富碳沼液施用对水稻分蘖期生长的影响

为探究施用富碳沼液对水稻生长的影响，以氮素含量为施肥指标，分别以原沼液（BS）、富碳原沼液（CO₂-BS）、5倍浓缩沼液（5CBS）和富碳5倍浓缩沼液（CO₂-5CBS）为肥料施用于水稻，对水稻的矿质元素吸收利用情况及生长状况进行研究，并与复合肥施用进行对比。结果表明，从生理学指标来看，与复合肥处理的水稻相比，施用BS、CO₂-BS、5CBS和CO₂-5CBS后的水稻根系活力提升了93%~437%，对P元素的吸收分别降低了22.42%、20.25%、42.75%和41.06%，但CO₂-BS组和CO₂-5CBS组对K元素的吸收量分别提高了9.95%和2.58%，而CO₂-5CBS组则对Ca元素吸收量提升了45.23%。从农艺性状角度来看，施用了BS和CO₂-BS后水稻的生长量比复合肥组分别提高了9.67%和25.25%，且施用CO₂-BS的水稻外观长势最好。从营养性状指标来看，施用沼液后水稻的可溶性糖含量比复合肥施用组提升14.45%~23.07%。研究表明，施用富碳沼液可促进水稻对矿质元素的吸收，提高水稻的物质同化能力，建议沼液施用前先进行富碳处理，并配合化学磷肥共同施用。

Growth performance of rice at the tillering stage after applying CO2-rich biogas slurry

In order to explore the growth performance of rice after applying CO₂-rich biogas slurry, the nitrogen content was selected as the index to determine the fertilizer amount for rice. Biogas slurry(BS), CO₂-rich BS(CO₂-BS), 5-times concentrated BS(5CBS), and CO₂-rich 5CBS (CO₂-5CBS) were the different fertilizer treatments applied. After their application during rice growth, the absorption and utilization of mineral elements by rice plants and growth rate were analyzed and compared with those of plants after applying the compound fertilizer(CK). The results showed that the root activities of rice treated with biogas slurry were 0.93~4.37 times higher than those under the compound fertilizer treatment. The uptake of P by rice plants treated with BS, CO₂-BS, 5CBS, and CO₂-5CBS decreased by about 22.42%, 20.25%, 42.75%, and 41.06%, respectively, when compared to the compound fertilizer treatments. However, the K absorption capacities of rice plants subjected to CO₂-BS and CO₂-5CBS treatments increased by 9.95% and 2.58%, respectively. Additionally, the Ca absorption capacity increased by 45.23% in the CO₂-5CBS treatment. Furthermore, the biomass of rice plants in BS and CO₂-BS treatments were 9.67% and 25.25% higher than that in the compound fertilizer treatments, respectively, and the phenotype of the rice plants in the CO₂-BS treatment was the best. The soluble sugar content of rice plants subjected to biogas slurry application increased by about 14.45%~23.07%. In conclusion, the application of CO₂-rich biogas slurry could promote the absorption of mineral elements and improve the assimilation ability of rice. It is suggested that CO₂ saturation should be treated before biogas slurry application, and the chemical phosphate fertilizer should be applied together.