We evaluated the effect of phosphorus application rates from various sources and in the presence or absence of filter cake on soil phosphorus, plant phosphorus, changes in acid phosphatase activity, and sugarcane productivity grown in Eutrophic Red Ultisol. Three P sources were used (triple superphosphate, Araxa rock phosphate, and Bayovar rock phosphate) and four application rates (0, 90, 180, and 360 kg ha−1 of P2O5) in the presence or absence of filter cake (7.5 t ha−1, dry basis). The soil P, the accumulated plant P, the leaf acid phosphatase activity and straw, the stalk productivity, the concentration of soluble solids in the juice (Brix), the juice sucrose content (Pol), and the purity were the parameters evaluated. We found that P applications increased levels of soil, leaf, and juice phosphorus and led to higher phosphorus accumulation and greater stalk and straw productivity. These levels were highest in the presence of filter cake. Acid phosphatase activity decreased with increasing plant phosphorus concentration. Phosphate fertilization did not show effect on sugarcane technological quality. We concluded that P application, regardless of source, improved phosphorus nutrition and increased productivity in sugarcane and, when associated with filter cake, reduced the need for mineral fertilizer.
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机译：我们评估了各种来源和有无滤饼下的磷施用量对土壤磷，植物磷，酸性磷酸酶活性的变化以及富营养红色Ultisol中生长的甘蔗生产力的影响。在存在或不存在的情况下，使用了三种磷源（三磷酸过磷酸钙，Araxa磷矿石和Bayovar磷矿石），四种施用量（P2O5的0、90、180和360 kg ha -1 ）滤饼（7.5 t ha -1 ，干基）。土壤P，累积的植物P，叶片酸性磷酸酶活性和秸秆，秸秆生产率，果汁中的可溶性固体浓度（白利糖度），果汁中的蔗糖含量（Pol）和纯度均是评估的参数。我们发现磷肥的施用增加了土壤，叶片和果汁中磷的含量，并导致更高的磷积累量以及更高的秸秆和秸秆生产率。这些水平在存在滤饼的情况下最高。酸性磷酸酶活性随植物磷浓度的升高而降低。磷酸盐施肥对甘蔗的技术品质没有影响。我们得出的结论是，无论来源如何，施用磷肥都能改善甘蔗中的磷营养并提高生产力，并且与滤饼结合使用时，减少了对矿物肥料的需求。
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