A Comparative Analysis of Carbon Footprint in the Andalusian Autochthonous Dairy Goat Production Systems

The small ruminant livestock sector faces the challenge of reducing greenhouse gas (GHG) emissions. Carbon footprint (CF) studies on dairy goats, the most widely used indicator to quantify the impact of livestock farming on global warming, are still few. The aim of this study was to calculate the CF of the different production systems of autochthonous dairy goat breeds presently occurring in Andalusia (S Spain) and identify systems and practices that can minimize their environmental impact in these terms. Twenty-one farms were monitored during a year, obtaining valuable information that allowed the CF calculation on a "cradle-to-gate" approach, taking into account both GHG emissions at the farm level and carbon sink by vegetation associated with land-based systems. Results showed similar CF values for the analyzed systems (1.42, 1.04, 1.15, and 1.17 kg CO2-eq kg-1 fat-protein corrected milk for indoor systems without associated crops, indoor systems with associated crops, grazing systems with high feed supply, and pastoral systems, respectively). To minimize their environmental impact, specific actions must be developed for each system, particularly regarding genetic improvement, reproductive and feeding management, including pasture management, and the integration of livestock activity into the bio-circular economy with the help of professional advice.

Soil physicochemical properties associated with the yield and phytochemical composition of the edible halophyte Crithmum maritimum

There is growing interest in the consumption of halophytes due to their excellent nutritional profile and antioxidant properties, and their cultivation offers viable alternatives in the face of irreversible global salinization of soils. Nevertheless, abiotic factors strongly influence their phytochemical composition, and little is known about how growing conditions can produce plants with the best nutritional and functional properties. Crithmum maritimum is an edible halophyte with antioxidant properties and considerable potential for sustainable agriculture in marginal environments. However, it is found naturally in contrasting habitats with variable soil physicochemical properties and the extent to which edaphic factors can influence plant performance, accumulation of phytochemicals and their quality remains unknown. We investigated the influence of soil physicochemical properties (texture, pH, electrical conductivity, organic matter content and mineral element concentrations) on growth and reproductive performance, nutritional traits, and the accumulation of specific metabolites in C. maritimum. Soil, leaf and seed samples were taken from eight C. maritimum populations located on the southern coasts of Spain and Portugal. We found greater vegetative growth and seed production in coarser, sandier soils with lower microelement concentrations. The nutritional traits of leaves varied, with soil organic matter and macronutrient content associated with reduced leaf Na, protein and phenolic (mainly flavonoid) concentrations, whereas soils with lower pH and Fe concentrations, and higher clay content yielded plants with lower leaf Zn concentration and greater accumulation of hydroxycinnamic acids. The nutritional value of the seed oil composition appeared to be enhanced in soils with coarser texture and lower microelement concentrations. The accumulation of specific phenolic compounds in the seed was influenced by a wide range of soil properties including texture, pH and some microelements. These findings will inform the commercial cultivation of C. maritimum, particularly in the economic exploitation of poorly utilized, saline soils.

Influence of soil salinity on the protein and fatty acid composition of the edible halophyte Halimione portulacoides

As the worldwide population continues to rise, so does global demand for agricultural production. This scenario of uncertain food supply is exacerbated by the high salinization of soils worldwide, a serious constraint to crop productivity. In this context, there is an increasing need for alternative sustainable crops. Halophytes are thought to be a promising alternative food source due to their natural ability to grow in saline soils and their multiple potential uses in the food industry. In this study, the protein and fatty acid content of the halophyte Halimione (Atriplex) portulacoides (L.) was studied in different saline conditions. Although more studies are needed to explore the nutritional properties of H. portulacoides, the data presented here suggest that this halophyte should be considered as a promising food crop for saline agriculture.

Effects of copper sulfate on growth and physiological responses of Limoniastrum monopetalum

A glasshouse study of the coastal shrub Limoniastrum monopetalum was carried out to evaluate its tolerance and capacity to accumulate copper. We investigate the effects of Cu from 0 to 60 mmol l(-1) on the growth, photosynthetic apparatus, and nutrient uptake of L. monopetalum, by measuring gas exchange, chlorophyll fluorescence parameters, photosynthetic pigments, and total copper, nitrogen, phosphorus, sulfur, calcium, and magnesium content in the plant tissues. Although L. monopetalum did not survive at 60 mmol l(-1) Cu, the species demonstrated a high tolerance to Cu-induced stress, since all plants survived external Cu concentrations of up to 35 mmol l(-1) and displayed similar growth in the Cu-enriched medium as in the control treatment of up to the external level of 15 mmol Cu l(-1) (1,000 mg Cu l(-1)). The reduced growth registered in plants exposed to 35 mmol Cu l(-1) can be attributed to reduced photosynthetic carbon assimilation associated with the adverse effect of the metal on the photochemical apparatus and a reduction in the absorption of essential nutrients. Copper tolerance was associated with the capacity of the plant to accumulate the metal in its roots and effectively prevent its translocation to photosynthetic tissues. L. monopetalum has the characteristics of a Cu-excluder plant and could be used in the revegetation of Cu-contaminated soils.

Tolerance and accumulation of copper in the salt-marsh shrub Halimione portulacoides

The present study evaluated the tolerance and accumulation potential in the salt-marsh shrub Halimione portulacoides under moderate and high external Cu levels. A greenhouse experiment was conducted in order to investigate the effects of a range of external Cu concentrations (0 to 60 mmol l(-1)) on growth and photosynthetic performance by measuring gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments. We also determined total copper, nitrogen, phosphorus and sulfur concentrations in the plant tissues. H. portulacoides survived with external Cu concentrations of up to 35 mmol Cu l(-1), although the excess of metal resulted in a biomass reduction of 48%. The effects of Cu on growth were linked to a drastic reduction in net photosynthesis. However, H. portulacoides tolerated Cu levels of up to 15 mmol Cu l(-1) without suffering adverse physiological effects. Our results indicate that this species could play an important role in the restoration of Cu-contaminated soils.

Zinc tolerance and accumulation in the salt-marsh shrub Halimione portulacoides

The halophytic shrub Halimione portulacoides is known to be capable of growth in soils containing extremely high concentrations of Zn. This study evaluated in detail the tolerance and accumulation potential of H. portulacoides under moderate and high external Zn levels. A greenhouse experiment was conducted in order to investigate the effects of a range of Zn concentrations (0-130 mmol L(-1)) on growth and photosynthetic performance by measuring relative growth rate, total leaf area, specific leaf area, gas exchange, chlorophyll fluorescence parameters and photosynthetic pigment concentrations. We also determined the total zinc, nitrogen, phosphorus, calcium, magnesium, sodium, potassium, iron and copper concentrations in the plant tissues. H. portulacoides demonstrated hypertolerance to Zn stress, since it survived with leaf concentrations of up to 2300 mg Zn kg(-1)dry mass, when treated with 130 mmol Zn L(-1). Zinc concentrations greater than 70 mmol L(-1) in the nutrient solution negatively affected plant growth, in all probability due to the recorded decline in net photosynthesis rate. Our results indicate that the Zn-induced decline in the photosynthetic function of H. portulacoides may be attributed to the adverse effect of the high concentration of the metal on photosynthetic electron transport. Growth parameters were virtually unaffected by leaf tissue concentrations as high as 1500 mg Zn kg(-1)dry mass, demonstrating the strong capability of H. portulacoides to protect itself against toxic Zn concentrations. The results of our study indicate that this salt-marsh shrub may represent a valuable tool in the restoration of Zn-polluted areas.