I have been following the development of Inga alley cropping in south america for quite a while and I am very excited by the results to date. https://www.ingafoundation.org/alley-cropping/ The idea is to use rows of densely planted ice-cream bean (inga) allowed to grow to 2-3 m to form a weed suppressing canopy and dense mulch to create a weed free space. You then chop back the trees, chop and drop the resulting green mulch, and sow an annual crop like maize through the mulch. This is easier than clearing grass to sow, protects the soil from disturbance and erosion, enriches the soil with nitrogen and deep soil minerals, and also provides firewood and fodder for animals if wanted (goats adore inga leaves and pigs love the pods). By the time the inga canopy closes over the crop is finished, then you rest the land until ready again. I have started my own trials now I have farming land to work on. I have started on a section of creek flats that occasionally gets inundated by slow moving water for about half a day each year. The soil here is deep and silty. The area was originally kikuyu pasture. I cleared it back with glyphosate last winter in 2014 over a patch of about 40 x 10 m making three long cropping rows between four rows of alley trees. (say what you will about the choice, but I am content to use it for landscape transformation as long as I don't get in the habit of using it for repeated maintenance). I sowed the main alley rows with pigeon pea as a pioneer last spring in 2014 and now they are all about 3 m tall and nicely shading the tree rows. I also planted bare root seedling Inga seedlings about 5 cm high in the spring from a mass planting pot, but about 90% of them didn't take due to the very dry spring. I suspect the direct sunlight finished them off as well- dry shade might be tolerated better. This autumn after the summer rains I planted out 10-15 cm tall Inga seedlings grown on over summer in 4cm tubes, about every 50cm within the rows. The shade from the pigeon pea made establishing them much easier. I also tried sowing excess Inga seed directly into the positions, but I was worried about rats taking them so sowed them about 2.5 cm deep, too deep it appears so only about 10% germinated successfully (lots of others found germinated but still buried a month later). The area also grew a magnificent crop of about 10 feedbags full of open pollinated white maize over summer, and I could have sowed twice as much again in the space. The ground is gradually covering up with Vigna parkeri and other soft weeds, and I spot spray/hand weed/ hoe any reestablishing grasses. I think next patch of pasture I will clear this winter, spring sow pigeon pea and other crops and then surface sow the Inga seed in the early autumn and just cover with a handful of hardwood mulch. This will save on potting and maintaining the Inga seedlings all summer, and making planting them out a lot faster (I can sow 40 seed positions in about 20 minutes, versus an hour for seedlings that need a deeper hole and greater care). Some of the few Ingas that did establish in the spring are now over a foot high, so they can grow quickly once established. I figure by the time the pigeon pea are running out of steam (2-3 years) the inga will be big enough to take over their role. I also think the system will work very well with arrowroot as the crop between the inga rows. This crop is ideal because it is tolerant of being harvested at unpredictable times, and also relatively shade tolerant, making the timing of pruning the inga easier. It also grows it tubers above ground so soil disturbance will be minimal (unlike cassava) and its aerial parts also make good animal fodder. I will be planting the first section rows to arrowroot tubers over the winter so they can take off in spring. Interested to hear if anyone has some feedback on my approach or suggestions. I'm in subtropical Australia, mild frosts every few years, hot humid summers, unpredictable rains at times, reasonably good old volcanic soil.