Yield maps reflect systematic and random sources of yield variation as well as numerous errors caused by the harvest and mapping procedures used. A general framework for processing of multi-year yield map data was developed. Steps included (1) raw data screening, (2) standardization, (3) interpolation, (4) classification of multi-year yield maps, (5) post-classification spatial filtering… More

in    0

Monitoring crop phenology is required for understanding intra- and interannual variations of agroecosystems, as well as for improving yield prediction models. The objective of this paper is to remotely evaluate the phenological development of maize (Zea mays L.) in terms of both biomass accumulation and reproductive organ appearance. Maize phenology was monitored by means of… More

in    0

Synoptic monitoring of vegetation dynamics relies on satellite observations of the distinctive spectral contrast between red and near infrared reflectance that photosynthetically active green vegetation exhibits. It has long been recognized that the Normalized Difference Vegetation Index (NDVI) suffers a rapid decrease of sensitivity at moderate-to-high densities of photosynthetic green biomass. This decrease can conceal… More

in    0

[1] There is considerable interest in assessing the magnitude of carbon sources and sinks for agricultural lands, grasslands, and forests. In this paper, we propose a novel technique to remotely assess CO2 fluxes in maize using reflectances (ρ) in two spectral channels either in the green around 550 nm or in the red edge near 700… More

in    0

Annual yield maps are spatially fragmented because of random variation caused by crop management as well as measurement errors. Two approaches for creating maps of spatially contiguous yield classes were evaluated at two irrigated sites. In the first approach, prior-classification interpolation (PCI), grid size was increased from 4, 8, 16, and 32 to 64 m… More

in    0

The Normalized Difference Vegetation Index (NDVI) is widely used for monitoring, analyzing, and mapping temporal and spatial distributions of physiological and biophysical characteristics of vegetation. It is well documented that the NDVI approaches saturation asymptotically under conditions of moderate-to-high aboveground biomass. While reflectance in the red region (ρred) exhibits a nearly flat response once the… More

in    0

Grain yield maps must accurately display general yield patterns as well as details of local yield variation. Different geostatistical procedures for creating interpolated yield maps by integrating yield data with remotely sensed vegetation indices (VI) were evaluated. Yield monitor data and a multispectral satellite image at 4-m spatial resolution were collected in an irrigated maize… More

in    0

Agriculture is a resource-intensive enterprise. The manner in which food production systems utilize resources has a large influence on environmental quality. To evaluate prospects for conserving natural resources while meeting increased demand for cereals, we interpret recent trends and future trajectories in crop yields, land and nitrogen fertilizer use, carbon sequestration, and greenhouse gas emissions… More

in    0