Gypsum is sulphate of lime. It is not detrimental to the land in after years except that its action is to render immediately available other plant foods and this may render the land poorer - not by the addition of anything that is injurious but by the quicker using up of plant food which it already contains. Black alkali is very common in California in alkali lands. In lands which show their quality by good cropping, there is no reason to apprehend black alkali nor to use gypsum to prevent its occurrence. The use of gypsum does stimulate the growth of alfalfa and makes its product greater just as you observe in the experience of your neighbors, but the more they use up the land now the less they will have later, unless they resort to regular fertilization to restore what has been exhausted. But even that may be a good business proposition. What Gypsum Does. I intend to fertilize alfalfa and should like to know about gypsum. I have heard it stimulates the growth temporarily but in three or four years hurts the land. I have heavy land. The functions of gypsum are: (a) to supply lime when the soil lacks it; (b) to make a heavy soil more mellow, and (c) to act upon other soil substances to render them more available for plant food. These are some of the soil aspects of gypsum; it may have plant aspects also. It is too much to say that gypsum hurts the land; it does, however, help the plant to more quickly exhaust its fertility, and in this respect is not like the direct plant foods which comprise the true fertilizers - one of which gypsum is not. It might be best for your pocketbook and for the mechanical condition of the soil to use it, but do not think that it is maintaining the fertility of the land (a service which we expect from the true fertilizers) except as it may supply a possible deficiency of lime. How Much Gypsum? How much per acre, how frequently and what seasons of the year are the best time to apply gypsum? Of gypsum on alkali, we should begin at the rate of one ton to the acre and repeat the application as frequently as necessary to achieve the desired result. If the alkali was quite strong we would use twice as much. Without reference to an alkaline condition in the soil, and to give heavy soil a more friable character, which promotes cultivation, aeration, etc., and, therefore, ministers to more successful production, half a ton to the acre can be used, applications to be repeated as conditions seem to warrant it. Wood Ashes in the Garden. There is available in my neighborhood a free supply of wood ashes. Can you tell me how best to distribute the same in a garden (flowers and garden truck), and what, if any, treatment is to be given the ashes for the best results.