Spatial variability of soybean responses to rhizobium inoculation – need for continuous investigation into integrated soil fertility management

In Nigeria, the participatory demonstration trials started at the beginning of COMPRO-II in 2012, under the collaborative work between Notore Chemical Industries (Notore) and Farm Inputs Promotions-Africa (FIPS-Africa). Since 2013, Notore started independently conducting the participatory demonstration trials and awareness creation. Notore is a private sector company involved in facilitating farmers' access to improved agricultural technologies including seeds and fertilizers. The company has shown significant interest in legume inoculants such as legumefix and nodumax; they are analyzing the market and participating in awareness creation before they can start commercializing the products at large scale not only in Nigeria, but also in other West Africa countries such as Ghana.

Results obtained during the period of 2012-2014 have not only shown significant yield increases, but also huge spatial variability (Yield map). The same trend was found in the other project countries i.e. Ethiopia, Ghana, Kenya, Tanzania, and Uganda. In 2015, the project started testing various components of Integrated Soil Fertility Management (ISFM) including interaction of organic manure, phosphorus (P) fertilizer, liming materials, and rhizobium inoculant to try to reduce the yield gap across regions and sites. In 2015, the dissemination campaigns continue under the supervision of the Village Promoters (VPs) of Notore to increase the awareness creation and the understanding of the know-how to effectively use inoculants in legume-crop production. The cycle of the participatory demonstration trials commences with the establishment of the demonstration trials together with farmers and ends with the harvesting of the demonstration trials including comparing the yields from all the sub plots containing improved technologies with those containing traditional practices. The participatory demonstration trials involve all sectors of the community including adult men, women and youths.

In 2015, over 260 VPs were trained and involved in the dissemination activities in four States (Benue, Kaduna, Kano, and Niger) to improve their skills for effective support to smallholder farmers. Approximately 30,000 smallholder farmers were exposed to the demonstration sites for training and given inputs to try at their own farms. In addition to farmer directly testing the inputs, 278 video sessions were organized to create the awareness of over 7,350 farmers about improved legume technologies including seeds, soybean inoculants, and P fertilizers among others to improve crop productivity, and consequently food security. The video viewing sessions are generally not implemented as a replacement for the participatory demonstration trials, but brings together both farmers who have attended participatory demonstrations and those who have not, within the same community thereby enabling knowledge diffusion between the participants. It is worth mentioning that 2015 was the project's last year of dissemination campaigns in all the project countries i.e. Ethiopia, Ghana, Kenya, Nigeria, Tanzania and Uganda.

Spatial variability of soybean responses to rhizobium inoculation – need for continuous investigation into integrated soil fertility management