Banca de DEFESA: MARIA RAQUEL DA SILVA FARIAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIA RAQUEL DA SILVA FARIAS
DATE: 28/08/2023
TIME: 14:00
LOCAL: Campus Arapiraca
TITLE:

COVER CROPS AND PHOSPHATE SOURCES SOLUBLE AND REACTIVE IN THE ACCUMULATION OF MASS AND NUTRIENTS BY CORN UNDER NO-TILLAGE SYSTEM

KEY WORDS:

Zea mays, cover crops, no tillage, phosphate solubility, nutrient cycling, phytomass.

PAGES: 66
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:

The no-tillage system stands out as the predominant model used for grain production. Thus, the use of cover crops provides soil protection and nutrient fixation/cycling. Understanding the dissolution and distribution capacity of different forms of P is essential to assess the availability of this element to plants and optimize the efficient use of phosphate fertilizers, especially in regions with electropositive soil and low precipitation. This study investigated whether the use of cover crops and different P sources affect corn yield and soil quality in a no-tillage system. The experiment was carried out in the experimental area of the Federal University of Alagoas, Arapiraca campus (9°42'00" and 36°41'12"W, 324 m latitude). The local soil is classified as dystrophic red-yellow argisol and the textural class is sandy loam. The experimental design was randomized blocks, with six replications. The plots (8 x 35 m) were represented by phosphorus sources: simple superphosphate (soluble), reactive natural phosphate (reactive) and without phosphorus application (without P). In the subplots (8 x 5 m) treatments were six species of cover crops: Crotalaria juncea, Crotalaria spectabilis, Cajanus cajan, Dolichos lablab, Canavalia ensiformis, Pennisetum glaucum and one treatment without cover (fallow). The productivity of the dry mass had higher yield in Crotalaria juncea (4,1 t ha^-1) and lower production for Cajanus cajan (1,1 t ha^-1). The cover crops accumulated greater amounts of nutrients: N, K and Ca. There was no significant effect on corn yield in succession of cover crops and P sources. Grain yield ranged from ~6,5 to ~8 t ha^-1. Corn plants extracted greater amounts of N, P and Ca. The cover crops are good nutrient recyclers and showed better extraction by the grains in the soluble source. On the other hand, the lowest nutrient extraction rates were found in fallow, except for Ca, differing only ~8% from Canavalia ensiformis. In general, cover crops contribute to soil ecosystem services, reducing temperature and water evaporation, maintaining higher humidity, and may contribute to corn productivity in regions with water scarcity, although long-term studies (>10 years) are required for positive conclusions.

BANKING MEMBERS:
Presidente - 2626313 - VALDEVAN ROSENDO DOS SANTOS
Externo(a) à Instituição - DAYANE MERCIA RIBEIRO SILVA - UNESP
Externo(a) à Instituição - EMERSON DOS SANTOS FERREIRA - UFAL
Externo(a) à Instituição - RICARDO BARROS SILVA - UFAL