Research And Extension Of Rice Cultivation Technology Of Selenium-rich In Chizhou

Selenium(Se) is one of the essential trace elements in the human body. Through the food way to fortified Selenium has become the hotspot of functional food. The Se content of the soil along the Qiupu river of Guichi area in Chizhou city ranged from 0.21mg/kg to 4.19 mg/kg, the soil belongs to medium-high Se content soil. Field experiments were conducted with Xinliangyouxiang 4, Huaan501, Xinliangyou 6 in Guichi. The effects of Na2SeO3 on the Se contents in different rice varieties were studied by foliar spraying, and the selenium-rich cultivation technology of rice was studied and popularized. The main results showed as follow:1.The researeh on the absoption ability differece betweeen different rice varieties for Se showed two-line indica hybrid rice accumulated Se, the Se levels and absoption ability were Xinliangyouxiang 4> Xinliangyou 6> Huaan 501. The analysis results of the Se level of rice showed that there were significant difference on Se absorption ability of rice between different growth stage. Under the same concentration, the best stage to apply Se to Xinliangyouxiang 4 and Huaan 01 were heading stage, while Xinliangyou 6 was full heading stage. Leaf Spraying Na2Se03 also increased the rice grain yield. The highest yield obtained when the Na2Se03foliage praying at the full heading stage, it was increased by 0.50～12.02% compared with rice leaf spraying Na2SeO3 at heading stage and booting stage. Leaf Spraying of Na2SeO3 at heading stage and full heading stage increased the 1000-grains weight by 0.2～0.5g compared with booting stage.2. The research on the effects of spraying small amount exogenous selenium to rice showed that:If the total Se of soil was 0.71mg/kg, Spraying selenium with the dosage from 7.5 g/hm2 to 11.25 g/hm2 obviously improved the Se absorption ablity of rice. Foliar application of Na2Se03 increased Se contents in rice grains, and the Se contents of rice grains increased with increasing Na2Se03 sprayed.The Se contents of rice grains for different treatments ranged from 0.08 mg/kg to 0.24 mg/kg, it was within the national standard safe rang of Se for food (0.1～0.3 mg/kg). Foliar application of Na2SeO3 was not significant affect the effective panicle, the rate of earbearing till and plant height of rice, but mature period was moved up 1-2 days, and it was helpful to increase seed setting rate and 1000-grains weight.3. The experiment of application milk-vetch to rice showed that:Selenium content of rice and Milk-vetch directly affected by the selenium contents of soil. There was a positive correlation between Milk-vetch and rice selenium contents snd the total Se of soil. The elenium contents of rice and Milk-vetch were significantly increased by spraying exogenous selenium. The Se absorption ability of milk-vetch was obviously strongger than that of rice. The selenium content of rice which sprayed selenium with the concentration of 25 mg/kg at the heading stage was 0.184 mg/kg, it was 0.121 mg/kg higher than CK(0.063 mg/kg). The selenium content of rice which applied ordinary milk-vetch or selenium-enriched milk-vetch were 0.112 mg/kg and 0.157mg/kg, that were increased by 0.049 mg/ kg and 0.094 mg/kg over CK, respectively. The proper milk-vetch application rate was about 22,500 kg/ha. Applyed milk-vetch was better for rice to absorpt selenium in soil and milk-vetch. It should be further studied whether it were related to higher selenium content in milk-vetch, stronger Se absorption ability of milk-vetch and the enhancment of water-soluble Se in the soil wiht the decomposed milk-vetch.4. The selenium-rich cultivation technology of rice integrated with the rice light planting technique, drought breeding and rarefaction planting technique, soil testing and fertilizer recommendation technique, water-saving irrigation technique and IPM, the demonstrtion area of the integrated technology was more than 2000 ha. According to the result of investigation the number of chemical sprayings in demonstration areas reduced 2.1 times, the cost of chemical sprayings reduced 480.0 yuan/ha, at the same time the loss caused by disease and pests decreased 400.5 yuan/ha, the grain yield increased 772.5kg/ha, equivalent to 1575.9 yuan/ha, and the rice value was incereased 1500 yuan by higher prices for better quality. The total earings by increase revenue and reduce expenditure of the demonstration area was 7.9128 million yuan.