坝系农业是黄土高原持续农业的发展方向

截至 １９９５年底，黄土高原 １０余万座淤地坝累计烂泥７１．２７亿 ｔ，占水保措施保土烂泥量的 ６６．９％；现有坝地３８．１万ｈｍ２，仅占耕地总面积的９．３％，但由于水肥条件好，其粮食产量却占总产量２０．５％，坝系建设较好的小流域，坝地产量占总产量的比例更大。黄土高原建坝资源丰富，坝地发展潜力巨大，坝系农业是极富竞争力的持续农业发展方向。     

基于提高农业综合生产力的区域土地整理时空配置研究

该文以山东省青州市为例，研究了基于提高农业综合生产力的区域土地整理时空配置指标体系、模型和方法。结果表明，青州市以提高农业综合生产力为目标的土地整理区主要位于丘陵区，整理面积655.14 km²，占可整理面积的48.37%，其中近期整理区主要分布于丘陵区西北部，中期整理区主要位于丘陵区东南部，均以耕地整理为主，远期整理区主要处于丘陵区西南部，耕地整理和未利用开发并重；非整理区主要分布于北部平原，为耕地，占51.63%。研究结果可为青州土地整理规划和实施提供科学依据。     

第二章 关于自然力在农业生产过程具有决定作用的原理

农业再生产的本质特征,是经济再生产与自然再生产的相互交织。但在过去的很长时期,严重忽视自然再生产,不按自然规律办事,曾给农业生产造成不应有的损失。为了发展农村大好形势,吸取历史教训,正确区分经济再生产对自然再生产的依赖关系,充分认识自然生产力的决定作用,不仅是促进农业生产持续稳定发展的需要,而且对实现党的十六大和十七大提出的宏伟目标有着重要意义。     

杜邦公司称农业在全球性问题中非常关键

2010年1月31日第40届世界经济论坛年会在达沃斯落幕,与会代表在瑞士达沃斯出席世界经济论坛年会的讨论.杜邦公司主席兼首席执行官Ellen Kullman参加了关于"反思如何反哺地球"的专题研讨会,根据联合国粮食与农业组织调查,到本世纪中叶,粮食生产将需要翻倍才能养活预期人口,专题小组成员得考虑如何实现食品安全,环境的可持续性和农业经济增长的问题.     

Perspectives of Using L-Tryptophan for Improving Productivity of Agricultural Crops: A Review

Plant growth regulators are biologically active signaling molecules that regulate a number of plant physiological processes. Auxin (indole-3-acetic acid) is an important plant growth regulator and is synthesized within plant tissues through L-tryptophan (L-TRP)-dependent and -independent pathways. It has been found that plants respond to exogenously applied L-TRP due to insufficient endogenous auxin biosynthesis. The exogenous application of L-TRP is highly significant for normal plant growth and development. L-tryptophan is applied through foliar spray, seed priming, and soil application. Soil-applied L-TRP is either directly taken up by plants or metabolized to auxin by soil microbiota and then absorbed by plant roots. Similarly, foliar spray and seed priming with L-TRP stimulates auxin synthesis within plants and improves the growth and productivity of agricultural crops. Furthermore, L-TRP contains approximately 14% nitrogen (N) in its composition, which is released upon its metabolism within a plant or in the rhizosphere and plays a role in enhancing crop productivity. This review deals with assessing crop responses under the exogenous application of L-TRP in normal and stressed environments, mode of action of L-TRP, advantages of using L-TRP over other auxin precursors, and role of the simultaneous use of L-TRP and auxin-producing microbes in improving the productivity of agricultural crops. To the best of our knowledge, this is the first review reporting the importance of the use of L-TRP in agriculture.     

制度因素对农业要素生产率的影响研究

在我国农业发展过程中，制度因素是影响农业要素生产率的重要因素。通过产业环境和技术效率影响农业产出的变动，是制度因素对要素生产率影响的主要表现形式；由数学模型测算，1952-1992年制度因素对我国农业总要素生产的贡献份额为40.97%。可见，制度因素的完善与提高创新，决定着我国农业持续稳定的发展。     

Chromium in Agricultural Soils and Crops: A Review

The mobility and distribution of metals in the environment is related not only to their concentration but also to their availability in the environment. Most chromium (Cr) exists in oxidation states ranging from 0 to VI in soils but the most stable and common forms are Cr(0), Cr(III), and Cr(VI) species. Chromium can have positive and negative effects on health, according to the dose, exposure time, and its oxidation state. The last is highly soluble; mobile; and toxic to humans, animals, and plants. On the contrary, Cr(III) has relatively low toxicity and mobility and it is one of the micronutrients needed by humans. In addition, Cr(III) can be absorbed on the surface of clay minerals in precipitates or complexes. Thus, the approaches converting Cr(VI) to Cr(III) in soils and waters have received considerable attention. The Cr(III) compounds are sparingly soluble in water and may be found in water bodies as soluble Cr(III) complexes, while the Cr(VI) compounds are readily soluble in water. Chromium is absorbed by plants through carriers of essential ions such as sulfate. Chromium uptake, accumulation, and translocation, depend on its speciation. Chromium shortage can cause cardiac problems, metabolic dysfunctions, and diabetes. Symptoms of Cr toxicity in plants comprise decrease of germination, reduction of growth, inhibition of enzymatic activities, impairment of photosynthesis and oxidative imbalances. This review provides an overview of the chemical characteristics of Cr, its behavior in the environment, the relationships with plants and aspects of the use of fertilizers.     

Soil Organic Carbon,Biochar, and Applicable Research Results for Increasing Farm Productivity under Australian Agricultural Conditions

The conversion of vegetative biomass waste to biochar (biologically derived charcoal) is a source of carbon (C) that can be used to increase the level of soil organic C (SOC) in agricultural soils. This review collates available research into the effects of biologically derived C species with respect to the direct and indirect effects on agricultural productivity and their potential for use in Western Australian agricultural systems. There is a growing requirement to quantify the effect of specific biochar applications for agroecological purposes and to verify biosequestered C for climate-change-mitigation activities. This work provides a review and assessment of safe biochar application rates and examines the present levels of scientific uncertainty surrounding the efficacy and reliability of applying biochar to soils in relation to crop productivity.     

黄土高原地区粮田主要作物生产力及提高途径的初步分析

本文在对黄土高原不同类型区的7个代表县5种主要粮田作物生产力进行统计分析的基础上,采用FAO推荐的农业生态地区法计算了各作物的最大生产潜力（Ymp）。通过调查与比较分析,初步提出了Ymp的主要限制因素和解决的基本途径,为作物生产力的提高和进一步研究提供科学依据。     

长期施肥对农田土壤氮素关键转化过程的影响

当前,如何合理施肥、提高作物产量、维持土壤肥力、并兼顾生态环境效应是农业研究的主要挑战之一。本文综述了长期施肥对农田土壤氮素关键转化过程的影响,主要从土壤氮转化过程的初级转化速率角度综述肥料(有机肥和化学氮肥)对土壤氮素关键转化过程的影响。土壤氮素矿化-同化循环是自然界氮循环过程中两个至关重要的环节,是决定土壤供氮能力的重要因素。总体而言,长期施用氮肥,尤其是有机肥能显著提高初级矿化-同化周转速率;长期施肥可以刺激自养硝化作用,且有机肥的刺激作用更明显;施用化学氮肥和有机肥均能提高反硝化速率,且有机肥的刺激作用高于化学氮肥。有机肥一直被提倡和实践用来改善土壤肥力和提高土壤固碳能力,无论是单施有机肥还是有机-无机配施,均能有效地减轻硝酸盐污染,改善土壤肥力并提高作物产量。但是有机肥的施用并不是多多益善,有机肥过多施用也会增加氮损失的风险。因此,本文综述了长期施肥对农田土壤氮素关键转化过程初级转化速率的影响,讨论了各个氮转化过程之间的联系,以期增强人们对长期施肥措施影响农田土壤氮素循环的理解,并为合理施用氮肥、提高氮肥利用率、减少与氮相关的环境污染提供理论依据。     

Agricultural Energy Crops and the Search for Alternative Energy: Analysis of the Current Research and Core Journal Literature on Biofuels and Bioenergy

ABSTRACT

This paper analyzes the agricultural research output on energy crops and bioenergy for the period 2000–2005. Seven hundred eighty-three (783) articles gathered from CAB Abstracts from this period were analyzed to determine which disciplines have been publishing the most on this subject. The findings show that engineering-related research is most prevalent but that twelve distinct agricultural disciplines produced research on the subject during the study period, with varying degrees of productivity for each discipline. The actual agricultural energy resources being researched were determined by examining the 783 articles. The resources were divided into woody crops, non-woody crops, and animal-based resources, and the number of articles for each was tabulated. The three resource types were further examined to create a list of the individual crops or animal-based resources under investigation, along with the number of articles for each individual crop or resource. The core journal literature dealing with energy crops and bioenergy was determined by doing searches in both CAB Abstracts and Web of Science and tabulating the number of articles appearing in each journal. This allowed for the creation of a core journal list, ranked by the number of appropriate articles appearing in each journal.