When living in an area with little rains, you can increase the chances of having good yield by by ensuring that you capture all the rains and that the crops is well fed.
Plough before the rains start and deeply along planting lines as this breaks up the compacted soil surface allowing the water to sink in. You can achieve deep tillage by modifying your plough by removing the sheer mould board and replacing it with a spike made of high density steel or using a chizzel plough incase a tractor is being used.
Fertilizer usage
Micro dose your manure or fertilizer by placing a handful of manure every foot along the planting line and plant the seed 5 cm away from the manure. Do not broadcast the manure as this leads to wastage.
In case of unreliabe rainfall, practice response fertilization where you wait for the seedlings to have 2 leaves and then you apply fertiliser close to the established plants to reduce the risk of wasting money on fertiliser and if the rains fail, you can decide not to buy the fertiliser at all. These practices can be used with maize, legumes and other crops.
To succeed, a combination of good varieties, good management and good crop nutrition is needed.