The supplementation of nitrogen can be increased by the use of nitrogen-fixing, diazotrophic bacteria such as Azospirillum brasilense. These bacteria can act to promote plant growth in various plant species, including corn (Zea mays L.). However, there is a need to understand the behavior of these bacteria in different agricultural systems. The objective of this study was to evaluate the effect on the growth and yield of corn inoculated with A. brasilense, and to identify the type of farming system which benefited most from the use of A. brasilense-based inoculants. The experiment conducted over two corn crop seasons was arranged in a 6 × 2 factorial scheme, consisting of six farming systems and the presence or absence of inoculation with the bacteria A. brasilense. The farming systems were derived from a long-term experiment with different fertilization systems that has been conducted since 1984. Among these systems, there were three conventional systems (CNT1: conventional no-till without fertilizer; CNT2: conventional no-till with 150 kg ha−1 of mineral fertilizer + 50 kg ha−1 of urea; CNT3: conventional no-till with 300 kg ha−1 of mineral fertilizer + 100 kg ha−1 of urea), and three organic systems (ONT1: organic no-till with 40 m3 ha−1 of organic compost; ONT2: organic no-till with 20 m3 ha−1 of organic compost; ONT3: organic no-till with 40 m3 ha−1 of organic compost and intercropped with Canavalia ensiformis). Although the Azospirillum population in the soil before planting was the same for all six systems, the count in the rhizospheric soil was higher in the organic systems, and there was no increase in that count due to inoculation. In this study, the only difference observed was within the CNT1 system, between the inoculated (CNT1-I) and uninoculated (CNT1-NI) treatments. In this system, inoculation resulted in an increase in plant height, in addition to higher concentrations of foliar N and P, and a higher plant survival rate, which culminated in higher yield. Corn inoculated with A. brasilense in the CNT1-I treatment showed a significant increase in yield—2839 kg ha−1 higher than that recorded for CNT1-NI. This study shows that, in the conventional low input treatment CNT1-I, inoculation with A. brasilense resulted in an increase in corn growth and yield.

中文翻译：

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Azospirillum brasilense 在传统的低投入种植系统中提高玉米生长和产量

可以通过使用固氮、固氮细菌如巴西固氮螺菌. 这些细菌可以促进各种植物的植物生长，包括玉米（玉米L.)。然而，有必要了解这些细菌在不同农业系统中的行为。本研究的目的是评估接种后对玉米生长和产量的影响。A.巴西兰，并确定最受益于使用A.巴西兰-基孕育剂。在两个玉米作物季节进行的实验以 6 × 2 因子方案安排，包括六个耕作系统以及是否接种细菌A.巴西兰. 耕作系统源自自 1984 年以来对不同施肥系统进行的长期试验。在这些系统中，有三种常规系统（CNT1：常规免耕不施肥；CNT2：常规免耕，150 kg哈-1矿物肥料 + 50 公斤公顷-1尿素；CNT3：传统免耕，300 kg ha-1矿物肥料 + 100 公斤公顷-1尿素）和三个有机系统（ONT1：有机免耕 40 m3哈-1有机堆肥；ONT2：有机免耕 20 m3哈-1有机堆肥；ONT3：40 m 有机免耕3哈-1有机堆肥和间作菜豆）。虽然固氮螺菌属所有六个系统种植前土壤中的种群数量相同，有机系统中根际土壤中的数量较高，并且由于接种，该数量没有增加。在这项研究中，观察到的唯一差异是在 CNT1 系统内，接种 (CNT1-I) 和未接种 (CNT1-NI) 处理之间。在该系统中，接种导致株高增加，此外叶面 N 和 P 的浓度更高，植物存活率更高，最终获得更高的产量。玉米接种A.巴西兰在 CNT1-I 处理中，产量显着增加——2839 kg ha-1高于 CNT1-NI 的记录。本研究表明，在常规的低输入处理 CNT1-I 中，接种A.巴西兰从而提高了玉米的生长和产量。