If only 20% of Ukraine is under Russian control, all being far in the east, away from the Polish border
If enormous amounts of donated western APC’s, ATGM’s and even tanks can cross the Polish - Ukrainian border, meaning it’s obviously more than safe enough for passage of civilian goods
If the wheat can’t magically teleport from the fields to the ports like Odessa, but first has to be transported there with trucks and rail, then…
…why can’t it simply be transported straight into Poland, instead of adding an additional complicated step of introducing boats in the equation?
Is it because ships can transport more than trucks can? Well that absolutely doesn’t matter, since trucks still need to transport the same exact amount to the ports in the first place. Not to mention the amount freight trains can transport at a relatively cheap cost.
Let’s say you have 10 trucks, and the boat can carry 100 truck loads. So to carry the same amount the same distance, each truck would have to make 10 trips. Even if the road distance was the same as the water distance, and they maintain the same average speed, it’s still going to take about 10 times as long to deliver the same amount.
And that’s not taking into account a bunch of Russians blowing up your bridges and such.
It absolutely does matter, because nobody has a private army of idle trucks to devote to the cause, and nobody has idle agricultural seaport capacity to take that much additional traffic. Plus trucks have additional overhead as far as loading/unloading and crossing international borders. Plus Russian missiles can still hit everywhere in Ukraine, and it would not take many attacks to deny the use of land shipping routes if it was a strategic priority.
If the price of grain goes up enough to justify reallocating to road and air, then we’ll start to see it shipped by road and air. Things would have to be rather dire for that to happen on a large scale.
Ukraine is exporting grain through land, but as has been pointed out there’s significant added overhead. Gas is also in short supply, so expensive and diverted to war efforts. Additionally Ukrainian rail is broad gauge, so any rail export has to be transferred to standard gauge trains at the border.
Also don’t forget that there just isn’t as much grain to export. You’re obviously not growing anything on the land that has tanks rolling through it, and even in the western parts of the country, a lot of the folks who would be growing grain are instead in the east fighting.
Moving grain requires ports with the necessary infrastructure to handle it. Just trucking over the border to Poland does not solve the problem. It is long way from there to ports where it can be exported in volume. Those ports may not have spare capacity because they will be sized for exports from the regular European grain harvest.
It is rather like the situation with the natural gas pipelines, it is not just a case of turning a tap to divert huge quantities in another direction. Infrastructure takes years to build and get operational if you want it flow in a different direction. The UK has Liquid Natural Gas terminals and pipelines to Europe that are working at capacity to supply Germany and other countries.
Something similar would have to be put in place with respect to grain shipments. Otherwise the Ukraine grain harvest will get stranded on the farms until the ports are unblocked. For that, Putin will want the sanctions lifted and he will not want Ukraine to benefit from these exports. There are reports of grain from occupied territories being sold as Russian.
So this is another bargaining chip in the economic war. The losers will be the countries dependent on Ukrainian grain exports, the poor will find the price of bread sky high. Europe is not directly dependent on this grain, but there are plenty of countries that are:
A similar situation prevails with the export of fertilizer and that will also increase the cost of food very widely.
Gasoline is in extremely short supply to the point that it is inhibiting people from fleeing westward in personal vehicles. The military is largely running on petroleum reserves which is a concern because while early in the was it was Russia that was suffering from logistical shortfalls it will soon be Ukraine that is running out of fuel, ammunition, and matériel unless the NATO member nations start providing these resources. For all of the “We stand with Ukraine!” rhetoric a lot of the European states are starting to look at what a winter without Russian oil and gas and Ukrainian wheat is going to do to their economies and likely starting to weight the advantages of some kind of negotiated settlement that will let them justify easing sanctions on Russia.
As for shipping, grain has to be shipped in purpose-designed bulk cars and containers to facilitate onload and offload; you can’t just load it into a CONEX or boxcar. Ukrainian ports on the Black Sea are specifically constructed with facilities for loading grain in bulk because much of Ukrainian grain goes to Turkey, the Middle East (especially drought-ridden Syria) and North Africa, so sea transport is faster and more direct than driving or train route through Moldova, Romania, and Bulgaria. But without being able to ship through the standard ports they just can’t move the same volume of grain. Like the rest of the globalized system of commerce it is well optimized but not robust (or “anti-fragile” as Nassim Nicholas Taleb would define it), and this disruption has major global impacts upon food security.
If rail is used they would have to face the problem that the track gauge changes at the border. Ukraine uses the Russian gauge of 5 feet (1,520 mm) while Poland and nearly all of western Europe uses standard gauge which is 4 feed 8 1/2 inches (1,435 mm).