One Thousand Questions in California Agriculture Answered Part 55

Nitrate With Stable Manure.

I am going to plant about 2000 plants of rhubarb. I intend to put some cow and horse manure under the plants as a fertilizer, but I do not think I will have enough for all the plants, so I bought some nitrate of lime, with the intention of mixing the cow and horse manure with the lime nitrate, which I thought would allow me to spread the manure much thinner and I could cover more surface. Now I am not sure but the nitrate of lime will burn the manure if mixed with it.

You can mix either nitrate of lime or nitrate of soda with the stable manure as you propose; in fact, it is frequently done. These nitrates are neutral salts and do not act on manure as caustic lime or wood ashes would do. They are quite content to keep along without kicking their neighbors. But, of course, the more nitrate you add the more careful you must be about using too much of the mixture, and as for putting manure under any plant, at spring planting particular, it is dangerous business.

Nitrate of Soda.

How shall I apply nitrate of soda as fertilizer for roses and other flowers and lawns during the summer months?

One has to be very careful in the use of nitrate of soda not to use too much and not to apply it unevenly, so that too much is brought in contact with the roots of particular plants. From one to two hundred pounds an acre evenly distributed is the usual prescription for nitrate of soda, although in the case of bearing orange trees considerably larger amounts have been successfully used. This would be at the rate of about one ounce to one square yard of surface. It would be a safe application to begin with and could be increased a little on the basis of observation of results. Of course, the application should be accompanied by copious irrigation in order to dissolve and distribute the substance.

Fertilizing Strawberries.

I have half an acre of strawberries which will fruit their second season this spring, and half an acre set last month. I had intended to use nitrate of soda on them, but was talking to a friend who told me it would kill my soil. That the first year it would produce an enormous crop and the next year I couldn't raise anything. Which would be better to use here, stable manure or commercial fertilizer?

It is true that nitrate of soda is a stimulant of plants, and by rendering soil fertility immediately available may seem to reduce the supply later, and yet it is a most available forcing fertilizer if used with great caution, not over 200 pounds to the acre evenly scattered over the whole surface or a less amount, of course, if confined to particular areas. If used in excess it may actually kill the plants.

Still nitrate of soda is being used actively and intelligently by nearly all growers of plants and must be counted on the whole a valuable agency. If you can get stable manure, nothing is better as a complete plant food. Application to strawberries must be made at the close of the season, rubbish sc.r.a.ped away and manure applied and allowed to stand on the surface during the early rains, being worked into the soil during the rainy season. If the soil is light, sandy loam, too much coa.r.s.e material must be avoided. Therefore, well-rotted manure is important on such soils while on a heavy soil coa.r.s.er material may be used to advantage if applied early in the rainy season. If you have no well-rotted manure, a complete commercial fertilizer will give best results.

Late Applications of Nitrate.

I have some prune trees which blossomed some time ago and the prunes are already set, and of small size. Would you recommend me to use an application of, say 100 pounds per acre of nitrate of soda, applied immediately, or is it a little too late in the season to get the desired result?

It would be perfectly safe to use 100 pounds of nitrate of soda to the acre well distributed now; in fact, you could safely use twice as much, but we doubt if you would get any benefit from it unless you should irrigate, for there is no reason to expect showers that would have penetrating powers enough to carry the nitrate any appreciable distance into the soil. Of course, the nitrate could be plowed or cultivated in to a considerable depth, but that would probably result in losing moisture by deep opening or turning, which would do more harm than any gain which the nitrate produces, if it were to become available. Our judgment would be, then, that it is too late for any benefit to accrue unless the land can be irrigated.

Charcoal is a Medicine, Not a Food.

Recently a lumberyard burned, leaving quite a quant.i.ty of charcoal. I have a lot 50 x 150 feet in rhubarb. Would the charcoal be of any service on that lot as a fertilizer? I now have it well fertilized with horse manure, but would like to use the charcoal if it would be of any material a.s.sistance to the plants.

Charcoal is of no value as a fertilizer. It is practically indestructible in the soil. In fact, they are digging up now charcoal in the graves of ancient Egyptians, who departed this life five thousand years ago. Charcoal has corrective influence in absorbing some substances which might make the soil sour or otherwise inhospitable to plants. It has been found desirable sometimes to mix a certain amount of charcoal with soil used in potting plants for the purpose of preventing such trouble. The only way to make your charcoal of any value as a fertilizer would be to set it on fire again and maintain the burning until it was reduced to ashes, which are a source of potash and, therefore, desirable, but it will probably cost more than the product of potash will be worth.

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 legumes which thrive under high temperature, like cowpeas and other members of the bean family, and for which water can be spared without injury to the fruit trees which share the application of the land with them. The plants which are worth trying are burr clover, common or Oregon vetch, Canadian field pea, and the common California or Niles pea. Whichever one of these makes the best winter growth so that it can be plowed under early in the spring, say in February or March, while there is still plenty of moisture in the soil for its decay, without robbing the trees or rendering the soil difficult of summer cultivation, is the plant for you to use largely. All these plants should be sown in California valleys and foothills, as soon as there is moisture enough from rainfall to warrant you in believing they will catch and continue to grow. If the land is light they can be put in with a cultivator and plowed under deeply in the spring, as stated. If the land is heavy, probably a shallow plowing would be better to begin with.

Cowpeas for Cover Crop.

I planted cowpeas between peach trees which I have kept irrigated; when should they be plowed under?

Cowpeas will be killed by frost in most places and should, therefore, be plowed in this fall whenever you have a large growth of green stuff and the ground gets moist enough so that the trees will not be endangered by drying out of the soil, which is likely to occur after plowing in coa.r.s.e material, unless the soil is kept moist by rain or otherwise.

Garden Peas for Green Manure.

Would it be possible to plant the Yorkshire Hero pea in on orange grove as late as December 25 and get a crop from the peas? Would this pea add much to the fertility of the soil?

You can sow any garden peas as late as December 25, if the ground is in good condition and the temperature not too low. They are grown as a winter crop except when the ground freezes. You would not get as much good for the grove by growing these peas for the market as you would by plowing the whole growth under green, but you certainly will get advantage from the decomposition of the pea straw and of the root growth of the plant.