Examinando por Materia "Nitrogen"

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Fertilisation Methods for Commercial Yield in Three Garlic Cultivars (Allium sativum L.)
(Universidad Nacional Agraria La Molina, 2019-12-30) Condor, J.; Olivera, J.; Pinedo, R.
Garlic (Allium sativum L.) is an important crop for domestic consumption in Peru. However, there is insufficient information available on crop management, particularly on fertiliser application to local cultivars. In order to evaluate the response of three garlic cultivars to three fertilisation methods, an experiment was conducted at the Donoso Experimental Station in Huaral district, a province of Lima. Three garlic cultivars were used as experimental materials: ‘Cincomesino’, ‘Arequipeño 14’ and ‘Margosino’. Three methods of fertilisation were applied as treatments: broadcast application before furrowing (M1), fertilisation in a superficial groove or false furrow (M2), and fertilisation in the lateral furrows, or band application (M3). The experiments were installed in three parcels for each cultivar, with a randomised complete block design for each parcel and four replications. In general, localised fertilisation methods showed the best performance for the broadcast method. Regarding total yield, fertilisation at the sides of the furrow (M3) for ‘Cincomesino’ reached 13.08 t/ha. The highest yield for the ‘Arequipeño 14’ cultivar (12.25 t/ha) was achieved using fertilisation with a surface groove or false furrow (M2). For the ‘Margosino’ cultivar, fertilisation on the sides of the furrow was ideal, and the yield was 10.95 t/ha.
Inoculation with Azospirillum brasilense as a strategy to reduce nitrogen fertilization in cultivating purple maize (Zea mays l.) in the Inter-andean valleys of Peru
(MDPI, 2024-10-21) Condori Ataupillco, Tatiana; Alarcón Romani, Susan; Huasasquiche Sarmiento, Lucero; García Blásquez, Cayo; Padilla Castro, César; Velásquez Mantari, José; Solórzano Acosta, Richard
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 nitrogenfixing 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 no 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.
Precipitation is the key determinant of topsoil δ15N values in southern Patagonia's semiarid rangelands
(Soil Science Society of America, 2022-02-11) Peri, Pablo L.; Duarte Guardia, Sandra; Amelung, Wulf; Ladd, Brenton
Nitrogen (N) cycling in rangeland soils could potentially be controlled by water supply, stocking rates, or a range of other variables, such as ecosystem N stocks. To gauge the relative importance and elucidate possible interactions among these factors, we measured many abiotic variables to identify first-order controls of δ15N for Patagonia's rangeland soils under contrasting historical grazing intensities. The results showed that δ15N values declined as water availability increased. The effects of precipitation and stocking rate on soil δ15N values were additive, and the effect of precipitation far outweighed the effects of grazing pressure. The soil N stock was a weak predictive variable for modeling variation in δ15N of the soil. Earlier assumptions about an inflection point for N cycling and δ15N values related to aridity were not confirmed. We conclude that variation in water availability drives variation in δ15N values irrespective of grazing intensity. We also conclude that meaningful interpretation of δ15N in soil will require a better mechanistic understanding of the interactions between water and N in the vadose zone than we currently possess.