Phosphate fertilizers used in planted forests mainly come from scarce and non-renewable sources, and there is a need for new sources of phosphorus (P). An alternative is the use of sewage sludge (SS), rich in organic matter, nitrogen, and P. The objectives were to evaluate the soil P availability and its effect on wood production in 22-month-old Eucalyptus urograndis plantation treated with SS. A field experiment was set up in a randomized complete block design, four replicates, with the following treatments: control without fertilization; mineral fertilization (MF); 14.5 Mg ha–1 of SS + 22 kg ha–1 of P (S1P1); 29 Mg ha–1 of SS (S2); 29 Mg ha–1 of SS + 17.5 kg ha–1 of P (S2P2); and 43.5 Mg ha–1 of SS (S3), dry base. Of the total P in SS, 65% was in organic form and 42% was in labile + moderately labile forms. S2P2 and S3 positively altered the pattern of soil P distribution, with more P in the labile and moderately labile fractions than in the non-labile fraction, along 0–20 cm depths, than MF and control. There were higher microbial and available P as a function of SS dose. Wood volume and biomass were highly related to soil P availability as a function of SS dose. Within the SS treatments, S2P2 resulted in higher gains of volume and biomass of wood. The SS application at the recommend rate, supplemented with 66% of recommended P fertilizer dose in Eucalyptus plantations, can reduce the use of P fertilizer by 33% and N fertilizer by 100% and maintain comparable soil P availability and wood production.

中文翻译：

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Eucalyptus urograndis种植园污水污泥的应用：土壤和木材生产中磷的有效性

人工林中使用的磷肥主要来自稀缺且不可再生的资源，因此需要新的磷（P）来源。另一种方法是使用富含有机质、氮和磷的污水污泥 (SS)。目的是评估土壤磷的可用性及其对用 SS 处理的 22 个月大的 Eucalyptus urograndis 种植园的木材生产的影响。田间试验采用随机完全区组设计，设四次重复，处理如下：对照不施肥；矿物施肥（MF）；14.5 Mg ha–1 SS + 22 kg ha–1 P (S1P1)；29 Mg ha-1 的 SS (S2)；29 Mg ha–1 SS + 17.5 kg ha–1 P (S2P2)；和 43.5 Mg ha-1 的 SS (S3)，干基。在 SS 中的总磷中，65% 为有机形式，42% 为不稳定 + 中度不稳定形式。S2P2 和 S3 积极改变了土壤 P 分布的模式，在 0-20 cm 深度，不稳定和中度不稳定部分中的 P 比非不稳定部分中的磷多于 MF 和对照。作为 SS 剂量的函数，存在更高的微生物和有效磷。作为 SS 剂量的函数，木材体积和生物量与土壤磷的有效性高度相关。在 SS 处理中，S2P2 导致木材体积和生物量的更高增益。在桉树人工林中，按推荐比例施用 SS 并补充 66% 的推荐磷肥剂量，可以减少 33% 的磷肥和 100% 的氮肥使用，并保持可比的土壤磷利用率和木材产量。比MF和控制。作为 SS 剂量的函数，存在更高的微生物和有效磷。作为 SS 剂量的函数，木材体积和生物量与土壤磷的有效性高度相关。在 SS 处理中，S2P2 导致木材体积和生物量的更高增益。在桉树人工林中，按推荐比例施用 SS 并补充 66% 的推荐磷肥剂量，可以减少 33% 的磷肥和 100% 的氮肥使用，并保持可比的土壤磷利用率和木材产量。比MF和控制。作为 SS 剂量的函数，存在更高的微生物和有效磷。作为 SS 剂量的函数，木材体积和生物量与土壤磷的有效性高度相关。在 SS 处理中，S2P2 导致木材体积和生物量的更高增益。在桉树人工林中，按推荐比例施用 SS 并补充 66% 的推荐磷肥剂量，可以减少 33% 的磷肥和 100% 的氮肥使用，并保持可比的土壤磷利用率和木材产量。