PRISMA and Sentinel-2 spectral response to the nutrient composition of grains

Micronutrient malnutrition is a global challenge affecting &gt;2 billion people, in particular those with a crop-based diet and limited access to nutrient-rich food sources. Conventional methods for measuring the crop nutrients such as wet chemical analysis of grains are time-consuming and cost-prohibitive and, consequently, unsuitable for the consistent quantification of nutrients across space and time. In this study, we propose a new method that is using PRecursore IperSpettrale della Missione Applicativa (PRISMA) and Sentinel-2 images to estimate the nutrient concentrations of crop grains before harvest. We collected grain samples for corn, rice, soybean, and wheat from a farm situated in Italy and measured their nutrient concentrations in the lab. These measurements together with the PRISMA and Sentinel-2 images acquired at the main phases of crop development (vegetative, reproductive, maturity) were used as input for two-band vegetation indices (TBVIs) and Partial Least Squares Regression (PLSR) to predict Calcium (Ca), Iron (Fe), Potassium (K), Magnesium (Mg), Nitrogen (N), Phosphorus (P), Sulphur (S) and Zinc (Zn). Models' performances were assessed using the coefficient of determination (R2) and Root Mean Square Error (RMSE). For PRISMA images, the best prediction results were obtained for P in soybean (R2 = 0.69), K in soybean (R2 = 0.66), Mg in soybean (R2 = 0.58), Fe in soybean (R2 = 0.57), K in wheat (R2 = 0.57), K in corn (R2 = 0.55), P in wheat (R2 = 0.51), S in rice (R2 = 0.58) using TBVIs. In contrast to PRISMA, PLSR outperformed TBVIs when Sentinel-2 images were used as input. For Sentinel-2, the best predictions were obtained for P in soybean (R2 = 0.73), K in wheat (R2 = 0.67), Mg in soybean (R2 = 0.62), Zn in wheat (R2 = 0.56), Fe in soybean (R2 = 0.52), P in wheat (R2 = 0.52). Our study showed that estimating the nutrient composition of crops using remote sensing images has the potential to change how we approach a cost-effective, timely, and spatially explicit representation of the crops' nutritional quality.</p

Evaluación de la respuesta espectral y biofísica de un cultivo de caña de azúcar a la fertilización nitrogenada

El Nitrógeno es el macroelemento más importante para garantizar el óptimo crecimiento del cultivo de caña de azúcar. Sin embargo, debido a su poca disponibilidad en formas fácilmente asimilables por las plantas, se ha recurrido a aplicaciones de fertilizante excesivas con el objetivo de garantizar una alta cosecha. En la actualidad, los grandes avances de la agricultura de precisión, permiten realizar una detección temprana y no destructiva de diferentes fenómenos que pueden ocasionar algún nivel de estrés en los cultivos. En el presente trabajo de investigación se realizó un diseño experimental de bloques completos al azar con cuatro tratamientos y cinco repeticiones con el objetivo de evaluar la respuesta espectral y biofísica de un cultivo de caña de azúcar (Variedad CC 01-1940) bajo diferentes dosis de fertilización nitrogenada (0% - 50% -100% - 150%) mediante el uso de microespectrómetros STS-VIS. Se encontró que el tratamiento de dosis nula de fertilización nitrogenada mostró una mayor reflectancia en la banda de máxima absorción de clorofila; y que los tratamientos con mayores dosis de fertilización nitrogenada mostraron tener una baja reflectancia en esta zona. Las zonas en las que se presentaron los mejores comportamientos de los índices de vegetación, correspondieron a las unidades experimentales ubicadas en suelos con mayores contenidos de materia orgánica. Se establecieron los modelos de regresión para las variables biofísicas (altura, número de hojas verdes, número de tallos e índice de área foliar) en relación con los índices de vegetación evaluados. Para la variable de altura (HTVD) e índice de área foliar (LAI) se encontraron coeficientes de determinación de 0.87 y 0.80 para los índices de NDRE y CIG respectivamente. Se encontraron diferencias significativas entre tratamientos y entre bloques para las variables biofísicas, siendo LAI la mas sensible a la fertilización nitrogenada por mostrar diferencias entre los tratamientos de 0% con los tratamientos de 100% y 150%.//Abstract: Nitrogen is the most important macro-element to guarantee the optimal growth of sugarcane crop. However, due to its limited availability in forms easily assimilated by plants, excessive fertilizer applications have been used in order to ensure a high yield. Nowadays, the great developments of precision agriculture allow an early and non-destructive detection of different events that can cause stress in crops. In the present research, an experimental design of completely randomized blocks with four treatments and five replicates was carried out in order to evaluate the spectral and biophysical response of a sugarcane crop (Variety CC 01-1940) at different doses of nitrogen fertilization (0% - 50% -100% - 150%) using STS-VIS microspectrometers. It was found that the treatment of null dose of nitrogen fertilization showed a greater reflectance in the band of maximum absorption of chlorophyll; and that the treatments with greater dose of nitrogen fertilization showed to have a low reflectance in this zone. The zones in which the best vegetation index behavior was presented corresponded to the experimental units located in soils with higher organic matter content. Regression models were established for the biophysical variables (height, number of green leaves, number of stems and leaf area index) in relation to the vegetation indices evaluated. For Height (HTVD) and leaf area index (LAI), determination coefficients of 0.87 and 0.80 were found for NDRE and CIG indices respectively. Significant differences were found between treatments and between blocks for the biophysical variables, being LAI the most sensitive to nitrogen fertilization because it showed differences between treatments of 0% with treatments of 100% and 150%.Maestrí

Evaluación del potencial de la reflectancia foliar y edáfica para la predicción de contenidos de nutrientes en plantaciones de plátano (Musa ABB Simmons) en el Urabá y Suroeste antioqueño

Este trabajo se realizó con la finalidad de identificar y evaluar algunos indicadores agronómicos en cultivos de plátano, para seleccionar una muestra que comprendiera el rango de variabilidad de los indicadores evaluados. El trabajo se desarrolló en siete municipios de la subregión del Suroeste (Andes, Betania, Hispania, Jardín, Jericó, Pueblo Rico y Támesis) y del Urabá antioqueño (Arboletes, Mutatá, Necoclí, San Juan de Urabá, San Pedro de Urabá y Turbo), donde se aplicaron 62 y 135 encuestas, respectivamente, para de estos. La encuesta, contó en total con 93 preguntas, entre las cuales, se trataron los siguientes temas: Información general del encuestado, fuentes de ingreso y manejo del cultivo de plátano. Se encontró que la producción de plátano Dominico Hartón en el Suroeste varía entre 5 y 3 ton año-1; la mayoría de los predios que presentaron racimos con pesos de entre 15 a 20 kg (47,3%) y entre 20 a 25 kg (32,7%), realizan todas las labores agronómicas recomendadas para el cultivo. Por otra parte se pudo observar que el 84 % de los lotes establecidos en plátano se clasifican como pequeños productores, con áreas sembradas menores a 5 ha. La producción de Hartón en el Urabá estuvo entre 7 y 23 ton año-1; a diferencia del Suroeste, se observó otra categoría de peso de racimo ( 10 kg) y no hubo racimos con más de 25 kg de peso. En ambas subregiones, la mayor proporción del área establecida en plátano corresponde a predios de economía campesina, pequeños productores.Abstract: The aim of the research was identify and evaluate some agronomic indicators of plantains agro-systems, in seven municipalities in the Southwest subregion and the Urabá of Antioquia, there were applied 62 and 135 surveys, respectively. The survey, was composed by a total of 93 questions covering the following topics: general information about the respondent, sources of income and plantain crop management. It was found that the production of plantains Dominico Harton in the Southwest varies between 5 and 3 tons year-1; most of the farms that presented bunches with weights of 15 to 20 kg (47.3%) and 20 to 25 kg (32.7%) carry out all the recommended agronomic work for cultivation. On the other hand it could be observed that the 84 % of the lands established in plantains are classified as small producers, with areas sown under 5 hectares. The production of Harton in Urabá was between 7 and 23 tons per year-1, unlike the Southwest, another category of bunch weight ( 10 kg) was observed and there were no bunches with more than 25 kg of weight. In both subregions, the largest proportion of the area established in plantain corresponds to the premises of peasant economy, small producers.Maestrí

Integrated nematode management

This book outlines the economic importance of specific plant parasitic nematode problems on the major food and industrial crops and presents the state-of-the-art management strategies that have been developed to reduce specific nematode impacts and outlines their limitations. Case studies to illustrate nematode impact in the field are presented and future changes in nematode disease pressure that might develop as a result of climate change and new cropping systems are discussed.illustrato

Berry Crop Production and Protection

Berry crops include, but are not limited to, the genera: Fragaria (strawberry, Rosaceae), Ribes (currant and gooseberry, Grossulariaceae), Rubus (brambles: raspberry and blackberry; Rosaceae), Vaccinium (blueberry, cranberry and lingonberry; Ericaceae) and Vitis (grapes, Vitaceae). The significant role of these fruits in maintaining human health has increased their popularity and production, dramatically, across the world. This Special Issue of Agronomy covers berry crops in the areas of breeding, genetics, germplasm, production systems, propagation, plant and soil nutrition, pest and disease management, postharvest, health benefits, marketing and economics and other related areas. The aim will be to bring together a collection of valuable articles that will serve as a foundation of innovative ideas for production and protection of health-promoting berry crops in changed environment

Gas exchange and hydraulic strategies of pasture species under climate change

Climate change-induced increases in global air temperature and concurrent modulations in the hydrological cycle have led to higher levels of drought stress globally. Grassland ecosystems such as pastures are particularly sensitive to climate change as they lack the deep roots and carbohydrate reserves that partially dampen the negative impact of abiotic stress in woody plant systems. Pastures have significant economic and ecological value, and it is important to assess the current and future impact of climate change on these systems. While many studies have investigated the response of pasture species to warming and drought separately, few studies have focused on their interactions. Furthermore, the mechanistic basis for the response of pasture species to abiotic stress, especially drought and heat stress, is not well understood. While the mechanisms underlying drought-induced impacts on hydraulic processes are well studied in woody species, there are currently few assessments in pasture grasses. In this thesis, I examined leaf gas exchange and hydraulic traits across a range of widely cultivated pasture species from different plant functional groups and investigated the response of these traits to warming and drought stress. My research sought to understand how these traits determine plant function under normal and abiotic stress conditions and how that will determine the response of pasture systems in a warmer, drier future. The primary objective was to identify more resilient pasture species and investigate the mechanistic basis for their resilience, aiding the development of species selection and management strategies that may mitigate the effects of climatic change. Findings show that increases in global air temperature may not have a positive impact on the productivity of pasture species in eastern Australia, even during the cool season and warming will have a more negative impact on C3 pasture species than C4 species during warmer periods. We found that the ability to resist xylem embolism and hydraulic dysfunction, rather than recovery, underpins pasture species resilience to drought, with early stomatal closure being crucial to species’ survival under water limiting conditions. Collectively, climate change induced increases in air temperature and drought are likely to have negative impacts on growth and productivity of temperate C3 pasture species and physiological adjustment may not be sufficient to alleviate the impacts of rapid global change. Therefore, an overall decline in temperate C3 species performance and an increase in C4 dominance are expected in pastures in a warmer, drier future