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Practical Tests.

Estimate of Water and Temperatures Beneath the Surface and Surrounding the Roots of an Orange Tree.

Being unable to learn that anything in particular has ever been done to encourage experimental horticulture or agriculture in Southern California, and much less for the diffusion of practical knowledge, an in-difference amounting to a culpablc neglect, or considering those vital interests entirely subordinate to other and much less worthy objects, I trust that modern research and inquiry will not be regarded as innovations upon a well-settled and unapproachable system. Viewed from an impartial and present standpoint, no light seems to have radiated even from the liberally endowed agricultural department connected with the State University touching these important interests for which it was originally intended to promote; and it is not an exaggeration to state that these industries are languishing, even in this fairest and most fertile portion of the habitable globe, for the lack of a little well-directed effort which would afford most reliable data from which invaluable practical knowledge could be obtained. "The blind are still leading the blind." Horticultural in: erests here have remained practically in statu quo for the past half century. The old ruts are a little deeper if anything, for the original stimuli that created an interest to embark m the enterprise has long ago become exhausted, and comparative indifference and apathy is almost universal among those who have grown grey in the pioneer effort, assuming an air of wisdom and dignity which, if not absolutely unapproachable, is quite humiliating to observe. Men of thought and culture seem also to have been lulled into comparative indifference concerning the great value of discussing the vital questions connected with economic horticulture, or more particularly the branch of fruitgrowing, insomuch that now, when dire calamity in the form of types of diseases and uncontrollable pests of various kinds threaten with cyclonic rapacity the very existence of their former resources they are amazed and dumb, knowing of no power to stay the ravages of the merciless destroyer. The thought perhaps has never crossed their minds that soil and long years of improper treatment lies at the foundation of their present trouble. However, they do not hesitate to inquire into the best methods of securing and keeping the orange, but ignore all investigations into the proper soils to plant and the best treatment to produce a long-lived, healthy tree, and the perfection of its fruit. This is left for the present and future new-comer to discover, and the indications already point unmistakably to the belt of mesa flanking the base of the Sierra Madre as the future and natural home of the entire citrus family.

That something is radically wrong in the old time-honored methods of treating the orange and lemon trees of this and adjoining counties, with page 61 rare and singularly obscure exceptions, cannot well admit of doubt, and the question is now forced upon us, what is to be done? Have we, late arrivals, encouragement to emulate the practice of these grey-haired patriarchs around us? Bathing in the rich and delicious ethers distilled from the delicate orange blossoms until narcotized into the belief that all is well, while disease and death is insidiously working disaster and ruin everywhere? While we desire information, we cannot look upon the destruction of the old orange groves going on around us and ask no questions, but blindly follow. Experiments are somewhat expensive, but ignorance, bigotry and guess work are much more so. Experience is a good teacher, guided by reason, founded upon facts, but generations of experience resting upon hypothesis only, is not worthy of respect.

Recent investigations into the quality of soil, moisture and temperature at the different depths which the orange roots have already reached or may penetrate the soil in which they grow, has led me into this discussion at this time, and without pursuing this inexhaustible subject further I will submit the result of my recent experiments around and beneath a growing and vigorous orange tree that has not been irrigated but once in the past two years and that once last year.

On the 5th instant, at 2 P.M., I made an excavation 3x4 feet and six feet deep on the north side of one of my six-year-old orange trees, leaving the inner wall four feet from the trunk of the tree. My first sample of earth was the top most dust, temperature of air, 76° Fahr. Below is the result, going down to 5 ½ feet, the present limit of the fibrous roots at that distance from the radical or tap root.

Surface dust at 135° Fahr. yielded 12 5-12 lbs. water per ton troy of soil, or 18 lbs. to the cubic yard. Same sample at 212° gave off 32 10-12 lbs. of water per ton, or 49 lbs. per cubic yard. Now, the roots of this tree under consideration have reached a distance of over 8 feet in every direction from the trunk, which gives us 11 cubic yards of soil penetrated by its roots.

Second sample, one foot below surface, temperature of soil, 60° Fahr. gave off 125 lbs. of water per ton at 212° Fahr., or 188 lbs. per cubic yard.

Third sample, two feet below surface, temperature of soil in place, 54° Fahr. gave off 124 11-12 Ibs. water per ton, at 212° Fahr., or 188 lbs. per cubic yard.

Fourth sample, 3 feet down, temperature of soil in place, 55° yielded 166 lbs. 8 oz. per ton at 212° or 250 lbs. per cubic yard.

Fifth sample, 4 feet deep, temperature of soil in place, 58° gave off 167 lbs. per ton, or 250 lbs. per cubic yard.

Sixth sample, 5 feet down, temperature of soil in place, 61° gave off 169 lbs. per ton, or 254 lbs. per cubic yard, at 212° Fahr.

It must be significant to all to note the difference in temperature of the soil at two and three feet below the surface, and that at four and five feet page 62 down, with a steady increase of moisture also.

Upon discovering this condition of things, a net of fibrous roots bathed in such rich, moist soil below the vicissitudes of surface temperatures, I no longer wondered why my trees kept up such a vigorous appearance and constant growth of new wood. The old method of blindly pouring on unmeasured streams of cold water every two or three weeks, and continued, could not but have worked irreparable injury and premature decay and death to all trees thus situated, and I venture the prediction that if an examination were made around and beneath the dead and dying trees in the old orchards, few if any vigorous roots would be found far below the surface. The orange tree is warm-blooded and must have warm, deep, mellow soil that its roots can penetrate, and such soil will gather water enough from the clouds, if kept in proper condition, to supply the natural wants of the tree during the interim of drouth nine seasons out of ten. The ground around my trees receives thorough surface cultivation once in four weeks and no oftener, as in my opinion, the soil needs rest and time for recuperation as well as organic substances. Many overwork their soil without doubt, as well as committing another error of over stimulating with fertilizers and water. The result of the examination as given above clearly demonstrates that roots of the orange tree will go down after the requisite moisture if permitted to do so, and moreover will supply the evaporation and other demands of the rapid-growing tree, while the surface roots are measurably off duty from any cause.

Neither the extreme heat nor its opposite cold affects these deep roots, and the percolation of the rain is so gradual that no sudden shock is experienced by the tree as in the case of sluicing on the water in the present artificial manner. The sap ceases to flow during the descent of any considerable quantity of water within a short interval, as all close observers will have noticed that if a tree is irrigated just as a new growth is putting out, it is checked at once, and will remain dormant from ten days to two weeks more or less, according to the season of the year, warmth of soil, temperature of air, etc. In short, solar heat has to again raise the temperature of the wet soil enclosing the roots to a degree compatible with conditions requisite to restore their deranged functions. The subject is so full of important details that will not admit of discussing in this already too lengthy article, I will simply consign my trees to the tender care of the clouds, capillary attraction, deep plowing, clean surface, and thorough cultivation until further developments, when, if of general interest, will report progress.