Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China.
Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China.
Sci Total Environ. 2021 Sep 15;787:147523. doi: 10.1016/j.scitotenv.2021.147523. Epub 2021 May 5.
High yields and environment-related issues because of over-fertilization in rice (Oryza sativa L.) production is a major concern in China. Partial replacement of mineral fertilizer (MF) with organic matter is considered a win-win approach for resource-saving and environmentally friendly rice production. Here, we examined the effects of reduced MF and in situ crop residue on the rice yield and soil fertility in the long term. A 27-year field experiment (a randomized block design with three replicates) in subtropical China was conducted to test the feasibility of the substitution in a double rice paddy ecosystem. The treatments were CT (no fertilizer application considered as control), NPK (mineral fertilizer N, P, and K), and RFC (reduced MF and in situ crop residue to supplement the reduced NPK dose). The crop residue included half of the rice straw and green manure contents, which were retained in situ in the RFC treatment. The RFC maintained the same rice yield and soil fertility levels as NPK. In general, soil organic carbon (SOC) and total nitrogen (TN) content in RFC increased by 10.3% -20.8%, and 7.5% -28.0%, respectively, than that in NPK from the 5th to the 25th years. There was no significant difference in the content and net accumulation of SOC, TN, and TP and soil available nutrients between the RFC and NPK treatments after 25 years. The average annual yields were 9690 and 9872 kg ha for the NPK and RFC treatments, respectively. There was no difference in the yield of the first, second, and annual rice crops between RFC and NPK in most years (six of the fifty-four seasons showed a significant difference). RFC increased the partial factor productivity (PFP), agronomic efficiency (AE) of MF, and yield stability (CV) (p < 0.05). Positive nutrient balance and a reduced loss of nutrients are evident reasons for achieving better indicators (PFP, AE, and CV) for nutrient compensation and organic nutrient utilization in the RFC treatment. The partial replacement of MF with in situ crop residue retention, is a simple and efficient way to maintain the soil fertility and rice yield as NPK in southern China.
在中国，水稻（Oryza sativa L.）生产中过度施肥导致的高产量和与环境有关的问题是一个主要关注点。用有机物部分替代矿物肥料（MF）被认为是一种资源节约和环保型水稻生产的双赢方法。在这里，我们研究了长期减少 MF 和原位作物残体对水稻产量和土壤肥力的影响。在中国亚热带地区进行了一项为期 27 年的田间试验（随机区组设计，重复三次），以测试在双季稻田生态系统中替代的可行性。处理方法包括 CT（不施肥，作为对照）、NPK（矿物肥料氮、磷、钾）和 RFC（减少 MF 和原位作物残体补充减少的 NPK 剂量）。作物残体包括一半的稻草和绿肥含量，在 RFC 处理中保留在原位。RFC 保持了与 NPK 相同的水稻产量和土壤肥力水平。一般来说，从第 5 年到第 25 年，RFC 土壤有机碳（SOC）和总氮（TN）含量分别增加了 10.3%-20.8%和 7.5%-28.0%。在第 25 年后，RFC 和 NPK 处理之间 SOC、TN 和 TP 的含量和净积累以及土壤有效养分没有显著差异。NPK 和 RFC 处理的平均年产量分别为 9690 和 9872 公斤/公顷。在大多数年份（54 个季节中有 6 个表现出显著差异），RFC 和 NPK 处理的第一季、第二季和全年水稻产量没有差异。RFC 提高了部分因子生产力（PFP）、MF 的农学效率（AE）和产量稳定性（CV）（p<0.05）。养分平衡良好和减少养分损失是 RFC 处理实现更好的养分补偿和有机养分利用指标（PFP、AE 和 CV）的明显原因。用原位作物残体保留部分替代 MF 是维持中国南方土壤肥力和水稻产量与 NPK 相当的简单而有效的方法。
