Why farmers prefer drip irrigation on onion farming

1st , let me start by saying that , to a plant, what matters is adequacy more than the method of delivering the water.

Probably, something else that I should mention is that plants requires water as a media of nutrients transfer from the root zones into the plant system through a process called

Transpiration. Once all the nutrients are removed , the water is emitted out at the leaf surface where it evaporates . This process as whole is known as Evap -Transpiration and it is influenced by , the size of the plant , root size , air temperature ,wind speed and relative humidity.

The water that is applied at the soil surface by whichever method is absorbed by the soil through a process called infiltration . Infiltration into the soil depends on several factors eg , The texture of the soil ( smoothness or roughness of the soil ) , rate of water application to the soil , topography of the land etc.

Let’s expound further on this. Take for example irrigating plants using a hose pipe . What happens is that water runs off faster before it infiltrates into the soil and therefore , it is a poor method of irrigation.

The rate at which water is applied to the soil is higher than the soil can absorb which results into runoff because the top 1nch of the soil gets saturated and hence water runs off instead of being absorbed deeper into the soil . This happens also when the rain intensity is high .

Compare this with the drip irrigation which drips water at a rate of 1lt per emitter which is almost equal to the infiltration rate of the soil and that’s why it is rare to find runoff in drip irrigation not unless in a case of over irrigation.

Over head irrigation. The sprinklers are designed to atomize the water droplets into various sizes depending on the design and the operating pressure. All this is done in order to match the soil infiltration rate . The bigger the droplets size , the higher the likelihood of a runoff .

Basin irrigation/ flood irrigation. This is a method of irrigation where water is applied to the surface of the soil in bulk . Because the soil can’t absorb water at once , a basin is designed with an objective of holding the water to allow for infiltration to take place with time .

Bucket irrigation. This is as simple as it sounds and need no explanation.

All the above method are good and the difference comes about in the system’s efficiency and cost of operation.

Drip system is the most efficient and therefore the most economical. It is followed by overhead irrigation whose major disadvantage is loss of water through the wind and irrigating areas that are not necessary eg the pathways.

The basin irrigation is the most common system practiced by small scale growers mostly because the cost of installation is minimal compared to drips and overhead.

This system has 3 major disadvantage which are . Un economical use of land because most of the area meant for cropping is taken up by many furrows , over application of water and leaching of nutrients.

However, it is possible to achieve over 20tons of onions on basins irrigation method especially if the farmer is calculative . Take for example a basin that measures 2m by 4m . At a spacing of 8cm onion to onion across the 2m , one would get 25 seedlings . with rows of 12cm across the 4m = 33 rows . 33×25 = 825 seedlings per Basin . From an acre , one can get upto 300 basins of 2m by 4m . So the plant population per acre would be 247,500 as opposed to 250,000 for drip irrigation which is insignificant.

The key thing is measurements.