Impact of amendments on the physical properties of soil under tropical long-term no till conditions

Tropical regions have been considered the world's primary agricultural frontier; however, some physico-chemical deficiencies, such as low soil organic matter content, poor soil structure, high erodibility, soil acidity, and aluminum toxicity, have affected their productive capacity. Lime and gypsum are commonly used to improve soil chemical fertility, but no information exists about the long-term effects of these products on the physical attributes and C protection mechanisms of highly weathered Oxisols. A field trial was conducted in a sandy clay loam (kaolinitic, thermic Typic Haplorthox) under a no-tillage system for 12 years. The trial consisted of four treatments: a control with no soil amendment application, the application of 2.1 Mg ha-1 phosphogypsum, the application of 2.0 Mg ha-1 lime, and the application of lime + phosphogypsum (2.0 + 2.1 Mg ha-1, respectively). Since the experiment was established in 2002, the rates have been applied three times (2002, 2004, and 2010). Surface liming effectively increased water-stable aggregates > 2.0 mm at a depth of up to 0.2 m; however, the association with phosphogypsum was considered a good strategy to improve the macroaggregate stability in subsoil layers (0.20 to 0.40 m). Consequently, both soil amendments applied together increased the mean weight diameter (MWD) and geometric mean diameter (GMD) in all soil layers, with increases of up to 118 and 89%, respectively, according to the soil layer. The formation and stabilization of larger aggregates contributed to a higher accumulation of total organic carbon (TOC) on these structures. In addition to TOC, the MWD and aggregate stability index were positively correlated with Ca2+ and Mg2+ levels and base saturation. Consequently, the increase observed in the aggregate size class resulted in a better organization of soil particles, increasing the macroporosity and reducing the soil bulk density and penetration resistance. Therefore, adequate soil chemical management plays a fundamental role in improving the soil's physical attributes in tropical areas under conservative management and highly affected by compaction caused by intensive farming

Prospective validation and application of the Trauma-Specific Frailty Index: Results of an American Association for the Surgery of Trauma multi-institutional observational trial.

BACKGROUND: The frailty index is a known predictor of adverse outcomes in geriatric patients. Trauma-Specific Frailty Index (TSFI) was created and validated at a single center to accurately identify frailty and reliably predict worse outcomes among geriatric trauma patients. This study aims to prospectively validate the TSFI in a multi-institutional cohort of geriatric trauma patients. METHODS: This is a prospective, observational, multi-institutional trial across 17 American College of Surgeons Levels I, II, and III trauma centers. All geriatric trauma patients (65 years and older) presenting during a 3-year period were included. Frailty status was measured within 24 hours of admission using the TSFI (15 variables), and patients were stratified into nonfrail (TSFI, ≤0.12), prefrail (TSFI, 0.13-0.25), and frail (TSFI, \u3e0.25) groups. Outcome measures included index admission mortality, discharge to rehabilitation centers or skilled nursing facilities (rehab/SNFs), and 3-month postdischarge readmissions, fall recurrences, complications, and mortality among survivors of index admission. RESULTS: A total of 1,321 geriatric trauma patients were identified and enrolled for validation of TSFI (nonfrail, 435 [33%]; prefrail, 392 [30%]; frail, 494 [37%]). The mean ± SD age was 77 ± 8 years; the median (interquartile range) Injury Severity Score was 9 (5-13). Overall, 179 patients (14%) had a major complication, 554 (42%) were discharged to rehab/SNFs, and 63 (5%) died during the index admission. Compared with nonfrail patients, frail patients had significantly higher odds of mortality (adjusted odds ratio [aOR], 1.93; p = 0.018), major complications (aOR, 3.55; p \u3c 0.001), and discharge to rehab/SNFs (aOR, 1.98; p \u3c 0.001). In addition, frailty was significantly associated with higher adjusted odds of mortality, major complications, readmissions, and fall recurrence at 3 months postdischarge ( p \u3c 0.05). CONCLUSION: External applicability of the TSFI (15 variables) was evident at a multicenter cohort of 17 American College of Surgeons trauma centers in geriatric trauma patients. The TSFI emerged as an independent predictor of worse outcomes, both in the short-term and 3-month postdischarge. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III