A farm-level evaluation of nitrogen and phosphorus fertilizer use and planting density for pearl millet production in Niger

Abstract

Mineral fertilizer use is increasing in West Africa though little information is available on yield response in farmers' fields. Farmers in this region plant at low density (average 5,000 pockets h a-1, 3 plants pocket-1), which can affect fertilizer use efficiency. A study was conducted with 20 farmers in Niger to assess the response of pearl millet [Pennisetum glaucum (L.) R. Br.] to phosphorus and nitrogen fertilizers under farm conditions. In each field, treatments included control, single superphosphate (SSP) only, SSP plus N (point placed near plant), and either SSP or partially acidulated phosphate rock (PAPR) plus N broadcast. N and P were applied at 30 kg N ha-1 and 30 kg P2O s h a-1. Farmers were allowed to plant, weed, etc., as they wished and they planted at densities ranging from 2,000 to 12,000 pockets h a-1. In the absence of fertilizer, increasing density from 2,000 to 7,000 pockets h a-1 increased yield by 400%. A strong interaction was found between fertilizer use and density. Farmers planting at densities less than 3,500 pockets h a-1 had average yields of 317 kg grain hawhile those planting at densities higher than 6,500 pockets h a-1 showed average yields of 977 grain h a-1. Though phosphate alone increased yields significantly at all densities, little response to fertilizer N was found at densities below 6,000 pockets h a-1. Significant residual responses in 1987 and 1988 were found to P applied in high-density plots in 1986. Depending on fertilizer and grain prices, analysis showed that fertilizer use must be be combined with high plant density (10,000 pockets h a-1) or no economic benefit from fertilizer use will be realized.

Soil water crop modeling for decision support in millet-based systems in the Sahel: a challenge

“…There is no positive response to N unless adequate P is supplied (Buerkert and Stern, 1995;Buerkert et al, 2001). There were many research works done to prove the beneficial effect of N and manly P fertilizer in the area (e.g., Christianson et al, 1990;Bationo et al, 1992;Subbarao et al, 2000;Bationo and Ntare, 2000;Buerkert et al, 2001;Yamoah et al, 2002). Single superphosphate (SSP) applied annually at 13 kg P ha -1 effectively removed P deficiency on most cases.…”

Soil productivity management and plant growth in the Sahel: Potential of an aerial monitoring technique

“…Given the low soil fertility and the lack of use of mineral fertilizers, planting densities are very low, usually around 5000 planting hills (pockets) ha -1 or even lower (Bationo et al, 1992;Mclntire, 1986).…”

Improving cereal productivity and farmers’ income using a strategic application of fertilizers in West Africa

“…The major constraints to arable agriculture are crop growth on the predominantly sandy soils that are of poor soil fertility; particularly in phosphorus (P) and nitrogen (N) (Bationo et al, 1992;1993;1998a;b); It has, however, been reported that phosphorus tends to be more limiting to crop productivity than nitrogen. Crop response to nitrogen was found to be minimal until crop phosphorous requirements had been satisfied (Traore, 1974).…”