Portal de Periódicos da CAPES

POTENTIAL PHOTOSYNTHESIS AND CROP PRODUCTIVITY

1970; American Association of Geographers; Volume: 60; Issue: 1 Linguagem: Inglês

10.1111/j.1467-8306.1970.tb00705.x

1467-8306

Jen-Hu Chang,

Solar Radiation and Photovoltaics

ABSTRACT A model for estimating net photosynthesis is presented, based on the relationship between gross photosynthesis and solar radiation and daylength derived by Monteith, and the relationship between respiration and temperature derived by Thomas and Hill. The model has been applied to 386 stations, and world maps of potential photosynthesis for three different periods have been constructed. For the four-month summer period the highest potential photosynthesis is found along west coasts in high latitudes near sixty degrees latitude. For both the eight-month period and the annual mean, the Mediterranean type of climate has the highest growth potential. Potential photosynthetic rates for various climatic types and for latitudinal zones have been summarized. Actual crop yields of rice, cotton, and sugar cane of leading producing countries have been correlated with the computed potential photosynthesis. The correlations are highly significant. The implications of the study of potential photosynthesis in the strategy of land-use planning, particularly in the so-called underdeveloped countries, are discussed.