Author(s)

D. Kaneko, T. Itohara, M. Ohnishi & T. Ishiyama

Abstract

This paper aims to develop a remote sensing method for monitoring grain production in the early stages of crop growth. Rasmussen has incorporated the photosynthetically active radiation PAR and the integrated amount of vegetation iNDVI based on satellite data. Here, a photosynthesis-based crop production index CPI is proposed that takes into consideration the solar radiation, the effective air temperature, and NDVI as a factor representing vegetation biomass. The CPI index incorporates temperature influences such as the effect of temperature on photosynthesis by grain plant leaves, low-temperature effects of sterility, cool summer damage due to delayed growth, and high-temperature injury. These latter factors are significant at around the heading period of crops, and go beyond Rasmussen’s model. The CPI index was validated at ten monitoring sites in the Kanto, Tohoku, and Hokkaido districts, which are in the northern half of Japan and tend to suffer poor harvests as a result of low temperatures. It is important to oversee the quantity of grain in production at an early stage in order to raise the alarm well in advance if a poor harvest is looming, especially in view of the rapid population increase in Asia and the long-term squeeze on water resources. Keywords: monitoring, rice, crop production index, photosynthesis, NDVI.

Keywords

monitoring, rice, crop production index, photosynthesis, NDVI.