Study On The Agricultural Utilization Of Calcium And Magnesium Muds As Fertilizer

In order to investigate the potential utilization of calcium and magnesium muds from nitro fertilizer industry in agricultural production, a constant temperature cultivation experiment and a pot experiment were conducted to study the effects of calcium and magnesium muds on the chengmical peroperties of three types of soils (laterite, red soil, and calcareous soil) and calcium and magnesium muds applied with peat and chemical fertilizers on the fertilities of two kinds of soils and on the growth of second crop maize at seedling stage.(1) The results of constant temperature cultivation experiment showed that different dosage of calcium and magnesium muds increased the pH value of the three soils and the increase of pH value of magnesium mud to the laterite was the largest. Different dosage of calcium and magnesium muds increased the OM of laterite soil, and the content of OM on red soil and calcareous are reduce as the application amount of calcium and magnesium muds increased. Different dosage of calcium and magnesium muds increased red soil and laterite the content of total N a little, higher amount of calcium and magnesium muds reduce the content of calcareous's total N. Lower amount of calcium and magnesium muds raised the available P contents of red soil and calcareous soil and higher amount of magnesium mud increased the available P content of laterite. The contents of water soluble Ca, water soluble Mg, active Fe, active Al, and active Mn all increased as the application amount of calcium and magnesium muds increased. This is mainly related to the properties of calcium and magnesium muds. Correlation analysis showed that the pH, available P, water soluble Ca, water soluble Mg, active Fe, active Al, active Mn of the 3 soils treated with calcium and magnesium muds had certain relevance. Overall, the effects of magnesium mud on soil pH value and available P content were bigger than that of calcium mud and the effects of calcium mud on soil water soluble Ca, water soluble Mg, active Fe, active Al, active Mn were bigger than that of magnesium.(2) The results of pot experiment showed that the different treatments have significant difference on soil organic matter, total nitrogen, available P content and the root dry weight of second crop maize at seedling stage of two kinds of soils. There are no significant difference on pH of two types soils, available K content of Guangzhou garden soil,the plant height and dry weight of calcareous soil.Compared with CK, the corn plant dry weight and root dry weight on Guangzhou garden soil were the biggest increase by PI+Ca6+W, the growth of 40.6% and 45.8%.Plant height growth under the maximum is 31.3% by P2+Ca 5+W. Calcium and magnesium muds with processing of Guangzhou garden soil organic matter content is significantly higher than CK, the biggest increase is 45.9% and 44.9%.All treatments of calcareous soil total nitrogen content than CK were improved, P3+Mg4+W is significantly increased 34.3% than CK. Calcium and magnesium muds of two types soils available P content than CK were significantly respectively increased 48.9% to 48.9% and 150.1% to 189.8%, and available P content of Guangzhou garden soil under inorganic fertilizer treatment than CK significantly increased 141.3%. Calcium and magnesium muds with processing of calcareous soils available K content were significantly increased 18.7% to 33.8% than CK. Visible, calcium and magnesium muds combined with peat and inorganic fertilizer have better aftereffect of soil fertilities than single inorganic fertilizer, and Guangzhou green soil is greater than calcareous.