Purple maize has gained global significance due to its numerous nutraceutical benefits. However, sustaining its production typically requires high doses of nitrogen fertilizers, which, when applied in excess, can contaminate vital resources such as soil and water. Inoculation with nitrogen-fixing microorganisms, such as those from the Azospirillum genus, has emerged as an alternative to partially or fully replace nitrogen fertilizers. This study aimed to evaluate the inoculation effect with A. brasilense and varying nitrogen fertilization levels on the yield and quality of purple maize. The experiment was carried out using a randomized complete block design (RCBD) with a 2 × 5 factorial arrangement and five replications. Treatments comprised two inoculation levels (control without inoculation and inoculation with A. brasilense) under five nitrogen doses (0, 30, 60, 90, and 120 kg∙ha⁻¹, applied as urea). Inoculation with A. brasilense resulted in a 10.5% increase in plant height, a 16.7% increase in root length, a 21.3% increase in aboveground fresh biomass, a 30.1% increase in root fresh biomass, and a 27.7% increase in leaf nitrogen concentration compared to the non-inoculated control. Regarding yield, the inoculated plants surpassed the control in both purple maize yield (kg∙ha⁻¹) and cob weight by 21.8% and 11.6%, respectively. Across all fertilization levels and parameters assessed, the inoculated treatments outperformed the control. Furthermore, for parameters, namely plant height, leaf nitrogen content, and cob dimensions (length, diameter, and weight), the A. brasilense inoculation treatment with 90 kg N∙ha⁻¹ was statistically equivalent or superior to the non-inoculated control with 120 kg N∙ha⁻¹. These results indicate that inoculation with A. brasilense positively impacted purple maize at all nitrogen levels tested and improved nitrogen use efficiency, enabling a reduction of 30 kg N∙ha⁻¹ without compromising performance in key parameters.

The propagation of avocado plants by seed presents the disadvantage that the population obtained is heterogeneous and of variable productivity. Instead, those obtained through stems have homogeneous productive characteristics. In order to study improvements to propagation through stems, the effect of applications of Azospirilum brasilense and indole-3-butyric acid (IBA), to the stem of the avocado, either independently or in combination, was evaluated. The experiment was conducted in a completely randomized design, with four treatments (A. brasilense, AIB, A. brasilense plus AIB, and a control) with five repetitions. Under laboratory and growth chamber conditions, grafting the nurse seedlings var. Villacampa with cuttings of the var. Topa Topa was performed. After the formation of the tissue union, the plant was kept in dark conditions to obtain ethiolate shoots. Theses stems were subjected to a scraping of approximately 0.5 mm deep in the basal part, where the treatments were applied. The variables evaluated were plant height and stem diameter, along with fresh weight of foliage and roots. The results showed that the combination treatment better promoted all variables, significantly exceeding the control. It is concluded that the combination treatment influences the rooting of etiolated and layered avocado shoots.

Efficient water management in agriculture is key to the sustainability of crops in inter-Andean valleys (IAV), where water availability is at risk due to climate change (CC). Quinoa, as a strategic crop in these ecosystems, requires a detailed analysis of its water use to optimize its production without compromising water resources. This study quantified the water footprint (WF) (green, blue and grey) of three quinoa varieties (INIA 415 Pasankalla, INIA 420-Negra Collana and INIA 441-Señor del Huerto) harvested in a sandy loam soil in an IAV of Peru. In addition, the trend of the WF in 12 agricultural seasons was evaluated, and future climate scenarios (SSP1-2.6, SSP3-7.0 and SSP5-8.5) were projected to estimate the impact of CC on the crop's water demand towards 2090–2100. The results showed significant differences in water-use efficiency among varieties. INIA 441-Señor del Huerto showed the highest water efficiency, with a 3.20 t ha⁻¹ yield and a low total WF, making it more sustainable under CC conditions. In contrast, INIA 420-Negra Collana had a higher water demand, making it less viable under water-stress scenarios. Climate projections indicate an increase in water demand for quinoa under scenarios of greater radiative forcing, which underscores the need to develop water management strategies. These findings highlight the importance of selecting more efficient varieties for water use and adopting sustainable practices to mitigate the effects of climate change on quinoa production at IAV.

Biochar and beneficial microorganisms have gained increasing attention as alternatives for improving soil properties and crop performance under sustainable agricultural systems. Wheat (Triticum aestivum L.), one of the major crops in the Andean region, requires management strategies that enhance productivity while improving soil quality. This study evaluated the effects of biochar from the native high-Andean grass Festuca glyceriantha Pilger, Trichoderma harzianum, and their combination (Trichoderma harzianum immobilized on biochar) on the growth, yield, grain protein, and soil organic carbon (SOC) storage of wheat (Triticum aestivum L.) in Ayacucho, Peru. A 2 × 2 factorial randomized complete block design with four replicates was used (biochar rate: 0.96 t ha⁻¹). Colonization of biochar by Trichoderma harzianum yielded 5 × 10⁸ spores mL⁻¹ in the recovered suspension, supporting its use as a microbial carrier. Both inputs improved root length, plant height, and biomass accumulation, with responses varying across phenological stages. Grain yield exceeded the control (1.86 t ha⁻¹) by 32.26% with biochar (2.46 t ha⁻¹), 17.74% with Trichoderma harzianum (2.19 t ha⁻¹), and 30.11% with both (2.42 t ha⁻¹). The combination did not outperform biochar alone. The significant biochar × Trichoderma harzianum interaction (yield, p = 0.03; grains per spike, p = 0.02) cannot be interpreted as biological antagonism because inoculum dose and delivery method were not equivalent between treatments (two drench applications in T03 vs. a single application of colonized biochar in the sowing furrow in T04), and the significant biochar × Trichoderma harzianum interaction (yield, p = 0.03; grains per spike, p = 0.02) reflected a less-than-additive response. Trichoderma harzianum increased grain protein content (p < 0.01), whereas biochar did not (p = 0.90); thousand-grain weight and chlorophyll content were unaffected. SOC storage did not differ among treatments (p = 0.101; 156.5–228.4 Mg C ha⁻¹), so no carbon sequestration benefit can be concluded after one growing season. Biochar mainly enhanced grain yield, whereas Trichoderma harzianum mainly improved grain protein. These results support applying each input independently according to the agronomic objective, pending multi-season and multi-site validation with equivalent inoculum doses and complete control treatments.