ISSN:
1573-0867
Keywords:
Bray P1
;
Bray P2
;
Mehlich 1
;
Olsen
;
water-extractable P
;
phosphate rock
;
partially acidulated phosphate rock
;
West Africa
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Field experiments were conducted in Niger with pearl millet (Pennisetum glaucum [L] R. Br.) in which the crop was fertilized with phosphate rock (PR) from two deposits from Niger (Tahoua and Parc W). The PR was applied either as ground rock or as partially acidulated phosphate rock (PAPR) and was compared to water soluble sources (TSP and SSP) in terms of millet yield response. The ability of five soil testing procedures (Bray P1, Bray P2, Mehlich 1, Olsen, and water extraction) to establish P sufficiency levels for millet was tested. The results of all soil testing methods were highly correlated amongst each other for the treatments receiving water-soluble fertilizers or PAPRs. None of the soil testing procedures which were evaluated was able to accurately measure available P when PRs were applied. Sufficiency levels were calculated for the PAPR and water-soluble fertilizers using nonlinear regression analysis and a graphic procedure for each of the P soil testing methods. The Bray P1 method appeared to be the most reliable procedure and was used to study the effect of accumulated total or total water + citrate-soluble P rates on final P availability. A single quadratic function was able to describe this effect when the P rates were expressed as water + citrate-soluble P for both PAPRs and water-soluble fertilizers independently of the P fertilizer source.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01054328
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