ICRISAT Archival Report 2010

Best-bet soil fertility management options and their interactions with genotype identified for the Sahelian
zone in Niger
Rationale
One of the constraints to agricultural production in the Sahel is low or absence of utilization of external
input due to their limited availability or high price. To help increase the rate of on-farm application of
sources of nutrients, the so-called fertilizer microdosing technology was developed and demonstrated in
farmers’ field with promising results. Organic amendments constitute the principal source of nutrients for
agriculture. Hill application of manure combined with mineral fertilizer microdose would be an optimal
way to gain the best from the potentials of both fertilizers, but also assure that there is enough manure for
wider area to sustain crop production. Combination of best genotypic potential of a crop with such
technology could be the key to increased crop production. The present work funded by the HOPE project
seeks to determine the optimal combination of the genotype, fertilizer microdosing and organic amendment
application that would favor the expression of the yield potential of millet crop.
Materials and Methods
Ten millet genotypes where evaluated under the combination of four mineral and organic fertilizer
management options in a split plot design laid in three replications. The experiment was conducted at
ICRISAT station at Sadore and at two INRAN research stations (Kollo, approximately 30 km from Sadore;
and Maradi, approximately 600 km East of Niamey). The field at Sadore was purposely selected for low
level of Bray P1 (Table 1). However it was a field under fallow cleaned for the purpose of the experiment.
The same experiment was conducted as baby trials in a participatory manner with farmers of 4 localities in
Western Niger (Bokki, Falwel, Tera and Dantchandou) and three localities in Eastern Niger (Serkin
Haoussa, Sae Saboua and El Kolta). Eight millet genotypes were tested under various combinations of soil
fertility management. During the cropping season and before harvest, the crops were evaluated with the
farmers who ranked the treatments according to their appreciation.
Results and Discussions
Table 1: Soil characteristic of the experimental field at Sadore, ICRISAT
Depth pH H2O Organic C Total N (mg N/kg) Bray P1
(cm) (1:2.5) (%)
(mg P/kg)
10 5.5 0.3 247.4 4.2
20 5.7 0.2 119.9 3.5
Soil data of the two other sites are being analyzed. However, prior to the selection, they were reported as
having low fertility, which is reflected in crop yield obtained. Grain yield was especially low on average at
Maradi (206 kg/ha), compared to 953 kg/ha at Sadore.
Genotype differences were observed. At Sadore MIL.DE.SIAKA".(=PE05578-C2), SOSAT-C88, and
PE05572.(KADO.NIO.DE.MALI) outperformed the other genotypes, but this trend was not consistent over
the two other sites (Figure 1) . Slight yield increase was observed due to mineral and organic fertilizer
application but the differences were statistically significant only at Maradi.
In the on-farm trials. grain yield obtained was 1000 kg/ha on average at Bokki and Falwel due to combined
effect of 200g of organic manure and 2g of DAP or 6g of NPK per hill . Grain yield at Serkin Houssa and
Sae Saboua were as high as 1500 kg/ha on average. According to farmers’ appreciation hill application of
manure brings additional work however it is a good practice as it increases crop yield. Among the varieties
tested ICMV 89305, ICMV 99001 and PE05578-C2 performed very well on all the sites however they were
not better than the local variety. The analysis of the soil samples collected on each site as well as manure
samples will help us to better understand the tendencies observed. The analysis is specific genotype by
fertilization interaction remains to be analyzed.
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