The Studies On Utilization For Cd-rich Reclaiming Substrate And Selection Of Crops

Recently as plantation resource is decreasing, coal mine subsidence land has became an important research project.Mostly the method of land reclamation is surface soil ,however, the soil resource is hard to be guaranteed. The subsided land reclamation research which coal mine subsidence land reclamation substrates is composed of mass ratios of fly ash to sludge or fly ash to distiller's grains in stead of surface soil has got some achievement.It is determined that the concentration of Cadmium in the new composed substrates is higher than"the quality standard of soil source"(National standardâ…¡).It is not suitable for growing the normal edible plants. It is necessary to find out the plants whose edible organs absorb the less heavy metals.This research is about outdoor potted plant experiment.The selected plants whose edible parts need relatively low heavy metal cadmium grow in substrates.The detection is about the plants'growth condition ,the nutrient ingredient of edible organs ,the concentration of Cd and so on. Meanwhile,it is about the comparison with multiple experimental plants.Research results show that(1)The physical and chemical properties of substrates can be suitble for the growth of variety plants.The substrates capacity is lower than normal soil resource on average. It is advantageous for plants development and substrates nutrient transformation.That the field moisture capacity keeps above 70% could provide with adequate water for plants growth. At the early phase of substrates allocation the salt content is relatively high .The general plants requirements are satisfied with the rainy season and plants growth in one year. The content of organic matter and rapidly available Azote,Phosphorus, Potassium are in the normal levels. (2) Rich Cadmium reclamation substrates 1 is not adaptive for planting mung bean,soybean,potatoes, kidney bean and cowpea. Rich Cadmium reclamation substrates 2 is not fit for mung bean,however, potatoes,soybean, kidney bean and cowpea grow very well.But soybean production is low. Potates not only grow very well but also the heavy metal concentrations of edible parts and straw are higher than the nation standard .And it can be widely applied. (3)The major nutrient source of potatoes ,soybean and kidney bean are not affected by the rich Cadmium reclamation groundmass.It is showed that the growth abilities of the above three plants in the rich Cadmium reclamation groundmass. It is provided the theory basis for the large scale application . (4)Analyzed and predicted the requisite time that Cadmium is reduced to the safety environment value in rich Cadmium reclamation substrates.(5)This application pattern of rich Cadmium reclamation substrates can get plants rehabilitation purpose while producing edible crops.It promotes the economic benefits ,accelerates area economic develo-pment and brings social and ecological benefits,and plays roles in improving resident living environment and keeping eunomy.