Presumably, with some somewhat simple PODs, most of which would have do with ignoring Lysenko's nonsense, the Soviet Union could achieve agricultural production levels that could feed it's domestic populace without the need to import by the late 50s.
The question I have is if this did happen, what effect would this have on the Soviet economy long term?
If it could become a net-exporter of foodstuffs, what effect would this have on western economies?
I avoided this thread because I despaired of anything good. I accept that the Communist system failed to motivate the farm workers to be as productive with what they had as Western capitalist landowners are. And that Soviet land was not all that good--not the worst and there was a lot of it, but like someone upthread said, like North Dakota on the verge of a dust bowl. And that some of Khrushchev's schemes did considerable harm due to lack of environmentalist insight and lack of effective internal political feedback to put the brakes on what was not working.
Put all that together and the POD seems pretty Utopian, so why look?
Now I see this OP. Skimming it, I took it to mean you had done some studying of the matter and that there are authoritative sources that outline how Russia (maybe with the help of other lands, like fining sustainable ways to farm more of Kazakstan or some other 'stans, or even growing a lot in Siberia) could technically have done it, and others or your own reasoning showing how it could have been done in a fashion suitable to Bolshevik ideology that still gives the farmers the incentives to deliver. And that you'd be pulling out your research and evidence to address in thread criticisms.
Now reading again more carefully, having seen quite a few caveats posters have offered reinforcing my initial pessimism, I see that you start with "Presumably." Yes, Lysenko falling down a well might have been a help, but it was after all Stalin who liked what he had to say, and presumably was looking around for someone who would say what he wanted to hear.
As also pointed out, the USSR generally did grow enough to give the populace a sustainable diet. Just not the sort of food they wanted to eat; they'd have to find ways to make more vegetarian/grain based meals both balanced nutrition and tasty instead of trying to treat the populace to more meat. Makes me wonder what switching everyone from red meat to mostly chicken might have accomplished.
So anyway---why "presumably?" just because Russia is big? Yes, but it is far north and inland on the biggest continent on Earth, which is to say desiccated! Why else would we presume the Soviets would be anything but hand to mouth? Another poster points out they used to export grain under the Tsars, and another that those exports coincided with famines--if Stalin didn't care about the fates of peasants, neither did the Romanovs.
I think that exploiting the land capitalist style surely would have resulted in better production but for whom? Who would have the money, or other goods the farmers would regard as being good enough to substitute for money, to pay on the scale needed to motivate superior production? Soviet rubles are useless unless the Soviet economy as a whole can produce a sufficient mass of consumer as well as capital goods to exchange for it.
Anyway the Bolsheviks most certainly would not like the prospect of the countryside being run capitalistically. It would be reneging on Lenins's promise of land and bread; no bread for the city industry workers who were the core demographic of Bolshevik support, no land for most peasants who would be squeezed out of effective ownership and control by rationalizing successful farmers, just a fraction of the agrarian demographic and the least friendly to Bolshevism. Maybe if the Bolsheviks had partnered more resignedly with the agrarian Social Revolutionaries, which was technically Kerensky's party by the way though I don't think he was accurately representative of their interests. But they were deep rivals, and the countryside interests would deadlock the urban industrial interests, so they cut through by taking over from the SRs.
Lenin was not "OK" with small scale capitalism. Neither were any leading Bolsheviks nor most of their rank and file who'd survived the Civil War (with much decimation). They launched NEP in sheer desperation. It looks good to liberal westerners, but awful to the Bolsheviks--a slap in their own faces to see chic little shops for people who had money opening up while the workers went hungry. A sop to the very kinds of people they swore to turn out and apparently if they could kill in vengeance for their greedy squeezing under the old order--now it should be their turn to starve but look at them, getting rich again! They hated NEP and the people it empowered and the fact that Western critics were mollified by it was just another stroke against it.
So too in the countryside. In the country, restoration of peace enabled farmers to grow more crops and live better than they had--ever really. Once again, the sacrifices of Red Workers turn to someone else's benefit and the Bolsheviks were turning even redder with envy. The farms, especially larger consolidated farms controlling the hired labor of less capable peasants who alienated control of their land for wages--meagre wages but better than they could do on their own--could produce plenty of food, but what did the city Soviets propose to give them for it? To make the consumer goods the countryside wanted on a scale they would judge fair versus the bumper crops and other foods they could offer would not be possible for Soviet industry damaged by the Civil War and with the cadres of the most loyal and intelligent experienced workers lying in graves for the most part they lacked expertise to rebuild as well. (POD--avoid the war, maybe by cutting a deal with the SRs early on if Lenin could ever stomach that, minimize the harm the foreign backed Whites could do with combined worker-peasant CPSU /SR armies, fewer defections of moderates to the White side--minimize the time wasted, the Red cadre lives lost, the generalized damage and sabotage and just maybe the Red controlled industries might under some sort of clever socialist organization delivered enough of the goods the farmers wanted to keep them happy and legitimately buy the food the workers needed. Perhaps).
The solution was political and terroristic of course--"simply" impose collective organization on the peasants and compel them to raise the food needed. With that decision regarded as inevitable, it was inevitable Soviet food production would become inefficient. It might not have been necessary to define adequately socialist countryside in such an extreme way, and it might have been possible to find a semi-market based solution that worked well enough for the USSR to still call itself socialist and hold out the hope that industrial labor and its rewards would be handled on a truly communistic basis, and shared with the countryside on terms the city could regard as reasonable or even favorable. But the Bolsheviks had little patience with revisionist shilly shallying around with markets, and systems that let some private owners grow rich while the majority of farm workers lived dependency on their handouts. This is not what they would promise the farm workers of the developed world and it would not inspire them to join a global Red revolution.
So--what are the relatively "easy" reforms that post-Stalin, or even with him, and by avoiding Lysenko, the Soviet authorities could come up with to encourage and entice better productivity from the marginal land? Having worked harder to produce more food what is the reward the country folk could expect for their benefit and how to avoid it producing a class of landed millionaires keenly interested in privatizing Soviet industry maybe willing to cut a deal with foreign invaders to accomplish this?
To what degree could Soviet industry, producing tractors or fertilizers or what have you, not to mention consumer goods desired in the country, enable higher yields in a sustainable manner, and again, why and how should Russian peasants, the stepchild of Lenin's favored urban proletariat, learn to use the higher tech and how do they benefit from it? OTl the USSR kept a higher percentage of people on the land than western developed nations did, but even so legions of peasants flocked to the cities and mines and new plant sites to become industrial workers--although they often managed to get a little plot of land and work the hell out of it, growing vegetables for themselves, raising chickens, and selling their surplus their neighbors--without this overtime work and side market, Soviet cities often would fall short of basic nutrition. Had that kind of intensive labor been done on the collective farms, the nation would be rich in food indeed! The more successful mechanization and other industrial type investments were, the fewer countryside farm workers would be needed. Who stays, who goes?
Before the question you focus on--what will the Soviet authorities do with the food surplus "presumed" to be available by say 1960 at the latest--can be asked, the industrial sector must first pick up to provide the agricultural sector the inputs and consumer goods it needs; if they can do that, perhaps Soviet industrial products can be sold abroad as well? Probably not; even with superior quality control the idealized socialist lifestyle would require different designs for different functions. Still they might export products targeted say for the rising Third World markets, to compete with European, US and Japanese exports?
They would do well to focus primarily on gratifying the farm sector markets, durable good washing machines, ovens, vacuum cleaners, better and more tractors and other farm machinery practical to maintain...this sort of output at a fair price might have done much to incentivize better food production practice. Again maybe--trying to squeeze good crops from marginal land might work well for a few years but then deplete the soil and other bad ecological outcomes, pollution from fertilizers and pesticides-the Soviet agricultural research establishment had better know what they are doing for sustainable results. OTL various fads that looked good to Party planners on paper--Khrushchev with a background in agrarian management but Stalinist style was vulnerable to being swayed by these looked like quick solutions but overlooked serious side effects that set productivity back after a few years of apparent success as with the "Virgin lands" program. If the Party is self-disciplined enough to make sustainability a key metric overriding quick dirty short term results to gain promotions for the apparatchiks, they could probably do better than OTL.
But the land remains scattered and margins, infrastructure scarce without massive investment to cover larger distances between good crop areas, more intensive work for poorer results than could be expected on American land would be the norm. It is no easy row to hoe,
I think if you've got data that tips the balance toward "presumable" success, it is time to share it!