Effects of deforestation and cultivation on soil CEC and contents of exchangeable bases: A case study in Simlipal National Park,India

Deforestation in the tropics seems to be a serious problem probably because of the reduction in soil CEC and the consequent losses of nutrients from the soils. Here, changes in these parameters as influenced by deforestation as well as vegetative cover were studied; statistical methods were applied to interpret the results. Cultivation causes a significant reduction in CEC, total content of the exchangeable bases and exchangeable Ca2+ and Mg2+ levels compared to the adjoining unmanaged forest land. Levels of exchangeable K⁺ and Na⁺, however, do not change significantly. Evergreen forest soils have the highest levels of CEC, total exchangeable bases, exchangeable Ca²⁺ and K⁺. Deciduous forest, grassland and cultivated soils have statistically similar contents of exchangeable Ca²⁺, Mg²⁺, K⁺ and Na⁺. Exchangeable Mg²⁺, however, is not affected by vegetative cover. Soil CEC shows fairly good correlation with the organic carbon content only in evergreen forest soils. In others, organic carbon apparently does not influence CEC significantly. All soils show excellent correlation between their CEC and total exchangeable bases. It is concluded that for regeneration of weathered tropical soils, an evergreen cover provides the most effective means; deciduous vegetation or grass cover do not seem promising.     

Effects of Prenatal Multiple Micronutrient Supplementation on Fetal Growth Factors: A Cluster-Randomized,Controlled Trial in Rural Bangladesh

Prenatal multiple micronutrient (MM) supplementation improves birth weight through increased fetal growth and gestational age, but whether maternal or fetal growth factors are involved is unclear. Our objective was to examine the effect of prenatal MM supplementation on intrauterine growth factors and the associations between growth factors and birth outcomes in a rural setting in Bangladesh. In a double-blind, cluster-randomized, controlled trial of MM vs. iron and folic acid (IFA) supplementation, we measured placental growth hormone (PGH) at 10 weeks and PGH and human placental lactogen (hPL) at 32 weeks gestation in maternal plasma (n = 396) and insulin, insulin-like growth factor-1 (IGF-1), and IGF binding protein-1 (IGFBP-1) in cord plasma (n = 325). Birth size and gestational age were also assessed. Early pregnancy mean (SD) BMI was 19.5 (2.4) kg/m² and birth weight was 2.68 (0.41) kg. There was no effect of MM on concentrations of maternal hPL or PGH, or cord insulin, IGF-1, or IGFBP-1. However, among pregnancies of female offspring, hPL concentration was higher by 1.1 mg/L in the third trimester (95% CI: 0.2, 2.0 mg/L; p = 0.09 for interaction); and among women with height <145 cm, insulin was higher by 59% (95% CI: 3, 115%; p = 0.05 for interaction) in the MM vs. IFA group. Maternal hPL and cord blood insulin and IGF-1 were positively, and IGFBP-1 was negatively, associated with birth weight z score and other measures of birth size (all p<0.05). IGF-1 was inversely associated with gestational age (p<0.05), but other growth factors were not associated with gestational age or preterm birth. Prenatal MM supplementation had no overall impact on intrauterine growth factors. MM supplementation altered some growth factors differentially by maternal early pregnancy nutritional status and sex of the offspring, but this should be examined in other studies.

Trial Registration

ClinicalTrials.gov NCT00860470     

Early newborn ritual foods correlate with delayed breastfeeding initiation in rural Bangladesh

Background

Early and exclusive breastfeeding may improve neonatal survival in low resource settings, but suboptimal breastfeeding still exists in areas with high infant mortality. Prelacteal feeding, the practice of giving a non-breastmilk food as a neonate’s first food, has been associated with suboptimal breastfeeding practices. We examined the association of feeding a non-breastmilk food in the first three days of life (early neonatal food, or ENF) with time from birth to initiation of breastfeeding among 25,286 Bangladeshi mother-neonate pairs, in a secondary analysis of a randomized controlled trial in northwestern rural Bangladesh conducted from 2001–2007.

Methods

Trained interviewers assessed the demographic characteristics during pregnancy. At three months postpartum, the interviewers visited participants again and retrospectively assessed demographic and breastfeeding characteristics surrounding the birth. We assessed the relationship between ENF and time to initiation of breastfeeding in hours in both unadjusted and adjusted linear regression analyses. We also calculated reverse cumulative distribution curves for time to initiation of breastfeeding and analyses were stratified by an infant’s ability to breastfeed normally at birth.

Results

The mean?±?SD time from birth to initiation of breastfeeding was 30.6?±?27.9 hours. Only 2,535 (10.0%) of women reported initiating breastfeeding in the first hour after birth and 10,207 (40.4%) reported initiating breastfeeding in the first 12 hours after birth. In adjusted linear regression analyses, feeding ENF was associated with a significant increase in time, in hours, to breastfeeding initiation both among children not able to breastfeed at birth (37.4; 95% CI 33.3, 41.5) and among children able to breastfeed at birth (13.3; 95% CI 12.7, 14.0).

Conclusions

Feeding ENF was strongly associated with delayed initiation of breastfeeding, even after adjusting for other related factors and stratifying on the neonate’s ability to suckle normally after birth. More research is needed to understand the impact of these findings on optimal breastfeeding in this setting. It is possible that ENF feeding and the ability to breastfeed immediately after birth are interrelated in their respective associations to suboptimal breastfeeding initiation. This study in a large population representative of other populations in rural South Asia, demonstrates significantly longer times to breastfeeding initiation than previously appreciated, with a possible important role of ENF feeding.

Trial registration

The randomized controlled trial on which this analysis is based, “Impact of Maternal Vitamin A or Beta-Carotene Supplementation on Maternal and Infant Mortality in Bangladesh”, was registered with ClinicalTrials.gov as trial number ID GHS-A-00-03-00019-00 and identifier NCT00198822. The identifier was first received September 12, 2005 (retrospectively registered). The first participant was enrolled in August 2001.

     

Changes in carbon,nitrogen and phosphorus levels due to deforestation and cultivation: A case study in Simlipal National Park,India

The study area, within the Simlipal National Park, India, provides a rare variety of soil sampling sites. These include virgin forests in the proximity of several cultivated areas (where no chemical fertilizers or any modern technology has been used and where periods of cultivation vary from 5 to a little over 100 yr); samples from evergreen forests, deciduous forests and natural grasslands could also be obtained. The availability of numerous such samples made it possible to use statistical methods to evaluate the changes. This study showed that deforestation and cultivation result in statistically significant (P_0.05) reduction in organic C, total N and C:N ratios but no significant changes in total and available P levels; C:P and N:P ratios are also reduced. Loss of organic C and N occurs rapidly in the first 15 yr of cultivation and reaches quasi-steady state values around 1–2% organic C and 0.1–0.2% total N; extent of reduction is not related to initial levels. Significant reduction in C:N, C:P ratios following cultivation suggest that mineralisation losses of C are higher than loss of N whereas loss of P is lowest. Lack of significant correlation between organic C and P levels in all types of soils, suggests that the bulk of the P is in the inorganic form. Highest levels of organic C and N were observed in evergreen forests followed by deciduous forests, grasslands and cultivated areas in that order; total and available P levels, however, showed no significant differences. Evergreen vegetative cover appears to provide the ideal environment for organic matter accumulation.