Banca de DEFESA: AMANDA SALES ALVES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : AMANDA SALES ALVES
DATE: 25/04/2022
TIME: 14:00
LOCAL: Video conferência
TITLE:

EVALUATION OF THE EROSIVE PROCESS UNDER SIMULATED RAINFALL PATTERNS BY INFIASPER, CONSIDERING SHAPES OF EXPERIMENTAL PLOT AND POLTRY LITTER FERTILIZATION

KEY WORDS:

Water erosion, InfiAsper rainfall simulator, precipitation intensity, organic fertilization, loss of nutrients.

PAGES: 57
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Manejo e Conservação do Solo
SUMMARY:

The erosion process is the main cause of soil degradation and has numerous consequences for the agricultural sector and the environment, such as the soil, water and nutrients losses. The use of rainfall simulators in studies related to water erosion has been widespread and the search for improvement in the quality of the data obtained represents a great effort by the scientific community as these equipments play an important role in the investigation of hydrological and erosive processes. A question that still remains open is the influence of the shape and area of experimental plots on the erosion process under simulated rainfall. Another important and less evaluated point is the loss of nutrients due to erosive rains, mainly in areas fertilized with poultry litter, used by many producers as a source of nitrogen, phosphorus and potassium and also as an input of organic carbon into the soil. Normally, natural rainfall events occur with intensity variation during their duration and therefore, simulators can better represent a natural event if they have mechanisms that allow the instantaneous variation of precipitation intensity throughout the tests, characterizing the precipitation patterns. This dissertation is presented in two chapters, whose objectives are: a) to evaluate the interference of the shape and area of the experimental plot in the rainfall distribution and in the erosive process using a simulator with different rainfall patterns; b) to evaluate the effect of simulated rainfall patterns on soil, water and nutrient losses in an area with and without fertilization with poultry litter. With the InfiAsper rainfall simulator, rectangular plots of 0.70 m² (1.0 x 0.7 m) and circular with 0.50 m² were used. In the laboratory stage, calibration, uniformity and water consumption tests of the simulator were carried out, using simulated rains of 5 min duration and obturator disk rotations of 138, 264, 420, 684 and 804 rpm. Uniformity was also evaluated considering advanced (AV), intermediate (IN), delayed (DL) and constant (CT) patterns in rainfall and 30 mm and 40 min duration. In the field, simulated rains were applied in a Red-Yellow Argisol, considering a randomized block design, in a factorial scheme 2 (plot format) x 4 (rainfall patterns), totaling eight treatments and four replications. To meet the second objective, rainfall with different patterns were simulated in the same experimental area and statistical design, adopting a circular experimental plot and considering areas with (WPL) and without (OPL) application of poultry litter, and the same four rainfall patterns, totaling 32 experimental units. Regarding the first objective, the rainfall uniformity ranged from 77.7 to 79.0% in the rectangular plot and from 81.7 to 83.8% in the circular plot, in the different rainfall patterns. In the circular plot, the AV pattern provided the drained depth of 14.41 mm and soil loss of 27.19 g m^-2, while in the rectangular plot, the AT pattern provided the highest drained depth (14.08 mm) and soil loss. (13.66 g m^-2). The use of the circular plot provided greater uniformity in the different rainfall patterns and the greatest soil and water losses in the AV pattern. Thus, we can conclude that for this type of simulator studied, the circular plot can better represent the distribution of rainfall and the erosive process. Regarding the second objective, the average values of runoff did not vary depending on the application of fertilization with poultry litter. However, there were differences in sediment losses between the OPL and WPL treatments for the DL and CT pattern. The greatest losses of soil and nutrients in the WPL treatment, regardless of the rainfall pattern, are related to the presence of poultry litter applied superficially. In general, the greatest losses of nutrients and organic carbon were obtained in the DL pattern, however the IN pattern provided the greatest losses of total N and P in the drained material, while the greatest loss of K was found in the AV pattern. Therefore, in an area with superficial application of poultry litter, the variation in the intensity of simulated rainfall interferes with the losses of N, P and K.

BANKING MEMBERS:
Presidente - 1224578 - DANIEL FONSECA DE CARVALHO
Interno - 2213075 - EVERALDO ZONTA
Externo à Instituição - JAMIL ALEXANDRE AYACH ANACHE - UFMS