We used to use Iron oxide. we applyed it with a wooden aplicator about five feet long.... some people calle it a hoe. Now, my wife and i use a lot of mulch. Some parts of the garden are not as good of soil as others, and they get wood mulch. it builds the soil as it decomposes, but uses nitrogen in the process. Have to add a little nitrogen there. some parts the composition and ph and tilth are what we have been working for, and we use newspaper, and wheat straw, although it has gotten expensive. grass clippings are o.k., but they also use a little nitrogen.
Always think"Am I building the soil, or depleting it?" And not just in terms of npk, or even micro nutrients, but in terms of tilth, bioactivity(worms are a real weathervane for the health of your soil) and friability. We started with red clay here, and still have parts or the garden that need sand. They get tthe heavy, wood or bark mulch. The deeper you can get the topsoil, the better it is, too. Mulch is a real help with all this. So are green manures, like buck wheat, but that is lesson two.
