| On the basis of analyzing the potential productivity and latent capacity in increasing yield of the main cereal crops and alfalfa in Tongliao city, it has shown that the photosynthetic, photosynthesis-temperature potential productivity is great, the potential productivity of agro-climatic resource in Tongliao is small, the temperature is the main factor that we couldn't control; the low organic matter content is the main limiting factor to low land potential productivity. It exists obvious difference in latent capacity in increasing yield in different areas and different crops. |