[Assessment of rice achievable productivity and its application in rice production management division: a case study in Fuyang County of Zhejiang Province, East China].

Rice productivity is the key factor affecting rice production and its sustainable development. Based on the gradation of cultivated land quality at county-level, this paper evaluated the rice productivity in Fuyang County of Zhejiang Province, and, through selected sampling field investigation and according to the land productivity index of paddy field quality, a model for assessing rice achievable productivity was established, aimed to analyze the regional rice productivity and its achievable productivity. In the study area, there was a positive correlation between the land productivity index and rice yield.

[Effect of planting densities on yields and zinc and cadmium uptake by Sedum plumbizincicola].

A field plot experiment was conducted to study the effects of planting densities on the growth and heavy metals uptake by Sedum plumbizincicola. The results showed that yields of Sedum plumbizincicola were enhanced with the increase of planting density; however, there was no further increase when planting density was too high. With planting density increasing from 1.