Farming activities in the Argentinean Pampa have focused on soybean production since the 1990s. The resulting cropping systems may not be sustainable in the long run due to development of glyphosate-tolerant weeds, homogenization of landscape mosaics, and pollutions. Here, we used the tracking on-farm innovation method to produce resources for the design of alternatives. The five steps of tracking on-farm innovation were (1) characterization of the soybean-based dominant cropping system, (2) identification of producers developing alternative systems, (3) description of these cropping systems and their agronomic logic, which is the link between the producer practices and their motives when choosing these practices, (4) multicriteria assessment of the performances of the systems, and (5) analysis of the development conditions of the most efficient systems. We identified 22 alternative cropping systems developed by farmers. These systems all include original practices: diversification of crop rotations (22 cases), occasional return to tillage (15 cases), and low pesticide use (16 cases). Some alternative systems were more sustainable than the soybean-based system, as shown by lower economic risk level, better ability to maintain soil organic carbon content, and less glyphosate-tolerant weeds. Our results show overall that tracking on-farm innovations is an efficient method to get references on alternative cropping systems developed by farmers.

International audienceIn Argentina, the recent expansion of agriculture has turned into an extreme process almost completely dominated by soybean. The magnitude and speed of soybean expansion are believed to be the main drivers behind social, organizational and economic changes, including the displacement of small-scale producers out of agriculture. Under these transformations, land leasing is a critical management practice and constitutes a link among agricultural actors. This study analyzes changes in land tenancy patterns considering the recent agriculturization process but also older drivers of change. Our results indicate that the expansion of agriculture affects small-and large-scale farms differently, as land renting practices and productive orientation show clear differences by size. In the land leasing market, local producers are the main tenants while sowing pools rent about one quarter of the leased land. The competition for leasing farmland appears to operate within farm sizes. Small-and medium-scale producers compete among them for land, while large-scale local producers compete with sowing pools for the larger plots. Sowing pools do not appear to be the main drivers of land tenancy changes as they are no more relevant than local actors in the land leasing market. However, results suggest that small-scale landowners renting out their land for several years are the ones with higher probabilities of selling their lands. This segment of producers appears to be the one most negatively affected by soybeanization

La formulation « ancrage territorial » nous interroge sur les variables qui déterminent

BackgroundSports injuries produce changes in movement characteristics, which can be measured qualitatively and quantitatively in the ground reaction force.ObjectiveTo characterize the strength curve of a counter movement jump (CMJ) in professional footballers who were suffering from sports injuries.DesignCase-control study.SettingProfessional footballers of Club Atlético Boca Juniors.Participants32 players suffering from sports-related ankle, knee and muscle injuries, who were tested during the first week that they were able to jump, and 52 as control group, who were tested during preventive medical controls.Main Outcome MeasurementsWe analysed 5 stages of the force curve during CMJ: 1. Starting movement, 2. Start of eccentric contraction, 3. Eccentric contraction, 4. Peak eccentric, 5. Peak concentric, and rate of force development (RFD). In areas 1, 2 and 3 asymmetry was examined qualitatively (curve shape ), in zones 4 and 5, quantitatively (>5%).ResultsAll of injured players showed asymmetry versus 48% in control group (p<0.05), 85% of injured players showed deficits in zone 4 (16.5% in peak force vs 11,6% in control; p<0.05). Asymmetry of RFD in players with ankle and knee injuries was 26% and 14%, respectively, while those with psoas injuries presented inverted asymmetry(less force in non injury leg). Players with ankle injuries showed asymmetry in zones 1–4 and knee injuries in zones 1–5 (73% and 85% of the cases, respectively). Players treated surgically for knee injuries (ACL and menisci) demonstrated asymmetry in zones 4 and 5 in 100% of the cases. Players with adductor and hamstring injuries displayed asymmetry in zones 4 and 2–3, respectively (100% of cases for both). All players were symmetrical at return to sports.ConclusionsThe force plate is a device that allows the characterization of function in sports injuries during the rehabilitation process, and help establish parameters for the return of the athlete to a normal athletic life.