Gunal Elif
Department of Soil Science and Plant Nutrition/Faculty of Agriculture, Tokat Gaziosmanpasa University, Tokat, Turkey.
PeerJ. 2025 May 28;13:e18823. doi: 10.7717/peerj.18823. eCollection 2025.
Nutrient leaching threatens sustainable agriculture by depleting soil fertility and contaminating groundwater. Biochar offers a promising solution, but its effectiveness varies with feedstock, production, and application rates. Specifically, the potential of hazelnut husk biochar for nutrient retention and soil improvement has not been extensively studied, leaving a gap in understanding its practical applications and optimal usage in different soil types and crop systems.
This study investigated the influence of hazelnut husk biochar application on leachate properties, soil column characteristics, and nutrient dynamics over a 112-day period. The experiment employed a randomized split-plot design with four hazelnut husk biochar application rates (0%, 0.5%, 1%, and 2%) on sandy loam soil. Leaching events were conducted six times over 112 days of incubation period, simulating irrigation and fertilizer application for potato cultivation. Leachates were collected at each leaching event for analysis of pH, electrical conductivity (EC), and various nutrient contents. Following the experiment, soil samples were analyzed at three depths to assess nutrient content.
The study revealed significant temporal dynamics in nutrient concentrations across different leaching events, emphasizing the impact of biochar on nutrient retention. Phosphorus (P) concentrations, for instance, decreased from 0.220 mg L to 0.176 mg L over four leaching events in the 2.0% biochar treatment. Similarly, potassium (K) concentrations declined from 6.44 mg L to 3.76 mg L, indicating improved nutrient retention with biochar application. These findings contrast with the control (0% biochar), where nutrient leaching was more pronounced. While biochar had little effect on nitrate leaching, its inherent P content and adsorption characteristics influenced P leaching. Higher biochar application rates resulted in significant changes in soil properties and nutrient concentrations, particularly in the surface layer (0-10 cm), such as an increase in organic matter content from 0.84% in the control to 1.20% in the 2.0% biochar treatment, suggesting improved nutrient availability for plant uptake.
These findings underscore the potential of hazelnut husk biochar as a sustainable soil management strategy for enhancing nutrient retention, reducing leaching, and improving soil fertility. However, the study also highlights the complexity of biochar-soil interactions and the need for further research to optimize biochar application practices for specific soil and crop systems.
养分淋失会消耗土壤肥力并污染地下水，从而威胁可持续农业。生物炭提供了一个有前景的解决方案，但其有效性因原料、生产和施用量而异。具体而言，榛子壳生物炭在养分保持和土壤改良方面的潜力尚未得到广泛研究，这使得在理解其在不同土壤类型和作物系统中的实际应用及最佳使用方法方面存在空白。
本研究调查了榛子壳生物炭施用在112天内对渗滤液性质、土柱特征和养分动态的影响。该实验采用随机裂区设计，在砂壤土上设置了四个榛子壳生物炭施用量（0%、0.5%、1%和2%）。在112天的培养期内进行了六次淋溶试验，模拟马铃薯种植的灌溉和施肥情况。每次淋溶试验后收集渗滤液，分析其pH值、电导率（EC）和各种养分含量。实验结束后，在三个深度采集土壤样本以评估养分含量。
研究揭示了不同淋溶事件中养分浓度存在显著的时间动态变化，突出了生物炭对养分保持的影响。例如，在2.0%生物炭处理中，经过四次淋溶事件，磷（P）浓度从0.220毫克/升降至0.176毫克/升。同样，钾（K）浓度从6.44毫克/升降至3.76毫克/升，表明施用生物炭可改善养分保持。这些发现与对照（0%生物炭）形成对比，对照中养分淋失更为明显。虽然生物炭对硝酸盐淋失影响不大，但其固有磷含量和吸附特性影响了磷的淋失。较高的生物炭施用量导致土壤性质和养分浓度发生显著变化，特别是在表层（0 - 10厘米），例如有机质含量从对照中的0.84%增加到2.0%生物炭处理中的1.20%，这表明植物吸收的养分有效性得到了提高。
这些发现强调了榛子壳生物炭作为一种可持续土壤管理策略在增强养分保持、减少淋失和提高土壤肥力方面的潜力。然而，该研究也凸显了生物炭与土壤相互作用的复杂性，以及进一步开展研究以针对特定土壤和作物系统优化生物炭施用方法的必要性。
