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The impact that future climatic conditions will have on agricultural productivity depends on the sensitivity to each environmental factor and relative changes in temperature, precipitation and UV-B radiation. The strawberry (Fragaria x ananassa) is a microclimatic crop cultivated almost worldwide and Spain is the world's second-largest strawberry producer after the USA. Strawberry production in Huelva has been affected by climate change in recent decades. Temperature and solar radiation are primary environmental factors controlling short-day strawberry plant growth and development. Temperature is a limiting factor in crop productivity. We assessed the effect of variations in temperature and solar radiation on strawberry production and crop cycle duration. The study was carried out in commercial strawberry fruit production fields in the province of Huelva (Spain's southwestern coast). Fresh plants of cv. Camarosa were cultivated from October to June. The resulting crop was recorded weekly in the production field: early and total strawberry productions (g/ plant), were recorded from January to March and from January to May, respectively. Data revealed that between early production and temperature (R 2 = 0.86) and between early production and solar radiation (R 2 = 0.73) there was a linear relationship. However, total production and temperature (R 2 = 0.69) and total production and solar radiation (R 2 = 0.69) were related by a quadratic relationship. Our estimates suggest that strawberry production could be affected by climate change. Due to the relationship between yield and temperature, and between yield and solar radiation, climate change scenarios were found to result in reductions in crop cycle duration.

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Comparative performance tests of perennial grasses for biomass yield, quality, and soil nutrient removal are needed to guide decisions toward meeting European Union targets for renewable energy production. We compared hybrid miscanthus (Miscanthus × giganteus Greef and Deuter ex Hodkinson and Renvoize) and switchgrass (Panicum virgatum L.) cultivars Cave-in-Rock, (upland type), Alamo, and Kanlow (lowland types) for biomass yield and changes in soil macronutrient levels and removal rates in a humid Spanish environment. Soil and plant nutrient and C levels were measured aft er each annual biomass harvest for 4 yr. Plant nutrient concentrations were multiplied by biomass yield to express nutrient removal. Yield ranking (4-yr mean) was miscanthus (17.6 Mg ha -1 ) > Kanlow (13.3 Mg ha -1 ) = Alamo (13.0 Mg ha -1 ) > Cave-in-Rock (7.7 Mg ha -1 ). Miscanthus biomass yield peaked in the third year at 27.0 Mg ha -1 . Th e high yield of miscanthus together with its relatively low macronutrient concentrations and intermediate removal rates, indicate its advantages over switchgrass as a biomass crop choice. Alamo and Kanlow usually removed more macronutrients than Cavein-Rock, suggesting a greater long-term fertilizer requirement for the lowland types. Soil C stocks increased by a mean of 2850 kg ha -1 over 4 yr at 0-to 20-cm depth. Phosphorus was the macronutrient most likely to become defi cient aft er repeated harvests. Miscanthus and lowland switchgrass cultivars performed well in the Atlantic maritime region of Spain, therefore the choice of crop would rely on economics of establishment and long-term stand maintenance.