Hi, I am looking to develop a piece of land in Thailand into a food forest/orchard. The empty piece is part of a bigger plot of land, and wasn't planted because the farmer found that the land was quite sandy and therefore not good at retaining water. The land is essentially flat, and will have access to water as close to a river. For now I have just planted sunn hemp to increase the bio mass. My question is essentially if swales have any purpose on flat, sandy ground? Or, do I just leave the land flat given water in any case drains down fast? Any experience/insight you can share would be much appreciated!
what is your water table like? instead of moving water from a river you may do better by pumping from a shallow well if your area has the groundwater. may save a lot of energy. pay attention to your amounts though because you want to keep your water use within the natural recharge rate. for large flat areas with very heavy rains some berms and swales can come in handy to keep flash floods from removing your topsoil and to give places to walk out of the water. i have no experience in tropcial/sandy/flatland though. here it is flatland, but clay, after a few days of rains we can get flash flooding so i have bermed an area hoping to protect the gardens out back. it hasn't been needed yet. as usual with any area with poor topsoil i always recommend people improve/amend to make it better if they can get the materials easily enough. for a sandy area i always bring in clay/loam and organic materials. for garden areas it makes it much easier to not have to water frequently and the plants do much better for the effort involved.