Pathway to Japanese Literature

Author: Nakaya Ukichiro

I

With the war's end, the Niseko Observatory was inevitably destined for closure.

This research institute, orphaned through its parent organization's dissolution—the Technology Agency—had no alternative but to face dismantlement first. Moreover, given that aviation meteorology—the very mission of this institute—had now become obsolete in our nation, even a contrarian philanthropist inclined to nurture such a field could scarcely be imagined under current circumstances.

While the Technology Agency's stance remained unequivocal—wartime research would cease with the conflict's conclusion, and consequently its facilities demolished—for us who had labored five years to build this institute from nothing, there lingered an unendurable quality in simply razing what we had created.

After much deliberation, we ultimately settled on a plan: why not revitalize this institute as a research center for agricultural physics?
When I give it some thought, it strikes me that while chemistry has been fairly well incorporated into our country's agriculture, physics seems to have hardly made any inroads.
Although the term "agricultural physics" exists and universities offer such courses, the main issues addressed in that field seem to predominantly concern agricultural engineering problems like land consolidation and subsurface drainage, or otherwise topics in agricultural machinery science such as the invention and improvement of farming tools.
In a completely different sense from those approaches, it should at least be possible to introduce physics into agriculture.

According to a senior professor in the agricultural department, farming was a comprehensive art of heaven, earth, and human effort, with weather governing eighty percent of it.
While "eighty percent" was likely a figure of speech, there could be no doubt that weather remained the greatest governing factor in agriculture.
Even in a year like the previous one, where fertilizer and labor had both been in short supply and everyone had worried, when the weather proved favorable, the rice plants grew without issue and produced yields close to an average year’s harvest.
Yet that year, particularly in Hokkaido, rice crops reached a disastrous state of 30% or 40% yields.
With hardly any hot days throughout the summer and weather conditions that had even brought frost in June depending on the region, it was no wonder that neither improved varieties nor cultivation techniques could make any headway.
Not only rice—there were many areas where legumes had been nearly nonexistent, and potatoes too had fared quite poorly.

In such years—so-called cold damage years—the most straightforward approach to increasing production lay in having the weather show some restraint.
Even in years without cold damage, achieving dramatic increases in production required devising methods that could somehow exert a degree of control over the weather.
Mentions of attempts to control the weather were immediately met with derision; yet while exhaustive attention was paid to improving crop varieties and researching fertilizers, apart from the work of a handful of scholars, people generally maintained an attitude of absolute passivity toward meteorological conditions.

II

Weather itself cannot be altered by human power.
However，if one gives it a little thought，there seem to be various paths available.
The best method among these is research on long-term forecasting，which knowledgeable meteorologists have been undertaking for ten years now and have already achieved considerable results.
It is research that predicts summer weather conditions through investigations of winter meteorological states; if this succeeds，one can adapt to the weather by selecting appropriate crop varieties.
In other words，it becomes possible to effectively control the weather through passive means.

There were various methods in long-term forecasting, but among these, the most intriguing and promising was the relationship between drift ice conditions in the Sea of Okhotsk and summer weather patterns in Tohoku and Hokkaido that year.
This research had been conducted every winter over approximately ten years by Mr. Negishi, an aviator with the Central Meteorological Observatory.
Mr. Negishi repaired decommissioned military aircraft himself and flew over the Okhotsk drift ice each winter using Memanbetsu Airfield as his base, yet few people appeared aware that this life-risking research had continued quietly for nearly a decade in Hokkaido's remote extremities.

When I met Mr. Negishi shortly after the war's end, he was deeply worried his hard-earned research might be discontinued through these circumstances.
It had been established that the abundance or scarcity of drift ice, its distribution patterns, and particularly the speed of its disappearance after spring indeed governed summer weather conditions.
Over recent years, they had finally developed sufficient understanding to issue forecasts, all reportedly proving remarkably accurate.
What seemed strange was that agricultural advisors utilizing Mr. Negishi's forecasts remained exceedingly few—or rather, practically nonexistent.
Even when occasionally employed, such instances remained exceptions, with the forecasts appearing scarcely used in practice.
In a year like this—when cold damage had been successfully predicted—there existed extreme cases across Hokkaido where solely late-ripening rice seeds were distributed, resulting in near-total crop failures.
Government offices and agricultural associations, perhaps preoccupied entirely with requisition quotas, may have neglected the essential matter of actual crop production.
Of course that remark constitutes jest; in truth, this likely represented merely one manifestation of the pervasive academic disregard suffusing both governmental and public spheres within our nation.
Though "respect for science" circulates as fashionable rhetoric, it remains superficial posturing.

By personally procuring small lathes and drill presses, fabricating components himself, and making adjustments on his own, he finally made the aircraft airworthy.
This research—conducted for ten years in such precarious aircraft through snowy skies over the Sea of Okhotsk—would ultimately go unused and be halted come winter.
This was no mere personal matter for Mr. Negishi, but a critical issue of national policy for Japan’s rebirth.
Yet even that outcome seemed unavoidable.
Though long-term forecasting through drift ice observations might prove futile, alternative methods existed.
Statistical approaches to long-term forecasting in particular had already yielded numerous published studies.
We would have to await progress in that academic domain.

III

The second method of overcoming weather conditions was a somewhat more cautious approach.
Even if one said that weather overwhelmingly governed agriculture, when considering its governing mechanisms, it appeared that part of this control operated through controllable ground conditions influencing crops.
Problems like sunlight deficiency in fog-prone areas—being directly governed by weather—would not be easily controllable.
However, issues such as delayed planting from slow spring snowmelt in heavy snowfall regions resulting in reduced harvests, or missing optimal timing for double cropping, represented weather influences exerted through controllable ground conditions.

Cold damage in the rice paddies of Hokkaido’s plains and Honshu’s highland regions was not solely due to insufficient cumulative temperatures or days falling below acceptable limits; the notably low water temperature also brought about significant effects.
While air temperature remained beyond control, water temperature could be regulated to some degree.
In those desolate peatlands of Hokkaido—largely left untouched—similar patterns could be observed.
For cultivating peatlands, raising ground temperature was considered the most direct approach; as for increasing ground temperature, this at least presented a problem that could be addressed.

When isolating problems such as accelerating snowmelt, raising paddy water temperatures, and increasing peatland ground temperatures, these emerge as matters of pure physics rather than agricultural physics.
If these problems could be solved, we would in a sense have successfully controlled the weather.

Incidentally, the issue of insufficient sunlight in fog-prone areas shouldn't be entirely dismissed from the start.
In last summer's comprehensive fog study conducted in Nemuro, Dr. Miyake of the Central Meteorological Observatory measured solar ultraviolet intensity within fog.
The results showed ultraviolet rays penetrate fog surprisingly well—even with sea fog of that density, roughly half typically reaches the ground.
Should the relationship between ultraviolet light and crop varieties be thoroughly researched, it might become possible to select scientifically validated suitable varieties through methods like ground temperature elevation.
While perfect solutions may not exist, I suspect these approaches shouldn't be discarded outright.

Now, whether speaking of accelerating snowmelt or raising water and ground temperatures, the problem ultimately came down to whether such measures could be practically implemented across vast expanses equivalent to all cultivated land.
In any case, being fundamentally a matter of thermal energy, resolving this through purely artificial means—such as employing electric power—was clearly impossible without even requiring calculation.
Ultimately, there remained no method except to harness the sun's power.
Artificial power should instead be applied sparingly as supplemental support at critical junctures.
With science's current capabilities, directly confronting natural forces remained utterly impossible.

IV

Among these problems, the one that was currently most clearly defined was research on snowmelt acceleration.
Fortunately, it was considered that the solution to this snowmelt problem would also prove extremely useful for raising water and ground temperatures.

Snowmelt acceleration had already seen its simplest method put into practice in some regions. This involved scattering soil on the snow surface in early spring to absorb solar radiation, thereby accelerating melt-off. To use farmers’ parlance, this approach seemed overrated—ultimately resulting in snow disappearing just five or six days earlier on average, a week at best. Yet in early spring when planting races against each passing day, even those few days proved non-trivial. For crops like potatoes, such gains were said to yield about twenty percent greater harvests. Though no scientific comparative trials substantiated that exact figure, significant yield increases remained undeniable. Thus farmers labored mightily to haul soil onto deep snowbanks and spread it thin.

The early spring sunlight in northern regions was intense.
As if compensating for half a year of gloomy overcast skies, there were periods when the sun blazed intensely in skies cleared to pure azure for days on end.
If such intense sunlight had been absorbed by the soil, the snow would likely have melted much sooner than five or six days.
There was a reason for this: this method had one drawback.
In late March, after waiting for snowfall to cease, they scattered soil; however, nighttime temperatures still frequently dropped below zero at that time.
When the soil layer became slightly thick during this stage, the melted surface layer froze into thin ice plates containing soil.
A narrow air gap tended to form between these ice plates and the underlying snow layer below. Due to this air layer's insulating effect, heat became less likely to transfer to the lower snow layer, consequently causing slower melting than anticipated.
Therefore, the soil needed to be made as fine as possible and spread thinly with uniform consistency.
However, achieving this proved extremely difficult in practice.

Taking this point into consideration, a researcher conceived a new and different snowmelt acceleration method.
That researcher was Mr. Takahashi Kihei of the Forestry and Water Management Experiment Station in Tokamachi, Echigo.

Because the April sun was still quite low, its rays struck the snow surface at an angle.
Mr. Takahashi considered that this might be one reason reflection intensified.
If sunlight were to strike the snow surface at a right angle, it would be absorbed more effectively, and consequently snowmelt might accelerate further.
For this purpose, Mr. Takahashi dug trenches across the snow-covered surface and piled the excavated snow on one side of each trench.
By doing this, a single tall ridge formed on the snow-covered surface.
When this ridge was aligned east-west, solar rays struck the southern slope at nearly right angles.
Though effective alone, spreading soil on the sunlit slope would allow far better sunlight absorption.

Figure 1: Ridge-style Snowmelt Acceleration Method (Takahashi Kihei)

The results of creating many such ridges in parallel across the entire field and testing them proved remarkably successful, with the snow disappearing nearly two weeks earlier.
This test was conducted in Tokamachi this early spring.
Speaking of Tokamachi, it is a place of particularly heavy snowfall even within Echigo, which is renowned for its snow.
Thus, the disappearance of this year’s heavy snow as much as two weeks earlier must be considered a great success.
Mr. Takahashi had long been conducting research on snow; around the time he began testing this new snowmelt acceleration method, the war situation had grown critical—Iwo Jima already lost, Okinawa also imperiled—and the nation was in turmoil.
Even during such times, in a corner of Echigo buried under snow over a meter deep, this research continued progressing steadily.

The snow melting two weeks earlier posed a major issue.
Farmers claimed that doubling potato production was certain.
While it remained uncertain whether yields would actually double, advancing planting by two weeks marked a groundbreaking development.
The problem lay in how to create such ridges across dozens of hectares of fields.
Since Mr. Takahashi’s research was conducted experimentally on a small area, they relied on manual labor for trench digging.
However, implementing this method in actual fields inevitably required machinery.
Though the principle had been established, devising what might be termed a snow plow-like implement and its practical application presented considerable challenges.
Furthermore, snow tractors would be necessary for large-scale implementation.
Such devices—originally developed for other purposes—had already proven successful in trials, showing ample promise if adapted.
However, research into practical application remained an outstanding issue requiring immediate attention.

Note: This research was subsequently repeated on a large scale at our institute, and it was ultimately found that while ridges did have some effect, spreading soil thinly and uniformly proved more effective.
However, this serves as a good example of how such research progresses through various stages.
(August 23)

V

Regarding the elevation of water and ground temperatures—a problem similar in nature to snowmelt acceleration—we should first consider utilizing solar energy.

Regarding the elevation of paddy water temperatures, it had long been vigorously discussed that methods such as lengthening irrigation channels or temporarily storing water in ponds to warm it were of course well-known.
In Hokkaido, having been chastened by that year’s cold damage, this problem had suddenly been taken up recently, with discussions emerging about using electric heating or utilizing hot springs.
While there was surplus electric power, when considering the total area of paddy fields and the volume of water involved, it should have been employed merely as a supplementary measure.
After all, there was no alternative but to utilize solar energy; therefore, applying results already thoroughly investigated in solar heat utilization research, the principle of flowing water as a thin film over surfaces coated with suitable black paint should first have been tested.
As an agricultural physics challenge, this principle should have been applied by using locally available materials as sparingly as possible in accordance with each region’s conditions.

While the above discussion amounts to common sense, what has been relatively neglected regarding water temperature elevation is snowmelt acceleration.
Though warming water remains crucial, pre-warming the land itself appears equally viable as a method.
If we were to remove paddy field snow cover two weeks early and let the black soil absorb intense spring sunlight for fourteen days, I suspect it might prove unexpectedly effective.
While its efficacy is clear, whether snowmelt efforts justify their labor costs remains unknowable without experimentation.
Proper research must undoubtedly be conducted.
The same principle applies equally to raising ground temperatures in peatlands and similar terrain.

It may seem all we discuss is snow removal, but in snow-prone regions, accelerating melt constitutes—in a sense—effectively controlling weather patterns.
In areas with scant snowfall like Manchuria and eastern Hokkaido, accelerating melt poses no concern; instead, the challenge shifts to ground freezing.
In Manchuria particularly, this issue grows acute—in Northern Manchuria, soil routinely freezes to depths approaching four meters.
Planting inevitably delays as farmers await thawing and drainage of this frozen ground's surface layer to sufficient depth.

According to Dr. Hamada, who until very recently was a professor at Harbin University, the Soviet Union employed a special cultivation method on frozen soil, thereby producing wheat in large quantities in Siberia, which reportedly made a significant contribution to the Soviet food situation during this recent war.

However, that represented a brilliant victory of Soviet science, while it had become common knowledge that in frozen soil regions, people struggled with delayed planting.

However, in snowfall regions, there was virtually no need to worry about the soil freezing.
Snow proved an excellent insulating material; even when air temperatures dropped to around minus twenty degrees Celsius, accumulation to three shaku (approximately 90 cm) prevented ground freezing.
Thus, relying on snow to prevent soil frost during severe cold spells before accelerating its spring melt emerged as the most ingenious method.
Provided one maintained confidence in achieving early melt-off come springtime, one could practically regard winter snowfall as deliberate insulation.
In this sense, snowmelt acceleration research could indeed be considered a form of weather control mastery.

VI

As a third method to overcome weather conditions, let us consider whether we might actively control meteorological phenomena.

Attempts at genuine active weather control appear to have seen some initial progress in America and the Soviet Union.
The Soviets seem particularly interested in this issue, with topics like desert greening, artificial rainfall, and Volga River improvements frequently appearing even in popular science books by Ilyin.
However, these approaches naturally require massive civil engineering projects, making them impossible for our country to immediately emulate.
Let us therefore consider a somewhat more modest methodology.

This year’s Hokkaido rice crop ended in disastrous results, with the damage being felt through daily rationing; let us consider this example.
In paddy fields being considered as candidate sites for the Agricultural Physics Institute's experimental rice fields, ears emerged in late August and remained standing upright as they entered the frost period, resulting in a harvest that was nearly nonexistent.
It was said that the minimum temperature limit required for pollen maturation and normal fertilization during the ear formation stage of rice plants ranged from approximately thirteen to fifteen degrees Celsius.
Even in years of severe cold damage, temperatures rarely fell below thirteen degrees Celsius from late July to early August.
In that case, they should cultivate the rice plants so that the ears would emerge exactly during that period.
Since Hokkaido’s standard meteorological conditions were understood—if one first considered the standard state and knew the properties of rice plants—it should have been possible to calculate when to plant them so that ears emerged during that period.
In this case, the required properties of rice plants would have been the cumulative amounts of various meteorological elements needed from transplanting to flowering, along with the permissible minimum temperature limit.
If one had understood how much those values differed among rice varieties, this calculation could have been performed for each variety.

The transplanting time calculated by working backward from a specified flowering period differed depending on the rice variety.
However, for any variety of rice - provided one planted at its designated time - even slight deviations from standard climatic conditions would likely avoid catastrophic crop failures.
The critical question lay in whether seedlings transplanted at these theoretically derived dates could successfully root and grow.
Suppose we took another variety and calculated its transplanting schedule.
Once determined - one would examine standard meteorological elements for that period and location.
As baseline - take average values from available records spanning decades.
Meanwhile - investigate each variety’s minimum meteorological thresholds required for post-transplant survival and growth.
Such data presumably existed within agronomic knowledge.
While numerous meteorological factors merit consideration - let us provisionally designate water temperature as primary.
Should other critical elements emerge - apply analogous analytical treatment.

We compared the water temperature at the desired transplanting time with the minimum water temperature required for seedlings to take root。
In this case，the former was probably lower than the latter。
Otherwise，they would have already been transplanting earlier。
As for air temperature，it was impossible to artificially raise it at that time；however，regarding water temperature，it remained possible to elevate it slightly for short periods。
If a rice variety could take root even when air temperatures were somewhat low—provided water temperatures stayed above the minimum threshold—that variety showed promise。
Among these，when we selected varieties where the gap between required and estimated temperatures did not exceed artificially achievable increases，those strains could be cultivated to produce ears by late July or early August。

VII

The next problem boiled down to whether seedlings could be prepared by the designated transplanting time once such a variety had been selected.
Since this concerned small-scale seedbeds, the approach was straightforward: perfect the hotbed, freely raise both air and water temperatures to necessary levels, and grow them even if it required some forcing.

Of course, abruptly moving seedlings from an excessively hot hotbed into cold air might have been detrimental, but they could likely have been acclimated to colder temperatures starting some time before the designated transplanting period.
There were likely many such supplementary problems, but with the advanced agricultural knowledge available at the time, there should have been numerous paths to resolving them.

If one selects varieties through such reasoning and cultivates them in this sequence, they would ultimately artificially control both air and water temperatures during the seedling period, control only water temperature immediately after transplanting, then leave the rest to weather conditions—thereby overcoming Hokkaido’s cold damage to a considerable degree.
This explanation may seem somewhat too neat, but if the nature of rice plants is as simple as described above, the reasoning holds true.

The problem lay in the inherent nature of rice itself; should it prove governed by factors beyond those previously discussed, one needed only to re-examine those elements through the same analytical framework.
If temperatures dipping below critical thresholds during reproductive growth phases—say fifteen or thirteen degrees—posed greater peril than cumulative temperature totals, then calculating the probability of such sub-threshold temperatures recurring multiple times and enduring prolonged periods emerged as an even more pressing concern.
This necessitated fresh statistical examination of those probabilities drawn from historical records.

Sunlight would likely be next considered in this problem.
This too would naturally be problematic if insufficient, but I suspect sunlight may be feared more than necessary due to confusion between its direct effects on crops and its indirect effects through the rise in air and water temperatures.
It goes without saying that a certain degree of light stimulation is necessary.
However, since this aspect requires only limited intensity, artificially providing it is entirely feasible, entailing only mechanical challenges.

It would be rare for sunlight to be insufficient throughout the entire period from growth to harvest.
I had heard that pure light stimulation proved most crucial during germination and ear formation periods - remarkably effective even with mere minutes of exposure.
Though my memory might falter on specifics, if irradiation during critical phases sufficed sequentially administering artificial sun lamps across vast fields seemed feasible.
Since sufficiently powerful lamps existed their parallel beams combined with slow rotators and mirrors could yield practical irradiation systems.
Such measures naturally warranted trial if boosting food production became imperative.
Redirecting even one percent of military budgets toward agricultural science would likely resolve most challenges.

VIII

The above discussion had described passive measures against weather patterns, or rather an exceedingly modest approach to overcoming them. This had fundamentally examined standard meteorological conditions. Now required was closer scrutiny of both this normative state and deviations from it.

Taking Sapporo's temperatures as an example, we would observe their standard annual variation. Sapporo maintained records spanning fifty-six years. To construct an annual variation curve from this data—to elaborate precisely—the procedure unfolded as follows: First compile January 1st temperatures across fifty-six years—averaging each day's maximum and minimum—then establish this mean as January 1st's standard temperature. By repeating this process daily throughout 365 days and charting the results, one could derive an annual variation curve.

Yet this proved immensely laborious—conducting such analyses for every region's temperatures would have been utterly insufferable. Upon deeper reflection, the methodology revealed itself as fundamentally meaningless.

If one takes an average over decades, the standard temperature for a given day becomes fixed—a calculated value that remains abstract in nature. In reality, temperatures on that particular day each year deviated considerably above and below this standard value. These deviations proved unexpectedly large; Sapporo’s September 15th standard temperature averaged over fifty-six years stood at 16.5 degrees Celsius, yet actual temperatures across those years ranged widely from a maximum of 23 degrees to a minimum of 11 degrees. That said, years exhibiting such extreme deviations remained rare, with most annual temperatures clustering closer to the standard value.

To visualize these fluctuations, researchers developed what they termed frequency curves—graphs plotting annual temperature occurrences against specific temperature ranges. When designating temperature values, they found it necessary to establish measurement intervals; in this case, one-degree increments were adopted. Thus emerged data showing seven years with temperatures between 14-15°C and ten years within 15-16°C—represented respectively as fourteen-point-five degrees occurring seven times and fifteen-point-five degrees occurring ten times in Figure 2a.

While fifty-six years’ data proved insufficient for eliminating scatter points, the results broadly formed the anticipated bell-shaped probability curve. This curve’s morphology expressed deviation likelihoods from the standard value—a tall, narrow peak indicating limited variability versus the actual gently sloping hill that revealed substantial spread. The quantitative measure of this dispersion became known as probable error: defined as the range around the standard value containing equal numbers of occurrences inside and outside its bounds. In this instance, that error reached a significant ±3.8 degrees.

Figure 2: Sapporo Temperature Frequency Curve Over 56 Years (Arakawa Jun)

When annual values exhibit such wide fluctuations, a standard temperature value for any specific day becomes practically meaningless.
However, given crops' inherent compensatory capacity, temperatures on individual days prove less critical—even if slightly cold conditions occur, subsequent warming typically allows recovery.
We therefore adopted five-day temperature averages as proxies for their midpoint days' temperatures to analyze annual variation patterns.

The average temperature over these five days appeared in the meteorological observatory's original records as a five-day average.
Thanks to the kindness of the Sapporo Meteorological Observatory, we were shown this data and consequently could create the frequency curve.
When creating a frequency curve for fifty-six years’ worth of temperature averages across five days around the aforementioned September 15th—specifically September 13th to 17th—the resulting form appeared as shown in Figure 2b, with the probable error becoming a smaller value of 2.6 degrees compared to previous figures.
Furthermore, when examining the average temperature over one month, the probable error became a small value of 1.6 degrees, and the frequency curve formed a narrow, tall peak as shown in Figure 2c.
The fact that expanding the range over which averages were taken reduced the probable error indicated that there was regularity in seasonal changes.

The smaller the probable error became, the greater practical significance the standard value gained.
To achieve this broadening of scope sufficed.
However averages taken over excessively broad ranges lost meaning from crop growth perspectives.
This recoverable period differed markedly by crop type - even within rice varieties alone distinctions likely existed.
Moreover it would naturally vary across growth stages.
On this matter we could only defer to agriculturists' judgment.
While specialists might already know this we elected provisionally to adopt five-day averages for our discussion.

IX

Taking the standard value of climatic five-day period averages and plotting their annual variation resulted in what appeared as shown in Figure 3.
In this figure, the black dots indicated their respective values.
Interestingly, when the monthly average standard values were plotted as white circles atop it, they fell precisely on the same curve.
Therefore, to create an annual temperature variation curve, one would take the standard values of monthly average temperatures and connect them with a smooth curve.

Figure 3: Sapporo Temperature Annual Variation - 56-Year Average (Arakawa Jun)

For this purpose, the Central Meteorological Observatory had published a convenient table called the Climatic Tables of Japan.
This table displayed the standard values of monthly average temperatures for each weather station.
This book had been classified during the war but could now be freely accessed by anyone.
The necessary numerical values were in this table, and since only twelve points needed to be taken, the process became straightforward.
Creating standard annual variation curves for all locations nationwide was also easy.
The laborious process of calculating daily standard temperatures could now be safely eliminated.

The standard annual variation curve could now be created this way alone remained insufficient.
Only by supplementing it with probable error ranges could one establish benchmarks for how much temperatures deviated from standards in any given year.
Yet as previously noted—since probable error varied depending on averaging periods—we resolved tentatively to adopt five-day averages for preliminary analysis.

Figure 4 presented Sapporo’s case from that year.
Though depicting only early spring through late October intervals within its frame，this illustration revealed summer cold damage’s severity through jagged deviations.
Within its coordinates，the thin solid line traced standard annual variation，while paired dotted lines demarcated five-day average probable error bounds.
Plotting that year’s five-day averages yielded Figure 4’s serrated trajectory—a thermal seismograph etching agricultural catastrophe.

Figure 4: 1945 (Showa 20) Temperatures (Arakawa Jun)

From early May through late June, temperatures remained consistently low, with many periods falling below the lower limit of probable error.
The probability of falling below this lower limit stood at one-fourth—meaning cold damage occurring once every four years struck this year.
However, matters grew even worse.
From late June to early July, temperatures rose slightly abnormally, but from July 10th through the end of the month—the most critical period—severe low temperatures struck.
Low temperatures approaching twice the probable error were recorded—cold damage of a severity seen once every decade.
Under these circumstances, a disastrously poor harvest became inevitable.
Throughout autumn, temperatures remained at standard levels, and upon entering October, they even rose slightly above the upper limit of probable error—but by then, recovery was already impossible.

The phrase about suffering terrible cold damage this year was heard almost daily, yet no one specified during which month or period they had experienced "cold damage of what degree."
Quantitatively expressing cold damage constitutes the first step in its scientific handling.
Without establishing this first step, progress becomes impossible.

Admittedly, specialists in agricultural meteorology may have long known such things. However, it remains a fact that neither experimental stations nor agricultural associations generally possessed such knowledge.

While it may not reach every individual farmhouse, it would be desirable for at least regional agricultural associations to possess their respective local standard annual variation curves and probable error curves, continuously monitoring weather conditions by plotting that year’s temperatures every five days on these charts.
It is the same as how a temperature chart becomes necessary during a prolonged illness.

These statistics were created by Dr. Arakawa of our laboratory. When he produced "fever charts" of crop failure years since the Meiji era at his desk, it became clear that they could be classified into two types, one of which was the pattern shown in Figure 4.
If scientific measurement of cold damage becomes possible, such matters will gradually come to be understood in greater detail.

X

Another challenge for agricultural physics lay in the problem of devising new instruments.

The instruments and measuring devices traditionally used in agricultural physics or agricultural meteorology seemed to largely consist of existing tools employed without modification.
For example, whether galvanometers, thermometers, or anemometers, all were existing instruments from conventional physics or meteorology that were used without alteration.
While such instruments were certainly necessary, there also seemed to be new types of devices particularly required for agricultural physics.
The creation of such new devices indeed constituted one of our tasks, and this necessitated specific requests from agricultural scientists.

For example, in research on the relationship between crop growth and air or water temperatures, cumulative temperature would often hold greater significance than temperature at any given time. In that case, it would be convenient to create something like a cumulative thermometer. If one measured the temperature every hour of every day and summed those measurements, one could obtain the cumulative temperature—so one might argue there was no need for such a new measuring instrument, and that would settle the matter. However, it would prove far more convenient if one could simply toss it into a rice paddy in early April and then easily read from a scale around June: "This year's cumulative temperature still falls eighty degrees short—we must take action now."

Such cumulative measuring devices have long been used in electrical applications—the "meter" installed in every household kitchen being one example.
Therefore, if one were to convert temperature into electricity and use that meter, it would in principle be clearly feasible.
However, employing such devices in rural areas—particularly outdoors—hardly constitutes an intelligent approach.

Accordingly, Dr. Magono Chōji of our laboratory exploited a physical property that changes linearly with temperature—one varying in exact proportion to thermal conditions—to devise a simple cumulative thermometer.
This involved channeling water through a slender capillary tube and dripping it as minute droplets from the tip.
The product of these droplets' size and quantity—that is, the total volume of discharged water—is governed by water's viscosity and surface tension, both properties that undergo significant temperature-dependent alterations.
Remarkably, these changes maintain precise proportionality to temperature variations.

An example of the experiment was shown in Figure 5.
The vertical axis of this graph represented the volume of water dripped per hour, while the horizontal axis indicated the temperature at that time.
From near zero degrees to about thirty degrees—within the temperature range ordinarily required for agriculture—the proportional relationship remained extremely accurate.
In an actual room with changing temperatures, when thermometer readings taken every hour totaled 228 degrees, the value measured from the total volume of dripped water amounted to 227 degrees.
The match was almost too perfect.

Figure 5: Calibration of Cumulative Temperature (Magono Chōji)

At present, this cumulative thermometer was only designed for approximately one week of use; however, were glasswork techniques to improve and some structural modifications added, creating versions lasting one or two months would likely not prove especially difficult.
Even for the one-week model, taking readings and replenishing water roughly once weekly would likely not have been particularly troublesome.

While this cumulative thermometer is but one example, the creation of such instruments is not particularly difficult.
When it comes to measuring temperature, the problem lies in the common assumption that thermometers are the sole available instruments.

11

The above discussion was that of a physicist who knew nothing about agriculture.
Therefore, its significance lay not in its content but in its methodology.
If physics was to prove truly useful to agriculture, this utility would reside not in devising specialized instruments or occasional clever contrivances, but rather in introducing a rigorous mode of thinking into agricultural practice.
This principle naturally extended beyond agricultural physics alone.

I have an interesting experience regarding that.
It was around mid-autumn when I visited the former farm of the late Mr. Arishima Takeo.
That farm lay at the heart of a region said to be Hokkaido's main potato-producing area.
In one basin there were thirteen agricultural cooperatives, and it was when I visited the cooperative head.
The topic of this year's potato harvest arose. Among those thirteen households, a person long known as a skilled farmer had again yielded fifty bales per *tan*, whereas the cooperative head had managed only twenty-five bales.
What astonished me was that the other cooperative members had achieved at most fifteen bales, with most yielding only around ten bales.

If we’re talking about ten versus fifteen bales, that might be a matter of skill difference, but when within the same basin we have ten versus fifty bales, this cannot be explained by mere skill difference.
I was surprised and attempted to ascertain the cause of this disparity.
Was it due to differences in cultivation methods, disparities in soil fertility, issues with fertilizer or labor, or perhaps—even within the same land—considerable microclimatic variations? I inquired which among these was the most significant cause and which should be considered secondary.

I elaborated various explanations and inquired thoroughly, but the response was: “Well, I don’t understand such matters. After all, that person is a skilled farmer here—they’re simply adept at growing potatoes.”
This problematic outcome stemmed from having taught them the term “skilled farmer.”
Merely being adept at potato cultivation does not account for harvesting fifty bales.
The crucial issue lies in understanding the specifics of their skill.
If the problem proves too complex to grasp, that would be acceptable; what truly vexes in this situation is the complete refusal to even contemplate such questions.

While officials and lawmakers were frantically clamoring about food production increases with plans like reclaiming millions of chō of land, it painted an amusing picture to see fifty-bale and ten-bale yields existing nonchalantly side by side.
We too had dreamed of doubling our yields next spring by accelerating snowmelt, but if this meant doubling ten bales, it would become a laughable joke.

12

When it comes to groundbreaking production increases, recent newspapers reported that the government had formulated plans to reclaim millions of *chō* of new land and achieve an increased yield of something like ten million *koku*.
The very notion that increased production must immediately mean reclamation was an utterly witless approach.
These days, one often hears people say, “When things get truly desperate, I’ll just become a farmer”—this mentality being precisely comparable.
Since farming is the most demanding occupation, returning to agriculture cannot be undertaken so lightly.

Land reclamation was certainly necessary, but what mattered more was increasing yields from existing cultivated land.
The comparison between fifty and ten bales of potatoes per *tan* constituted an extreme example, but even without such disparity, raising ten bales to twenty in this case seemed relatively simple to achieve.
If that had been an exceedingly difficult task, one's neighbor would never have managed a harvest of fifty bales.
And rather than speaking of turning ten bales into twenty—securely increasing them to thirteen or fifteen bales represented what counted as a groundbreaking production increase.
Such measures posed no issue for extensive agriculture like that practiced in Hokkaido.
As for intensive agriculture in regions like Honshu, while the rate of increase would likely be smaller, I felt that merely introducing some scientific thinking might render it achievable to a degree.
However, having not yet actually engaged in farming myself, I could state nothing definitive.
When I inquired about one skilled farmer's method for raising water temperatures, it turned out to involve placing an iron plate over the irrigation intake and burning a fire atop it.
Such measures appeared achievable.

Securing some percentage increase in yield without using materials or altering methods, but by meticulously applying detailed attention throughout—this was true agricultural physics, and that was what was most crucial at the time.
Since such was the essential nature of physics, agricultural physics would likely prove no exception to this pattern.
However, in reality, that which appeared most straightforward proved to be the most arduous.
Rather than that, raising water temperatures or accelerating snowmelt was far easier and more in line with agricultural physics.

13

To melt snow, scattering soil sufficed, and for raising paddy water temperatures, this year too we had achieved favorable experimental results using electric power.
One might have thought the problem had already been solved.
However, actions like "absorbing solar heat through soil" or "utilizing electric heat" alone do not constitute physics.
At what time period, using what type of soil and scattering method, could we achieve the greatest effect with the least labor?
That is ultimately determined by the general weather conditions of that year, the topography of each locality, the microclimatic conditions of the area, and the snowmelt method.
Raising water temperatures involves even more factors—the complication lies in having to seek the most effective method for each respective stage of crop growth.
The accumulation of such detailed knowledge pursuing what might be called technical minutiae constitutes not periphery but agricultural physics itself.
Grand plans prove hollow in reality.

At least grand plans involving electric heating were still somewhat reasonable, but recently, when I met a technician from a village agricultural association, they told me they were troubled by a directive ordering them to “achieve increased yields through water temperature elevation.”
I had thought grand plans were confined to the political sphere, but they appeared to have infiltrated agricultural physics as well.
In short, humans in any field always seemed inclined to take the easier path.

In contrast, the work of truly establishing the essence of agricultural physics proved an extraordinarily arduous and challenging endeavor.
Physics constitutes the discipline that distills purest principles from infinitely complex natural phenomena, but I maintain that agricultural physics should be a discipline employing knowledge of those principles to directly confront complex natural phenomena themselves.

If this holds true, researchers must necessarily immerse themselves within nature's very core—to speak concretely, reside at experimental farms and personally undertake cultivation.
True agricultural physics research is conducted through farming alongside ordinary peasants while observing reality through a physicist's lens.
Physics could attain its brilliant modern achievements precisely because its subject matter comprised simple inanimate entities like molecules and atoms.
To blindly apply identical methodologies to agricultural physics—which addresses weather patterns and living organisms—under the spell of those dazzling accomplishments would be profoundly perilous.

Until now, it had been impossible to secure many outstanding young physics researchers for this kind of work—extremely difficult, laborious, and yielding unspectacular results.
That was likely the primary reason physics could not be introduced to agriculture.
However, today the circumstances have completely changed.

It may be wrong to say we are taking advantage of defeat, but today is precisely the opportune time to establish agricultural physics in our country.
If through this endeavor we can contribute even modestly to realizing the human miracle of seventy million people living comfortably within 360,000 square kilometers, then all such labor will be amply repaid.

(December 1945)