Value of Chemical and Bacteriological Investigation

VALUE OF CHEMICAL AND BACTERIO- LOGICAL INVESTIGATION By J. E. Greaves, Chemist and Bacteriologist, Utah Agri- cultural College Experiment Station The history of the development of bacteriology from 1675 to 1865 is a story of man's attempt to answer the theoretical ques- tion— what is the origin of life? Is it spontaneously generated or is it the descendant of preexisting life? Few more theoretical considerations could be imagined, yet upon the basis of the answer to this question has been reared those three magnificent structures — bacteriology, preventative medicine, and surgery — which alone have done more to administer to and alleviate the suffering of mankind than all other subjects combined. When Pasteur undertook a micro- scopic study of the diseased silkworm and a bacteriological study of tis- sues of animals which had died of spleenic fever, even the most optimis- tic would not have dared to predict that the outcome of these two studies was destined in a few years to net in money to France more every four years than was paid by her to Germany after the Franco-Prussian War. In the Smithsonian Institution at Washington is a crude cumbersome machine which if one turns until he is blue in the face emits a small flash of electricity. Yet had Benjamin Franklin predicted that from it would have come all our modern electrical wonders, they probably would have found a place for him in the insane asylum. Hence, it is hard to foretell what will be the outcome of this or that investigation, but all the work which has been done and is in progress in the Department of Bacteriology has been planned with the idea that what we desire is the underlying laws governing this or that phase of argicultural practice and not an accumulation of a mass of unrelated data that may appear to have a greater monetary value but which can be applied only in the specific case, for once having dis- covered the law it is easy to apply it to specific cases. A careful bacteriological examination of the soils of the dry- farm and irrigated soils of Utah extending over a period of fifteen years has fully demonstrated that alfalfa entering into systems of crop rotation stimulates the soil to part with its stored-up fertility more rapidly than does the one-crop system. Furthermore, the direct analysis of a great number of Utah soils which have grown various crops for a number of years — some of them having been into alfalfa or wheat for upward of thirty years — reveals the fact that almost invariably the alfalfa soil contains less total nitrogen than does the wheat soil. The average for a great number of determinations made from alfalfa soil was 7,232 pounds per acre of total nitrogen, while the average

103 8 IMPROVEMENT ERA for a great number of determinations of wheat soil was 7,398 pounds. These conclusions clearly indicate that crop rotation even where the legumes largely enter does not maintain the fertility of the soil where the complete crop is harvested. It does, however, point the way to a system of permanent soil improvements — the combined rotation and livestock method which, if systematically applied, would ward off for hundreds of years the day when commercial fertilizers would have to be used on Utah soils. Moreover, it would result in an increased agricultural revenue to the state, which very conservatively can be placed at one-third greater than it is at the present time. Systematic analysis of the dry-farm soils of Utah reveals the fact that they vary in nitrogen-fixing powers of from zero to twenty- five pounds per acre. Now, twenty-five pounds of nitrogen at its market price in commercial fertilizers is worth $3.75. We have dis- covered some vof the factors which are governing this highest fixation to be aeriation and sufficient organic matter for the necessary energy of the lower plants which take part in the fixation. If in time we are able to unravel all of the complex factors which are governing this change and make all of the dry-farm soils gain each year $3.75 worth of nitrogen per acre in place of only the exceptional soil, will it not be worth the money invested? In most of our western districts water is the limiting factor in crop production, if viewed from the standpoint of the whole area. Therefore, a vital question is, what is the optimum moisture for maximum crop production? Our bacteriological work indicates this to be for the beneficial bacteria of the soil between 60 and 70 per cent of the water-holding capacity of the soil, and although not absolute it is quite certain that this is not far from the ideal for the higher plants. This far-reaching law could have been gotten on the higher plants only with the expenditure of large sums of money, and it would have required a series of years. As it is, these factors can be taken with slight variation and tested out for the various plants. The intelligent use of water also has another economic phase, for our work demonstrates that its excessive use may at times carry as much as 30 pounds of nitrogen an acre from the soil. This at its market price would be worth $4.50. If one-third of the 20,000,000 acres of land in the United States is being over-irrigated with this average annual loss, there would be a loss of plant-food amounting to $85,000,000. This only tells part of the story, for this excessive irrigation is carrying beyond the feeding powers of the plant roots the soluble plant-food which would probably account for another loss in diminished crop yields equal to or even greater than the above. There are millions of acres of land in the arid west which contain varying amounts of soluble salts. Some of these soils contain such large quantities of the so-called "alkalies" that no vegetation grow upon them. These can be reclaimed only by the leaching out of the

BACTERIOLOGICAL INVESTIGATION 1039 soluble salts. But actual experience teaches us that in some soils the salts "just won't wash out;" hence, we have to learn the laws under- lying this leaching process, and having learned them apply them to natural field conditions in such a way as to increase the leaching process. Some of the work now in progress has as its aim this goal. Moreover, the results which so far have been obtained show that the toxicity of the alkali salts toward bacteria and probably to the higher plants is due ( 1 ) to a physiological effect upon the proptoplasm composing the plant, and (2) an injurious osmotic pressure. Our laboratory work indicates that in so far as the bacteria are concerned the first effect can in some cases be cheaply overcome by the use of certain salts, thus creating an antagonistic action in the soil. Can this be carried over and applied to the higher plants? Only future work can answer. The results have already accumulated sufficiently to make it certain that alkali salts in some concentrations may injure the plants only indirectly through their action on the bacteria. Re- move this ill effect upon the bacteria and the injury to the plant disappears. The main toxic effect is due to excess osmotic pressure. It is evident that this can be overcome by either of two methods: (1) the removal of the salts which produce the osmotic effect, or (2) the formation of complex molecular aggregates which would have a cor- responding lower osmotic pressure. Now, it is well-known that organic compounds possess the power of combining with the common alkali salts. Our work so far has indicated that we can take some alkali soils which are barren, apply to them 1 5 tons of barnyard manure and produce on them fair crops. If even 10 per cent of the alkali area of Utah can be partially reclaimed by this method it will mean a net gain to the state far greater than all that has been invested in experimental work. Moreover, it has been found that many alkali soils are non productive for a number of years after the soluble salts have been removed. Our work indicates that this is due to (1) physical condition, (2) a small quantity of available plant-food, and (3) the absence of the normal bacterial flora. All three ot these can be corrected by a liberal use of fresh barnyard manure. Hence, it is certain that the combined livestock and rotation system of farming is essential not only for the maintaining of the nitrogen content of the soil but for the reclaiming of alkali lands. It is also quite possible that having learned the action of the various alkali salts upon the bacterial flora of the soil, that we may in time come to use them as a measure of the soil's productive power. We have already found that there is a close correlation between the soil microflora and the higher flora. Others have found that the azotobacter can be used as a very sensitive test for available phos- phorus. Then why not use them as an indicator of the alkali content?

1040 IMPROVEMENT ERA Time and systematic work arc required to answer this question. But if it ever does become possible it will place in the hands of the in- vestigator a new tool, and it is well-known that the advancements which have been made in the past in all fields of human endeavor are intimately linked with the discovery of new and better methods. Our study of the irrigation waters of the state clearly shows that their influence upon the soil may be four-fold: (1) they may increase or decrease the available plant-food of the soil without changing the total quantity; (2) they may carry from a soil plant-food, thus leaving it intrinsically less productive; (3) they may carry to a soil phosphorus, potassium, and nitrogen, therefore increasing its total plant-food; and (4) water may carry to and deposit in a soil "alkali" salts which in time will render it barren. It is therefore evident that irrigation water may be used to make the desert blossom like the rose, or it may transform the most productive field into a barren waste. Which of these shall occur will be governed by the knowledge which the farmer has of the composition of the water he is using and the composition of the soil on which it is to be used. This knowledge which we are trying to obtain linked with a judicious use of irrigation water, can save thousands of acres of the state's best land from be- coming useless. Logan, Utah Hobart, Tasmania Good Philosophy I asked a sister in passing, "Well, how are things today?" And she answered me quick and cheerily, In a bright and cheerful way, "There are plenty of things to growl at, But we've got to live them down." Her face was sunny and pleasant When there might have been a frown. "There is no use in growling, I've got to do my part, And keep a smile on my face, friend, As well as in my heart." These wise, sweet words were cheering, And helped me on my way. For we all have things to growl at, That worry us day by day. I've been doing a lot of thinking, And this is part of my thought — Do we all meet life as bravely And pleasantly as we ought? For there's plenty in life to growl at, No matter how fair things be; And I want you to learn the answer, That good sister gave to me. A. C. A. Dean Hewer.

Lake Lillian, in the Hidden Valley of the Wasatch A GROUP OF WASATCH LAKES By Alfred Lambourne It is an egotism, is it not, to begin a short reminiscence like this with the presonal pronoun? Therefore, it is avoided with a state- ment: many times has the writer been asked to tell of his first visit to certain of the Wasatch High Lakes, and also to relate some- what of the naming. This is a pleasant task; that is, to concede to the leading request, but in regard to the second he will be silent and give his reasons later. We confess to a growing coldness toward those fiiends of ours who stop one upon the street and ask: "How old are you now?" We place them upon a par with those inquisitive ones who demand to know how many big simoleons one receives for an article — this reminiscence, for instance. Tut! Tut! man — in regard to age, talk about something pleasant and respecting finance, remember that ex- cellent admonition used in the Pioneers Days, "Mind your own business!' Yet, after all, Mr. Editor, the thinking, the writing of of these few words does carry me back in memory for many a year. Why now that we think of it, our earliest looking into the Hidden Valley — then unnamed — and also our first looking upon three se- questered bodies of mountain water — then also unnamed — which it