Banca de DEFESA: EDMAÍRIS RODRIGUES ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : EDMAÍRIS RODRIGUES ARAÚJO
DATE: 27/02/2025
TIME: 15:00
LOCAL: UFAPE
TITLE:

SICHAR IN THE MITIGATION OF WATER STRESS IN MAIZE CULTIVATION: effects on growth and nutrient uptake

KEY WORDS:

biochar; abiotic stress; silicon; Zea mays L.

PAGES: 98
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

Due to its characteristics, corn (Zea mays L.) is considered a crop of high economic and social importance, being the most produced cereal worldwide. In the Northeast region of Brazil, in addition to its socioeconomic importance, corn holds significant cultural value, primarily cultivated by family farming under rainfed conditions. Due to the predominant semi-arid edaphoclimatic characteristics in much of the Northeast region, water deficit is a highly limiting factor in grain production, leading to reduced yields and decreased viability of crops. In light of this, the objective of this study is to evaluate the potential use of biochar as an alternative source of silicon-rich fertilizer and its suitability as a mitigator of water stress in corn cultivation. The experiment was conducted in a greenhouse at the Universidade Federal do Agreste de Pernambuco – UFAPE, located in the city of Garanhuns. The trial was conducted using a completely randomized design under a factorial scheme (5x3), with three replications. The first factor consisted of 4 fertilizers and an absolute control (1-Sugarcane Biochar (BCA); 2-Pine Biochar (BP); 3-Modified Pine Biochar (BPM); 4-Alg Sil© (COM); and 5-Control (Ctrl)), the second factor was composed of three water stress conditions based on available water (AW) in the soil at pot capacity (40, 60, and 80%). A high-yield corn hybrid was used, grown for 80 days. During the vegetative cycle, physiological indices – gs, A, E, Ci, WUE, iWUE, and chlorophyll index at 43 DAE – and biometric parameters – stem diameter and canopy height of plants, every 14 days, starting from 15 days after emergence (DAE) – were measured. At 80 DAS, the plants were cut at soil level and separated into shoot and root to determine dry matter production and quantify the accumulation of nutrients P, K, Na, S, and Si, as well as substrate analysis for the same nutrients. The biochars were efficient in releasing Si (dissolution kinetics) and significantly influenced the remaining levels of P and K in the substrate. However, regardless of the stress level, all fertilizers were equal to or inferior to the control. The physiological indices A, Ci, WUE, and iWUE were significantly affected by the simple effect of the highest water stress level (40% AW). The biometric parameters were directly affected by the application of stresses, with reductions in height, accumulation of green and dry matter in the shoot, and dry matter and root volume as the stress level increased. Silicate fertilization significantly influenced the absorption and accumulation of P in the shoot and Si accumulation in the root, especially under moderate stress. Under the conditions provided by this study, no significant effective effect of using biochar as an alternative source of Si was identified, nor a direct contribution of Si in mitigating water stress in corn cultivation. Additional studies using biochar with higher Si content in its composition are suggested.

COMMITTEE MEMBERS:
Presidente - MARCELO METRI CORREA
Interno - ALEXANDRE TAVARES DA ROCHA
Externo ao Programa - 1538852 - VALDOMIRO SEVERINO DE SOUZA JUNIOR - UFRPE