The residual effects of gypsum rates and the interaction with N-fertilization on soil fertility, black oat root growth and aboveground biomass yield under no till lacks information. This study evaluated soil chemical attributes up to 0.8 m depth and aboveground biomass of black oat in a continuous no-till area as affected by gypsum rates (0, 3, 6, 9 and 12 Mg ha −1) and topdressing N-fertilization (0, 50 and 100 kg ha −1) to a Typic Hapludox in Southern Brazil. Black oat root growth was also evaluated for two gypsum rates (0 and 6 Mg ha −1) and all N treatments. Gypsum application increased Ca 2+ and SO 4 2 −-S fraction and reduced Mg 2+ levels in all soil layers, and N-fertilization increased NO 3 − and NH 4 + levels in the soil. Gypsum increased root length, superficial area and volume up to 0.8 m depth, while N-fertilization reduced root growth attributes in soil layers between 0.4 and 0.8 m depth. Gypsum increased (quadratically) the aboveground biomass yield of black oats in the two growing seasons, as did N-fertilization, but no interaction between gypsum and N-fertilization was observed. Gypsum can be used to improve soil fertility attributes, black oat biomass and root growth under no till. The higher N-fertilization (100 kg ha −1) increased black oat yield and reduced root growth in depth. In the average of the growing seasons, the gypsum rate of 7.36 Mg ha −1 applied 54 months earlier, associated with a rate of at least 50 kg ha −1 of N (urea) applied at the beginning of black oat tillering achieved the higher aboveground biomass yield.

It is estimated that 17.3% of the world population is at risk for Zn deficiency, and annually, about half a million children under five years of age die from causes related to Zn malnutrition. Low-cost strategy to increase Zn intake by humans is to increase the consumption of biofortified crops. Biofortification comprises the process for increasing contents of one or more nutrients in the edible parts of agricultural crops in order to increase their nutritional value. For biofortification to reach one billion people by 2030, mutual efforts must be added. Among them, policies must place more emphasis on agriculture role in improving health. Governments and institutions must include biofortification on food security policy, and food processors and others responsible for production chain must include biofortified crops in their product lines. The objective of this study was to carry out a bibliographic review to elucidate the dynamics of Zn in soil, the essential function of Zn in plant yield, the plant role in transfer Zn to human body, the importance of Zn in the human health and current measures that have been taken to mitigate Zn malnutrition in the world.

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Zinc (Zn) is one of the most deficient plant micronutrients in agricultural crops. The objective of this study was to evaluate plant nutrition, grain yield and nutrient export rate in response to soil and foliar Zn fertilization in common bean (Phaseolus vulgaris L.). Two field experiments in no-till system were carried out using two common bean cultivars, BRS Esteio (black bean) and IPR Campos Gerais (Carioca bean). Treatments were composed of soil Zn application during sowing and foliar Zn spray at flowering stage. Soil Zn application had effect on leaf Zn concentration in IPR Campos Gerais and did not affect grain yield of both cultivars. Foliar Zn spray increased leaf Zn concentration by approximately two times in both cultivars, but negatively affected the grain yield in BRS Esteio. Leaf concentration of N, Ca and S were affected by soil Zn application and leaf concentration of Mn was affected by foliar Zn spray, while leaf concentration of P, K, Mg, Cu and Fe were not influenced by the soil and foliar Zn treatments. In treatments without Zn, the descending order of nutrient export rate from the experimental site was as follows: N > K > P > Ca ≈ S > Mg for macronutrients and Fe > Mn > Cu > Zn for micronutrients. Foliar Zn spray increased the export rate of Zn, P, Ca, Mg, S, Mn, Cu and Fe in IPR Campos Gerais, while soil Zn application resulted in higher export rate of P, K and Mn in BRS Esteio.