Effect of Potassium and Zinc Nutrition on Growth and Yield of Short Duration Maize (Zea mays L.) under Dryland Vertisols

Background: The black soils (vertisols) are often considered to be high in potassium content however; under intensive cultivation of high nutrient demanding crop like maize; the soil available potassium might not be sufficient to fulfil the demand. Moreover; the interaction between potassium and micronutrients like zinc has to evaluated for higher crop yield under dryland condition. Methods: The experiment was laid out in factorial RBD design with two factors, i.e., potassium (K) and zinc (Zn), with three levels of each (K1- 30 kg K2O ha-1, K2- 60 kg K2O ha-1, K3- 90 kg K2O ha-1; Zn1- 20 kg ZnSO4 ha-1, Zn2- 30 kg ZnSO4 ha-1 and Zn3- 40 kg ZnSO4 ha-1). Result: Statistical interpretation of experimental data revealed that application of potassium at 60 kg K2O ha-1 and 30 kg of ZnSO4 ha-1 resulted improved plant height, number of functional leaves plants-1, leaf area index, dry matter accumulation, grain yield, stover yield and shelling percentage in maize. Interestingly positive interaction has also been recorded between potassium and zinc nutrition.

Zinc Nutritional Status and Risk Factors of Elderly in the China Adult Chronic Disease and Nutrition Surveillance 2015

Objectives: To analyze the serum zinc nutrition status of the Chinese elderly, and to assess the risk factor for zinc deficiency. Methods: 3727 elderly people over 60 years old were randomly selected from 302 monitoring points in 31 provinces of China Adult Chronic Disease and Nutrition Surveillance (CACDNS) 2015. Blood samples were selected from the biological sample bank of CACDNS 2015 and the basic information were collected by questionnaires. The criteria of serum zinc deficiency recommended by the International Zinc Nutrition Consulting Group (IZiNCG) were adopted, and the related factors were also analyzed. Results: The median serum zinc concentration of Chinese elderly was 99.2 (84.3~118.7) μg/dL. The overall adjusted prevalence of zinc deficiency was 8.68%, with a 95% confidence interval (CI) of 7.74% and 9.61%. Significant differences were found in different sex, age groups, Body Mass Index (BMI), residence region, race and education level in terms of serum zinc status in the elderly (p < 0.05). Participants who are males, aged above 70y, with BMIs of less than 18.5 kg/m2, living in rural areas, minority, and with the lowest income had a higher prevalence of zinc deficiency in the subgroups under different classifications. The risk of zinc deficiency in the elderly over 70y was 1.44 higher than those aged 60–69y (OR = 1.44, 95%CI 1.14–1.82), and the minority elderly has a 1.39 higher risk than Han nationality (OR = 1.39, 95%CI 1.01–1.91), while overweight/obesity and female elderly were at lower risk (OR < 1, p < 0.05). Conclusions: The overall prevalence of zinc deficiency in the elderly was highest in all adults in the CACDNS. It is recommended that the male elderly, over 70 years, and the minority elderly should pay more attention to the zinc nutrition status of their own.

Evaluation of Serum Zinc Status of Pregnant Women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) 2015

Objective: The purpose of this study was to evaluate serum zinc status of pregnant women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) in 2015–2016. Methods: A total of 7147 apparently healthy pregnant women were randomly selected in 302 national monitoring sites. Information on age, race, residence region, education, pregnancy, and family income per annum was collected, and the concentration of serum zinc was determined. The evaluation of serum zinc status was further performed according to the recommendations by the International Zinc Nutrition Consultative Group (IZiNCG). Results: The median concentration of serum zinc was 858.9 μg/L with an interquartile range (IQR) of 712.9 μg/L and 1048.9 μg/L, while the overall prevalence of zinc deficiency was 3.5% with a 95% confidence interval (CI) of 3.0% and 3.9%. Serum zinc status of pregnant women changed greatly in the different categories, particular in pregnancy and family income per annum (p < 0.05), but no significant difference was observed in the prevalence of zinc deficiency (p > 0.05). Conclusions: The lower prevalence of zinc deficiency generally indicated a better zinc status for pregnant women in the CACDNS in 2015–2016. However, a well-designed evaluation system of zinc status for pregnant women should be continually optimized and improved by inducing more parameters such as biochemical, dietary, or functional indicators.