Co-pyrolysis of animal manure biomass with bone meal (BM) and soaking of the resultant biochar in urea containing solutions may offer a sustainable and cheap way of formulating slow-release nitrogen (N) and phosphorus (P) fertilisers. This method can lead to optimisation of the carbon sequestration capacity of the biochar, abatement of environmental pollution by P and N and alleviation of the severity of the projected future scarcity of P. A few studies have indicated that sorption can create efficient slow-release fertilisers although all of them utilised charged moieties such as ammonium ions to formulate them and as a result, there is a paucity of data concerning the efficiency of fertilisers formulated using uncharged compounds like urea. It’s against that background that we examined the possibility of leveraging co-pyrolysis and sorption with urea containing solutions to formulate slow-release N and P fertilisers along with assessing the agronomic efficiency of the formulated fertilisers through cultivating lettuce in pots for two seasons. Both urea-hydrogen peroxide (UHP) and urea were utilised as N sources. UHP (CDBM-UHP) and urea (CDBM-Urea) containing biochars averagely released 64.40% and 87.00% of the added N, respectively over the 28-day incubation period with the amount of N released decreasing with increasing concentrations of BM in the biochar. Lettuce yields and nutrient use efficiencies of N and P were higher in the CDBM-UHP than in the CDBM-Urea treatments. It’s therefore clear that sorption of UHP by BM containing biochar concomitantly slows-down releases of N and P and boosts the agronomic efficiency of the fertilisers.

中文翻译：

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共热解骨粉和牛粪对尿素过氧化氢的吸收减慢了磷和氮的释放，但提高了农艺效率

动物粪便生物质与骨粉（BM）的共热解以及将所得生物炭浸泡在含尿素的溶液中可能提供配制缓释氮（N）和磷（P）肥料的可持续且廉价的方法。这种方法可以优化生物炭的固碳能力，减轻磷和氮对环境的污染，并减轻预计的磷未来稀缺性的严重性。一些研究表明，吸附可以产生有效的缓释肥料尽管它们全部利用带电荷的部分如铵离子来配制它们，因此，关于使用不带电荷的化合物如尿素配制的肥料效率的数据很少。在这种背景下，我们研究了利用含尿素的溶液进行共热解和吸附来配制缓释氮磷肥的可能性，以及通过在盆中种植生菜两个季节评估配制肥料的农学效率的可能性。尿素-过氧化氢（UHP）和尿素均用作氮源。在培养的28天中，含Uchar（CDBM-UHP）和尿素（CDBM-Urea）的生物炭平均分别释放出添加的N的64.40％和87.00％，随着生物炭中BM浓度的增加，释放的N量减少。CDBM-UHP的生菜产量和N和P的养分利用效率高于CDBM-Urea处理。