Flood irrigation question

Welcome Darren, We have 6 acres of mixed pasture which varies 3 to 7% grade all of which is flood irrigated. Without going into the details of our place do you have any general comments on the potential cautions and benefits specific to flood irrigation. We get water from April through August and other wise it is fairly dry, our annual rainfall for our part of Montana averages 12 inches. Hoping this is not just too general of a question!

Thanks Scott,

These days with the advent of plastic pipe and technologies such as K-line irrigation (from NZ) etc. I think that flood irrigation is no longer that relevant. Another issue is that it uses a tremendous volume of precious water and so a lot of properties are not going to have access to it, especially smaller ones. The gradient that you have is pretty good. A lot of border check style flood irrigated country is laser graded to be much flatter than that such that flooded fields have water standing for often too long, causing the air in the soil to be replaced completely with water, drowning aerobic organisms and causing soil structural collapse, mobilisation of salts and on it goes: such is the reason behind the collapse of nearly every hydraulic civilisation...(add to that overgrazing, soil exposure etc. and you have the degenerative landscape blueprint of humans for the last 10K years!). So keyline flood-flow irrigation is designed to flood landscapes at gradients of 1:300 to 1:400 and accordingly do so without the water 'hanging around' and resembling a ephemeral, live giving, floodplain event rather than a lasting, and often septic deluge. So I would look at using plastic pipe to reticulate water across your property and look to having the soils accept a lot more of the snow and rainfall available. 12" is about 300litres of water per m2 per year. As I have been saying for many years now, if you took a 44 gallon drum (200 litres) and set it up with a drip system for the growing season in most places then it would be green the whole time. That is the gift of plastic pipe! It allows us to deliver water at a rate that is slightly ahead of transpiration, seepage and evaporation...Practice carbon farming, mulch heavily, agroforestry, use pressure compensating 'on-line' 1 gallon per hour drippers or less and you'll not need much head pressure (try about 12' minimum) and away your place will go. When the biomass then climaxes you'll have a water-dense system that can run on a new rain-fed 'barrel a metre' economy! But you have to get started.....'Accelerate Succession & Evolution' (Mollison)

All the best,

Darren

Who ever can help me understand for sure...

Heenan Doherty wrote:laser graded to be much flatter than that such that flooded fields have water standing for often too long,

So keyline flood-flow irrigation is designed to flood landscapes at gradients of 1:300 to 1:400

Do I understand the gradient?
1:300, I write it 1/300 or 0,3% and that is very flat.
So this delivers water very slowly.

12" is about 300litres of water per m2 per year.

of what is this size of 12"?

As I have been saying for many years now, if you took a 44 gallon drum (200 litres) and set it up with a drip system for the growing season in most places then it would be green the whole time. That is the gift of plastic pipe! ... use pressure compensating 'on-line' 1 gallon per hour drippers or less

A drum for what surface and what rate of delivery?
44 gallon is 44 hours of dripping isn't it?

and you'll not need much head pressure (try about 12' minimum)

Again, of what is this size please?
Sorry in case part of my questions come from some equipment and sizes that are familiar or not according to the country...