From 2012-2013, two sets of on-farm trials, involving farmer practice (FP) and an integrated approach to Striga management, were conducted and managed by farmers themselves in 81 villages of the Bauchi and Kano States. The on-farms trial fields were located in the northern Guinea and semi/Sudan savannah zone of the Kano State that is characterised by a sub-humid climate. This area has an average daily temperature of 30°C to 33°C between March and May, with a minimum temperature of 10°C observed between September and February. The rainfall pattern is unimodal (only one season) lasting between 4-6 months in a year with an average of 600 mm per annum. The Kano State has a total land mass of 2,076,000 ha of which 1,754,200 ha is arable land and the remaining 75,000 ha reserved for grazing and forest vegetation. The Kano State is within the region of Sahel Savannah of West Africa. The raining season varies from year to year but usually starts in May and ends in October, while the dry season runs from November to April.
The Bauchi State is situated in the north-eastern part of Nigeria (see Appendix 1). It has a total land hectarage of 4,925,900.00 ha, representing about 5.3% of the total national land mass, and has about 3,448,100 ha under cultivation. The average daily temperatures range from 29.2°C in July and August to a maximum of about 37.6°C in March and April. The average minimum daily temperature ranges from 11.7°C in December to January to an average of 24.7°C in April and May. The state enjoys both rainy and dry seasons with a maximum rainfall of about 1300 mm per annum in the south to about 700 mm per annum in the north. These states and communities were selected for the study due to their severe Striga infestation.
8.2.1 Experimental design
The method adopted for this experiment followed the one described by Schulz et al. (2003). The trials were conducted in 400 farmers’ fields, and each farmer’s field was used as a replica of the two treatments, namely ISM technology and FP. The ISM technology treatment involved the
planting of improved soya beans in the first year, followed by Striga-resistant maize in the second year (see Ellis-Jones et al., 2004, for details). The FP treatment consisted of a farmer’s best maize variety in the vicinity in the second year, following the soya beans planted in the first year as per the ISM technology. The IITA recommended legume-cereal rotation with soya beans and STR maize as one of the options of Striga control for farmers in the Striga-infested area, since it is affordable to smallholder farmers.
The farmers managed their own on-farm trials, ranging from land preparations to harvesting with advisory service from other stakeholders such as ABU, Zaria, IITA Nigeria, BUK, BSADP and KNARDA. All the soya beans and STR maize seed materials (Table 8.1) were provided by the IITA. The farmers provided all the other farm inputs for the on-farm trials’ STR maize and farmer variety in rotation with soya beans. All trials were carried out on Striga-infested fields and concurrently served as technology promotion plots for farmers within and outside the communities to see. Each farmer managed his/her two plots for two cropping seasons and shared his/her experiences with other farmers during field days.
The varieties of maize and soya beans used in the on-farm trials are presented in Chapter 3 and Table 3.4. Only results from the maize grain yield are reported in this study.
8.2.2 Sampling strategies
The multi-stage random sampling procedure was adopted for the study. Only households involved in growing maize were drawn from the maize growing areas of northern Nigeria. The first stage involved the purposive selection of the Bauchi and Kano States, based on the importance of maize production and the level of Striga infestation, followed by the selection of five LGAs per state, based on the biophysical survey preceding the baseline survey. A “three-stage sampling technique”
comprising:
(i) selection of grid cells on digital maps of target LGAs;
(ii) selection of communities within grid cells; and
(iii) selection of farms within communities and grid cells. Grid cells measuring 10 km × 10 km each were superimposed on the Google maps of the Kano and Bauchi States.
In each LGA, five grid cells were randomly selected. In each grid cell, a community closest to the centre of the cell was selected. The crop fields were systematically sampled at 5km intervals along
a transect in each of the four cardinal points of the community. The position of the community and farms sampled were recorded by means of the Global Positioning System (GPS) model. The third stage involved the selection LGAs where maize production was constrained by Striga infestation.
All the households within the villages in the surveyed area formed the sampling frame developed by extension officers and some assistance from community heads. In each community, a source list was used and all households were subjected to a random selection using the Microsoft Excel RAND funtion, which generates a random number. Additionally, the following criteria were used in selecting participating farmers for the on-farm ISM technology trial: farmers had to have Striga- infested fields; an excellent knowledge of the production of these crops; sufficient resources to manage and maintain the plots; willingness to host and accommodate other farmers to view and learn from the farm; and accessibility of the trial site for on-farm training and field days.
The trial was farmer-managed and successfully conducted in many of the communities in 10 LGAs from the two states (Bauchi and Kano) during 2012 and 2013. The trials were established successfully on 400 farmers’ fields across 81 communities in the two states. Due to some logistics and security reasons (Boko Haram insurgents prevailing in the north-eastern region), only 40%
(160) of the farmers were randomly selected for analyses, but only 148 farmers’ logbooks met satisfactory requirements for evaluation across the study locations (Table 8.1).
The villages had similar soil and climatic conditions and were less than 5 km from each other.
Every farm had two plots that formed a replica. The total plot area was 800 m2 and the net size of each of the two sets of trials was 400m2. In 2012 and 2013, each variety of crop was sown on ridges as a monocrop. Three seeds of maize were sown per hill at a spacing of 75 cm× 20 cm. The maize was thinned to one plant per hill two weeks after planting, while soya beans was drilled at a spacing of 5 cm on ridges with a 75 cm inter-row space. In 2012 and 2013, the same operations were performed. Table 8.1 shows the trial locations and number of sampled participating farmers.
Due to the multi-location nature of the trial, we found justification in the trials’ evaluations and documentation.
Table 8.1: Trial locations and number of sampled participating farmers, northern Nigeria, 2012/13
Number of sampled farmers in each location
Kano State N=64 Bauchi State N=84
Bebeji 18 Alkaleri 18
Doguwa 8 Bauchi 16
Kiru 11 Dass 20
Rano 20 Ganjuwa 12
Tudun Wada 7 Toro 18
Source: ISMA survey data 2013
8.2.3 Statistical and economic analysis
Data analysis was achieved by using paired t-tests, and farm budgeting techniques by using Microsoft Excel spreadsheets. Parameters used in expressing the performance of maize enterprises under Striga infestation included yield in kilogram per hectare and returns to investment in inputs, which is expressed as GM per hectare. Crop yields were multiplied by 2013’s average market prices (mean of prices immediately after harvest and at the onset of the new season) to compute revenues. The GM is a straightforward and fast approach of planning changes in farm activity, or in analysing an enterprise. The GM is the difference between the gross farm revenue earned and the incurred VCs. For a farm involved in different enterprises, the total GM is the summation of the individual GM of each enterprise. The analysis by means of GM was used to justify that the selected projects were financially and technically viable to the need of the targeted client (Ghimire, 2003; Gittinger, 1982; Kalash, 2010; Mignouna et al., 2011b; Olukosi & Erhabor, 2005). The basic equation for the GM computation and other economic indicators were the same as the ones earlier presented in section 7.1.
Certain assumptions were made to determine the GM of each production method, namely all the crops were subjected to the same seed quantities, fertilizer rates and agronomic practices. The only difference was the cost of the technology, which was the seed of the Striga-resistant maize. This study only focused on the cost-benefit ratio associated with maize production under Striga infestation. All crops harvested at the end of the season were priced at the prevailing market price
which was an average of N60.25k/kg, translated to about US$380/ton of maize grain using the naira exchange rate of N162 to US$112 at the time of this study.