An agronomist, Mr Andergachew Detebo, associated with Gircha Highland Fruits and Vegetable Research Centre at Chencha has hit the bull’s eye in his potato research. Using lime to detoxify soil, he got annual potato yield increased from 24 to 32 tons of marketable quality in Chencha. Click here to see the pictures.
Starting research in November 2016, he said, Chencha situated over 3000-meter above sea-level is suitable for potato crop. Focusing on agronomy practices and use of fertilizers, we found Chencha soil has highest pH level of 5.2 and lowest 4.6 that is deleterious for plant growth. But, when lime is applied it increases pH from 4.6 to 5.8, adding 10 hydrogen ions in it.
The pH level 5.8 to 7 is appropriate for plant will efficiently absorb nutrients, if it’s below 5.8 then important nutrients get attached to soil collides therefore, plants can’t absorb them; only aluminum is left out that is toxic for plants.
Elaborating further on imbalances, he said, ‘pH’ stands for potential hydrogen that spurs formation of acids in soil. Ratings far below 7 indicate very acidic, while higher readings reflect high alkalinity. In very alkaline soil, micronutrients such as zinc and copper become chemically unavailable to plants and macronutrients such as calcium, magnesium and phosphorous are not absorbed while aluminum residue reaches toxic levels.
In some mineral soil’s aluminum can be dissolved at pH levels below 5.0 becoming toxic to plant growth. It may also affect the availability of plant nutrients, which are mostly available to plants in optimum 5.5 to 7.0 range; it also affect the structure of the soil, especially in clay soils.
Before the commencement of research, potato’s annual yield in Chencha was 24 tons per hectare but after first year of in-depth research with lime application it has now increased to 32 tons, with better quality. It augur well for community because it’s very promising, he, averred.
On soil acidity, he said, we researched on two types of lime with four-time application to ascertain what type and time is appropriate to apply lime before planting. The time interval first begins with no application, then 30, 60 and finally 90 days before planting fetched absolutely expected results.
He adds we have limes that contain 90% and 100% Calcium Carbonate and its convertible acidity of area that tells us as to which type and what amount is right for a soil. And Chencha having convertible acidity level of 2.32 entailed the usage of 2.32 tons of lime per hectare land.
Unraveling technicality, he said, we discovered that potato is moderately tolerant to acid with coefficient 1, while standard coefficient for all crops is 1.5; if any crop remains unaffected coefficient will be zero and that helped us to ascertain quantum of lime to be used per hectare.
Initially, plots were designed, plowed thrice and rows and plants spaced with standard specification - 0.7 & 0.3 meters for it facilitate better growth and even determines edible potato’s size. This space specification whittled away to 0.6 and 0.3 meters if potato is for seed purpose.
At the outset research focused on five improved varieties - Gudene, Jalene, Belete, Susalo, Digame. And primarily the trial was on Gudene because it’s found to be consumable and gives higher yield, while Belete and Jalene are for ‘chips’ for having high starch and carbohydrate.
He informed that during research, 27 farmers always used to be at Gircha farm learning the techniques being applied to enhance soil pH to improve yield. He reiterated that potato farming is lucrative and proved to be best livelihood option.
Our study output strongly corroborates that a farmer after investing ETB 23,000 per hectare of land in a year to cultivate potato crop for seed will have 32.43 tons of yield accruing total prize of ETB 324,300 (ETB 1000 per ton); while yield for consumption purpose will bring ETB 162,000 at the rate of ETB 500 per ton. It will greatly impact their financial and social life.
Farmer Research Groups at Chencha are already apprised of research output. The study has now entered into 2nd phase; thereafter it will be disseminated to all clients, he signed off.
(Corporate Communication Directorate)