NITROGEN FERTILIZATION ASSOCIATED WITH INOCULATION WITH RHIZOBACTERIA ON NUTRITION AND PRODUCTIVE PERFORMANCE OF GRAIN MILLET HYBRID IN NO-TILLAGE

• Grant number: 25/13630-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Marcelo Carvalho Minhoto Teixeira Filho
• Grantee: Caio Henrique Oliveira Schussler
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

Grain millet (Pennisetum glaucum L.) is cultivated in several parts of the world, whose grains are used for human or animal food. Currently, it is the sixth most consumed cereal in the world, and has been gaining ground among Brazilian crops, especially in the Cerrado region, as it has a low production cost, being an alternative for planting diversification in areas at risk of corn sowing outside it is ideal season (window), thanks to its characteristic of greater drought tolerance. However, there are few studies on the recommendation of nitrogen (N) for grain pearl millet, as well as responses to rhizobacteria inoculation N is the nutrient required in greater quantity, the most complex to manage and consists of one of the highest costs of high productivity production systems for grasses, such as grain millet hybrids. Therefore, developing management techniques that minimize the need for mineral N application and provide better use of nutrients is essential for an increasingly sustainable, productive and less polluting agriculture, aiming at food security and low-carbon agriculture. In this aspect, it was established the hypothesis that the combined inoculation of two rhizobacteria promotes additive effects of individual benefits, which optimize biological nitrogen fixation the efficiency of nutrient use, which positively reflect on the nutrition, vegetative and productive performance of the plant and, thus, reduce the need to use fertilizers in the cultivation of grain millet in the second harvest ('off-season'), with the advantage of recycling nutrients and producing straw for the soil cover under no-tillage system (NTS). The study will be carried out at the Faculty of Engineering of Ilha Solteira, UNESP, Selvíria-MS, in a dystroferric Rhodic Haplustox, Cerrado phase, under NTS. The objectives will be to evaluate the effects of inoculation, via seeds, with Azospirillum brasilense applied alone and associated with Bacillus subtilis, on the development, nutrition and grain yield of grain pearl millet (hybrid) combined with N rates; and evaluate the extraction (grains + straw), removal (grains) and return of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (B, Cu, Fe, Mn and Zn) to the soil by crop residues. The experimental design will be randomized blocks, in a 3x5 factorial scheme, with four replications. The treatments will be: i) control, without inoculation; ii) inoculation of Azospirillum brasilense; and iii) Azospirillum brasilense associated with Bacillus subtilis, combined with five N rates (0, 30, 60, 120 and 180 kg ha-1), as urea, applied in covering. Chemical analyses of soil and plants will be carried out in UNESP laboratories. Analyses of the nutritional status of the pearl millet plant at the beginning of flowering will be carried out; biometric growth assessments (plant height, stem diameter and final stand); production components; grain productivity; extraction (whole plant), export (grains) and return of macronutrients and micronutrients to the soil (crop residues - straw), in addition to bromatological analyses, C/N ratio and straw production for soil cover. It is hoped that the results can expand scientific knowledge regarding the optimization of the N dose for grain pearl millet with and without inoculation of rhizobacteria, as well as information that demonstrates the influence of inoculation on the development, nutrition and productivity of this cereal, which can help to improve the recommendation of more accurate doses of N-fertilizer for millet. In addition, knowledge that encourages the use of inoculation associated with inoculation or co-inoculation with rhizobacteria, which is low cost, easy to apply and acquire, and thus contribute to decision-making regarding N management in the cultivation of grain millet, which has increased significantly in Brazil, both for human and animal consumption. (AU)