With the advent of mechanized sugarcane harvesting in Brazil around 70 Mt of straw each year is left on the field, and ∼70% of its carbon (C) is decomposed and returned to the atmosphere on the same timeframe. The adoption of a stabilised C product such as biochar as a vehicle for nutrient delivery might address two ends of a problem: to increase nutrient use efficiency by plants while creating a viable and efficient strategy to increase stable C in soil. This study proposed a production route for a biochar fertiliser (BF) from sugarcane straw biochar (SSB), by activation of SSB with KOH and subsequent neutralisation with H₃PO₄. The phosphorus (P) content of BF (8.6% P) was superior to SSB. It was also noticed that structure of SSB matrix was altered, creating increased sorption capacity, with the fertiliser bound to the biochar rather than physically mixed. The BF was tested in a controlled condition experiment with sugarcane for 120 days using three low P soils with different clay contents (147, 326 and 528 g kg⁻¹). BF led to higher biomass yield (15%) and P use efficiency (PUE) (∼10%) compared to standard P source (triple superphosphate – TSP) in the most clayey soil. The adoption of a fertiliser based on a nutrient enriched biochar can increase the effectiveness of crop production. Enhanced delivery of crop nutrients increases the attractiveness of increased soil C.

随着巴西机械化甘蔗收割的兴起，每年大约有70吨秸秆被留在田间，约有70％的碳（C）分解并在同一时间返回大气。采用稳定的碳产品（例如生物炭）作为营养物输送的媒介可能会解决两个问题：提高植物对营养物的利用效率，同时制定可行且有效的策略来增加土壤中的稳定碳。这项研究提出了一种用甘蔗秸秆生物炭（SSB）生产生物炭肥料（BF）的生产路线，方法是用KOH活化SSB，然后用H ₃ PO _4中和。。高炉的磷（P）含量（8.6％P）优于SSB。还注意到，SSB基质的结构发生了变化，从而增加了吸附能力，肥料与生物炭结合，而不是物理混合。在甘蔗的可控条件实验中，使用三种具有不同粘土含量（147、326和528 g kg ^-1）的低磷土壤对高炉进行了120天的测试。在大多数粘性土壤中，与标准磷源（三磷酸过磷酸钙– TSP）相比，高炉导致较高的生物量产量（15％）和磷利用效率（PUE）（〜10％）。采用富含营养素的生物炭的肥料可以提高农作物的生产效率。作物养分的增加输送增加了土壤碳的吸引力。