Alysson Roberto Baizie E Silva

Micronutrients are strategic elements for increasing the production of crops and improving the quality of harvested products. Despite this, they have been neglected in cassava (Manihot esculenta Crantz), one of the most important root vegetables in the tropics. This chapter aims to show how micronutrients can increase yield and improve nutritional quality of cassava. Research results covering the influence of micronutrients on yield and biofortification of roots of the plant are reviewed in detail. Boron, Cu, Mn, or Zn fertilization can increase root yield. Genetic biofortification is efficient in increasing Fe and Zn concentrations in cassava roots. The increase in Zn concentration can also be achieved by agronomic biofortification. A combination of genetic and agronomic strategies to biofortify cassava needs to be studied. In addition, further studies are needed to establish criteria for the large-scale application of micronutrient fertilizers in cassava. Use of genetically biofortified cultivars and judicious application of micronutrients are essential to increase production and improve the nutritional quality of cassava and thus ensure food security in the tropics.

Green economy is a model designed for economic growth in line with socio-environmental equity. Practices, processes, and products characterized by low carbon consumption and emissions, innovation and efficiency in the management of natural resources and waste, as well as social inclusion and governance, contribute to this transition. Bioinputs and bioenergy represent two pillars of a more environmentally and socially sustainable economy, being intrinsically linked to the reduction and optimization of the use of chemical fertilizers, pesticides, and non-renewable components in production systems. Both topics will be addressed in this article, with emphasis on the contributions of Brazilian Agricultural Research Corporation (Embrapa). The corporation’s research into bioinputs and bioenergy began in the 1970s, and had resulted in knowledge and technology transfer for the production sector, and the development of innovative products through partnerships with both public and private sectors. The diversification of raw materials and processes, with a focus on agronomic efficiency, energy security, economic resilience, and reduced environmental impact, is contemplated in Embrapa’s research for a better use of biomass. A proposal for future advances and an overview of the challenges yet to be overcome in these areas are also presented in this article.

Influence of boron (B) on photosynthesis and water use has not sufficiently been evaluated in soybean despite its worldwide importance as a crop. The objective of this work was to evaluate the effects of B application on photosynthesis and water use in soybean at vegetative growth stage. A pot experiment was carried out in a greenhouse. Soybean [Glycine max (L.) Merrill cv. M8644 IPRO] was grown in a clayey Oxisol previously fertilized with 4 B rates (0, 1.5, 3.0, and 6.0 mg dm⁻³). Net photosynthesis rate (P_n), intercellular CO₂ concentration (C_i), transpiration rate (E), stomatal conductance (g_s) were measured in the second trifoliate leaf of plants at the V4 growth stage. Instantaneous water use efficiency (WUEis = P_n/E) and intrinsic water use efficiency (WUEic = P_n/g_s) were calculated. B application to soil increased all these variables. The most consistent increases were in P_n, WUEis, and WUEic. The critical level of hot water extractable B in soil that maximized photosynthesis and optimized water use by soybean at vegetative growth stage was calculated to be 0.38 mg dm⁻³.

Authors: Alysson Roberto Baizi e Silva and Fábio Camilotti

Application of sewage sludge with high lead (Pb) contents may pollute soils and contaminate crops. The objective of this work was to evaluate peanut responses to application of sewage sludge with varying Pb contents in order to supply phosphorus (P) to the plant. A greenhouse experiment was carried out with peanut grown on soil sample from a medium-textured Haplustox. Treatments were arranged in 3 × 2 + 2 factorial scheme, replicated three times, distributed in randomized block design, and consisted of: three Pb rates applied to soil with sewage sludge (3, 21, and 42 mg kg⁻¹) × two times of sewage sludge application (30 days before peanut sowing and at the day of the sowing) + mineral fertilization + control (without sewage sludge and mineral fertilization). Sewage sludge was efficient to supply P to peanut. Sewage sludge containing high rates of Pb, when applied, did not harm biomass and yield of the plant, but increased HCl-extractable Pb in soil and Pb content in shoot, roots, and pod husks. Increase of Pb content in pod husks may represent contamination risk of kernels and their products with fragments from husks detached during manipulation or industrial processing of peanuts.

REVISTA NUCLEUS - ISSN 1982-2278(ISSN 1678-6602-formato impresso) é uma publicação semestral da FUNDAÇÃO EDUCACIONAL DE ITUVERAVA multidisciplinar; print ISSN 1678-6602; ISSN on-line 1982.2278; DOI 10.3738/1982.2278