ABSTRACT

The establishment of high-yielding agricultural production systems is severely restricted by low soil organic carbon (SOC) and high Na⁺ concentration in saline-alkaline soils. In order to confirm the effects of biochar and phosphorus (P) fertilization on SOC sequestration, soil physical structure and inorganic P (Pi) fractions, as well as optimize the amount of P fertilizer, a field experiment was designed with two factors: with biochar at 0 (C0), 1% (C1) and 3% (C2); with P at 0 (P0), 64 (P1) and 128 kg ha⁻¹ (P2). The results indicated that biochar input enhanced SOC, however, the effect of P application on SOC and soil physical structure were negligible. Compared to C0, SOC was increased by 98–113% for C1 and 180–195% for C2. Due to the SOC enhancement and reduction of soil Na⁺ concentration, biochar input decreased ρb, increased MWD and WSMA. For Pi fractions, soil Olsen-P, Ca₂-P, Ca₈-P, Fe-P and Al-P were increased, mainly due to the direct supply, retention and the improvement of biological availability. Overall, C2P1 was the most efficiency treatment to enhance SOC, improve soil physical structure, and C2P2 avail to increase the supply capacity of soil P, but had no significant difference with that in C2P1.

摘要

高产农业生产体系的建立受到盐碱地土壤有机碳（SOC）低和Na ⁺浓度高的严重制约。为了确认生物炭和磷（P）施肥对 SOC 固存、土壤物理结构和无机 P（Pi）组分的影响，以及优化磷肥用量，设计了一项田间试验，该试验涉及两个因素：生物炭在 0 (C0)、1% (C1) 和 3% (C2)；P 为 0 (P0)、64 (P1) 和 128 kg ha ^-1 (P2)。结果表明，生物炭的输入提高了 SOC，但施磷对 SOC 和土壤物理结构的影响可以忽略不计。与 C0 相比，C1 的 SOC 增加了 98-113%，C2 的 SOC 增加了 180-195%。由于土壤中 SOC 的增加和减少⁺浓度，生物炭输入减少 ρb，增加 MWD 和 WSMA。对于 Pi 组分，土壤 Olsen-P、Ca ₂ -P、Ca ₈ -P、Fe-P 和 Al-P 增加，主要是由于直接供应、保留和生物有效性的提高。总体而言，C2P1是提高SOC、改善土壤物理结构最有效的处理，C2P2有利于提高土壤磷的供给能力，但与C2P1无显着差异。