Study on melting available silicone from coal gangue

Available silicone was melted from coal gangue samples from Hancheng dig- gings through calcination, digestion, and other means. The best calcination temperature was determined from a range of 550-1 150 ℃; and the best time, from a range of 0.5-5 h by colorimetry method. The proper ratio of coal gangue, limestone, sodium carbonate, and caustic soda was then determined through orthogonal experiment. The results show that the proper extraction condition for available silicone is the ratio of coal gangue, limestone, sodium carbonate, and caustic soda at 1：0.5：0.1：0.05, calcination temperature at 700 ℃, and calcination time at 2 h. In this condition, the available silicone content can be more than 19.65%.

Available Silicon Contents of Paddy Soils and the Effect of Silicon Fertilization on Rice in Sichuan Province

Based on the results of field trials and soil and plant measurements, the available silicon contents ofpaddy soils, their relations with the SiO_2 content of rice plant, the relationships between rice yield on theone hand and the SiO_2 content and SiO_2/N ratio of rice plant on the other, the effects of silicon on riceyield and resistance to diseases and pests and the effective conditions and causes for increasing rice yield inSichuan Basin are expounded in the present paper. The study results show that about one half of the paddysoils developed from yellow soil, purple soil, alluvial soil, etc. in Sichuan Province were insufficient in siliconsupply. Critical values for silicon fertilization were 98 mg kg￣(-1) available Si in the paddy soils and < 112.8gkg￣(-1) SiO_2 in the rice plants. A SiO_2 content of rice plant over 121.6g kg￣(-1) and a SiO_2/N ratio maintainedat about 12 were required for gaining a rice yield of 7500 kg ha￣(-1). The yield increase by silicon fertilizationwas due to the improvement of silicon nutrition in rice plants and the balance of SiO_2/N ratio, and the reasonfor enhanced resistance to diseases and pests was concerned with the inhibition of luxury N absorption andthe raising of plant SiO_2/N ratio. Silicon fertilization tended to balance the uptake of N, P and K by riceplant .

Effects of Silicon Preparation on Different Forms of Silicon in Soil and Silicon Content in Rice Plants

Rice is a typical silicon-loving crop,known as"representative of silicic acid plant".Southeast Asia and other rice-producing countries have listed silicon fertilizer as the fourth most elemental fertilizer after nitrogen,phosphorus and potassium.Therefore,improving the utilization of soil silicon and promoting the transformation of soil silicon form is of great significance to the growth of rice and the development of agriculture.In order to investigate the effects of silicon preparations on different forms of silicon in soil and silicon contenst in rice plants,a pot experiment with Dongnong 427 was carried out,spraying on rice leaves at the booting stage,and three treatment groups(Si-TG,Si-EG and Si-60G)and a control group(CK)were set up.The contents of available silicon,water-soluble silicon,amorphous silicon,active silicon in soil and plant silicon were measured at the heading stage and the maturity stage of rice,then the effect of silicon preparation on the silicon content of rice soil and plant was analyzed.The results showed that spraying silicon preparation could significantly improve the silicon content of rice plants,promote the transformation of silicon forms in soil to varying degrees,and improve the silicon supply capacity of soil.Compared with CK,the soil available silicon content increased by 7.42%-8.26%at the heading stage and 6.70%at the maturity stage.The Si-EG treatment at the heading stage had the best effect on increasing the available silicon content of the soil,which was 8.26%higher than that of CK,reaching a significant level;the Si-TG treatment at the maturity stage had the best effect on increasing the silicon content of the plant,and the silicon content of the plant was 27.17%higher than that of CK,reaching a significant level.

Effects of Silicon Fertilization on Soil Chemical Properties and Phytolith Formation of Phyllostachys pubescens

Silicon is benefit to Gramineae plants in growth and resistance to various stresses.However,the effect of silicon fertilizer application on Phyllostachys pubescens is still not investigated yet.Phyllostachys pubescens Mazel ex J.Houz is one kind of Gramineae plants which distributes in a large area.In this study,a field experiment with five Si fertilizer application rates(0,125,250,375,and 500 kg ha-1)was setup in a Phyllostachys pubescens forest in China to examine the effects of Si fertilizer on bamboo Si and phytolith accumulation in fresh leaf and leaf litter.Results showed that Si application increased soil available Si content in deep layers.Si content of leaf-litter increased with the increasing level of Si fertilizer application rate,with the value ranging from 114.3 g kg^(−1)to 172.7 g kg^(−1),however,no significant difference was observed in fresh leaf,with the value ranging from 84.0 g kg^(−1)to 115.0 g kg^(−1).The phytolith contents of leaf-litter and fresh leaf were consistent with the Si contents,the phytolith content in leaf-litter of T4(500 kg ha^(−1))was 48.4%higher than the control,suggesting Phyllostachys pubescens exhibited an increasing carbon sink in phytolith when Si fertilizer applied,which is an effective way to increase long-term soil organic carbon storage in Phyllostachys pubescens forests with a suitable Si fertilization.