Low-altitude aerial photography for optimum N fertilization of winter wheat on the North China Plain

Abstract

Previous research has shown that site-specific nitrogen (N) fertilizer recommendations based on an assessment of a soil's N supply (mineral N testing) and the crop's N status (sap nitrate analysis) can help to decrease excessive N inputs for winter wheat on the North China Plain. However, the costs to derive such recommendations based on multiple sampling of a single field hamper the use of this approach at the on-farm level. In this study low-altitude aerial true-color photographs were used to examine the relationship between image-derived reflectance values and soil-plant data in an on-station experiment. Treatments comprised a conventional N treatment (typical farmers' practice), an optimum N treatment (N application based on soil-plant testing) and six treatments without N (one to six cropping seasons without any N fertilizer input). Normalized intensities of the red, green and blue color bands on the photographs were highly correlated with total N concentrations, SPAD readings and stem sap nitrate of winter wheat. The results indicate the potential of aerial photography to determine in combination with on site soilplant testing the optimum N fertilizer rate for larger fields and to thereby decrease the costs for N need assessments.

Use of a Networked Digital Camera to Estimate Net CO2Uptake of a Desiccation‐Tolerant Moss

“…Lukina et al (1999) used digital images to estimate the vegetation coverage and biomass of wheat, and Purcel (2000) compared captured images with under-canopy measurements of light for estimating total ground cover of soybean. Using digital cameras for the measurement of yield and nutrient status of wheat (Hafsi et al 2000;Jia et al 2004aJia et al , 2004b and corn (Daughtry et al 2000;Graeff et al 2001), for the measurement of the quality of turf grasses (Karcher and Richardson 2003), and for counting the number of flowers of cultivated Lesquerella fendleri (Adamsen et al 2000) underscores the utility and potential applications for such devices.…”

Geographical model for precise agriculture monitoring with real-time remote sensing

“…Aerial photography is already used to map wheat nitrogen status (Jia et al, 2004) or water stress in cotton (Falkenberg et al, 2007). The model proposed here utilizes these approaches to deliver the crop requirement appropriate for each crop.…”

Nitrogen Status Estimation of Winter Wheat by Using an IKONOS Satellite Image in the North China Plain

“…However, aerial photography is always restricted by the weather conditions and flying control on the ground. Another shortcoming is that aerial photography can only cover small areas with plane [12] or hellium balloon [11,15]. When it comes to regional scale, such as a county level or provincial level, the acquisition of crop canopy images will be too time-consuming and expensive.…”

“…Aerial photography, which uses color or infrared film, has been used in detection N deficiency, evaluation of plant growth status and prediction of N fertilizer requirements of wheat [10][11] and maize [12][13][14]. In these contributions, aerial photography provided high spatial resolution images of crop canopy and showed the potential of quantifying crop N status variation within and between fields.…”