Yes chalk is part of the mix for mushroom compost. It does not improve the drainage as it breaks down into cloying particles Old lime morter was the all time best for compost mixes years ago. It always stays open. I don't like manure though in any form except on roses and veg plots. Even there I prefer good garden compost. > Message du 08/12/13 12:01 > De : "Alberto" > A : "Pacific Bulb Society" > Copie à : > Objet : Re: [pbs] Stagonospora & Leafmold > > The medium for champignon mushrooms is strongly alkaline and therefore a problem if added to not acidic soils. > > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/