Increasing complexity of agroforestry systems benefits nutrient cycling and mineral-associated organic carbon storage, in south-eastern Brazil

Agroforestry systems are often promoted as solutions to address land degradation and climate change. However, agroforestry is an umbrella term for a large variety of systems and it is not clear how their degree of complexity influences their provision of soil-based ecosystem services, such as soil organic carbon (SOC) storage and nutrient cycling. Furthermore, a knowledge gap remains whether agroforestry systems perform equally well on all soil types. The objectives of this study were 1) to assess the links between agroforestry complexity, nutrient cycling and SOC fractions, and 2) to assess how soil texture influences these relationships in Brazilian agroforestry systems. We sampled 59 agroforestry plots across 30 sites in Sao Paulo state, Brazil, and 8 monocrop sites (6 pastures and 2 crop monocultures). The 38 sites represented a soil textural gradient, ranging from very sandy to very clayey (clay content range 25 – 620 g kg−1). An Agroforestry Complexity Index (ACI) was defined based on tree species richness, stem density and pruning management. Nutrient (N, P, K, Ca, Mg) and C contents were determined in litter and soil (0–30 cm depth) samples, and mineral-associated organic C (MAOC) and particulate organic C (POC) in soil samples were assessed as well. ACI was positively associated with C, N, P, Ca and Mg stocks in litter, and these litter nutrients were in turn positively associated with the corresponding soil nutrient stocks. Associations between soil nutrients and MAOC were stronger on sandy soils than on clayey soils, particularly for P, Ca and Cation Exchange Capacity (CEC). For POC, robust relationships with nutrients were only found on sandy soils. Structural Equation Models indicated causal relationships between agroforestry complexity, P and Ca cycling, and MAOC and POC stocks in topsoils. Our results indicate that nutrients effectively cycle from in situ mulch into plant-available soil pools and highlight the synergies between nutrient cycling and stable C stocks that can be achieved in complex agroforestry systems. These synergies seem to be particularly strong on sandy soils (<15 % clay)

Polypharmacy in older people: lessons from 10\ua0years of experience with the REPOSI\ua0register

As a consequence of population aging, we have witnessed in internal medicine hospital wards a progressive shift from a population of in-patients relatively young and mainly affected by a single ailment to one of ever older and more and more complex patients with multiple chronic diseases, followed as out-patients by many different specialists with poor integration and\ua0inevitably treated with multiple medications. Polypharmacy (defined as the chronic intake of five or more drugs) is associated with increased risks of drug\u2013drug interactions and related adverse effects, prescription and intake errors, poor compliance, re-hospitalization and mortality. With this background, the Italian Society of Internal Medicine chose to start in 2008 a prospective register called REPOSI (REgistro POliterapie SIMI, Societ\ue0 Italiana di Medicina Interna) in internal medicine and geriatric hospital wards. The country wide register is an ongoing observatory on multimorbidity and polypharmacy in the oldest old, with the goal to improve prescription appropriateness and, thus to avoid potentially inappropriate medications. The main findings of the register, that has accrued so far, 7005 older patients throughout a 10\ua0year period, are summarized herewith, with special emphasis on the main patterns of poor prescription appropriateness and related risks of adverse events