Mavi Manpreet Singh, Singh Gurpreet, Choudhary Om Parkash, Dey Debomita
Department of Soil Science, Punjab Agricultural University, Ludhiana, 141004, India.
Environ Monit Assess. 2023 Mar 14;195(4):467. doi: 10.1007/s10661-023-11052-9.
Soil application of pyrolyzed biomass (biochar) has been proposed as an effective strategy for managing degraded land, but its limitations as a sole nutrient supplier discourage its widespread application as a soil amendment. Excessive use of saline water for irrigation leads to buildup of salts and other toxic ions, which cause a decline in the availability of essential nutrients due to negative effects on the mineralization process. Therefore, a long-term incubation experiment was conducted for 52 weeks to study the individual or combined impact of pyrolyzed [biochar derived from rice residue (RB)] and unpyrolyzed organic materials [rice residue (RR) and animal manure (AM)] on nitrogen (N) dynamics in soil irrigated with water of varying electrical conductivity (EC) (EC [non-saline canal water), EC, and EC dS m (saline)]. Increasing salinity had an adverse effect on N mineralization, reducing it by 20-70% during the incubation period. Irrespective of the EC, soil amended with AM showed greater and faster N mineralization than unamended control, while individual application of RB or RR showed immobilization of N during the early period of incubation. However, conjoint application of pyrolyzed (RB) and unpyrolyzed organic materials (RR or AM) showed enhanced mineralized N content (26-96%) compared with the sole biochar-amended soil irrigated with water of different EC levels. It was most likely due to the synergic effect of unpyrolyzed materials on the mineralization rate of biochar. On the other hand, the high cation exchange capacity, large surface area, and greater total porosity of the biochar may cause stronger adsorption of free NH-N released from the labile organic amendments, thereby moderating the N mineralization process under saline conditions. Therefore, it is recommended that biochar be used in conjunction with AM or RR to ensure the prolonged availability of N in a saline environment.
有人提出，将热解生物质（生物炭）施用于土壤是治理退化土地的有效策略，但因其作为单一养分供应源存在局限性，阻碍了它作为土壤改良剂的广泛应用。过度使用咸水灌溉会导致盐分和其他有毒离子的积累，由于对矿化过程产生负面影响，会使必需养分的有效性下降。因此，进行了一项为期52周的长期培养试验，以研究热解[稻壳残渣衍生生物炭（RB）]和未热解有机物料[稻壳残渣（RR）和动物粪便（AM）]单独或联合使用对不同电导率（EC）（EC[非咸水运河水]）、EC和EC dS m（咸水）灌溉土壤中氮（N）动态的影响。盐度增加对氮矿化产生不利影响，在培养期间使其减少20%-70%。无论EC如何，施用AM的土壤比未改良对照表现出更大且更快的氮矿化，而单独施用RB或RR在培养初期表现出氮的固定。然而，与用不同EC水平水灌溉的单一生物炭改良土壤相比，热解（RB）和未热解有机物料（RR或AM）联合施用显示矿化氮含量增加（26%-96%）。这很可能是由于未热解物料对生物炭矿化速率的协同作用。另一方面，生物炭的高阳离子交换容量、大表面积和更大的总孔隙率可能导致对不稳定有机改良剂释放的游离NH-N的更强吸附，从而在盐渍条件下调节氮矿化过程。因此，建议将生物炭与AM或RR结合使用，以确保在盐渍环境中氮的长期有效性。
