Showing papers by "Eduardo Fávero Caires published in 2022"

Improving soil fertility with lime and phosphogypsum enhances soybean yield and physiological characteristics

Abstract: In tropical no-till systems, applying lime (L) and phosphogypsum (PG) on the soil surface may be a potential strategy for reducing soil acidification and improving soybean root growth, thereby enhancing plant nutrition and physiological responses and, in turn, crop resistance to dry spells. This study evaluated the impact of long-term (17 years) surface soil amendment on soil fertility and soybean root development, nutrition, gas exchange, carbon and antioxidant enzyme activity, and grain yield in a tropical region subject to dry spells. The treatments consisted of the following long-term soil amendments: control (no soil amendment); L alone; PG alone; and L + PG (LPG). Liming, especially when combined with PG, improved soil fertility, as evidenced by increases in pH and P, Ca2+, and Mg2+ levels throughout the soil profile, but reduced Al3+ and micronutrients (Fe, Mn, Cu, and Zn). The improvements in soil fertility were associated with increased root development throughout the profile. Long-term application of LPG reduced the negative impacts of dry spells on pigment concentrations, gas exchange, Rubisco and sucrose synthase activities and antioxidant metabolism, and increased soybean grain yield. Our results reveal that long-term application of LPG is an important approach for increasing the vertical movement of cationic bases and roots in no-till systems to improve soybean nutrition. Long-term amendment with LPG enhanced both carbon and antioxidant metabolism in soybean plants, resulting in higher soybean grain yield, despite the predisposition of this tropical region to dry spells.

Improving soil fertility with lime and phosphogypsum enhances soybean yield and physiological characteristics

Abstract: In tropical no-till systems, applying lime (L) and phosphogypsum (PG) on the soil surface may be a potential strategy for reducing soil acidification and improving soybean root growth, thereby enhancing plant nutrition and physiological responses and, in turn, crop resistance to dry spells. This study evaluated the impact of long-term (17 years) surface soil amendment on soil fertility and soybean root development, nutrition, gas exchange, carbon and antioxidant enzyme activity, and grain yield in a tropical region subject to dry spells. The treatments consisted of the following long-term soil amendments: control (no soil amendment); L alone; PG alone; and L + PG (LPG). Liming, especially when combined with PG, improved soil fertility, as evidenced by increases in pH and P, Ca2+, and Mg2+ levels throughout the soil profile, but reduced Al3+ and micronutrients (Fe, Mn, Cu, and Zn). The improvements in soil fertility were associated with increased root development throughout the profile. Long-term application of LPG reduced the negative impacts of dry spells on pigment concentrations, gas exchange, Rubisco and sucrose synthase activities and antioxidant metabolism, and increased soybean grain yield. Our results reveal that long-term application of LPG is an important approach for increasing the vertical movement of cationic bases and roots in no-till systems to improve soybean nutrition. Long-term amendment with LPG enhanced both carbon and antioxidant metabolism in soybean plants, resulting in higher soybean grain yield, despite the predisposition of this tropical region to dry spells.

Crop nutrition and grain yield as affected by phosphorus fertilization and continued use of phosphogypsum in an Oxisol under no-till management

Abstract: ABSTRACT The benefits of applying phosphogypsum to the soil are widely known. However, the effect of phosphogypsum on phosphate fertilization efficiency is still unclear. A long-term field experiment was performed on an Oxisol in Parana State, Brazil to evaluate the effects of triple superphosphate (TSP) and phosphogypsum application rates on nutrition and grain yield of soybean, wheat, and black oat under no-till. Applying TSP in the sowing furrow of soybean and wheat increased soybean yield by 14 to 24%, wheat yield by 57%, and black oat yield by 78%. Soybean yields varied in different cropping seasons in response to phosphogypsum application (with no response to increases of up to 15% in yield), while phosphogypsum increased wheat yield by 23% and black oat yield by 59%. The water balance during crop flowering possibly interfered on crop yield response to phosphogypsum. The use of phosphogypsum increased agronomic P-use efficiency by 20%, regardless of the TSP-P application rates. Changes in P-leaf concentration caused by TSP fertilization and phosphogypsum use had a positive impact on crop grain yield. Our results reveal that the continued use of phosphogypsum to alleviate subsoil acidity could increase the phosphate fertilization efficiency and improve crop yield performance under drought stress.

Efeito de bioestimulante de solo na nutrição e no rendimento de grãos de soja e trigo / Soil biostimulant effect on nutrition and yield of soybean and wheat grains

Abstract: A utilização de bioestimulantes à base de microrganismos, sejam eles vivos ou a partir de seus metabólitos, pode ser uma alternativa potencialmente sustentável para melhorar a eficiência de uso dos fertilizantes. O presente trabalho foi realizado com o objetivo de estudar a influência da utilização de um bioestimulante de solo (BS) na nutrição das plantas e no rendimento de grãos de soja e trigo. O experimento foi realizado no município de Ponta Grossa, PR. O delineamento experimental utilizado foi em blocos ao acaso com cinco repetições para a cultura da soja e em esquema de parcelas subdivididas, com cinco repetições para a cultura do trigo. Na cultura da soja foram empregadas quatro doses de BS (0, 2, 4 e 6 L ha-1). Na cultura do trigo, as parcelas foram divididas em duas subparcelas, sem e com a reaplicação do BS nas mesmas doses utilizadas para a cultura da soja. As doses de BS aplicadas na cultura da soja proporcionaram aumento na massa seca de raiz e na massa seca total da parte aérea aos 30 dias após a semeadura, no número de nós e na produtividade de grãos. Também não afetou negativamente a nodulação de plantas de soja. Na cultura do trigo, as doses de BS proporcionaram aumento na massa fresca total, na extração de N, P, K, Ca, Mg e S, no peso hectolítrico dos grãos (PH) e não influenciou significativamente a produtividade de grãos.