连增,但供需压力持续加大,海外贸易和投资是中国保障国内粮食安全的重要渠道。     

河北省玉米生产面临的形势问题与对策研究

针对当前河北省玉米生产面临的各种形势及突出问题,提出了河北省玉米生产的发展思路及对策。     

兵团农机产业化的若干思考

农机产业化是社会分工细化、生产专业化深化的必然产物,其实质是传统农业转变为现代产业的过程。日前,兵团农机产业化进程中存在着一些问题。为此,结合兵团实际,提出了推进农机产业化发展的基本思路。     

杂交水稻新组合特优172的高产制种技术

特优172是容县农科所选育出的感温型杂交稻新组合,2006年通过广西区种子审查委员会审定,该组合制种高产的主要经验是：掌握好父母本的播错期及抽穗期;重施父本肥,使父本早生快发,穗大粒多,花粉充足;适时适量喷施九二0。     

海涂实行草地农业的综合生态学方法

依据海涂独特的自然属性确定开发利用方案是保证土地资源持续生产的关键。采用降低土壤盐分、实行保护性耕作、用植物残余物覆盖地面、种植牧草防止土壤侵蚀和促使生草层土的发育，保证了以潜在形式集中的富含必需营养元素的腐殖质在土壤中聚积，改善土壤结构，提高土壤水分和养分的利用效率，并以牧草饲养家畜的土地经营活动形成了成功的草地农业生产。     

蔗田立体生产研究初报

建立蔗田的立体生产比单纯种蔗能提高经济效益。其中以“甘蔗+青椒+凤尾菇”的生产模式经济效益最高,亩纯收入是单纯种蔗的10.65倍。“甘蔗+绿豆+凤尾菇”和“甘蔗+花豇豆+凤尾菇”的生产模式亩纯收入分别是单纯种蔗的8.46倍和8.17倍。同时还获得良好的生态效益和社会效益。     

彼子和榧实原植物的本草考证——兼与陈重明先生等商榷

中国唐代以来的多数本草著作,均认定《神农本草经》中的彼子和《名医别录》中的榧实,与《唐本草》中的榧子为同物。现代中药学论著考订其原植物为今红豆杉科榧树（榧子）Torreya grandis Fort.ex Lindl.。殊误。经全面考证后确认,彼子是今三尖杉科三尖杉属Cephalotaxus Sieb.et Zucc.植物,榧实是红豆杉科红豆杉属Taxus L.植物,后世本草中的榧子与它们并非同物。     

Recovery of photosynthetic capacity in Scots pine: a model analysis of forest plots with contrasting soil temperature

Both aboveground and belowground climate affects net primary production (NNP) and forest growth. Little is known about how above and belowground factors interact. The BIOMASS-model was tested to simulate photosynthetic recovery over a wide range of soil temperatures created by snow cover manipulations on tree-scale plots in a 20-year-old Scots pine stand in northern Sweden. The differences in timing of soil warming between the plots covered a span of two months. Carbon assimilation in needles, sap flow, needle water potential and climatic parameters were measured in the field. The simulations revealed that an early start of soil warming gave a relatively early photosynthetic recovery and a 7.5% increase of NPP. Late soil warming delayed the photosynthetic recovery and reduced the NPP by 13.7%. This indicated that soil temperature needed to be accounted for, as well as air temperature, when analysing photosynthetic recovery and NPP in boreal environment. The effects of differences in soil temperature were reflected in the simulated photosynthetic recovery. The model did not fully capture the delay of photosynthetic recovery caused by a late soil warming. It was possible to integrate the complexity of the soil climate effects into a threshold date for soil thaw, using sapflow measurements together with information about air temperature and a day degree sum, as long as water availability was not limiting water uptake by roots. Although a more realistic mechanism than that currently in BIOMASS is desirable as climate change shifts the typical patterns of interplay between air and soil temperature dynamics.