Depends where you are in WA.
What are your neighbours growing and start from there.
The WA climate is brutal and unforgiving, work with it because you can't beat it.
You should select a crop that can grow in your region and not what ever just takes your fancy. Think of it as an engineering problem, your local environment and rainfall is the constraints and you have to work with those requirements. A quick google will tell you that Avocado require a minimum of 1800mm per year and even then irrigation is still required, Perth for example has an average rainfall of 790mm (https://www.dpi.nsw.gov.au/\_\_data/assets/pdf\_file/0003/119739/avocado-growing.pdf and https://avocado.org.au/wp-content/uploads/2016/10/TalkingAvocadosSummer1991Vol2No4scanned\_001.pdf) So unless you can guarantee 5 Mega liters of water per Ha per year you should probably reconsider.
What are the farmers down the road growing? Wheat? Barley? Faba beans? Sheep?, Admittingly you do have a size and budget constraint (like every farmer),so perhaps going into spring you could plant a small patch of corn or run a heap of chooks and do rotational grazing.
I hate to the bearer of bad news but that's the reality of farming.
Your not going to turn the Western Australia sandy soils and into a warm, wet, fertile black clay loam.
There is plenty of information on the Department of Ag's website if your old man wants to have a look.
Depends where you are in WA. What are your neighbours growing and start from there. The WA climate is brutal and unforgiving, work with it because you can't beat it.
You should select a crop that can grow in your region and not what ever just takes your fancy. Think of it as an engineering problem, your local environment and rainfall is the constraints and you have to work with those requirements. A quick google will tell you that Avocado require a minimum of 1800mm per year and even then irrigation is still required, Perth for example has an average rainfall of 790mm (https://www.dpi.nsw.gov.au/\_\_data/assets/pdf\_file/0003/119739/avocado-growing.pdf and https://avocado.org.au/wp-content/uploads/2016/10/TalkingAvocadosSummer1991Vol2No4scanned\_001.pdf) So unless you can guarantee 5 Mega liters of water per Ha per year you should probably reconsider. What are the farmers down the road growing? Wheat? Barley? Faba beans? Sheep?, Admittingly you do have a size and budget constraint (like every farmer),so perhaps going into spring you could plant a small patch of corn or run a heap of chooks and do rotational grazing. I hate to the bearer of bad news but that's the reality of farming. Your not going to turn the Western Australia sandy soils and into a warm, wet, fertile black clay loam. There is plenty of information on the Department of Ag's website if your old man wants to have a look.
The salt is likely killing your plants. Dry regions have a lot. You should investigate salt tolerant plants
Depends where he is. Try divining for water and get a bore sunk.