Taken by 2mm aperture sieve dried samples of about 10g, into the known mass (M0) the proportion of the bottle, said bottle + dry sample mass (M1) (accurate to 0.01g). Another is about 10g sample by-NY 525-2002 method for the determination of water content 5.6 ‖ (X0). The proportion of the sample slowly into the flask with carbon dioxide to distilled or deionized water to a volume of water sample and about 1/3 to 1/2 is preferably pycnometer. Slowly shaking pycnometer make fully wet nursery substrate, the specific gravity bottle on a hot plate heated to maintain micro-boiling after boiling for 1 hour, boiling process should always shake pycnometer, get rid of the matrix air. Boiling is completed, carbon dioxide-free distilled water cooled slowly added along the sides of the bottle pycnometer to bottlenecks, fingers tapping the bottle wall, the residual air in the matrix Yi to do. Leaving to cool, water bottle after clarification measured (T1). Add distilled water to the bottle, the plug capillary plug, i.e., the excess water overflows the bottle plug from the capillary, the outer wall of the bottle with a filter paper is weighed after the dry time T1 (bottle + water + matrix) weight (M2). The proportion of nursery matrix liquid pour bottle, wash pycnometer, filled with carbon dioxide-free distilled water cooling, measuring bottle water (T2), add water to the bottle, stuffed capillary plugs, the outer wall of the bottle with dry filter paper said T2 is the time to take (bottle + water) weight (MT). If each pycnometer have been corrected in advance in the determination of this step may be omitted. Shouguang rice 田镇振 sea plant nursery substrate Address: Paddy Town, Shouguang City, Shandong Province Contact: Manager Li Mobile: 15263663166 Website: www.sgzhenhai.net Weifang Fushun Energy Technology Co., Ltd. Address: Shandong Province Linqu Xinzhai Wolong industry garden