Huang Zhuang, Zhang Xiaoqing, Peñuelas Josep, Sardans Jordi, Jin Qiang, Wang Chun, Yang Liuming, Fang Yunying, Li Zimin, Wang Weiqi
Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350117, China; Institute of Geography, Fujian Normal University, Fuzhou 350117, China.
CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain; CREAF, Cerdanyola del Vallès 08193, Catalonia, Spain.
Sci Total Environ. 2023 Nov 25;901:166364. doi: 10.1016/j.scitotenv.2023.166364. Epub 2023 Aug 18.
Adding industrial and agricultural wastes to farmland can increase soil available phosphorus (P) pool and boost crop production, but the process affecting soil P transformation and bioavailability is still poorly understood. We studied the effects of straw (ST), biochar (BC) and Si-modified biochar (Si-BC) amendments on the available-P content and its fraction transformation in rice-paddy soils. Our results showed that these three soil amendments significantly increased the concentrations of both microbial biomass carbon (MBC) and microbial biomass-P (MBP) during the first rice season; by contrast, the effects of ST and BC application were relatively poor on acid-phosphatase (ACP) activity, which was increased by 24 % under ST and 14 % under BC. Soil total P concentrations did not differ significantly, although the concentration and percentage of each P-fraction were altered significantly among treatments. Although all three applications increase soil available-P concentration by promoting the transformation of organic-P (Po) components to inorganic-P (Pi), there are differences in the transformation efficiency of the soil P fraction between these amendments. Redundancy analysis results also showed significant clustering of soil P-fraction transformations after ST and BC treatments. Structural equation model analysis further indicated that all amendments regulated microbial processes by changing soil pH and dissolved organic carbon (DOC), thereby promoting soil P transformation and improving P efficiency. Sodium bicarbonate-extractable Po (NaHCO-Po) contributed most to soil available-P under the different amendments. Compared to ST and Si-BC, BC application improved more soil microbial status and the transformation of soil unavailable-P into available-P, therefore the application of BC in rice fields is the most beneficial method to promote phosphorus use and production sustainability in rice. These findings helped to understand the effects of using industrial and agricultural waste (e.g. straw, biochar and Si-modified biochar) on soil P-fractions and so provided a reference for sustainable resource use and green production in rice-paddy ecosystems.
向农田添加工农业废弃物可增加土壤有效磷库并提高作物产量，但影响土壤磷转化和生物有效性的过程仍鲜为人知。我们研究了秸秆（ST）、生物炭（BC）和硅改性生物炭（Si-BC）改良剂对稻田土壤有效磷含量及其组分转化的影响。我们的结果表明，在第一季水稻生长期间，这三种土壤改良剂均显著提高了微生物生物量碳（MBC）和微生物生物量磷（MBP）的浓度；相比之下，ST和BC对酸性磷酸酶（ACP）活性的影响相对较小，ST处理下ACP活性提高了24%，BC处理下提高了14%。各处理间土壤总磷浓度无显著差异，尽管各磷组分的浓度和百分比有显著变化。虽然这三种改良剂均通过促进有机磷（Po）组分向无机磷（Pi）的转化来提高土壤有效磷浓度，但这些改良剂之间土壤磷组分的转化效率存在差异。冗余分析结果还表明，ST和BC处理后土壤磷组分转化存在显著聚类。结构方程模型分析进一步表明，所有改良剂均通过改变土壤pH值和溶解有机碳（DOC）来调节微生物过程，从而促进土壤磷转化并提高磷效率。在不同改良剂处理下，碳酸氢钠可提取态Po（NaHCO-Po）对土壤有效磷的贡献最大。与ST和Si-BC相比，BC的施用改善了更多的土壤微生物状况以及土壤无效磷向有效磷的转化，因此在稻田中施用BC是促进水稻磷利用和生产可持续性的最有益方法。这些研究结果有助于了解使用工农业废弃物（如秸秆、生物炭和硅改性生物炭）对土壤磷组分的影响，从而为稻田生态系统的可持续资源利用和绿色生产提供参考。
