Irrigation water is limited and scarce in many areas of the world, including Comarca Lagunera, Mexico. Thus better estimations of irrigation water requirements are essential to conserve water. The general objective was to estimate crop water demands or crop evapotranspiration (ETc) at different scales using satellite remote sensing-based vegetation index. The study was carried out in northern Mexico (Comarca Lagunera) during four growing seasons. Six, eleven, three, and seven clear Landsat images were acquired for 2013, 2014, 2015, and 2016, respectively, for the analysis. The results showed thatETcwas low at initial and early development stages, whileETcwas high during mid-season and harvest stages. These results are not new but give us confidence in the rest of ourETcresults. DailyETcmaps helped to explain the variability of crop water use during the growing season. Based on the results we can conclude thatETcmaps developed from remotely sensed multispectral vegetation indices are a useful tool for quantifying crop water consumption at regional and field scales. UsingETcmaps at the field scale, farmers can supply appropriate amounts of irrigation water corresponding to each growth stage, leading to water conservation.

Accurate estimation of crop evapotranspiration (ET) is a key factor in agricultural water management including irrigated agriculture. The objective of this study was to compare ET estimated from the satellite-based remote sensing METRIC model to in situ atmometer readings. Atmometer readings were recorded from three sites in eastern South Dakota every morning between 8:15 and 8:30 AM for the duration of the 2016 growing season. Seven corresponding clear sky images from Landsat 7 and Landsat 8 (Path 29, Row 29) were processed and used for comparison. Three corn fields in three sites were used to compare actual evapotranspiration (ETa). The results showed a good relationship betweenETaestimated by the METRIC model (ETa-METRIC) andETaestimated with atmometer (ETa-atm) (r2= 0.87, index of agreement of 0.84, and RMSE = 0.65 mm day⁻¹). However,ETa-atm values were consistently lower thanETa-METRIC values. The differences in dailyETabetween the two methods increase with high wind speed values (>4 m s⁻¹). Results from this study are useful for improving irrigation water management at local and field scales.

The verification of remotely sensed estimates of surface variables is essential for any remote sensing study. The objective of this study was to compare leaf area index (LAI), surface temperature (Ts), and actual evapotranspiration (ETa), estimated using the remote sensing-based METRIC model and in situ measurements collected at the satellite overpass time. The study was carried out at a commercial corn field in eastern South Dakota. Six clear-sky images from Landsat 7 and Landsat 8 (Path 29, Row 29) were processed and used for the assessment. LAI and Ts were measured in situ, and ETa was estimated using an atmometer and independent crop coefficients. The results revealed good agreement between the variables measured in situ and estimated by the METRIC model. LAI showed r² = 0.76, and RMSE = 0.59 m² m⁻², the Ts comparison had an agreement of r² = 0.87 and RMSE 1.24 °C, and ETa presented r² = 0.89 and RMSE = 0.71 mm day⁻¹.

The vermicompost is used as a source of nutrients and substrate in protected horticulture because it promotes crop production more sustainable. The objective was to evaluate different proportions of vermicompost: sand (VC:S, v:v) on quality and yield of jalapeño pepper produced in greenhouse environments. Five proportions were compared VC:S, 1:1, 1:2, 1:3, 1:4, 1:5 and a control: (Steiner nutrient solution). The experiment was established in a randomized blocks design with ten replications. On average ratio, VC:S (1:1) produce highest fruit weight, fruit length, total phenolic compounds, flavonoids, and antioxidant capacity against to control treatment (0:1 VC:S). Those results indicate that VC is a fertilization alternative to increase nutraceutical fruit quality, without decrease the jalapeño pepper yield.

Irrigated agriculture requires better estimates of crop water demand. The aim of this study was to estimate the evapotranspiration (ETc) in forage corn through vegetation indices obtained in situ and estimated with remote sensing in the Comarca Lagunera, Mexico. The research was carried out in 2011 and 2012 in four 900 m2 plots irrigated with a subsurface drip irrigation system. Normalized Difference Vegetation Index (NDVI) and crop coeff icient (Kc) during crop development were determined. The initial, maximum and f inal NDVI values were 0.13, 0.79 and 0.63 for both methods and in both cycles. The maximum Kc values were obtained 54 and 48 days after sowing (DDS) with GreenSeeker, and at 61 and 59 DDS with satellite images in 2011 and 2012, respectively. The results showed a good relationship between ETc estimated in situ and ETc estimated with remote sensing (r = 0.98) for both years. Although the variation of ETc using both methods was 1.2 mm day‑1, early in the cycle and 7.4 mm day-1 to flowering start-milky grains. Water needs of forage corn were estimated with similar precision using remote sensing and in situ measurements. Therefore, both methods can be used to improve irrigation scheduling and preserve water resources in agriculture.

De acuerdo con la FAO, aproximadamente un tercio de la producción mundial de alimentos se pierde o desperdicia. Estos desperdicios reducen la disponibilidad de alimentos para la población, incrementan sus precios y generan problemas de contaminación ambiental. Un problema común en los países en desarrollo es la escasez de datos acerca de la cantidad, causas y usos de las pérdidas de alimentos. En este trabajo se realizó la cuantificación, por etapas de siembra, de las pérdidas de melón cantaloupe, sus causas y usos en los eslabones de producción, empaque y transportación en una región del norte-centro de México conocida como la Comarca Lagunera. Esta región es la mayor productora de melón cantaloupe de México con una superficie de más de 4 565 ha y una producción de 165 663 t. Se aplicó, de manera presencial, un cuestionario estructurado a una muestra estadística de 47 productores y ocho empacadores. Se encontró que las pérdidas, tanto en producción como en los empaques, varían de acuerdo con la etapa de siembra, con mayores pérdidas en las siembras tardías, seguido por las tempranas e intermedias. Las principales causas de las pérdidas son el tamaño de fruto inadecuado (pequeño o muy grande), deforme, excesiva madurez, manchado y con rajaduras. El producto que se desperdicia en la huerta es destinado a la alimentación de animales domésticos o como abono a la tierra; mientras que el que se desecha en los empaques se revende a pequeños intermediarios locales para su comercialización y para la alimentación de animales domésticos.