【摘要】 本文主要介绍了我国在稀土农用施用技术、稀土土壤学、稀土植物生理、毒理卫生学、稀土农用分析和稀土农用产品及其应用方面的进展和成果。简要介绍了国外开展稀土农用研究的情况并分析了其未取得成果的原因。合理施用稀土可使农作物增产5～15％,并有改善作物品质的作用。经济效益大约是一元投资七元收益。稀土农用的关键技术已获突破,建立一个稀土应用的新领域已成为现实的任务。更多还原

【Abstract】 In China rare earth research in agriculture began in 1972. In 1979 multisubject rare earth comprehensive research has developed. By near 6 years of systematic work the achivement in many field have been obtained.So-called "Nong-le" is a complex product in which soluble rare earth compound is the main component used in agriculture. Ning Jiafen, Xie Huiguang, Wang Guohong, Cai Changbei, Lin Xijie et al. have done more than 100 experiments of various crops on potting, small area and field in different districts. The results prove that in certain conditions rare earths can increase the yield and improve the quality of some crops. When the crop is at the primary growth stage, the rare earth amount is 450～750 g/ha with spraying leave or seed dressing for field crop. The rare earths applied too much or later will be harmful to crop growth. "Nong-le" can’t replace manure and nutrient elements. Liu Zheng, Zhu Qiqing et al. approached the method for determining soluble rare earths in soil. They presented that soluble rare earths can be assayed using acetate buffer as the extractant. The experiment proves that application of "Nong-le" to areas of low content of soluble rare earths in soil shows good efficiency.From Wu Zhaoming, Qi Tiangqing and Zhu Yongyi’s experiments, plant may absorb soluble rare earths quite fastly. For example, the young leave of cucumber plant contain more lanthanum. Tang Xike et al. studied effects of rare earths with diffrent concentration on growing of barley and Chinese cabbage roots. In certain concentrations rare earths stimulate rooting, but high concentration will inhibite growing. Liu Hantu et al. approached that appling rare earths the root activity of peanut increase 30%. Zhu Zhaomin and Zhu Wemin established that treatment for crops with rare earths increased the uptake ablities of N, P and K nutrient elements. Rare: earths enhance plant rooting, germinating and raising its photosynthesis and improving its uptake for macroelements. Most explain the rare earths are really a group of beneficial elements, even though it is uncertain now that rare earths belong to essential elements for plants.Ji Yunjing, Mu Chuangjie, Cui Mingzhen, Zhang Kailin et al. studied toxicology of rare earths. Their experiments prove that rare earth nitrate and chloride belong to low toxic substances. Their LD₅₀ are 1000～4000 mg/kg. Feeding animal with rare earths at high concentration for a long time, the animal develops and propagates normally. Sub-chronic toxicological test shows that the invalid does via mouth for mouse is 20～200rog/day·kg. According to calculation the allowed dose for mankind is 12～120mg/day·man. Su Dezhao et al. analyzed rare earth content: in about 300 samples of food at home and abroad and there is no obvious difference betwwen the sample treated with rare earths and the control. Generally every body absorbs about 2 mg rare earths per day from food and water.In China standardized methods to assay microcontent of rare earths in soil and grain have been developed. Liu Wenhua et al. determined Ce in hair, soil and grain with fluorospectrometer. Zhao Guiwen et al. determined content of individual rare earths in soil with ICP spectrum. Cui Hulin el al. measured rare earths in animal, viscera with neutron activation method. The development of modernized analytical methods for rare earths will provide a reliable mean for exploring transition and distribution of rare earths in soil, plant and animal bodies.In order to provide rare earth agricuitural product of high quality, Zheng We: et al. studied the technological process, quality standard and the form of"Nong-le" product. The radioactity of the product is lower than 10-⁸Ci/kg. The harmful impurity in "Nong-le" is lower than that in all microelement fertilizers. "Nong-le" has a characteristic of high adherence and dispersion and wide availability to various water and crops.更多还原