Pablo Preciado-Rangel

Localization of local soil classes in an arid region of Mexico, using satellite imagery

A map of local soil classes (LSCs) was used to make digital maps of soil classes using computer-assisted cartography. The objectives were to establish classes of the local soils of an arid locality; to determine their physical and chemical characteristics; to relate the content of clay (Cl), organic matter (OM) and electrical conductivity (EC) to the levels of reflectance from the classes of soil; and to obtain a digital map of classes of local soils using a supervised classification of the image and verify its precision. The map of LSCs was used as basis for generating information about the physical and chemical characteristics of soils. The information was related to digital levels of a Landsat 7 Enhanced Thematic Mapper Plus (ETM+) image, and a supervised classification was performed. The precision of the digital maps was verified. The results show that a map of LSCs can be used as basis for generating digital maps.

Nutrients Use Efficiency in Legume Crops to Climatic Changes

Legumes, with the ability of 88% of the species examined to date to form nodules with rhizobia and fix nitrogen, are second only to the Gramineae in their importance to humans. Legume species are going to play a very important role in relationship to the nutrient use and efficiency in agriculture under climate changes resulting from human activity. Climate change associated with increased human caused CO2 pollution will affect weather patterns, resulting in increased global temperatures and rainfall, more extreme events, and regional changes in annual mean temperatures and precipitation. These changes will impact all inhabitants in the world, including through food production. The effects may be direct, for example via increased photosynthesis or indirect via changes in soil microclimate affecting rates of mineralization of nutrients. In this sense, climate change may have beneficial as well as detrimental consequences for agriculture and crop nutrient use efficiency. Some research indicates that warmer temperatures lengthen growing seasons and increased carbon dioxide in the air results in higher yields. Together these would increase nutrient demand from some crops and potentially may lead to either increased nutrient use efficiency or reduced efficiency for example via inability to supply adequate P resulting in reduced N fixation. While changes, will likely vary significantly by region a warming climate and decreasing soil moisture can also result in production patterns shifting northward and an increasing need for irrigation. These shifts in production system are also likely to lead to changes in nutrient use efficiency by legumes.

Hot Pepper (Capsicum annuum L.) Growth, Fruit Yield, and Quality Using Organic Sources of Nutrients

ABSTRACT Many greenhouse-vegetable growers cannot participate in the organic market due to the scarcity of organic fertilizers, which are able both to (a) satisfy the crops nutritional needs similarly to when using a nutrient solution, and (b) be regarded as biological, ecological, or in general terms “sustainable.” Four different fertilization regimes using three different hot pepper genotypes were applied under greenhouse conditions in arid land of Mexico. The three genotypes were of the “Serrano” variety and were obtained from different arid lands in northern Mexico. The entire crop management was 100% organic according to United States organic standards. We found that vermicompost—obtained from the metabolism of Eisenia fetida feed with cow manure plus maize waste—was able to supply the needed nutrients to the cultivars to obtain a growth and yield similar to the plants supplied with nutrient solution. The most productive genotype (Don Diego) showed the following fresh yield values: 1.98, 1.84, 1.24, and 1.11 kg plant−1 for treatments with conventional nutrient solution, vermicompost, solarized cow manure, and solarized poultry manure, respectively. The fertilization with poultry manure resulted in lower values in every growth and yield variable measured. However, this same treatment showed the highest values in ascorbic acid with 328.6 and 327.4 mg 100 mL−1 for genotypes Don Ramón and Don Vicente, respectively. The overall results suggest that organic sources of nutrients may be able to supply the needs of greenhouse hot peppers as alternative for organic farmers. Treatment with vermicompost showed the general best behavior in all of the plants.

Does zinc biofortification affects the antioxidant activity in common bean

Abstract The purpose of this work was to assess the consequence of zinc biofortification on zinc (Zn) content, natural processes of hydrogen peroxide-scavenging enzymes, and biomass production of green bean (Phaseolus vulgaris L.) under greenhouse conditions. Zn was applied using two forms (ZnSO4 and DTPA-Zn) at four doses of application (0, 25, 50 and 100 μM) added under a hydroponic system, and were tested over a period of 60 days. The Zn content was assessed in seeds, as well as the activity of antioxidant enzymes, and hydrogen peroxide production. The results showed that application of low-dose zinc increased concentration in the seed, regardless of the form of application. Respect to antioxidant enzymes, dose of 25 μM of Zn significantly increased activity of the enzyme superoxide dismutase. Finally, to raise the Zn concentration in bean under biofortification program was a promising strategy in cropping systems in order to increase the ingestion of iron and antioxidant capacity in the general population and provided the benefits that this element offered in human health.

Bioactive compounds and phytonutrients in edible part and nutshell of pecan (Carya illinoinensis)

Abstract Nuts contain compounds in their mineral composition. Nutrients, and fatty acids, when consumed in sufficient quantities, provide health benefits. In this research the nutritional and functional contribution of bioactive compounds and phytonutrients of the edible part and two varieties of shell of the pecan from the Wichita and Western Schley trees was evaluated. Physicochemical results and the content of mineral elements had high nutrient levels, the fatty acid content showed high levels of 69%, the presence of unsaturated acids such as oleic, linoleic, palmitic was determined, the content of vitamin E was determined by high-performance liquid chromatography with 47.38%. Finally, the range of the Western Schley pecan tree had the highest values in most of the bioactive compounds and phytonutrients

Calidad nutracéutica de melon cantaloupe producido bajo fertilización con soluciones nutritivas orgánicas

Consumption of fruits and vegetables provides natural antioxidants in the human diet that are capable of preventing diseases resulting from the action of free radicals. The aim of the current study was to evaluate the effect of organic nutrient solutions on the nutraceutical quality of hydroponic cantaloupe melon ( Cucumis melo L.) produced under greenhouse conditions. The applied organic solutions consisted of compost and vermicompost teas and vermicompost leachate, while Steiner nutrient solution was used as a control. Analytical tests were run to determine the antioxidant capacity and total phenolic content of the melon fruits. The nutraceutical quality (antioxidant capacity and phenolic content) of the fruits fertilized with the organic solutions was higher than that of melons fertilized using Steiner solution. Treatment with vermicompost leachate led to the highest antioxidant capacity and phenolic content among all of the treatments, resulting a 46.1% higher in antioxidant capacity (DPPH + method) and a 29.3% higher phenolic content compared with inorganically fertilized fruits. Vermicompost solutions (leachate and tea) are viable alternatives for use as a nutrient source in the production of hydroponic cantaloupe melon with improved nutraceutical quality under greenhouse conditions. El consumo de frutas y vegetales incluye antioxidantes naturales a la dieta humana, los cuales son capaces de prevenir enfermedades derivadas de la accion de radicales libres. El objetivo del presente estudio fue evaluar el efecto de soluciones nutritivas organicas sobre la calidad nutraceutica de melon Cantaloupe ( Cucumis melo L.) producido bajo condiciones de invernadero. Las soluciones organicas usadas fueron tes de compost y de vermicompost, lixiviado de vermicompost, y solucion nutritiva Steiner como control. Las pruebas analiticas realizadas fueron: capacidad antioxidante y contenido fenolico total del fruto de melon. La calidad nutraceutica (capacidad antioxidante y contenido fenolico) de los frutos fertilizados con las soluciones organicas fue mayor que en los melones fertilizados con la solucion Steiner. El tratamiento con lixiviado de vermicompost obtuvo los mayores valores de capacidad antioxidante y contenido fenolico de todos los tratamientos, resultando un 46,1% mayor en capacidad antioxidante (metodo DPPH + ), y 29,3% mayor en contenido fenolico que los frutos fertilizados inorganicamente. Las soluciones obtenidas a partir de vermicompost (lixiviado y te) son alternativas viables de fuentes nutricionales para la produccion de melon Cantaloupe hidroponico bajo condiciones de invernadero, el cual tendra una calidad nutraceutica mejorada.