Cover crop introduction in a Mediterranean maize cropping system. Effects on soil variables and yield

Cover crops (CCs) are able to affect subsequent crop behaviour by acting on many soil variables and affecting the dynamics of different ecological processes. This study aimed to investigate the effects of introducing CC in continuous-maize cropping systems within Mediterranean areas. The experimental site was located in Central Italy, on a sandy loam and the research activity was carried out over two years (2019–2020). The two cropping systems in comparison differed from each other in terms of the CC cultivation: TR (treated, with CC) and CO (control, without CC). In both years, we observed a significant reduction (p < 0.05) of soil nitrate and water content for the TR system. In the shallowest layer (0–30 cm), nitrate content was reduced by up 80% and 65% (July 2019 and 2020), whereas soil moisture showed decreases ranging from 13% (July 2019) to 34% (May 2019). In 2019, the TR-maize (Zea mays L.) yield was statistically lower than CO (443 g dm m2), whereas in 2020 the yields of the two systems resulted statistically equivalent. This different behaviour can be explained with the serious delay in the CC sowing occurred in 2019 (12 December). Conversely, an increase in the apparent remaining N in the soil (+140 and +133 kg N ha1 for 2019 and 2020, respectively) and in the C (carbon) inputs (+4.78 and +7.39 t dm ha1 of biomass) were pointed out for the TR system. The large use of inputs in Mediterranean maize cropping systems limited some of the benefits from CCs, but their suitability has to be evaluated by considering all the involved effects, some of which need a long time to become appreciable

Recent Trends and Perspectives on Defect-Oriented Testing

Electronics employed in modern safety-critical systems require severe qualification during the manufacturing process and in the field, to prevent fault effects from manifesting themselves as critical failures during mission operations. Traditional fault models are not sufficient anymore to guarantee the required quality levels for chips utilized in mission-critical applications. The research community and industry have been investigating new test approaches such as device-aware test, cell-aware test, path-delay test, and even test methodologies based on the analysis of manufacturing data to move the scope from OPPM to OPPB. This special session presents four contributions, from academic researchers and industry professionals, to enable better chip quality. We present results on various activities towards this objective, including device-aware test, software-based self-test, and memory test

Session 17 Ecophysiology

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N source affects freeze tolerance in bermudagrass and zoysiagrass

During cold acclimation, warm-season grasses exhibit growth stall and eventually the onset of rest. Late-season N fertilization is an alternative way for reduction of the dormancy period. The objectives of the present study were (1) to assess the effects of different N sources, and timing on freezing tolerance using controlled environment acclimation and freezing procedures and (2) to determine the relationship of nonstructural carbohydrates and photosynthetic pigments with the freeze tolerance of bermudagrass and zoysiagrass. NH+ 4 source treatment exhibited a relative peak at 14 days (2 weeks) before the NO- 3 treatment. In bermudagrass, NH+ 4 treatment depressed starch accumulation at 14 and 28 days compared to the control. As expected, in both species a higher concentration of soluble carbohydrates were observed in sprigs tissues. A sharp decline was evident on the NH+ 4 treatment in leaves, stems, and roots tissues at 14 days, in correspondence with a lower freeze tolerance, whereas in the treatment an accumulation in total soluble sugars was observed in rhizomes at 28 days. Over the time, chlorophylls showed a slight increase in the NH+ 4 treatment, while an opposite trend was detected in the NO- 3 treatment. Overall, N source provided consistent differences in freeze tolerance in both species. © 2013 Copyright Taylor and Francis Group, LLC