Novel Feature-Extraction Methods for the Estimation of Above-Ground Biomass in Rice Crops.

Traditional methods to measure spatio-temporal variations in above-ground biomass dynamics (AGBD) predominantly rely on the extraction of several vegetation-index features highly associated with AGBD variations through the phenological crop cycle. This work presents a comprehensive comparison between two different approaches for feature extraction for non-destructive biomass estimation using aerial multispectral imagery. The first method is called GFKuts, an approach that optimally labels the plot canopy based on a Gaussian mixture model, a Montecarlo-based K-means, and a guided image filtering for the extraction of canopy vegetation indices associated with biomass yield. The second method is based on a Graph-Based Data Fusion (GBF) approach that does not depend on calculating vegetation-index image reflectances. Both methods are experimentally tested and compared through rice growth stages: vegetative, reproductive, and ripening. Biomass estimation correlations are calculated and compared against an assembled ground-truth biomass measurements taken by destructive sampling. The proposed GBF-Sm-Bs approach outperformed competing methods by obtaining biomass estimation correlation of 0.995 with R2=0.991 and RMSE=45.358 g. This result increases the precision in the biomass estimation by around 62.43% compared to previous works.

Supply chain and environmental assessment of the essential oil production using Calendula (Calendula Officinalis) as raw material.

Biomass has been considered a potential source of value-added products and energy vectors. Most biomass studies have researched the best pathways or processes to upgrade this renewable raw material through stand-alone processes or biorefineries. The biomass supply chain is a crucial aspect in the economic analysis of biomass upgrading since most of the raw materials need to be transported. A supply chain analysis gives an idea about the availability, real costs, and storage conditions of the raw material to guarantee an accurate feasibility analysis and a standardized production process. Calendula (Calendula Officinalis) is an aromatic plant used to produce valuable extracts in the cosmetic and pharmaceutical industries. Nevertheless, high amounts of exhausted biomass (more than 95% w/w) are produced and wasted. Theseresidues represent an environmental issue to be solved through the implementation of valorizing options. This paper analyses the supply chain and environmental impact of essential oil production using Calendula (Calendula Officinalis) as a raw material in the Colombian context. The case study comprises a single-objective optimization of the calendula supply chain to produce essential oil and the life cycle assessment (LCA) of the process through a cradle-to-gate approach in the Colombian context. The results showed the best locations to upgrade Calendula in Colombia (i.e., Manizales and Bucaramanga), supplying 1.1 % of the total product demand. The optimal product flow to customers was 0.32 tons/year, and the required feedstock from suppliers was 162 tons/year. The agricultural stage of essential oil production represented the highest environmental impact of the supply chain. In particular, plastic sheets, organic fertilizers, and chemical fungicides were the main contributors to this impact.

Salt-tolerance induced by leaf spraying with H2O2 in sunflower is related to the ion homeostasis balance and reduction of oxidative damage.

Salinity is still one of the main factors that limit the growth and production of crops. However, currently, hydrogen peroxide (H2O2) priming has become a promising technique to alleviate the deleterious effects caused by salt. Therefore, this study aimed to test different leaf spraying strategies with H2O2 for acclimation of sunflower plants to salt stress, identifying the main physiological and biochemical changes involved in this process. The experiment was conducted in a completely randomized design, with four replications. Initially, four concentrations of H2O2 were tested (0.1; 1; 10 and 100 mM) associated with different applications: 1AP - one application (48 h before exposure to NaCl); 2AP - two applications (1AP + one application 7 days after exposure to NaCl) and 3AP - three applications (2AP + one application 14 days after exposure to NaCl), besides this two reference treatments were also added: control (absence of NaCl and absence of H2O2) and salt control (presence of 100 mM of NaCl and absence of H2O2). The experiment was conducted in hydroponic system containing Furlani's nutrient solution. Salt stress reduced the growth of sunflower plants, however, the H2O2 priming through leaf spraying was able to reduce the deleterious effects caused by salt, especially in the 1 mM H2O2 treatment with one application. H2O2 acts as a metabolic signal assisting in the maintenance of ionic and redox homeostasis, and consequently increasing the tolerance of plants to salt stress.

Evaluation of nutritional values of wild mushrooms and spent substrate of Lentinus crinitus (L.) Fr.

In Colombia, despite the great diversity of mushrooms, most are yet unknown from the taxonomic point of view, and even less known from their nutritional composition or their possible application to obtain value-added products from agro-waste. The mycelial growth of Lentinus crinitus (L.) Fr strain was investigated on agro-waste in culture media agar and correlation analyses were performed. The proximate and mineral element composition was determinate in wild mushrooms and spent substrate of L. crinitus, obtained in the solid-state fermentation. The evaluation of the mycelial growth of the L. crinitus strain confirmed that it can grow on agro-waste. The treatment T6 (Orange peel and brand) was determined to be the best for the mycelial growth of L. crinitus (0.0790 cm/h), T7 (Bran, Orange peel and rice husk) and T5 (Rice hush and orange peel) followed, with mycelial growth rates of 0.0753 cm/h and .0720 cm/h, respectively. The growth rate was positively correlated with C/N ratios but negatively correlated with Zn, N and protein. The combination of the agro-waste (T6, T7 and T5) were used to obtain the spent substrate and assess its nutritional potential. The results showed that wild mushrooms of L. crinitus had protein contents of 14.42%, and fiber of 57.18%. The spent substrate of L. crinitus increased their protein content (10.5-11.22%), fiber (44.1-56%) and nitrogen (1.64-1.28%). These advances are promising for the use of L. crinitus as degrader of agro-waste to obtain different products of food and agro-industrial interest.