Use of sugar (monosaccharides) or osides in straw residues of soil or seeds before seedling of major non-leguminous crops, where the sugars are easily generated by simple hydrolysis, is claimed. An independent claim is included for sugars (monosaccharides) or simple osides applied to the straw residue in soil or to seeds of non-leguminous winter crop for temporarily immobilizing the mineral nitrogen which is present at the surface of the arable soil, during autumn, to develop the yield of crop.