ghajar

Since you mention it, I think an even better system would be to simply have every crop remove all three nutrients, but in different amounts. Crops need all three to grow, of course, and a host of minerals, as well as a certain range of pH, but to keep things relatively simple, focusing just on NPK is more than enough to improve realism and add challenge to the game. Most crops will remove more N than P or K--even legumes, if the aboveground leaves are harvested or not incorporated back into the soil. This website has a handy illustration of some removal rates for different crops when completely harvested: https://www.ipni.net/app/calculator/home If you click around a bit, you'll see that most crops listed will remove N the most, K the second most, and P the least of the three. There are some exceptions when it comes to the P and K side, like sunflower grain will take more P than K off a field, but in-game they're an N--which should be the case for nearly every plant, if we had to pick one of the three to focus on. That's why I think having each plant take NPK (unless it's used as a cover crop and/or is a legume) but in differing amounts would be the most realistic and add richness to farm management in-game.

I just want to start off by saying this is by far the best survival game I've ever played. It's amazing, and the level of detail and immersion are beyond impressive! By way of background, I do agricultural research for a living, so perhaps I'm the only one who cares about the crop side of this so much, but here are some quick suggestions to tweak things for realism and gameplay. Leguminous crops such as soybeans and peanuts should add a little N to the soil--in real life, soybeans sequester at least 30-50kg/ha of N, and often much more if the crop residue is incorporated into the soil after harvest; peanuts can add even more that. This would be a nice addition to the game IMO. Some science for those who may be interested: PDF Cover crops! Cover crops IRL can add nitrogen if leguminous, and/or scavenge NPK from deeper soil layers and make the nutrients more available for the next crop on the land. Perhaps this could be implemented by growing a crop and using a hoe on it to incorporate it into the soil instead of a knife/scythe to harvest. Manure is already added in mods, but IRL we use poultry litter extensively as an organic source of NPK. It's fantastic stuff. Maybe the laying bins already in-game could be cleanable to get a small amount of poultry litter. Forage crops specifically for sheep or other future ruminant species could be fun--alfalfa and red clover are both fantastic forages AND if used of cover crops, add tens of kg/ha of N wherever they're grown IRL. These wouldn't directly feed players, but would feed soil or livestock. Anyways, as someone who works in agriculture, and flintknaps and smelts bronze IRL, I am just delighted to have gotten this game. What a treat, and an obvious labor of love by devs!