Citas bibligráficas
Tácuna, R., (2022). Cambios en la estructura de la vegetación, función hidrológica y condición del pastizal por efecto del descanso y diferimiento [Universidad Nacional Agraria La Molina]. https://hdl.handle.net/20.500.12996/5301
Tácuna, R., Cambios en la estructura de la vegetación, función hidrológica y condición del pastizal por efecto del descanso y diferimiento []. PE: Universidad Nacional Agraria La Molina; 2022. https://hdl.handle.net/20.500.12996/5301
@phdthesis{renati/1117107,
title = "Cambios en la estructura de la vegetación, función hidrológica y condición del pastizal por efecto del descanso y diferimiento",
author = "Tácuna Céspedes, Raúl Enrique",
publisher = "Universidad Nacional Agraria La Molina",
year = "2022"
}
The objective of this study was to evaluate the effects of rest and deferred grazing on changes in vegetation structure, hydrological function and ecological status in grassland and was conducted under the development of three trials. The first study had the purpose of evaluating the effects of rest on the structure of the vegetation, the hydrological response and the ecological status in grasslands dominated by tall perennial grasses during a period of four years. The research was developed in two communal usufruct areas called Sillacancha and Cotocancha, located in the rural community of Cordillera Blanca in the Ancash Region, at an altitude of 4095 meters above sea level. The experimental design was one of complete factorial random blocks, where the treatments resulted from the combination of two grazing systems, P1: uncontrolled grazing in communal usufruct lands and P2: rest or total exclusion of grazing; and four years of evaluation, from 2010 to 2013. The blocks were made up of each communal usufruct area, Sillacancha and Cotocancha. The results revealed that after four years, rest exceeded continuous grazing in proportion of grasses and their dominance over the pasture (55.0 vs 76.0%) (P = 0.0001) and reduced the presence of other functional groups such as grass-like plants (13.9 vs 14.5%) (P = 0.7099), grasses (12.7 vs 24.4%) (P = 0.0002) and shrubs (0.9 vs 2.7%) (P = 0.0918). Likewise, rest exceded continuous grazing in vegetation cover (85.0 vs 74.4%) (P = 0.0793), biomass accumulation (1684.7 vs 1142.2 kgMS / ha) (P = 0.0001) and mulch on the ground (426.1 vs 277.9 kgMS / ha) (P = 0.0005). Finally, rest exceeded continuous grazing in infiltration rate (0.19 vs 0.12 cm / min) (P <0.0001), soil moisture (19.6 vs 14.7%) (P <0.0001) and improved pasture condition (56.5 vs 46.5 %) (P = 0.0157). It was concluded that the rest improved the pasture condition and its most important effects were on the hydrological function, by showing a greater accumulation of mulch, better levels of humidity and infiltration of the soil compared to continuous grazing. The purpose of the second study was to evaluate the variation of the ecological condition and health status of a puna tussock, dominated by Festuca humilior, managed under three grazing systems: seasonal continuous (SC), short duration (SD) and deferred rotational (DR), for a period of four years. The research was carried out in the Mesapata sector, Consac Production Unit located in the Sociedad Agrícola de Interés Social (SAIS) Tupac Amaru (Junín region), at an altitude of 4168 meters above sea level. The experimental design was a completely randomized 3 x 4 factorial with covariance. The results showed that grazing systems improved the condition of the rangeland SC: 39.1%, SD: 53.1% and DR: 58.3%. The systems also improved the health status and its attributes biotic integrity, site stability and hydrologic function respectively, SC (2.4, 2.2 and 2.5), SD (1.7, 1.8 and 1.7), DR (1.6, 1.6 and 1.5). The improvement in the hydrologic function was reflected in higher rates of infiltration and soil moisture SC (0.19 cm/min and 25.8%), SD (0.25 cm/min and 30.1%) and DR (0.35 cm/min and 38.7%). The best ecological response obtained with deferred rotational grazing was associated with a greater accumulation of biomass, soil protection and reproduction of key plants. While in short duration grazing was probably due to a better control over pressure, forage allowance and grazing density, key variables in grazing management. The purpose of the third study was to compare the composition of the diet under a deferred grazing system with one of short duration for four years. The research was carried out in the Mesapata sector, Consac Production Unit located in the Sociedad Agrícola de Interés Social (SAIS) Tupac Amaru (Junín region), at an altitude of 4168 meters above sea level. The experimental design was completely randomized 2 x 2 factorial, where the treatments resulted from the combination of two grazing systems: short duration (SD) and deferred rotational (DR), and two seasons (wet and dry). The results showed that there was an effect of the grazing system on the botanical composition of the diet between SD vs DR. Grasses were the main component of the diet (79.9 vs 86.5%, P<0.01), followed by grass-like plants (11.0 vs 7.3%, P = 0.02) and forbs (9.0 vs 6.2%, P =0.04), respectively. The animals preferred leaves (67.8 vs 78.3%, P = 0.01) over stems (26.3 vs 15.4%, P <0.01) and flowers (5.9 vs 6.4%, P = 0.59) and green over (74.4 vs 78.3%, P = 0.05) over dead (25.6 vs 21.7%, P = 0.05). Diet quality was similar between SD vs DR systems, in vitro dry matter digestibility (41.5 vs 40.0%, P = 0.25), neutral detergent fiber (76.6 vs 78.5%, P = 0.20) and crude protein (9.6 vs 8.9%, P = 0.39). There were no interactions between grazing systems and the season, but the diets were of lower quality during the dry season. It is recommended to investigate the role of forage allowance and grazing pressure in the nutritional response in grazing systems.
Este ítem está sujeto a una licencia Creative Commons Licencia Creative Commons