The partial substitution of chemical nitrogen fertilizers with organic fertilizer and slow-release fertilizer could improve pineapple yield and nitrogen use efficiency (NUE) and decrease greenhouse gas (GHG) emissions. However, the effect of organic and slow-release fertilizer substitution strategies on the carbon footprint (CF), nitrogen footprint (NF) and net ecosystem economic benefits (NEEB) from pineapple fields in the tropics remains largely unclear. Therefore, we conducted a long-term pineapple field trial (2017–2021) for the first time with five fertilization strategies (CK: no fertilizer; F: conventional fertilization(nitrogen (N) 817 kg ha⁻¹, phosphorus pentoxide (P₂O₅) 336 kg ha⁻¹, potassium oxide (K₂O) 945 kg ha⁻¹); RF: reduction of 41.7% N, 72.0% P₂O₅ and 33.1% K₂O on an F basis; RFO: replacement of 20% N input with organic fertilizer on an RF basis; RFOS: replacement of 15% N input with slow-release fertilizer on an RFO basis) to identify the pineapple fruit yield, NUE, CF, NF and NEEB in the tropics. The results showed that in comparison to the F treatment, the RF, RFO and RFOS treatments improved pineapple yield (7.6%, 12.4% and 26.3%, respectively), NUE (66.4%, 75.5% and 87.7%, respectively, p < 0.05) and partial factor productivity of nitrogen (PFP_N) fertilizer (84.8%, 92.8% and 116.7%, respectively, p < 0.05). Additionally, of all the treatments, the RFOS treatment had the highest yield (87.8 t ha⁻¹). N leaching (50.1–69.1%) and ammonia volatilization (21.6–26.2%) were the two primary routes for reactive nitrogen (Nr) loss. The field soils (36.8–45.7%) and N fertilizer production and transportation (21.2–29.5%) dominated the GHG emissions. Compared to the F treatment, the RF, RFO and RFOS treatments showed decreases in Nr losses, NF, GHG emissions and CF of 36.6–41.1%, 43.3–51.9%, 19.0–29.1% and 24.5–41.7%, respectively. Of all the treatments, the RFOS treatment had the lowest CF (191.8 kg CO₂eq ha⁻¹ season) and NF (1.9 kg N t⁻¹ season). Additionally, the NEEB of the RF, RFO and RFOS treatments improved by 13.0–39.9% over that of the F treatment. The RFOS treatment (54,880 USD ha⁻¹) resulted in the highest NEEB of all treatments. Therefore, the substitution of conventional inorganic fertilizers with organic and slow-release fertilizers is an effective method for achieving sustainable pineapple production. However, a process for further reducing GHG emissions from farmland soils and Nr losses from organic fertilizer addition still need attention in terms of pineapple production.

Pineapple is widely cultivated in tropical regions, but intensive management and improper residue disposal can accelerate soil degradation and yield decline. To evaluate under-ridge residue burial (URRB) as a soil improvement practice, parallel field experiments were conducted from 2023 to 2024 at two sites in tropical southern China. A two-factor randomized complete block design was used, with two burial rates (half- and full-rate, i.e., 10 and 20 t ha⁻¹) and three burial depths (10, 20, and 30 cm), plus a residue removal control (CK). Compared with CK, URRB generally increased soil pH and the stocks of soil organic carbon and available nitrogen (N), phosphorus (P), and potassium (K), accompanied by higher leaf area index (LAI), total root surface area (TRSA), photosynthetic pigment contents, fruit vitamin C content, and plant N, P, and K accumulation. Increasing burial rate significantly enhanced plant P and K accumulation and fruit yield, while burial at 30 cm produced greater improvements in soil pH, soil organic carbon (SOC), and available N, P, and K stocks than burial at 10 cm and 20 cm. Compared with other treatments, full-rate residue burial at 30 cm depth under the ridge (FD30) most effectively promoted canopy growth, root development, fruit yield, and chlorophyll a content. On average across the two sites, FD30 increased LAI and TRSA by 20.9% and 34.0%, respectively, compared with CK, with significant increases of 20.1% in fruit yield and 25.3% in fruit vitamin C content. Partial least squares path modeling identified positive indirect associations of soil pH and nutrient availability with yield. Although pineapple yield did not differ significantly between FD30 and FD10, SOC, available N, P, and K stocks were significantly greater under FD30 than under FD10. Thus, FD30 is a more promising strategy for improving both soil fertility and pineapple production under the present experimental conditions. This study also provides new insights into crop residue management in tropical cultivation systems.