The use of mixed mineral fertilizers consisting of macro- and micronutrients, which are already routinely used for leaf fertilization, in the treatment of corn and soybean seeds would positively influence germination and vigor, consequently improving growth and seedling development. This study aimed to evaluate the physiological potential of corn and soybean seeds treated with mixed mineral fertilizers. The seed treatment efficiency test with mixed mineral fertilizers was conducted at the Federal University of Jataí—UFJ—using Vital^®, Lança^®, Ídolo^®, Massivo^®, and their combinations. The treatments consisted of two controls for soybean and three for corn. Analysis of variance was performed using the F-test (p ≤ 0.05), and when there was significance, the means were compared using the Scott–Knott test (p ≤ 0.05). The mixed mineral fertilizers Vital^® + Massivo^® (T6), Lança^® + Ídolo^® (T7), and Vital^® + Lança^® + Ídolo^® (T10) used in the seed treatment benefit the development of soybean (NS7667 IPRO) seeds. The treatments for corn (MG744 PWU) had little effect on germination and seedling development. The use of mixed mineral fertilizers in the seed treatments did not affect the physiological potential of the soybean and corn seeds, keeping the lots with germination values within commercialization standards.

Corn (Zea mays L.) is the most cultivated cereal in the world. The high yields obtained for this crop are mainly linked to nitrogen requirements. Technologies that aim to reduce costs with nitrogen fertilizers, with less environmental impact, such as diazotrophic bacteria, should be considered an advantageous alternative for this crop. The present study aimed to evaluate two corn hybrids, BioGene 7046® and Dekalb 310®, with three topdressing nitrogen doses (0.35 and 70 kg ha-1 of N) associated with four application methods of Azospirillum brasilense (without inoculation, seed inoculation, foliar inoculation, and the combination of inoculation via seeds and leaves). A randomized block design with four replications arranged in a 2x3x4 factorial scheme was used to evaluate variables related to growth and development, physiological analysis of nitrate reductase enzyme activity, and yield variables and their components. The use of Azospirillum brasilense did not affect the development of corn plants and did not increase grain yield. In the edaphoclimatic conditions in which this research was developed, nitrogen fertilization at doses of 35 and 70 kg ha-1 benefit nutrition, development, and corn yield components but are insufficient to increase grain yield.

Corn (Zea mays L.) is one of the most important cereals grown and consumed in the world not only for its economic value but also due to its importance in human and animal nutrition. This study aimed to assess the initial development of corn as a function of increasing nitrogen doses. The study was carried out in a greenhouse on the Sipal Farm, Confresa, MT, Brazil. The experiment was set up in a completely randomized design, consisting of five treatments (0, 100, 200, 300, and 400 mg N dm−3 soil), with four replications, conducted from April to June 2020. Four seeds of the hybrid K 9606 VIP 3 were sown per 8-L polyethylene pot. The plants were thinned at 7 days after emergence (DAE), leaving only one plant per pot. Morphological components were assessed. A significant effect was found for almost all the analyzed parameters, except for stem diameter and root dry matter. The maximum plant height, shoot fresh matter, leaf area index, shoot dry matter, root fresh matter, and root volume was obtained by applying the maximum agronomic efficiency doses of 248.83, 271.90, 336.91, 279.66, 403.92, and 272.90 mg N dm−3 soil, respectively. Nitrogen doses influenced the initial development of the corn crop.

Advancing nitrogen (N) application in cropping systems, using cover crops, is an alternative to improve the efficiency of use of this nutrient and to optimize the operational issue. The aim of this study was to evaluate the efficiency of advancing N fertilization for corn crop, with Brachiaria ruziziensis as cover crop. The experiment was conducted at the experimental field of the Federal University of Jataí / Regional Unit of Jataí, GO, Brazil, with history of soybean-corn/sorghum succession in the last 20 years and a high organic matter content in the soil, which reaches 39.5 g kg-1. A randomized complete block design was used in a 5x2 + 1 factorial scheme with 4 replicates, corresponding to five N doses: 0; 50; 100; 150 and 200 kg ha-1 and two times of application in B. ruziziensis: Time 1 - N application 90 days before planting of corn, and Time 2 - N application 60 days before planting, plus an additional treatment with conventional N fertilization, 150 kg ha-1 of N, not advanced, applied to the corn crop, split into planting fertilization and top -dressing fertilization. Except for the N dose of 200 kg ha-1 applied 90 days before corn sowing, advancing N fertilization for this crop using B. ruziziensis as cover plant proved to be as efficient as conventional fertilization for the soil and climate conditions under which the study was carried out, that is, soil with high content of organic matter, built fertility and absence of water restriction.

The objective of this work was to evaluate the agronomic performance of a second crop maize grown under different methods of inoculation with Azospirillum brasilense. The experiment was conducted in a randomized block design with 6 treatments and four replications. The treatments used were: no inoculation (T1); inoculation with A. brasilense via seed (T2); inoculation with A. brasilense via sowing furrow (T3); inoculation with A. brasilense via leaf (T4); two inoculations with A. brasilense via leaf (T5); and combination of inoculations via seed, sowing furrow, and leaf (T6). Physiological, morphological, production, and yield components of the second crop maize were evaluated. The data were subjected to analysis of variance at 0.05 probability level and when significant, the means were subjected to the Scott-Knott test at 0.05 probability level, using the R-bio statistical program. Inoculation via seed results in higher nitrate reductase enzyme activity. The inoculation with A. brasilense does not result in gains in grain yield for second crop maize; however, it improves the maize quality by increasing its gross protein contents.