Humus Burning Out.

I would like to know whether or not dry-plowing land, in preparation for sowing oats for hay, injures the soil?  I have heard that dry plowing tends to wear out the soil, as the soil is exposed to the sun a long time before harrowing.  I have been dry-plowing my land to kill the, weeds, but had a light crop of hay this year.

There is believed to be what is called “a burning out of humus,” by long exposure of the soil to the intense heat of our interior districts.  It is probable that the reduction of humus is due more to the lack of effort to maintain the supply than to the actual destruction of it by culture methods.  Such a little time as might intervene between dry plowing and sowing could not be charged with any appreciable destruction of soil fertility.  It is altogether more probable that your hay crop was less from loss of moisture than from loss of other plant food; and it is desirable to harrow a dry plowing, not so much to save the soil from the action of the atmosphere, as to conserve the moisture, which, as you know, will rise from below and will rapidly be evaporated from the undisturbed bases of your furrows.  Therefore, we should harrow a dry plowing as soon as practicable, but with particular reference to the moisture supply rather than to other forms of fertility.

Straw for Humus.

Do you consider straw good to plow under for humus, and which kind, wheat, oat, or barley straw, is best?

Straw, by its decay in the soil, produces humus and, therefore acts in the same way just as does the decay of other forms of vegetation.  As, however, straw is less easily decomposed than fresh vegetation, it is less valuable and may be troublesome by acquiring a greater amount of moisture by interfering with cultivation or by tending to dry out the soil to the injury of other plants.  If the soil is heavy and moisture abundant, straw may be desirable, while in the case of a light soil and scant moisture, may be injurious.  There is no particular difference in the straw of the different grains from this point of view.

The Best Legume for Cover Crop.

What would you advise to sow as a crop to plow under?  When should it be sowed, and when plowed under?

The best crop for green-manuring in any locality is the one which will make the best growth when surplus moisture is available for it, and when its growth can be undertaken with least interference with irrigation, cultivation and other orchard operation.  Generally in California, such a crop can be most conveniently grown during the rainy season, but in some parts of the State where irrigation water is available, a summer growth can be procured with very satisfactory results; so that we are now growing in California both wintergrowing legumes, like field peas, vetches, burr clover, etc., which are hardy enough to grow in spite of the light frosts which may prevail, and are also growing summer