Legumes are neat, useful, fascinating crops, and we grow a lot of them. So here’s a quick tour through the different types and uses of legumes on our farm.
Beans, peas, clover, and other legumes improve nitrogen levels in their soil through a symbiotic relationship with specialized bacteria which live on the plants’ roots. These bacteria fix nitrogen into the soil through the nodules shown above, increasing the usable amount of this essential element for future crops without the need for artificial fertilizer. Thus, legumes are an essential part of most crop rotations, particularly on sustainably minded farms.
Legumes are a good crop for us, as they improve our soil naturally while being reasonably easy to manage. The fast growth and wide canopy of bush-type varieties, like the soybeans shown above, crowd out weeds pretty quickly and don’t take nearly as much weed management as, say, lettuce. They are susceptible to some insect damage, but with healthy plants and soil we haven’t had too much trouble with this. We also grow vine-type beans on tall (8+ feet) trellises, which have me up a ladder almost every day picking.
In fact, harvest is definitely the hardest and most time-consuming part of growing legumes, at least for us. Fresh items like snap peas and green beans need to be picked every day or two to get the individual pods at optimum size. We picked any given planting of edamame every 3-4 days, and at the peak of soybean season we were in the field for 2-3 hours almost every day picking along the rows. Some folks just let most of the plant mature and harvest all at once, but we feel our approach yields a higher percentage of edamame at an optimum size for the best quality. Another option is large mechanical harvesters, but heavy equipment brings a whole new set of costs to the table, including soil compaction and damage, pollution, and cost. We’re a manual farm and prefer to keep our costs personal rather than mechanical. Manually picking each planting 3-4 times ensures that the customer gets the highest quality edamame, and really increases the overall yield as well.
Other legumes are meant to be harvested when dry, like cowpeas and the mixed heirloom beans shown above. These we let go until the plant starts to die back and the pod dries up, then we move along the row pulling whole pods. We prefer to let beans of this sort dry in the field, but this year has been so wet that we have beans sprouting in their pods before they ever fully dry. So we’ve been harvesting whole rows and bundling the half-dry plants, then hanging them from the rafters of our barn to finish drying. Shelling these is a major project, so we’re likely to order a small mechanical sheller to make the task practical. The flavor of the above beans is truly fantastic, like nothing you’ll get in a store. We’re trying to decide whether and how many to sell versus keep.
Legume beds are also easy to turn around to the next crop. Above is a set of four early edamame beds that we were able to quickly clear, hoe, and replant into fall crops because the heavy bean bushes shaded out most weeds and kept the soil in good condition. I have a photos series from this vantage showing us clearing the old plants, hoeing, seeding, and mulching. When I have time, I’ll convert that into a stop-action series showing how this quick turnaround is achieved.
So anyway, we like legumes, they’re fun to grow, they improve our soil, and they provide us and our customers with some of the best-tasting and unique food on the farm. Pretty good for a staple plant.