Examinando por Materia "Phenological phases"

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Agronomic and Nutritional Potential of Ryegrass (Lolium multiflorum Lam.) Accessions as Raw Material for Silage in the Tropical Andes of Peru
(MDPI, 2026-01-22) Bobadilla , Leidy G.; Altamirano Tantalean, Miguel A.; Carrasco Chilón, William Leoncio; Silva Baca, Vanesa Lizbeth; Mejía, Flor L.; Paucar, Ysai; Valqui, Leandro; Bardales, William; Maicelo, Jorge L.; Vásquez, Héctor V.
In the tropical Andes, rangeland degradation has become one of the main threats to the sustainability of livestock production in the face of climate change. In this context, optimizing the yield and nutritional quality of raw material for silage is essential to sustain livestock productivity. The aim of this study was to identify local accessions (LM) of Lolium multiflorum Lam. with greater forage potential through evaluations in consecutive cuts made at the anthesis phenological stage, using a randomized complete block design with four replicates and ten local accessions (LM1, LM2, LM3, LM4, LM6, LM7, LM8, LM11, LM12 and LM13). The statistical analysis, based on linear mixed models, showed that cuts at anthesis had a significant effect among accessions, revealing high variability in agronomic and nutritional performance across cuts. In LM4, plant height at the fourth cut was 2.48-fold higher than at the first cut. Likewise, LM4 and LM13 were identified as the latest accessions to reach anthesis in the first cut, with a decreasing trend across cuts and stabilization from the third cut onward. These accessions also showed the greatest basal coverage area, increasing 9.94- and 8.18-fold in the fourth cut relative to the first. Fresh forage yields in LM4 and LM13 increased 13.2- and 10.1-fold, and dry matter yields 13.98- and 9.86-fold, compared with the first cut. They also exhibited the highest average daily dry matter accumulation rate. By contrast, the fresh forage and dry matter yields of the remaining accessions were significantly lower than those of LM4 and LM13. The main difference between these two accessions was observed in dry matter percentage, with higher values and a stable trend in LM4 across all cuts. In terms of nutritional quality, LM4 presented crude protein of 24.2% in the second cut and 24.0% in the fourth cut, while digestibility was 86.2% in the second cut and 85.0% in the fourth cut. In conclusion, although the ensiling process was not evaluated in this study, LM4 showed the most stable and outstanding values in both agronomic and nutritional performance, thus emerging as a promising accession for selection and use as raw material for silage production in the tropical Andes.
Geospatial distribution of heavy metals in rice soils of northwestern Peru
(Nature Portfolio (Springer Nature), 2025-08-21) Tarrillo Julca, Ever; Arce Inga, Marielita; Torres Herrera, Pedro Antonio; Tineo Flores, Daniel; Taboada Mitma, Victor Hugo; Cruz Luis, Juancarlos Alejandro; Rojas Briceño, Nilton B.; Atalaya Marin, Nilton; Gómez Fernández, Darwin; Goñas Goñas, Malluri
The presence of heavy metals in agricultural soils poses a threat to the development of sustainable agriculture and ensuring food security. The objective of this study was to evaluate the geospatial distribution of heavy metals in rice-growing soils within the Amojú River Basin, Jaen, Peru. Ninety-five soil samples were collected randomly, covering four altitudinal ranges, namely, very low (374–450 m above sea level (m a.s.l.)), low (450–571 m a.s.l.), medium (571–701 m a.s.l.) and high altitudes (701–1,034 m a.s.l.), and different agronomic management stages, including four phenological phases (seedling, tillering, filling and ripening) and two agricultural practices (resting and stubble burning). The evaluation was conducted via physicochemical analysis, the single-factor pollution index, and spatial interpolation techniques through the empirical Bayesian kriging (EBK) method. The results indicated that the contents of cadmium (Cd) and chromium (Cr) exceed the limits established in the Environmental Quality Standards (EQSs) for agricultural soils, with maximum Cd and Cr concentrations of 2 and 21 mg kg ⁻¹, respectively, mainly in very low-altitude areas (374–450 m a.s.l.). The single-factor pollution index results indicated slight Cd contamination and intense Cr contamination. Likewise, high levels of arsenic (As), Cd, and Cr were detected in soils managed via stubble burning, reaching 2, 2, and 16 mg kg ⁻¹, respectively. The highest Cr concentrations were located in the northeastern and western parts of the study area, whereas the highest Cd concentrations occurred in the northeastern and southwestern parts. These concentrations may be associated with potential contamination sources, with the use of phosphate fertilizers, water for cultivation, and soil erosion as key contributors. This study highlights the potential risk to rice productivity and crop safety, emphasizing the importance of implementing sustainable agricultural practices and monitoring strategies for heavy metals in soils associated with crops.