Sustainable resource management coupled to resilient germplasm to provide new intensive cereal–grain–legume–livestock systems in the dry savanna

Sustainable resource management is the critical agricultural research and development challenge in sub-Saharan Africa. The accumulated knowledge on soil management gathered over the last 10 years, combined with solid crop improvement and plant health research at farmers’ level, has brought us to a stage where we can now address with confidence the intensification of cereal–grain–legume-based cropping systems in the dry savanna of West Africa in a sustainable and environmentally positive manner.Two sustainable farming systems that greatly enhance the productivity and sustainability of integrated livestock systems have been developed and implemented in the dry savanna of Nigeria. These are: (i) maize (Zea mays L.)–promiscuous soybean [Glycine max (L.) Merr.] rotations that combine high nitrogen fixation and the ability to kill large numbers of Striga hermonthica seeds in the soil; and (ii) miflet [Eleusine coracana (L.) Gaerth] and dual-purpose cowpea [Vigna unguiculata (L.) Walp.]. Improvement of the cropping systems in the dry savanna has been driven by the adoption of promiscuously nodulating soybean varieties (in particular TGx 1448-2E) and dual-purpose cowpea. The rate of adoption is very high, even in the absence of an efficient seed distribution system. The number of farmers cultivating the improved varieties increased by 228% during the last 3 years. Increased production of promiscuous soybean has been stimulated by increased demand from industries and home utilization. Production in Nigeria was estimated at 405,000 t in 1999 compared to less than 60,000 t in 1984. Economic analysis of these systems shows already an increase of 50–70% in the gross incomes of adopting farmers compared to those still following the current practices, mainly continuous maize cultivation. Furthermore, increases in legume areas of 10% in Nigeria (about 30,000 ha in the northern Guinea savanna) and increases of 20% in yield have translated into additional fixed nitrogen valued annually at US$ 44 million. This reflects, at the same time, an equivalent increase in land-use productivity, and with further spread of the improved crops, there are excellent prospects for additional economic and environmental benefits from a very large recommendation domain across West Africa.     

Hybridization between wheat (Triticum aestivum) and the wild species Aegilops geniculata and A. biuncialis under experimental field conditions

Hybridization between Aegilops geniculata, A. biuncialis and bread wheat Triticum aestivum has been evaluated during two seasons under simulated field conditions to estimate the field hybridization rate under Central Spain conditions. The mean frequencies of hybridization between A. biuncialis and A. geniculata with wheat were 0.34% and 0.31%, respectively. Data from 10 hybrid plants for each combination showed that hybrids can be partially fertile by backcrossing with wheat parent, with percent averages of 3.17 grains/spikelets for A. biuncialis × wheat hybrids and 2.87 grains/spikelets for A. geniculata × wheat hybrids. Self-pollination, although at very low rates, was also possible in hybrids. The potential risks associated with natural hybridization in the context of transgenic wheat cultivation are discussed.     

冀南野生木本资源植物研究

冀南产野生木本资源植物200种，隶属43科91属。其中超过5种的科有13个，蔷薇科30种最多，其次为豆科24种，忍冬科、榆科、杨柳科均在10种以上。1、油松Pinustabulaeformis松科。木材可供建筑、电杆、矿柱、造船、家具及木纤维工业原料等用材；树干可提取松节油；树皮可提取栲胶     

Fisheries management: integrating societal preference, decision analysis, and ecological risk assessment

Fisheries management is the practice of analyzing and selecting options to maintain or alter the structure, dynamics, and interaction of habitat, aquatic biota, and man to achieve human goals and objectives. The theory of fisheries management is: managers or decision makers attempt to maximize renewable `output' from an aquatic resource by choosing from among a set of decision options and applying a set of actions that generate an array of outputs. Outputs may be defined as a tangible catch, a fishing experience, an existence value, or anything else produced or supported by renewable aquatic resources. Overall output is always a mix of tangible and intangible elements. However defined, management goals and objectives are essential components of fisheries management or any other field of renewable natural resource management. Reaching consensus on management goals and objectives has never been a simple task. Beyond the broad and often conflicting goals of an agency, managers must decide who should set specific management objectives — agency personnel, the public, or a combination of the two. Historically, rhetoric aside, fisheries managers in North America nearly always have consulted with professionals in governmental roles to set management objectives. In a strongly pluralistic society, this often resulted in protracted political and legal conflict. Increasingly, there are calls for use of risk assessment to help solve such ecological policy and management problems commonly encountered in fisheries management. The basic concepts of ecological risk assessment may be simple, but the jargon and details are not. Risk assessment (and similar analytical tools) is a concept that has evoked strong reactions whenever it has been used. In spite of the difficulties of defining problems and setting management objectives for complex ecological policy questions, use of risk assessment to help solve ecological problems is widely supported. Ecological risk assessment will be most useful (and objective) in political deliberations when the policy debate revolves around largely technical concerns. To the extent that risk assessment forces policy debate and disagreement toward fundamental differences rather than superficial ones, it will be useful in decision making.     

干旱区城市水资源开发与环境保护

水资源是干旱区生态环境中最活跃的因子，城市是自然系统与人工系统耦合成的大系统，也是地下水高度集中开发的地区。地下水是干旱区城市的主要供水水源。文章从内蒙古自治区城市水资源供需现状出发，阐述了城市水资源开发带来的环境问题，重点探讨了城市地下水超采对周边地区环境的影响。最后提出了城市水资源开发与环境保护对策措施。     

岱海流域水资源可持续利用研究

本文通过对岱海流域水资源进行深入的调查，研究和分析岱海流域水资源所面临的水量、水质以及环境生态问题，得出岱海流域水资源以及水环境问题的成因，提出岱海流域环境、资源、人口、社会经济相协调的可持续发展方案。     

略论麦草资源的综合利用

本文简单介绍了麦草的纤维特性与小麦苗营养价值，在此基础上，总结了我国近几年发展的麦草利用途径与评价，最后讨论了麦草综合利用的前景。     

主次波长新分光光度法测定天然水硝酸盐

在硫酸介质中,邻苯氨基苯甲酸与硝酸盐(NO_3~-)生成紫红色络合物.本文依据悬浮颗粒对光的吸收性质研究利用该灵敏反应测定 NO_3~—N 新光度法——(?)次双波长法,通过对样品分析,可提高分析灵敏度和精密度,回收良好,且操作简单快速,计算曲线稳定,适合于测定地下水,湖水等天然水体 NO_3~-—N.     

沉淀混凝法处理含硫气田水

本文介绍用沉淀混凝法处理含硫气田水的室内试验及现场试验情况。用三氯化铁、聚合氯化铝及ＳＷ－Ⅰ处理含硫气田水，能有效地去除硫化物，而且处理后水不会因三氯化铁过量而发黄。该方法的特点是工艺简单，处理效果显著，能很好地解决含硫污水的污染问题。     

Comparison of UV-based advanced oxidation processes for the removal of different fractions of NOM from drinking water

This study examined the effectiveness for degradation of hydrophobic (HPO), transphilic (TPI) and hydrophilic (HPI) fractions of natural organic matter (NOM) during UV/H₂O₂, UV/TiO₂ and UV/K₂S₂O₈ (UV/PS) advanced oxidation processes (AOPs). The changing characteristics of NOM were evaluated by dissolved organic carbon (DOC), the specific UV absorbance (SUVA), trihalomethanes formation potential (THMFP), organic halogen adsorbable on activated carbon formation potential (AOXFP) and parallel factor analysis of excitation–emission matrices (PARAFAC-EEMs). In the three UV-based AOPs, HPI fraction with low molecular weight and aromaticity was more likely to degradate than HPO and TPI, and the removal efficiency of SUVA for HPO was much higher than TPI and HPI fraction. In terms of the specific THMFP of HPO, TPI and HPI, a reduction was achieved in the UV/H₂O₂ process, and the higest removal rate even reached to 83%. UV/TiO₂ and UV/PS processes can only decrease the specific THMFP of HPI. The specific AOXFP of HPO, TPI and HPI fractions were all able to be degraded by the three UV-based AOPs, and HPO content is more susceptible to decompose than TPI and HPI content. UV/H₂O₂ was found to be the most effective treatment for the removal of THMFP and AOXFP under given conditions. C1 (microbial or marine derived humic-like substances), C2 (terrestrially derived humic-like substances) and C3 (tryptophan-like proteins) fluorescent components of HPO fraction were fairly labile across the UV-based AOPs treatment. C3 of each fraction of NOM was the most resistant to degrade upon the UV-based AOPs. Results from this study may provide the prediction about the consequence of UV-based AOPs for the degradation of different fractions of NOM with varied characteristics.