Microsoft Word - 4-Agra_45632_citaeref-PG 1528 Bioscience Journal Original Article Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 MINERAL AND ORGANOMINERAL SOURCES OF NITROGEN TO MAIZE AGRONOMIC PERFORMANCE FONTES MINERAIS E ORGANOMINERAIS DE NITROGÊNIO PARA AUMENTAR O DESEMPENHO AGRONÔMICO DO MILHO Marcelo Alves da Rocha DIAS1; Regina Maria Quintão LANA2; José Geraldo MAGESTE2; Odair José MARQUES3; Adriane de Andrade SILVA3; Ernane Miranda LEMES4; Daniel Martins da SILVA5; Jéssica Mieko Ota ALVES5 1. Mestre em Agronomia Instituto de Ciências Agrárias da Universidade Federal de Uberlândia-ICIAG-UFU, Uberlândia, MG, Brasil. mardias@ufu.br; 2. Professor do ICIAG-UFU, Uberlândia, MG, Brasil; 3. Professor do ICIAG-UFU, Monte Carmelo, MG, Brasil; 4. Pós-doutorando na Universidade Federal de Uberlândia-ICIAG-UFU, Uberlândia, MG, Brasil; 5. Técnico de Laboratório do ICIAG-UFU, Uberlândia, MG,Brasil. ABSTRACT: Nitrogen (N) is one of the nutrients absorbed in great quantity by maize crop. Also, N fertilizers are of high costs and subject to large losses into the agricultural environment. There are various categories of fertilizers known as fertilizers of improved efficiency that can minimize such N losses. The objective of this study was to evaluate the effect of different sources and doses of N in maize agronomic performance. The experiment was installed in randomized blocks, with four replications, designed as a factorial 5 x 5 + 1, constituted by five N sources (urea, urea polymerized, urea with NBPT, organomineral with and without NBPT), five N doses (40, 80, 120, 160, 200 kg ha-1) plus a control (no N supply). The chlorophyll contents and grain yield were evaluated. The results showed no differences for the different N sources, indicating that the organomineral sources are as efficient as the mineral sources. The addition of N fertilizers in increasing doses, regardless of the source tested, has increased the levels of chlorophylls and grain yiled. KEYWORDS: Zea mays L.. Fertilizer technology. Grain yield. Urea. Organomineral. INTRODUCTION Maize (Zea mays L.) is one of the main cereals produced in the world. Its economic importance is due to its many uses from food to high-tech industry. Given the importance of this crop, farmers must treat the agronomic managements with caution, especially regard to mineral nutrition. Among the essential mineral nutrients, nitrogen (N) is considered one of the most demanded by maize plants because it is in the composition of proteins, enzymes, coenzymes, nucleic acids, phytocromes and chlorophylls (BÜLL, 1993). Nitrogen deficiency during any crop stage is highly damaging to crop development, and its inadequate supply and low soil levels are limiting factors to lower maize grain production. The soil N availability is mainly controlled by the mineralization of organic matter and by nitrogen fertilization (ALVA et al., 2016). A low organic matter level in soil is a common condition in the Brazilian Cerrado biome (Savannah like biome), which holds most of the agricultural production area in countries like Brazil. In these soils, nitrogen fertilization becomes an essential practice to achieve high productive levels (SILVA et al., 2005). The amount, timing and precise location of the N fertilization is essential for a profitable maize grain production. The N fertilizers are mainly produced from non-renewable fossil fuels and, when used in large quantities or in inadequate field conditions, they may lose N through erosion, leaching, denitrification and volatilization (LARA CABEZAS et al., 2000). A strategy to improve N fertilizations efficiency and losses is through the use of improved fertilizers. Slow release fertilizers (release N during several months), and controlled and stabilized fertilizers (fertilizers containing inhibitors of urease and nitrification) are widespread improved fertilizers for sustainable farming (TRENKEL, 2010). Common slow release fertilizers are the fertilizers coated with polymers that hinder fertilizer solubilization in soil solution; common stabilized fertilizer containing inhibitors of urease, as NBPT (N-(n-butyl) thiophosphoric triamide), reduces the activity of this enzyme responsible to hydrolyzes urea to volatile ammonia (NH3) (KRAJEWSKA, 2009). Thus, the objective of this work was to evaluate the effect of different N sources, minerals and organomineral, with different technologies and Received: 08/04/19 Accepted: 30/12/19 1529 Mineral and organomineral… DIAS, M. A. R. et al. Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 levels, in agronomic aspects of maize cultivated in the region of the Brazilian Cerrado. MATERIAL AND METHODS Experimental area and study design The field experiment was conducted in 2015/1 in Monte Carmelo city, Minas Gerais state, Brazil, at the experimental area of the Federal University of Uberlândia (latitude: 18º 44' 5" S, longitude: 47° 29' 47" W). Terrain altitude is about 890 m from sea level, and climate is an Aw (tropical with dry winter), according to the Köppen climate classification (ALVARES et al., 2013). The soil of the experimental area is classified as a dystrophic red Latosol (EMBRAPA, 2013). Prior to implementation of the experiment the experimental area remained for three years under grass (Brachiaria decumbens). The soil chemical characteristics and texture were: pH (H2O): 5.7; P (Mehlich): 17.9 mg dm -3; K: 187 mg dm-3; 2.1, 0.7, 0, 3.6 cmolc dm-3, respectively, for Ca, Mg, Al, H+Al; 48% base saturation; soil organic matter: 4.2 dag kg-1, and 54% clay (EMBRAPA, 2011). The experiment was carried out in a randomized block design (RBD) with four replications. The treatments were distributed as the factorial scheme: 5 x 5 + 1 control, with the first factor as five N fertilizer sources [urea, urea polymerized, urea with NBPT, organomineral with NBPT, organomineral without NBPT)] and the second factor as five N doses (40, 80, 120, 160, 200 kg ha-1 N) - all ureias used had 45% N and the organomineral source was equivalent to the formulation 26-0-0 (NPK). The treatments application (sidedressing) was performed 34 days after sowing when plants were awarded V4 stage. The control treatment consisted of no N application. The NPK sowing fertilization was indicated by the Minas Gerais state recommendations for maize crop (ALVES et al., 1999). The P source used was the mono-ammonium phosphate (49% P2O5; 10% N) at 70 kg ha -1 of P2O5 dose. The K source was the potassium chloride (60% K2O) at 60 kg ha-1 of K2O dose. The N sources used at sowing were urea (45% N) and the mono-ammonium phosphate totalizing 20 kg ha-1 of N. Each plot consisted of four 5.5 m rows spaced 0.9 m between rows. The useful plot area consisted of the innermost rows, dropping 0.25 m from each end. The maize hybrid planted was 30F53YH (65,000 plants ha-1). Leaf chlorophyll and yield The chlorophylls (a, b, a+b) estimations were performed at the third middle of the maize shoot with a chlorophyll meter model CFL 1030 Falker (Falker Agricultural Automation, Porto Alegre, Brazil), which releases results as Falker Chlorophyll Index (FCI). Five plants in each useful plot were measured in five moments during maize cycle, at 44, 55, 76, 101 and 118 days after sowing. The chlorophyll contends in those moments were used to calculate the area under the chlorophyll progress curve (AUCPC). The AUCPC is a variable that summarizes in a value a given set of data and enables the comparison of treatments during a certain period. The AUCPC is calculated by the method of integration trapezoid in the expression described by (CAMPBELL, MADDEN, 1990): , where: n = number of assessments; yi and yi+1 = values of analyzed variable observed in two consecutive assessments; (ti+1 - ti) = interval between two ratings (days). To estimate yield the harvested ears (140 days after sowing) were dried in full sun during 5 days and threshed after drying. The grain mass obtained from the useful area (9 m2) was extrapolated to “kg ha-1” and corrected to 13% moisture. Statistical analysis started by checking ANOVA presumptions through the tests: homogeneity of variances (Levene test, P ≤ 0.01), normality of residues (Shapiro-Wilk test, P ≤ 0.01) and additivity (Tukey test for non-additivity, P ≤ 0.01) using the software SPSS 16.0. After attendance of those presumptions, the ANOVA (F test, P ≤ 0.05) was executed. The means of the N fertilized treatments were compared to the control treatment (0 kg ha-1 N) by Dunnet's test (p ≤ 0.05), using Assistat software (SILVA et al., 2009). Tukey test (P ≤ 0.05) for the factor source and analysis of polynomial regression for the factor dose, were subsequently performed using the Sisvar software (4.0) (FERREIRA, 2000). RESULTS AND DISCUSSION Usually, the 200 kg ha-1 N dose differ (AUCPC) chlorophyll a, b and a+b (Table 1). The AUCPC of chlorophyll a and a+b increased for the doses exceeding 80 kg ha-1 and 120 kg ha-1 of N of the sources urea with NBPT and organomineral with NBPT, respectively (Table 1). For the urea polymerized source the AUCPC of the of 80 kg ha-1 of N dose differed from the control treatment (Table 1). 1530 Mineral and organomineral… DIAS, M. A. R. et al. Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 Table 1. Area under the chlorophyll progress curve (AUCPC) of chlorophylls a, b, total (a+b) and production of the control treatment (no N supply) compare to other sources and doses. N SOURCE DOSE kg ha-1 AUCPC chlorophylls (FCI) PRODUCTION A b a+b kg ha-1 Urea 40 2719.01 831.89 3550.90 5292.89 80 2658.96 818.88 3477.84 5688.88 120 2709.05 864.08 3573.13 6605.47 160 2693.91 842.67 3536.59 6470.13 200 2977.14* 1007.55* 3984.70* 6756.16 Urea Polymerized 40 2716.59 855.88 3572.47 5037.81 80 2756.23* 881.64* 3637.88* 5124.93 120 2701.81 820.27 3562.08 5755.86 160 2697.57 836.84 3534.42 5206.22 200 2710.69 847.22 3557.91 6600.72 Urea + NBPT1 40 2704.56 826.43 3530.99 5443.81 80 2697.66 825.75 3523.42 5189.63 120 2832.01* 918.12* 3750.13* 6658.61 160 2744.57* 863.46 3608.04* 6902.04 200 2792.01* 888.24* 3680.25* 4810.49 O.M.2 – NBPT 40 2765.51* 829.98 3595.50 5408.16 80 2638.14 827.72 3465.87 6222.19 120 2707.34 854.92 3562.27 6203.98 160 2738.96 843.67 3582.63 5582.29 200 2864.82* 930.01* 3794.83* 6112.49 O.M. + NBPT 40 2542.89 783.98 3326.87 6179.05 80 2582.33 766.52 3348.85 5639.51 120 2632.77 800.42 3433.19 531715 160 2756.72* 866.36 3623.09* 6896.99 200 2742.96* 916.86* 3659.82* 5507.95 Control 0 2459.65 697.70 3157.36 5143.28 CV (%) 4.94 9.46 5.88 21.11 1 - N-(n-butyl) thiophosphoric triamide. 2 - Organomineral. Averages followed by an asterisk (*) differ significantly from the control (0 kg ha-1) by Dunnet's test at 5% probability. For yield there was no difference between the treatments with N compared to the control (Table 1). According to Raij et al. (1997) the soil responses to N fertilization is expected to be low for soils after fallow periods (two or more years), soils from pasture lands, and soils intensively cultivated with leguminous species or with green manure. The chlorophyll a, b and a+b for the different nitrogen sources were similar among each other (Table 2). The ‘dose x AUCPC’ of chlorophyll a, b and a+b regression model indicate the highest chlorophyll levels at the doses 211, 217 and 213 kg ha-1 of N, respectively (Figure 1). Table 2. Area under the chlorophyll progress curve (AUCPC) of chlorophylls a, b e total (a+b). N SOURCE AUCPC chlorophylls (FCI) A b a+b UREA 2.702.95ns 843.79ns 3.546.75ns UREA POLYMERIZED 2.673.76 829.93 3.503.69 UREIA + NBPT1 2.705.08 836.61 3.541.70 O.M.2 – NBPT 2.695.73 830.67 3.526.41 O.M. + NBPT 2.619.55 805.31 3.424.86 AVERAGE 2.679.41 829.26 3.508.68 CV (%) 4.72 9.17 5.63 1 - N-(n-butyl) thiophosphoric triamide. 2 - Organomineral. ns: non-significant differences between sources by Tukey's test of means at 5% probability. 1531 Mineral and organomineral… DIAS, M. A. R. et al. Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 Dose (kg ha-1) 0000 40404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 200200200200 A U C P C o f c hl o ro p hy lls ( F C I) 0 400 800 1200 1600 2000 2400 2800 3200 3600 4000 Chlorophyll a Chlorophyll b Chlorophyll a+b %56.82=R x×0.009997-x×4.2572+3229.59=b+a.AUCPCchlor 2 2 %51.81=R x×0.006286-x×2.6495+2506.67=a.AUCPCchlor 2 2 %83.83=R x×0.003711-x×1.6077+92.227=b.AUCPCchlor 2 2 Figure 1. Graph of the area under the chlorophyll progress curve (AUCPC) of chlorophylls a, b, total (a+b) by the doses of nitrogen. Nitrogen participates in the composition of the chlorophylls and the assessment of the need for N by plants can be determined by indirect measurement of chlorophylls content (SHADCHINA, DMITRIEVA, 1995; DEBAEKE et al., 2006). The relationship between the chlorophyll assessment and the chlorophyll content in leaf, and between chlorophyll content in leaves and the N content in the plant are reported in literature (ARGENTA et al., 2004; SCHLEMMER et al., 2013). The results found in this study for the chlorophylls response to N application were positive and reached a maximum level of chlorophylls in doses around 213 kg ha-1 of N which was similar to the responses founded by Teixeira Filho et al. (2009) in wheat. The maize grain yield among the different N sources was similar, averaging 5,777 kg ha-1 (Table 3). FONTOURA and BAYER (2010) also found no differences in the productivity of corn fertilized with urea or controlled release N sources. The N efficacy of the slow release, or stabilized fertilizers, compared to mineral soluble fertilizers is similar under field conditions and consequently to grain maize production (KAPPES et al., 2009; SORATTO et al., 2010; CARDOSO et al., 2011; SCHIAVINATTI et al., 2009). Table 3. Production of grain (kg ha-1) for the different nitrogen sources. N SOURCE PRODUCTION kg ha-1 UREA 5992.80ns UREA POLYMERIZED 5478.14 UREIA + NBPT1 5691.31 O.M.2 – NBPT 5778.73 O.M. + NBPT 5780.66 AVERAGE 5744.33 CV (%) 21.19 1 - N-(n-butyl) thiophosphoric triamide. 2 - Organomineral. ns: non-significant differences between sources by Tukey's test of means at 5% probability. The maize grain yield, for any of the sources evaluated, raises about 4.87 kg ha-1 per each kilogram of N from (Figure 2), reaching up to 5,993 kg ha-1 of grain (Table 3). The low yield response to N fertilization caused by the immobilization of nitrogen probably affected the productive potential of the plant and, consequently, the productivity obtained in this work (Table 3). 1532 Mineral and organomineral… DIAS, M. A. R. et al. Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 Figure 2. Graph of the grain production (kg ha-1) by the doses of nitrogen. Andrade et al. (2014), Soratto et al., (2010) and Kappes et al. (2009) also found significant responses in maize grain yield, regardless of the N source, with the application of doses up to 134, 120 and 70 kg ha-1 of N, respectively. Linear responses of maize grain yield were also observed in studies of Sichocki et al. (2014) and Valderrama et al. (2014). According to Fageria et al. (2013) the N, further than a component of chlorophylls, is also associated to leaf area increases, high solar radiation interception efficiency and photosynthetic rate, consequently improving grain yield, justifying higher yields where there was an application of higher N doses. CONCLUSIONS There were no significant differences for the different N sources, indicating that the organomineral source is as efficient as the mineral source. The increasing doses of N fertilizers, regardless of the source used, increased the levels of chlorophylls and grain yield. ACKNOWLEDGEMENTS To CAPES and to the Support Program for Qualification of UFU, by the financial aid. To all faculty and staff members of the Graduate Program in Agricultural Engineering from UFU. RESUMO: O nitrogênio (N) é um dos nutrientes absorvidos em grande quantidade pela cultura do milho. Além disso, os fertilizantes nitrogenados são de alto custo e sujeitos a grandes perdas no ambiente agrícola. Existem várias categorias de fertilizantes, conhecidas como fertilizantes de maior eficiência, que podem minimizar essas perdas de N. O objetivo deste estudo foi avaliar o efeito de diferentes fontes e doses de N no desempenho agronômico do milho. O experimento foi instalado em blocos casualizados, com quatro repetições, delineadas como fatorial 5 x 5 + 1, constituído por cinco fontes de N (uréia, uréia polimerizada, uréia com NBPT, organomineral com e sem NBPT), cinco doses de N (40, 80, 120, 160, 200 kg ha-1) mais um controle (sem fornecimento de N). O conteúdo de clorofila e o rendimento de grãos foram avaliados. Os resultados não mostraram diferenças para as diferentes fontes de N, indicando que as fontes organomineral são tão eficientes quanto as fontes minerais. A adição de fertilizantes N em doses crescentes, independentemente da fonte testada, aumentou os níveis de clorofilas e rendimento de grãos . PALAVRAS-CHAVE: Zea mays L .. Tecnologia de fertilizantes. Rendimento de grãos. Uréia. Organomineral. Dose (kg ha-1) 0000 40404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 20020020020040404040 80808080 120120120120 160160160160 200200200200 P ro d uc tio n (k g h a -1 ) 3600 4200 4800 5400 6000 6600 7200 %29.77=R x×8744.4+5256.89=PRODUCTION 2 1533 Mineral and organomineral… DIAS, M. A. R. et al. Biosci. J., Uberlândia, v. 36, n. 5, p. 1528-1534, Sept./Oct. 2020 http://dx.doi.org/10.14393/BJ-v36n5a2020-45632 REFERENCES ALVA, A. K.; PARAMASIVAM, S.; FARES, A.; DELGADO, J. A.; MATTOS, Jr, D.; SAJWAN, K. Nitrogen and irrigation management practices to improve nitrogen uptake efficiency and minimize leaching losses. Journal of Crop Improvement, v. 15, n. 2, p. 369-420. 2005. https://doi.org/10.1300/J411v15n02_11 ALVARES, C. A.; STAPE, J. L.; SENTELHAS, P. C.; GONÇALVES, J. L. 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