ABSTRACT

Soil stability, yield decline and higher carbon decomposition are the key issues in intensive agriculture. Long-term integrated nutrient management (INM) influences carbon (C) dynamics and maintains the soil aggregate stability, which driven by the type of cropping system and climatic zone. Therefore, the specific effects of rice-wheat-jute cropping system on soil aggregate distribution, C-stability, and trade-off between C-storage and decomposition rate were studied of a long-term INM trial in the sub-tropical zone. We investigated the effect of four long-term nutrient management practices that include, control, N (nitrogen (N) and no phosphorus (P), and potassium (K)), NPK (N, P and K) and INM (N, P, K + farmyard manure (FYM)). Results showed that the addition of FYM with NPK improved macro-aggregates by 71%, and associated C-pools by 30%. The INM enhanced C-storage (20%), however, the decomposition rate was also higher (28%) over control at 35 °C at field capacity. A trade-off exists between the soil-aggregate stabilization and C-decomposition rate. The proportion of C-storage was higher than decomposition in INM. Further, the C-sequestration varied (0.17 to 0.26 t ha⁻¹ y⁻¹) under different treatments and were found highest in INM, indicating long-term soil stability and yield sustainability in the rice-wheat-jute system.

摘要

土壤稳定性、产量下降和更高的碳分解是集约化农业的关键问题。长期综合养分管理 (INM) 影响碳 (C) 动态并维持土壤团聚稳定性，这由种植系统类型和气候带驱动。因此，在亚热带地区进行的长期 INM 试验研究了水稻-小麦-黄麻种植系统对土壤团聚体分布、碳稳定性以及碳储存和分解速率之间权衡的具体影响。我们调查了四种长期养分管理措施的影响，包括控制、N（氮 (N) 和无磷 (P) 以及钾 (K)）、NPK（N、P 和 K）和 INM（N、 P, K + 农家肥 (FYM))。结果表明，添加含有 NPK 的 FYM 可将宏观聚集体提高 71%，并将相关碳池提高 30%。INM 增强了碳储存 (20%)，但是，在 35 °C 的现场容量下，分解率也高于对照 (28%)。土壤团聚体稳定性和碳分解率之间存在权衡。C-存储的比例高于 INM 中的分解。此外，碳固存变化（0.17 至 0.26 t ha⁻¹ y ⁻¹ ) 在不同的处理下并且在 INM 中最高，表明水稻-小麦-黄麻系统中的长期土壤稳定性和产量可持续性。