Research Priorities in Natural Systems Agriculture

SUMMARY

Over the course of millennia and most dramatically in recent years, agriculture has eroded natural capital as it has supplied human demands. These tendencies can be offset by infusions of fossil fuels for fertility, pest control and traction, but only partially and not over the long term. This could be called the “problem of agriculture,” in contrast to problems in agriculture. Natural ecosystems are unmatched for efficient nutrient recycling, solar energy use, and biodiversity preservation, but they cannot feed dense human populations. An ecological agriculture that is a synthesis of natural and agricultural systems can save soils from erosion and reduce chemical and water use. Reducing chemical pollution of air, water and soils will conserve wildlife habitat, improve water quantity and quality and protect human health. By practicing an agriculture that has conservation as a direct result, farmers can become better stewards of the land. Lower input costs and inherent sustained soil fertility will mean more profit for farmers and communities. Principles of natural systems agriculture (NSA) are applicable to any food- or fiber-production system worldwide. In the central Great Plains of the United States, agriculture should mimic the native prairie, which is a polyculture of herbaceous perennial plants. The Land Institute has spent 25 years studying the structure and function of prairies. Now we and other research organizations are breeding perennial grain crops, including cool- and warm-season grasses, legumes, and composites. We are following two parallel strategies: selecting wild perennials for greater seed production and other traits of domestication and hybridizing wild perennials with annual crops to combine desired traits. Although the breeding process will take many years, the effort will be repaid many times over if we achieve our goal: a lasting solution to the 10,000-year-old problem of agriculture.     

Disturbances in tallgrass prairie: local and regional effects on community heterogeneity

Community heterogeneity in tallgrass prairie was analyzed at regional and local levels to assess the effects of disturbances on community structure at different spatial scales. The sites were part of NASA's First ISLSCP Field Experiment (FIFE) in Kansas, and were located on grassland treatments that were undisturbed, and burned-only on Konze Prairie Research Natural Area, and grazed-only and grazed + burned on adjacent ranch land. Sites in grazed-only or grazed + burned treatments were less similar to each other, on a regional scale (15 × 15 km), than were burned-only or undisturbed sites. Grazing reduced the cover of dominant species, making space available for the establishment of immigrants from the region. Each site was different because of establishment by different species from the large regional species pool. At the local scale (0.1 ha), the most homogeneous treatments were those that were most heterogeneous at the regional scale. Undisturbed treatments at the local scale were the most heterogeneous compared to sites under other treatments. Therefore, regional responses to disturbances were more variable than local responses, and were not predictable from within-site analyses.     

中国西门塔尔牛——科尔沁(草原)型在扎鲁特旗的培育发展

扎鲁特旗中国西门塔尔牛－科尔沁（草原）型培育工作,经过多年的努力,取得了较好的经济效益和社会效益。良种母牛成年平均体高达129.9cm,平均体重达568.5kg;305天平均产奶量达3187.5kg,乳脂率4．21％;24月龄阉牛120天育肥平均日增重1369g,屠宰率55．76％,净肉率45．57％;总体经济效益投入产出比为1：4．24。     

Genetic transformation of Eustoma grandiflorum Griseb. by microprojectile bombardment

Summary Foreign DNA was introduced into cell suspension cultures and leaf tissue of Eustoma grandiflorum Griseb. (lisianthus) by microprojectile bombardment. For this purpose a low-cost bombardment device that uses a helium flux to accelerate microprojectiles was built. When cell suspensions were used, an average of 4.1 Kan resistant calli were recovered per shot after 4 months' cultivation on selective medium. Most of the Kan resistant plants regenerated from calli were positive to GUS assay. Both the nptII and gus genes were successfully amplified from alkali-treated leaves of putative transgenic plants by PCR analysis. Transgenic plants were not recovered from bombarded leaves. Considering the host range specificity of Agrobacterium, and the response of the species to plant regeneration from suspension culture, microprojectile bombardment is, at present, the most efficient procedure for genetic transformation of lisianthus.Abbreviations BA 6-benzyladenine - Cx cefotaxime - 2,4 D (2,4-dichlorophenoxy) acetic acid - FDA fluorescein diacetate - gus -glucuronidase - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2iP (2-isopentenyl) adenine - Kan kanamycin - nptII neomycin phosphotransferase II - PCR polymerase chain reaction     

河北省坝上红松洼草原蝗虫群落结构与多样性调查

为明确不同分区治理下河北省坝上红松洼草原生态环境对蝗虫群落多样性的影响,采用样方法于2019-2020年在不同草原类型和不同功能分区对蝗虫群落进行调查,通过丰富度、个体数、多样性指数以及均匀度指数分析蝗虫的多样性,并对不同生态因子和蝗虫多样性指标进行相关性分析.结果 表明:该地区蝗虫发生种类共有5科8亚科14属25种,...