It’s a hot sunny day, but Abdulai Alhassan is walking a long way from his home to his farm where he grows soybeans. When he arrives, the 49-year-old farmer finds his labourers busy harvesting soybeans. He smiles because he is expecting a larger harvest compared to previous years.
For the first time, Mr. Alhassan has used inoculants to increase his soybean yield. He says, “This year I am a happy man because I can vividly see that my soybean harvest will be more because I used inoculants.”
Mr. Alhassan has six children and lives in Dingaani village in Kumbungu district in northern Ghana. He has been growing soybeans for the past 10 years. He adopted inoculants as a way to increase his yields.
He says, “Many farmers in my village have already adopted the use of inoculants as a new innovative way of increasing soybean yield.”
Soybean inoculation is a technique that helps soybean plants fix nitrogen. About 50 to 70% of soybean’s nitrogen requirements come from the air. Inoculants introduce nitrogen-fixing bacteria into the soil. The bacteria form nodules on the roots that help to convert nitrogen from the air into nitrogen that a soybean plant can use.
Iddrisu Imoro is the extension officer at the Department of Agriculture in Sagnerigu district. He says, “It is a best practice for farmers to use inoculants in soybeans. Inoculation is effective and helps soybean roots to build more productive nodules which help in fixing nitrogen.”
Mr. Imoro explains that, like all other legume crops, soybean hosts the nitrogen-fixing nodule bacteria called Bradyrhizobium japonicum, which is not found in all soils.
He adds: “Inoculation is required so that the bacterium adheres to and proliferates on the developing plant root. If properly inoculated, the soil can fully meet the nitrogen needs of the crop. Inoculation typically increases soybean yield, as well as improving the protein concentration in soybeans by 40 to 60%.”
According to Mr. Imoro, the inoculant is purchased as living strains of rhizobium bacteria, either in moist solid or liquid forms. The bacteria is applied to the seed or the soil so that it remains viable and can infect all the emerging roots. The easiest way to inoculate soybeans is to buy pre-inoculated seed.
He adds: “Soybean inoculation is being piloted in the Kumbungu district under the Ghana Agriculture Sector Investment Programme, or GASIP. Under this scheme, GASIP is supplying the inoculants to beneficiary farmers.”
Ibrahima Shaibu is another farmer who grows soybeans with inoculants. He lives in Cheshegu village in Kumbungu district and is delighted with his increased yields.
The 37-year-old farmer says: “Last year, I harvested 12 bags of soybeans. From the onset, I knew I was going to have a great harvest because of the good green crop stand in my field. My family members were excited when I did indeed achieve a larger yield.”
Mr. Shaibu adds: “I just added inoculants to my seeds before planting because I have learned how to add the inoculant to soybean seed. Because it fixes nitrogen from the air, inoculant enriches the soil and boosts crop yields.”
Mr. Shaibu says he is making more money from soybeans now that he is using inoculants. His yield per acre has increased from four bags to seven. He sells a 50-kilogram bag of soybeans at 250 Ghanaian Cedis (US$39.84).
Yahaya Iddrisu is a soybean farmer in Kumbong-Kukuo. He says, “This was the first year that I’ve used the inoculant when planting soybeans and my yield has improved considerably.”
He adds, “The germination percentage is very good with inoculated seed. The improved seed germination is a result of the high-quality soybean seed that has been inoculated.”
Before he started using inoculant, Mr. Alhassan used to harvest just one to two bags of soybeans per acre. But with inoculation, he has increased his yield to six or seven bags per acre. He explains: “I will earn more and be able to use part of the money to employ other people to plough more land for soybeans.”
This resource was produced with support from Alliance for a Green Revolution in Africa (AGRA) as part of the Partnership for Inclusive Agricultural Transformation in Africa (PIATA).
Photo: An extension officer shows farmers how to add inoculants to soybeans before planting. Credit: Iddrisu Imoro.