Abstract: Turf can be grown by mixing an artificially-granulated soil and turfgrass seeds, sprinkling the resultant seed-soil mixture on a ground and then covering a surface of the thus-sprinkled mixture with an artificially-granulated soil of the same type as the first-mentioned artificially-granulated soil to a thickness at least equal to the average grain size of the seeds but not greater than 5 mm. The artificially-granulated soils contain 0.01-2.00 wt. % of a fertilizer as calculated in terms of effective components of the fertilizer, is pH 6-7 and has an average grain size 0.5-1.5 times the average grain size of the turfgrass seeds. To prepare the seed-soil mixture, the soil is mixed with the turfgrass seeds at a rate of 30-300 g of the soil per gram of the seeds. The seed-soil mixture may be subjected to germination-hastening treatment before being sprinkled on the ground.

Abstract: A process of producing a high-pure dichloroacetaldehyde trimer with high yield by cyclodehydrating dichloroacetaldehyde hydrate in the presence of concentrated sulfuric acid.

Abstract: A process for producing a hydrazone derivative represented by the following formula at a high purity at a high yield by decomposing monochloroacetaldehyde trimer into monochloroacetaldehyde monomer and then reacting the monomer with an alkyl carbazate in an organic solvent:Cl--CH.sub.2 --CH.dbd.N--NH--COOR(R represents an alkyl group).

Abstract: A method for preparing a monochloroacetaldehyde trimer in a high yield is here disclosed which comprises the steps of dissolving, in an organic solvent, a solution containing monochloroacetaldehyde as the main component, and then trimerizing monochloroacetaldehyde in the presence of sulfuric acid. The thus prepared monochloroacetaldehyde trimer can be heated at 120.degree. C. under atmospheric pressure to obtain pure monochloroacetaldehyde.