ABSTRACT Wind erosion is the main problem that arid lands in northern Mexico are facing. Quantification of this phenomenon is crucial for planning purposes and to scale its impact. The challenge is to assess the problem under limited availability of climatic information. This study aimed to identify potential areas of dust emissions in an arid zone of Northern Mexico. Wind direction and intensity were characterized through a robust index that involves rainfall and evaporation as well as the climatic factor of the general wind erosion equation. A method for assessing the likelihood of dust emission associated with wind erosion was applied. Data from twelve weather stations within the region of the study was analyzed. The variables considered were wind velocity and direction, temperature, and precipitation. A wind rose of wind direction and intensity was obtained. Results showed that the Thornthwaite’s method for computing the Soil Moisture Index (SMI) is a good approach when computing the climatic factor C of the general function of the potential average annual soil loss. Given the lack of local evaporation data, the precipitation-evaporation ratio P E for each weather station was computed as an intermediate step towards the computation of C. Three of the analyzed climatic stations had intermediate C values (36-71 %) in the scale of wind erosion climatic factor. The wind velocities registered in these climatic stations ranged from 15 to 30 km h -1 . The magnitude-frequency analysis of the P E parameter for the stations showed the differences in rainfall and evaporation regimes. Dust pollution prone areas were identified, showing areas where conservation strategies should be directed.

The growing interest in information about soil traits quickly, accurately and cheaply has resulted in an increase in the use of near-infrared spectroscopy (NIRS) for this application. The main objective of this study was to evaluate the ability of NIRS to predict soil traits on 12 agronomically important in northern Mexico. Samples were collected from agricultural plots of two regions designated as site 1, Baja California (BC, n= 128) and site 2, Chihuahua (n= 143). Infrared spectra were obtained from two sizes of soil particles: thick (<2 mm) and thin (<0.5 mm), creating two libraries. An accurate prediction (RPD> 1.4) for pH, EC, CEC, K content of sand, clay and silt in the group of cross-validation samples for at least one site was obtained. The results were consistent with those obtained in the group of independent validation, except for pH and silt which had a RPD <1.4. The traits without predictability by NIRS were N-NO3, N-NH4, P, total carbonates (CO3) and organic matter. An important advantage of NIRS for soil analysis is that from a spectrum can be determined many traits. One limitation of this study was the number of samples used for independent validation, which consisted of 10% of total samples.

El creciente interés por obtener información sobre las propiedades del suelo de forma rápida, precisa y a bajo costo ha resultado en un aumento en el uso de la espectroscopia de infrarrojo cercano (NIRS, por sus siglas en inglés) para esta aplicación. El principal objetivo de este estudio fue evaluar la capacidad del NIRS para la predicción de 12 propiedades de suelo de importancia agronómica en el norte de México. Las muestras fueron recolectadas en parcelas agrícolas de dos regiones denominadas como sitio 1, Baja California (BC, n = 128) y sitio 2, Chihuahua (n =143). Los espectros de infrarrojo fueron obtenidos a partir de dos tamaños de partículas de suelo: gruesos (< 2 mm) y finos (< 0.5 mm), creando dos librerías. Se obtuvo una predicción acertada (RPD >1.4) para pH, CE, CEC, K, contenido de arena, arcilla y limo en el gr upo de muestras de la validación cruzada para al menos un sitio. Los resultados fueron consistentes con los obtenidos en el grupo de validación independiente, excepto para pH y limo los cuales tuvieron un RPD < 1.4. Las propiedades sin capacidad de predicción por NIRS fueron N-NO3, N-NH4, P, carbonatos totales (CO3) y materia orgánica. Una ventaja importante del NIRS para análisis de suelos es que a partir de un espectro pueden determinarse muchas propiedades. Una de las limitaciones de este estudio fue la cantidad de muestras empleadas para la validación independiente, la cual consistió de 10% del total de muestras.