Sorghum Grain and Stover Nutrient Concentrations as Influenced by Tillage and Soil Amendment in Semi-Arid Burkina Faso

Abstract

Sorghum [Sorghum bicolor (L) Moench) is a major grain crop in Burkina Faso. Two three-year experiments were conducted in the Sudanian and Sudano-Sahelian zones to determine how plant nutrient concentrations are affected by tillage methods (T) and soil amendments (SA). In both locations, T and SA had little effect on grain and stover nutrient concentrations with some cases of inconsistency across years. Some nutrient concentrations differed by year. The grain nutrient concentrations of N, P, Mg, S, Zn, and Fe were adequate for human nutrition at both locations, but deficient for K, Ca, Mn and Cu. Sorghum nutrient concentrations for feeding cattle were adequate for K, Ca, Mg, S, Mn, and Zn in most cases at both locations but low for N, P, and Cu. The stover N and P concentrations also appeared to be deficient for optimal plant growth. In both agroecological zones, nutrient applications or genetic enhancement to improve deficient nutrient concentrations, or use of diverse foodstuffs, or biofortified sorghum to provide deficient nutrients in human and cattle diets is needed to meet dietary requirements. In addition to grain and stover yield, studies need to evaluate grain nutrient and stover nutrient concentrations to meet human and cattle dietary requirements.

Tillage, sole and intercrop systems and soil amendment influence on sorghum grain and stover nutrient levels

“…Nutrient concentrations for N, P, Mg, S, Fe and Zn were adequate to meet human nutritional requirements, while K Ca, Mn, and Cu were low [12,13] and may need to be supplemented in human diets. Grain nutrient concentrations were similar to those reported by Pale et al [7][8][9], Wortman et al [15], Mabelebele et al [16], Liboreiro Paiva et al [18] and van Duivenbooden [19], except for (1) grain Ca being lower than for several references, (2) Fe being higher except for Pale et al [7][8][9], (3) grain Zn concentration being much lower than Wortmann et al [15], and (4) grain Cu concentration being higher than most references. Clearly, wide variation in sorghum grain concentration occurs across years and the world.…”

“…Stover N and P concentrations were higher than other world reports, but lower for K and Ca stover concentrations [7][8][9][19][20][21]. Concentrations for stover Mg was lower than other reports except for Palé et al [9]. Concentrations for S and Cu were similar to other world reports, while stover concentrations for Fe and Zn were similar for other reports except higher than by Maw et al [21].…”

“…In contrast to previous studies [7][8][9], tillage, cropping system and soil amendment had no influence on the stover nutrient concentrations in spite of having influence on stover yields [4][5][6]. Mean stover nutrient concentrations indicated that N, P, Mg, Fe and Zn were adequate to meet cattle nutritional requirements, while K, Ca, S, Mn and Cu were inadequate [14].…”

“…Stover nutrient concentrations at physiological maturity were adequate for P, Mg, S, Fe, Zn, Mn, and Cu, but inadequate for N, K and Ca which may have been deficient earlier during reproductive growth [22,23]. Stover N and P concentrations were higher than other world reports, but lower for K and Ca stover concentrations [7][8][9][19][20][21]. Concentrations for stover Mg was lower than other reports except for Palé et al [9].…”

“…and sorghum grain and stover yields increased with use of zaï or tied ridges combined with compost and fertilizer application [4][5][6]. Tillage and soil amendment has been shown to have only a small influence on sole and intercropped pearl millet and sorghum grain nutrient concentrations [7][8][9].…”