Effects of Biochar with Organic Materials on Substratum for Raising Rice Seedlings

[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks（the treament HC） is the optimal substratum in this study.

Preparation of Rice Seedling-raising Substrate with Spent Mushroom Substrate of Pleurotus eryngii

This study aimed to explore the effect of fermented spent mushroom substrate(SMS) of Pleurotus eryngii as a basic material on rice seedling-raising substrate. The physical and chemical indices of the SMS indicated that the fermented SMS was fully composted and was very suitable for preparing rice seedling-raising substrate. The fermented SMS effectively regulated the bulk density, total porosity, aeration porosity and water-holding porosity of rice seedling-raising substrate. With the increased addition amount of fermented SMS, the bulk density of rice seedling-raising substrate was decreased, but the total porosity, aeration porosity and water-holding porosity were increased. Compared with those in the substrates of 100% soil and 100% SMS,the height, chlorophyll content, 100-shoot dry weight, 100-root dry weight, root activity, nitrogen content, phosphorus content and potassium content of rice seedlings in the substrate composed of spent mushroom substrate of P. eryngii and soil were higher.The quality of rice seedlings in the substrate composed of 20% soil and 80% SMS was best, followed by that in the substrate composed of 30% soil and 70% SMS.

Application of a Soil Nutrient Measuring Instrument in Vegetable Seedling Substrate

[Objective] The aim was to find an efficient method to measure available nitrogen, phosphorus and potassium content in vegetable seedling substrate. [ Method] The suitable dosage of leaching agent, ratio of the substrate to water and leaching time for the detection of nutrient contents in the substrate by a soil nutrient measuring instrument were discussed firstly, and then the results of nutrient contents measured by the soil nutrient measuring instrument were compared with that by conventional approaches. [ Result] In compadson with the conventional methods, the av- erage content of available nitrogen measured by the soil nutrient measuring instrument was slightly higher, while the average content of available phosphorus measured by the instrument was lower; the average content of available potassium measured by the instrument was close to that by the conventional method. [ Conclusion] This study could provide us a new method to detect available nitrogen, phosphorus and potassium content in seedling substrate efficiently.