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Acknowledge I expresses thanks to Assoc. Prof. rob Reid of Adelaide university of Australia, Dr Jeff Gale, foreign teacher of northwest A&F University of China, and Prof. Zhang Fusuo, Prof. Li Xiaolin of China Agriculture University, Prof Liu Yuanyin of Northeast agriculture Unversity and other authors who provide materials for me, or whose materials, such as photographs and figures etc, I used in the lectures
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Phosphorus in plant physiology P content of plants Approximately 0.2% of plant dry weight is P Plants require a relatively large amount of P. The phosphate concentration in the cytosol is maintained at fairly constant concentrations in the 5 to 8 mol/m3 regardless of the external phosphate concentration except under severe P deficiency. By contrast is the vacuolar phosphate concentration
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一、目的意义 为了切实作好化肥的合理贮存、保管和施用,充分发挥肥效,避免不必要的损失, 防止出现事故,对化肥的品种名称必须明确。一般化肥出厂时在包装上都标明该肥料的 名称,成分和产地,但在运输贮存过程中常因包装不好或转换容器而混杂,因此必需 进行定性鉴定加以区别,以能做到合理保管施用
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Factors effecting the plant uptake 影响养分吸收的因素主要包括介质中的养分浓度、温 度、光照强度、士壤水分、通气状况、土壤pH值、养分离 子的理化性质、根的代谢活性、苗龄、生育时期植物体内养 分状况等
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The short distance transports of nutrients There are two main steps nutrients translocation in plant after nutrients absorbed by the root. One is the centripetal transport from the rhizoplane through the cortex tissue of the roots towards the xylem vessels of the central cylinder. Another one is the vertical transport from from the root towards the leaves
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Calcium in physiology Uptake and translocation Higher plants often contain apprecia ble amounts Ca and generally in the order of about 5-30 mg Ca/g dry matter The high Ca2+ concentrations related with the high Ca2+ levels in media not related with the Ca2+ uptake
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第一节复(混)合肥料的概念 第二节复(混)合肥料的成分、性质与施用 第三节复(混)肥料的合理施用
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Plant K A. Potassium content of plants 1.20-50gkg-1 2. Plants take up large amount of K. Only N is taken up more. 3. In some plants (sugar beets and potatoes) K uptake is greater than N uptake
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Concept of organic fertilizers Organic fertilizers-that are derived from the wastes and residues of plants or animals. Such as manure, sewage sludge etc. Some consist of unprocessed plant materials(such as tree leaves, grass clipping, crop residues, and green manure crops)
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磷是作物必需的三要素之一 磷肥是世界上仅次于氮肥的主要肥料产品 磷在自然界中一般不以游离态(元素态)存在,而以磷酸盐形 式存在于矿物中。最常见的含磷矿物是磷灰石,通式为 Ca5X(PO4)3,其中X代表一F,-OH或-Cl等。最常见的氟磷灰 石的化学式为CaF(PO4)3。1989、1990年度,我国生产各种磷肥 453万吨(P2O5),居世界第二位
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