An Ning, Zhang Lei, Liu Yaxian, Shen Si, Li Na, Wu Zhengchao, Yang Jinfeng, Han Wei, Han Xiaori
College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China; National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, Shenyang, Liaoning, China.
College of Land and Environment, Shenyang Agriculture University, Shenyang, Liaoning, China.
Chemosphere. 2022 Jul;298:134304. doi: 10.1016/j.chemosphere.2022.134304. Epub 2022 Mar 14.
Biochar is an efficient amendment to improve soil quality and crop productivity, but the potential of biochar as a substitute for chemical fertilizers is still unknown. Here we conducted a 6-year field experiment to investigate how partial substitution of biochar to NPK fertilizers affect soil quality and rice yield in the northeast of China. The experiment included three treatments: Control (B0: NPK fertilizers only: 240 kg N ha, 52 kg P ha, and 100 kg K ha); Low-input biochar (B1.5: 95% N, 89% P, 75% K + 1.5 t biochar ha year); and High-input biochar (B3.0: 90% N, 78% P, 50% K + 3.0 t biochar ha year). The amounts of NPK application in the biochar treatments were determined according to an equivalent method. We evaluated the soil pore structure characteristics via a CT technology, and investigated soil nutrients, plant biomass, root growth, and grain yields. The results showed that, after the 6-year application, the soil pore structure and rice productivity of B1.5 were significantly improved in compared to those of B0 and B3.0. B1.5 had similar soil available NPK contents, but 6.6% higher rice yield as compared to B0, because of increased root length density (33.2%) and aboveground biomass (10.2%). B1.5 also increased soil macroporosity (>100 μm) (141.4%), fraction dimension (8.4%), and pore connectivity (16.6%) in compared with those of B0. However, B3.0 showed the lowest rice yield due to lower soil available N content (19.2%), macroporosity (28.5%), fraction dimension (5.5%), and pore connectivity (85.3%) than B0. This study demonstrated that a moderate NPK fertilizer replacement by biochar could be an effective practice that improves soil quality, increases rice growth and yield, and reduces the input of chemical fertilizers for rice production.
生物炭是一种改善土壤质量和作物生产力的有效改良剂，但生物炭替代化肥的潜力仍不明确。在此，我们进行了一项为期6年的田间试验，以研究在中国东北用生物炭部分替代氮磷钾（NPK）肥料如何影响土壤质量和水稻产量。该试验包括三个处理：对照（B0：仅施用NPK肥料：240千克氮/公顷、52千克磷/公顷和100千克钾/公顷）；低投入生物炭处理（B1.5：95%的氮、89%的磷、75%的钾 + 每年1.5吨生物炭/公顷）；以及高投入生物炭处理（B3.0：90%的氮、78%的磷、50%的钾 + 每年3.0吨生物炭/公顷）。生物炭处理中NPK的施用量根据等效方法确定。我们通过CT技术评估土壤孔隙结构特征，并调查土壤养分、植物生物量、根系生长和谷物产量。结果表明，经过6年的施用，与B0和B3.0相比，B1.5的土壤孔隙结构和水稻生产力显著改善。B1.5的土壤有效NPK含量相似，但与B0相比，水稻产量高6.6%，这是由于根长密度增加（33.2%）和地上生物量增加（10.2%）。与B0相比，B1.5还增加了土壤大孔隙度（>100微米）（141.4%）、分形维数（8.4%）和孔隙连通性（16.6%）。然而，由于土壤有效氮含量（19.2%）、大孔隙度（28.5%）、分形维数（5.5%）和孔隙连通性（85.3%）低于B0，B3.0的水稻产量最低。这项研究表明，用生物炭适度替代NPK肥料可能是一种有效的做法，可改善土壤质量、增加水稻生长和产量，并减少水稻生产中化肥的投入。
