Pak J Biol Sci. 2021 Jan;24(1):90-98. doi: 10.3923/pjbs.2021.90.98.
The use of biochar, a charred organic material, is becoming a sustainable technology that leads to the improvement of highly weathered tropical soils. A study was conducted at the Teaching and Research Farm of the University of Calabar to compare the effects of integrated use of Biochar (B), Poultry Manure (PM) and urea on the pH and microbial properties of soil-grown with Amaranthus cruentus.
A total of 15 treatments consisting of a sole and combined use of biochar, poultry manure, urea and control were fitted on a randomized complete block design with 3 replications. The organic amendments were applied 2 weeks before sowing while urea was applied 2 weeks after sowing. Composite soil samples (0-15 cm) were taken before and after the experiment for pH and microbial analysis.
Soil pH was raised from a strongly acidic level to values ranging from 5.73-6.8 (moderately acid-slightly acid, respectively) pH level after the experiment with the highest obtained in Full B+½PM amended soil. The fungal population was maximum in PM (sole and combinations) (18×103-20×103 CFU g-1) and minimum in sole biochar and control (×-10×103 CFU g-1). The bacterial population exhibited a similar trend with the maximum value in PM (sole and combinations) (98×106-148×106 CFU g-1) and minimum in control (×-36×106 CFU g-1).
This suggests that biochar addition alone did not cause any apparent alteration to the microbial population and diversity compared to its complementary use.
生物炭是一种碳化的有机材料，它的使用正成为一种可持续的技术，可以改善高度风化的热带土壤。本研究在卡拉巴尔大学教学和研究农场进行，旨在比较生物炭（B）、家禽粪便（PM）和尿素综合使用对苋菜生长土壤的 pH 值和微生物特性的影响。
采用完全随机区组设计，设置 15 个处理，包括生物炭、家禽粪便、尿素单独和组合使用以及对照，每个处理重复 3 次。在播种前 2 周施加有机肥料，在播种后 2 周施加尿素。在实验前后采集 0-15cm 土壤样品进行 pH 值和微生物分析。
实验后土壤 pH 值从强酸性升高到 5.73-6.8（分别为中度酸性和弱酸性），其中全量 B+半量 PM 处理下土壤 pH 值最高。真菌种群在 PM（单独和组合）中最高（18×103-20×103 CFU g-1），在单独生物炭和对照中最低（×-10×103 CFU g-1）。细菌种群也表现出相似的趋势，在 PM（单独和组合）中最高（98×106-148×106 CFU g-1），在对照中最低（×-36×106 CFU g-1）。
这表明与单独使用相比，生物炭的添加并没有对微生物种群和多样性造成明显的改变。
