Search

Introduction: Micronutrient deficiencies are prevalent in West Africa, particularly among women of reproductive age (WRA) and young children. Bouillon is a promising food fortification vehicle due to its widespread consumption. This study aims to evaluate the impact of multiple micronutrient-fortified bouillon cubes, compared to control bouillon cubes (fortified with iodine only), on micronutrient status and hemoglobin concentrations among lactating and non-lactating WRA and young children in northern Ghana. Methods: This randomized, controlled doubly-masked trial will be conducted in the Kumbungu and Tolon districts in the Northern Region of Ghana, where prior data indicate multiple micronutrient deficiencies are common. Participants will be: 1) non-pregnant non-lactating WRA (15–49 y), 2) children 2–5 y, and 3) non-pregnant lactating women 4–18 months postpartum. Eligible participants will be randomly assigned to receive household rations of one of two types of bouillon cubes: 1) a multiple micronutrient-fortified bouillon cube containing vitamin A, folic acid, vitamin B12, iron, zinc, and iodine, or 2) a control cube containing iodine only. Each participant's household will receive a ration of bouillon cubes every 2 weeks, and households will be advised to prepare meals as usual, using the study-provided cubes. The trial duration will be 9 months for non-pregnant non-lactating WRA and children, and 3 months for lactating women. The primary outcomes will be changes in biomarkers of micronutrient status and hemoglobin among WRA and children and milk micronutrient concentrations among lactating women. Secondary outcomes will include change in prevalence of micronutrient deficiency and anemia; dietary intake of bouillon and micronutrients; inflammation, malaria, and morbidity symptoms; and child growth and development. Discussion: Evidence from this study will inform discussions about bouillon fortification in Ghana and West Africa. Trial registration: The trial was registered on ClinicalTrials.gov (NCT05178407) and the Pan-African Clinical Trial Registry (PACTR202206868437931). This manuscript reflects protocol version 4 (August 29, 2022). [ABSTRACT FROM AUTHOR]

Background: Information on salt consumption patterns is needed to inform the need for and design of salt reduction strategies. Objectives: In northern Ghana, this study aimed to estimate household consumption of salt, including salt from bouillon, and compare (estimated) women and children's salt intake to global recommendations; to estimate the proportion of salt consumed from bouillon; and to identify factors, including knowledge, attitudes, and practices, associated with household salt consumption. Methods: Employing mixed-methods methodology, we conducted a pilot survey (n = 369 households enrolled) and focus group discussions (FGDs; n = 20) in Tolon and Kumbungu districts (14 urban, 14 rural clusters) (clinicaltrials.gov registry: NCT04632771). Households reported purchases of discretionary salt (DS, "table salt") and bouillon cubes. DS and total salt (TS; DSþsalt from bouillon) consumption for women (15-49 y) and children (2-5 y) were estimated using the Adult Male Equivalent method and compared with global recommendations (<5 g/d women; <3.75 g/d children). Women's salt intake was also predicted from urinary sodium excretion (INTERSALT equation). Associations between DS and TS consumption, as well as household and women's characteristics, were tested with minimally adjusted and multivariable linear mixed-effects models. Qualitative FGD themes were generated using the Framework Method. Results: From household purchase data, estimated TS consumption exceeded global recommendations for 44% of children [median: 2.9 (IQR: 1.9, 5.2) g/d] and 60% of women [6.0 (4.0, 10.2) g/d]; 35% of children and 50% of women exceeded recommendations from DS alone. Bouillon contributed <25% of households' TS consumption. Few characteristics were associated with DS or TS consumption. Salient qualitative themes that shaped salt consumption behaviors included salt's ubiquity as a seasoning, key household members' influence on food procurement and preparation, and perceptions about health. Conclusions: Purchase data suggest salt consumption among women and children exceeds recommendations, even when excluding salt from bouillon; food prepared outside the home likely further contributes. Salt reduction interventions may be warranted in this context. [ABSTRACT FROM AUTHOR]

Background: Bouillon is a promising large-scale food fortification vehicle, but there is uncertainty regarding the types and concentrations of micronutrients that are feasible to add without compromising consumer acceptability. Objective: The objective of this study was to evaluate the acceptability of 2 different multiple micronutrient-fortified bouillon cube formulations, compared with a bouillon cube fortified with iodine only. Methods: We conducted a double-blind, randomized, controlled acceptability study in 2 districts in northern Ghana. Two nonproprietary, noncommercialized formulations of multiple micronutrient-fortified bouillon cubes containing iron, zinc, folic acid, vitamins A and B12, and iodine at "upper-level" (45-125% CODEX NRV/2.5g) or "lower-level" (15-50% CODEX NRV/2.5g) concentrations, and a control cube that contained iodine only (50% CODEX NRV/2.5g) were evaluated. Eligible women (n = 84) were invited to participate in 1) center-based sensory evaluations designed to permit within-individual comparisons among the different study products; and 2) in-home evaluation of bouillon acceptability and use, in which participants were randomized to receive 1 of the 3 study products to use in household cooking for a 2-wk period. Acceptance test ratings were based on a 5-point Likert scale (1 = dislike very much, 5 = like very much). Results: In the center-based evaluations, overall liking of the 3 bouillon cube formulations both dry and in prepared dishes ranged from 4.3 to 4.6 on the 5-point Likert scale and did not differ among formulations (P > 0.05). After the 2-wk in-home trial, 93.8% of index participants (n = 75/80) rated their overall liking of the bouillon product formulation to which they were randomly assigned as "like" or "like very much" (4-5 on the 5-point Likert scale) and median apparent intake of study-provided bouillon over 2 wk was 3.6 g/capita/d; neither value differed by study group (P = 0.91 for both). Conclusions: All 3 formulations of bouillon cubes assessed were acceptable to women and their households in 2 districts in northern Ghana. [ABSTRACT FROM AUTHOR]

Pregnancy and breastfeeding make demands on maternal nutrient stores. The extent of depletion and the degree to which nutrient stores are replenished between pregnancies has implications for a mother's nutritional status at conception of the subsequent child and therefore that child's birth outcomes and growth. Using follow‐up data collected several years after a randomized effectiveness trial conducted in rural Bangladesh and a randomized efficacy trial conducted in semiurban Ghana, we evaluated the impact of maternal supplementation with small‐quantity lipid‐based nutrient supplements (LNS) or multiple micronutrients (MMN) through pregnancy (the index pregnancy) and 6 months postpartum on the growth status of the next living younger sibling conceived and born after the index pregnancy. In both Bangladesh (n = 472 younger siblings) and Ghana (n = 327 younger siblings), there were no overall differences in the growth status or the prevalence of undernutrition among younger siblings whose mothers had received LNS (or MMN, Ghana only) during and after the index pregnancy compared with the younger siblings of mothers who had received iron plus folic acid (IFA) during the index pregnancy (Ghana) or during and for 3 months after the index pregnancy (Bangladesh). These findings do not indicate that preconception nutrition interventions do not improve child growth. Rather, they suggest that any benefits of maternal LNS or MMN supplementation during one pregnancy and for 6 months postpartum are unlikely to extend to the growth of her next child beyond any effects due to IFA alone. [ABSTRACT FROM AUTHOR]

Objective: We aimed to identify factors (child diet, physical activity; maternal BMI) associated with body composition of Ghanaian pre-school children. Design: Longitudinal analysis of the International Lipid-Based Nutrient Supplements (iLiNS)-DYAD-Ghana randomized trial, which enrolled 1320 pregnant women at ≤20 weeks’ gestation and followed them and their infants until 6 and 18 months postpartum, respectively. At follow-up, child age 4–6 years, we collected data on body composition (by 2H dilution), physical activity and diet, extracted dietary patterns using factor analysis, and examined the association of children’s percentage body fat with maternal and child factors by regression analysis. Setting: Eastern Region, Ghana. Participants: Children 4–6 years of age. Results: The analysis included 889 children with percentage body fat and dietary data at follow-up. We identified two major dietary patterns, a snacking and a cooked foods pattern. Percentage body fat was positively associated (standardized β (SE)) with maternal BMI at follow-up (0·10 (0·03); P = 0·003) and negatively associated with physical activity (−0·15 (0·05); P = 0·003, unadjusted for child gender), but not associated with the snacking (0·06 (0·03); P = 0·103) or cooked foods (−0·05 (0·07); P = 0·474) pattern. Boys were more active than girls (1470 v. 1314 mean vector magnitude counts/min; P < 0·0001) and had lower percentage body fat (13·8 v. 16·9 %; P < 0·0001). Conclusions: In this population, maternal overweight and child physical activity, especially among girls, may be key factors for addressing child overweight/ obesity. We did not demonstrate a relationship between the dietary patterns and body fatness, which may be related to limitations of the dietary data available. [ABSTRACT FROM AUTHOR]

Evidence on whether nutritional supplementation affects physical activity (PA) during early childhood is limited. We examined the long-term effects of lipid-based nutrient supplements (LNS) on total PA, moderate-to-vigorous PA (MVPA) and sedentary behaviour (SB) of children at 4–6 years using an accelerometer for 1 week. Their mothers were enrolled in the International Lipid-based Nutrient Supplement-DYAD randomised controlled trial in Ghana, assigned to daily LNS or multiple micronutrients (MMN) during pregnancy through 6 months postpartum or Fe and folic acid (IFA) during pregnancy and placebo for 6 months postpartum. From 6 to 18 months, children in the LNS group received LNS; the other two groups received no supplements. Analysis was done with intention to treat comparing two groups: LNS v. non-LNS (MMN+ IFA). Of the sub-sample of 375 children fitted with accelerometers, 353 provided sufficient data. Median vector magnitude (VM) count was 1374 (interquartile range (IQR) 309), and percentages of time in MVPA and SB were 4·8 (IQR 2) and 31 (IQR 8) %, respectively. The LNS group (n 129) had lower VM (difference in mean −73 (95 % CI −20, −126), P = 0·007) and spent more time in SB (LNS v. non-LNS: 32·3 v. 30·5 %, P = 0·020) than the non-LNS group (n 224) but did not differ in MVPA (4·4 v. 4·7 %, P = 0·198). Contrary to expectations, provision of LNS in early life slightly reduced the total PA and increased the time in SB but did not affect time in MVPA. Given reduced social-emotional difficulties in the LNS group previously reported, including hyperactivity, one possible explanation is less restless movement in the LNS group. [ABSTRACT FROM AUTHOR]

It is important to identify the periods during childhood when exposure to environmental risk factors results in long‐term neurodevelopmental deficits. Stunting and anaemia may be sensitive indicators of exposure to such risks. In a prospective cohort enrolled before birth, we investigated the association of developmental scores at 4–6 years with (a) birth length and linear growth during three postnatal periods and (2) haemoglobin (Hb) concentration at three time points. Children were participants in a follow‐up study of a randomized controlled trial of nutritional supplementation in Ghana. At 4–6 years, cognitive, motor, and social–emotional developments were assessed using standard tests adapted for this population. We estimated the associations of length‐for‐age z‐score (LAZ) at birth and postnatal linear growth (n = 710) and Hb (n = 617) with developmental scores in regression models, using multistage least squares analysis to calculate uncorrelated residuals for postnatal growth. Cognitive development at 4–6 years was significantly associated with LAZ at birth (β = 0.12, 95% CI = 0.05, 0.19), ΔLAZ from 6 to 18 months (β = 0.16, 95% CI = 0.04, 0.28), and Hb at 18 months (β = 0.13, 95% CI = 0.06, 0.20), but not with ΔLAZ during 0–6 months, ΔLAZ from 18 months to 4–6 years, Hb at 6 months, or Hb at 4–6 years. No evidence of associations with motor or social–emotional development were found. These results suggest that in similar contexts, the earlier periods prior to birth and up to 18 months are more sensitive to risk factors for long‐term cognitive development associated with LAZ and Hb compared with later childhood. This may inform the optimal timing of interventions targeting improved cognitive development. [ABSTRACT FROM AUTHOR]

Consumption of multiple micronutrient supplements (MMS) during pregnancy offers additional benefits compared with iron‐folic acid (IFA) supplementation, but the tablets are more expensive. We estimated the effects, costs, and cost‐effectiveness of hypothetically replacing IFA supplements with MMS for 1 year in Bangladesh and Burkina Faso. Using baseline demographic characteristics from LiST and effect sizes from a meta‐analysis, we estimated the marginal effects of replacing IFA with MMS on mortality, adverse birth outcomes, and disability‐adjusted life years (DALYs) averted. We calculated the marginal tablet costs of completely replacing MMS with IFA (assuming 180 tablets per covered pregnancy). Replacing IFA with MMS could avert over 15,000 deaths and 30,000 cases of preterm birth annually in Bangladesh and over 5000 deaths and 5000 cases of preterm birth in Burkina Faso, assuming 100% coverage and adherence. We estimated the cost per death averted to be US$175–185 in Bangladesh and $112–125 in Burkina Faso. Cost per DALY averted ranged from $3 to $15, depending on the country and consideration of subgroup effects. Our estimates suggest that this policy change would cost‐effectively save lives and reduce life‐long disabilities. Improvements in program delivery and supplement adherence would be expected to improve the cost‐effectiveness of replacing IFA with MMS. [ABSTRACT FROM AUTHOR]

Background: Few studies have evaluated the long-term effects of nutritional supplementation during the first 1000 d of life. We previously reported that maternal and child lipid-based nutrient supplements (LNS) increased child length by 18 mo.Objective: The aim of this study was to examine the effects of LNS on later growth and body composition at 4-6 y of age.Design: This was a follow-up of children in the International Lipid-based Nutrient Supplements (iLiNS)-DYAD trial in Ghana. Women (n = 1320) at ≤20 weeks of gestation were randomly assigned to: 1) iron and folic acid during pregnancy and 200 mg calcium/d for 6 mo postpartum, 2) multiple micronutrients (1-2 RDA of 18 vitamins and minerals) during both periods, or 3) maternal LNS during both periods plus child LNS from 6 to 18 mo. At 4-6 y, we compared height, height-for-age z score (HAZ), and % body fat (deuterium dilution method) between the LNS group and the 2 non-LNS groups combined.Results: Data were available for 961 children (76.5% of live births). There were no significant differences between LNS compared with non-LNS groups in height [106.7 compared with 106.3 cm (mean difference, MD, 0.36; P = 0.226)], HAZ [-0.49 compared with -0.57 (MD = 0.08; P = 0.226)], stunting (< -2 SD) [6.5 compared with 6.3% (OR = 1.00; P = 0.993)], or % body fat [15.5 compared with 15.3% (MD = 0.16; P = 0.630)]. However, there was an interaction with maternal prepregnancy BMI (kg/m2) (P-interaction = 0.046 before correction for multiple testing): among children of women with BMI < 25 , LNS children were taller than non-LNS children (+1.1 cm, P = 0.017), whereas there was no difference among children of women with BMI ≥ 25 (+0.1 cm; P = 0.874).Conclusions: There was no overall effect of LNS on height at 4-6 y in this cohort, which had a low stunting rate, but height was greater in the LNS group among children of nonoverweight/obese women. There was no adverse impact of LNS on body composition. This trial was registered at clinicaltrials.gov as NCT00970866. [ABSTRACT FROM AUTHOR]

Background The impact of feeding a slightly sweet nutrient supplement early in life on later sweet taste preference is unknown. Objective We tested the hypothesis that the level of sucrose most preferred by 4–6-y-old children exposed to a slightly sweet lipid-based nutrient supplement (LNS) early in life would not be higher than that of children never exposed to LNS. Design We followed up children born to women (n  = 1,320) who participated in a randomized trial in Ghana. In one group, LNS was provided to women on a daily basis during pregnancy and the first 6 mo postpartum and to their infants from age 6 to 18 mo (LNS group). The control groups received daily iron and folic acid or multiple micronutrients during pregnancy and the first 6 mo postpartum, with no infant supplementation (non-LNS group). At age 4–6 y, we randomly selected a subsample of children (n  = 775) to assess the concentration of sucrose most preferred using the Monell 2-series, forced-choice, paired-comparison tracking procedure. We compared LNS with non-LNS group differences using a noninferiority margin of 5% weight/volume (wt/vol). Results Of the 624 children tested, most (61%) provided reliable responses. Among all children, the mean ± SD sucrose solution most preferred (% wt/vol) was 14.6 ± 8.6 (LNS group 14.9 ± 8.7; non-LNS group 14.2 ± 8.4). However, among children with reliable responses, it was 17.0 ± 10.2 (LNS group 17.5 ± 10.4; non-LNS group 16.5 ± 10.0). The upper level of the 95% CI of the difference between groups did not exceed the noninferiority margin in either the full sample or those with reliable responses, indicating that the LNS group did not have a higher sweet preference than the non-LNS group. Conclusion Exposure to a slightly sweet nutrient supplement early in life did not increase the level of sweet taste most preferred during childhood. This trial was registered at clinicaltrials.gov as NCT00970866. [ABSTRACT FROM AUTHOR]

Background: In the International Lipid-Based Nutrient Supplements (iLiNS)-DYAD-Ghana trial, prenatal small-quantity lipid-based nutrient supplements (LNSs) had a positive effect on birth weight. Birth weight may be inversely related to blood pressure (BP) later in life.Objectives: We examined the effect of the intervention on BP at 4-6 y of age, and maternal and child factors related to BP.Methods: The iLiNS-DYAD-Ghana study was a partially double-blind, randomized controlled trial which assigned women (n = 1320) ≤20 weeks of gestation to daily supplementation with: 1) iron and folic acid during pregnancy and 200 mg Ca for 6 mo postpartum , 2) multiple micronutrients during pregnancy and postpartum, or 3) LNSs during pregnancy and postpartum plus LNSs for infants from 6 to 18 mo of age. At 4-6 y of age (n = 858, 70% of live births), we compared BP, a secondary outcome, between non-LNS and LNS groups and examined whether BP was related to several factors including maternal BP, child weight-for-age z score (WAZ), and physical activity.Results: Non-LNS and LNS groups did not differ in systolic (99.2 ± 0.4 compared with 98.5 ± 0.6 mm Hg; P = 0.317) or diastolic (60.1 ± 0.3 compared with 60.0 ± 0.4 mm Hg; P = 0.805) BP, or prevalence of high BP (systolic or diastolic BP ≥90th percentile of the US National Heart, Lung, and Blood Institute reference: 31% compared with 28%; P = 0.251). BP at 4-6 y of age was positively related to birth weight; this relation was largely mediated through concurrent WAZ in a path model. Concurrent WAZ and maternal BP were the factors most strongly related to child BP.Conclusions: Despite greater birth weight in the LNS group, there was no intervention group difference in BP at 4-6 y. In this preschool population at high risk of adult hypertension based on BP at 4-6 y, high maternal BP and child WAZ were key factors related to BP. This trial was registered at clinicaltrials.gov as NCT00970866. [ABSTRACT FROM AUTHOR]

Background: Whether consuming sweet foods early in life affects sweet food preferences and consumption later in childhood is unknown.Objective: We tested the hypothesis that exposure to a slightly sweet lipid-based nutrient supplement (LNS) early in life would not increase preference for or consumption of sweet items at preschool age.Methods: We followed up children who had participated in a randomized trial in Ghana in which LNS was provided to 1 group of women during pregnancy and 6 mo postpartum and to their infants from ages 6-18 mo (LNS group). The control group (non-LNS group) received iron and folic acid during pregnancy or multiple micronutrients during pregnancy and 6 mo postpartum, with no infant supplementation. At 4-6 y, we obtained data from caregivers on children's food and beverage preferences and consumption (n = 985). For a randomly selected subsample (n = 624), we assessed preference for sweet items using a photo game (range in potential scores, 0-15). For the photo game and reported consumption of sweet items, we examined group differences using predetermined noninferiority margins equivalent to an effect size of 0.2.Results: Median (quartile 1, quartile 3) reported consumption of sweet items (times in previous week) was 14 (8, 23) in the LNS group and 16 (9, 22) in the non-LNS group; in the photo game, the number of sweet items selected was 15 (11, 15) and 15 (11, 15), respectively. The upper level of the 95% CI of the mean difference between LNS and non-LNS groups did not exceed the noninferiority margins for these outcomes. Caregiver-reported preferences for sweet items also did not differ between groups (P = 0.9).Conclusion: In this setting, where child consumption of sweet foods was common, exposure to a slightly sweet LNS early in life did not increase preference for or consumption of sweet foods and beverages at preschool age. This trial was registered at clinicaltrials.gov as NCT00970866. [ABSTRACT FROM AUTHOR]

Background: Adequate nutrition is necessary for brain development during pregnancy and infancy. Few randomized controlled trials of supplementation during these periods have measured later developmental outcomes. Objective: Our objective was to investigate the effects of provision of prenatal and postnatal lipid-based nutrient supplements (LNS) on child development at preschool age. Methods: We conducted a follow-up study of 966 children aged 4–6 y in 2016, born to women who participated in the International Lipid-Based Nutrient Supplements-DYAD trial conducted in Ghana in 2009–2014, representing 79% of eligible children. Women ≤20 weeks of gestation were randomized to daily LNS or multiple micronutrient (MMN) capsules during pregnancy through 6 mo postpartum or iron and folic acid (IFA) capsules during pregnancy and calcium placebo capsules during 6 mo postpartum. Children in the LNS group received LNS from 6 to 18 mo. Primary outcomes of this follow-up study were (1) a cognitive factor score based on a test battery adapted from several standard tests, 2) fine motor score (9-hole pegboard test), and (3) social-emotional difficulties (Strengths and Difficulties Questionnaire; SDQ). Eight secondary outcomes were calculated in specific domains (e.g., language, SDQ prosocial). Analysis was by a complete case intention to treat in a 2-group comparison: LNS compared with non-LNS (MMN + IFA). Results: Children in the LNS group had significantly lower social-emotional difficulties z-scores than children in the non-LNS group (adjusted for child age β =−0.12, 95% CI: −0.25, 0.02, P = 0.087; fully adjusted β = −0.16, 95% CI: −0.29, −0.03, P = 0.013). The effect of LNS on social-emotional difficulties scorewas larger among children living in households with lower home environment scores (P-interaction = 0.081). No other outcomes differed between the 2 intervention groups. Conclusions: Provision of LNS during the first 1000 d of development improved behavioral function, particularly for children from low nurturing and stimulation households, but did not affect cognition at preschool age in this setting. [ABSTRACT FROM AUTHOR]

Biochar has shown potential in reducing inorganic nitrogen ( N) leaching losses from inorganic and organic fertilizer sources in coarse-textured soils. Little information, however, is available on the effect of biochar on the availability of the retained inorganic N in biochar-amended sandy soil. The objective of our study was to determine the potential of pine wood biochar to reduce the leaching of ammonium nitrate fertilizer (100 kg N ha−1) from sandy soil ( W. Cape, South Africa) and to quantify the exchangeable inorganic N (2 m KCl) remaining after intensive leaching. Laboratory columns containing sandy soil and biochar (0, 0.5, 2.5 and 10.0% w/w) were leached weekly over a period of six weeks simulating heavy winter rainfall. Biochar (0.5, 2.5 and 10.0% w/w) significantly reduced the cumulative amount of ammonium (12, 50 and 86%, respectively) and nitrate (26, 42 and 96%, respectively) leached relative to the control soil. Despite the observed strong reduction in inorganic N leaching, the leached biochar-amended soils contained only small amounts of exchangeable ammonium (0-7.3 mg kg−1) and nitrate (5.8-8.0 mg kg−1). The results show that pine wood biochar can strongly reduce not only the amount of ammonium and nitrate leached from sandy soils, but also the amount of recoverable exchangeable ammonium and nitrate after leaching. Furthermore, the 2.5 and 10.0% biochar application rates led to over-liming. This raises some concerns as to the practical use of biochar in improving N fertilizer-use efficiency of plants. [ABSTRACT FROM AUTHOR]

Phosphorus (P) deficiency is a major constraint to upland rice production on Ultisols in the humid zone of West Africa. Integrated use of P-efficient cultivars and P nutrition is needed for enhanced sustainable productivity on these soils. This article reports on the P responsiveness of interspecific rice hybrids (crosses from Oryza sativa and O. glaberrima) along with O. sativa and O. glaberrima cultivars grown on an acidic Ultisol, low in available P. The cultivars differed in yield and P-uptake response to fresh and residual P. Two interspecific cultivars gave a linear response to P and produced the greatest grain yield under direct and residual P. The O. glaberrima cultivar CG 14 did not respond to the applied P, whereas the O. sativa cultivar was moderate in its performance. Our results show that the interspecific rice cultivars have the potential to adapt and perform well on acidic upland soils. [ABSTRACT FROM AUTHOR]

Phosphorus (P) deficiency is a major constraint to upland rice production on highly weathered, low activity clay soils in the humid zone of West Africa. There is a paucity of information on the long-term fertilizer P effects on rice on these soils. A field experiment was conducted for six years (1993–1998) to determine the response of four upland rice cultivars to fertilizer P applied at 0, 45, 90, 135, and 180 kg P ha-1 only once in 1993, and to residual P in 1994, 1995, 1996, and 1998. The experimental site was located on an Ultisol, low in available P, in the humid forest zone of Côte d'Ivoire, West Africa. This paper discusses long-term P effects on P uptake and efficiency of upland rice cultivars. The cultivars evaluated differed in cumulative agronomic and physiological P efficiencies, and the efficiencies were higher at lower P rates for the P-efficient cultivars. The P uptake response and P harvest index were affected by P rate and its residual effect, which decreased with time after P was applied. The mean cumulative recovery of applied P in five crops of four rice cultivars varied from 5.5 to 9.4%. The results suggest that the variation in P efficiency of the cultivars is due to differences in the efficiency of utilization of P for grain production. [ABSTRACT FROM AUTHOR]