Soil correction and Azospirillum brasilense: strategies in the cultivation of maize genotypes in semi-arid regions.

Abstract: The replacement of Caatinga by extensive agriculture has led to soil degradation in maize (Zea mays L.) growing areas. The objective of this study was to evaluate the effects of soil correction in association with Azospirillum brasiliense to replace nitrogen (N) fertilizer on the vegetative growth of two maize genotypes cultivated on degraded soil. The soil was collected in an area undergoing desertification in Irauçuba, Ceará state, Brazil. A 2x2x5 factorial experiment was carried out in blocks: two soil fertility levels (corrected and uncorrected soil in terms of fertility), two maize genotypes (BRS Caimbé and BRS Gorutuba), and five nitrogen sources (control, inoculation with A. brasilense, inoculation with A. brasilense + 50 kg ha-1 of N, 50 kg ha-1 of N,and 100 kg ha-1 of N). BRS Gorutuba genotype showed greater adaptability to the growing conditions evaluated. However, macronutrient concentration did not affect maize dry matter yield. The response of maize inoculated with A. brasiliense suggests the inoculation efficacy, supported by the N accumulation and the effect on plant growth. The dry matter yield in A. brasilense inoculated plants was equivalent to using N fertilizer. Therefore, the inoculation of BRS Gorutuba maize grown on degraded soil with A. brasilense is a promising alternative for farmers in semi-arid regions. Resumen: The replacement of Caatinga by extensive agriculture has led to soil degradation in maize (Zea mays L.) growing areas. The objective of this study was to evaluate the effects of soil correction in association with Azospirillum brasiliense to replace nitrogen (N) fertilizer on the vegetative growth of two maize genotypes cultivated on degraded soil. The soil was collected in an area undergoing desertification in Irauçuba, Ceará state, Brazil. A 2x2x5 factorial experiment was carried out in blocks: two soil fertility levels (corrected and uncorrected soil in terms of fertility), two maize genotypes (BRS Caimbé and BRS Gorutuba), and five nitrogen sources (control, inoculation with A. brasilense, inoculation with A. brasilense + 50 kg ha-1 of N, 50 kg ha-1 of N, and 100 kg ha-1 of N). BRS Gorutuba genotype showed greater adaptability to the growing conditions evaluated. However, macronutrient concentration did not affect maize dry matter yield. The response of maize inoculated with A. brasiliense suggests the inoculation efficacy, supported by the N accumulation and the effect on plant growth. The dry matter yield in A. brasilense inoculated plants was equivalent to using N fertilizer. Therefore, the inoculation of BRS Gorutuba maize grown on degraded soil with A. brasilense is a promising alternative for farmers in semi-arid regions.

Título em espanhol: Corrección de suelos y Azospirillum brasilense: estrategias en el cultivo de genotipos de maíz en regiones semiáridas.