Sulfometuron-methyl is a broad-spectrum herbicide, used throughout Brazil; however, its environmental impacts in biochar (BC) amended soils is not fully understood. Biochar is known to enhance soil quality but can also have undesired effects such as altering the bioavailability and behavior of herbicides. Microbial communities can degrade herbicides such as sulfometuron-methyl in soils; however, they are known to be affected by BC. Therefore, it is important to understand the tripartite interaction between these factors. This research aimed to evaluate the sorption-desorption and biodegradation of sulfometuron-methyl in Amazonian soils amended with BC, and to assess the effects of the interactions between BC and sulfometuron-methyl on soil bacterial communities. Soil samples were collected from field plots amended with BC at three doses (0, 40 and 80 t ha^-1) applied ten years ago. The herbicide sorption and desorption were evaluated using a batch equilibrium method. Mineralization and biodegradation studies were conducted in microcosms incubated with ¹⁴C-sulfometuron-methyl for 80 days. Systematic soil sampling, followed by DNA extraction, quantification (qPCR) and 16S rRNA amplicon sequencing were performed. The presence of BC increased the sorption of the herbicide to the soil by 11% (BC40) and 16% (BC80) compared to unamended soil. The presence of BC also affected the degradation of ¹⁴C-sulfometuron-methyl, reducing the mineralization rate and increasing the degradation half-life times (DT50) from 36.67 days in unamended soil to 52.11 and 55.45 days in BC40 and BC80 soils, respectively. The herbicide application altered the bacterial communities, affecting abundance and richness, and changing the taxonomic diversity (i.e., some taxa were promoted and other inhibited). A tripartite interaction was found between BC, the herbicide and soil bacterial communities, suggesting that it is important to consider the environmental impact of soil applied herbicides in biochar amended soils.

This study evaluated the suitability of three floodplain environments near Iquitos for cowpea cultivar recommendation. It also estimated the adaptability and phenotypic stability of 12 cowpea lines evaluated in 2004 and compared the climatic conditions between 2004 and the period of 2020–2024. Field trials were conducted using a randomized complete block design with 12 treatments and two replications. Five traits were assessed: grain yield, number of pods per plant, days to flowering, days to physiological maturity, and days to harvest. Combined ANOVA revealed significant environmental effects for all traits. Analyses using Duncan’s means test, GGE biplot, and AMMI indicated that the three sites are contrasting. The Annicchiarico index, GGE biplot, and AMMI analyses identified line CAR 3010 as having superior adaptability and stability. Paired t-tests showed that the conditions in 2020-2024 were warmer and drier than those in 2004. Therefore, Muyuy, Rafael Belaunde, and San Miguel are suitable locations for testing new cowpea lines, and CAR 3010 line is recommended for inclusion in cowpea breeding programs in the Peruvian Amazon in response to ongoing climate change.

El caupí (Vigna unguiculata) es un cultivo transitorio adaptado a climas tropicales y subtropicales, clave en la seguridad alimentaria. En este contexto, el Instituto Nacional de Innovación Agraria (INIA) en 2021 implementó la colección de leguminosas tropicales para su propagación, conservación y estudio. Este estudio evaluó su variabilidad fenotípica e identificó accesiones promisorias mediante descriptores agromorfológicos. En 2022-2023 se evaluaron 23 accesiones con 10 descriptores (7 cuantitativos y 3 cualitativos); se detectó variación sólo en tres descriptores, mientras que los cualitativos mostraron alta concordancia. En 2024 se evaluaron 26 descriptores (14 cualitativos, 12 cuantitativos), encontrándose diferencias significativas en todos los descriptores; los de mayor partición fueron peso de 100 semillas y tamaño del pedúnculo. El análisis multivariado de componentes explicó el 60,3 % de la varianza total, Dim1 separó principalmente los rasgos biométricos de la semilla y Dim2 la variación fenológica. Los índices de Shannon-Weaver (H’) y Gini-Simpson evidenciaron que el patrón del hilio, la textura de la testa, la forma de la semilla, el color del hilio y la pigmentación de la vaina inmadura presentaron mayor capacidad discriminante y diversidad. Con los resultados obtenidos se seleccionaron accesiones promisorias para consumo humano (PER1005854 y PER1005858) y para forraje/cobertura (PER1005851, PER1005852, PER1005853 y PER1005857).

In Amazonian Spodosols, soil acidity and nutrient constraints limit the cultivation of cutleaf groundcherry. One sustainable alternative for cultivating this species is the use of Trichoderma inoculants, but studies on their use in this crop are scarce. This study evaluated whether rice-based inocula of Trichoderma harzianum (TH) CCB-LA101 and T. viride (TV) CCB-LA103 improved growth and fruit production of cutleaf groundcherry and whether the responses varied with the application dose. Plants were grown in a randomized complete block design with a 2 × 3 factorial arrangement: two Trichoderma species and three inoculum doses applied to the soil (0, 4, and 8 g plant⁻¹; Trichoderma concentration of 3.2 × 10⁹ CFU g⁻¹). Species and dose affected fruit width, length, number, and yield, with TH more effective than TV at increasing fruit number and yield. The contrast between inoculated and non-inoculated plants was significant for all traits. The 8 g plant⁻¹ dose significantly increased fruit number and yield by 22.8% and 17.7%, respectively, relative to the non-inoculated control, whereas fruit width and fruit length decreased by 8.3% and 7.3%, respectively. Considering the six treatment combinations, the 8 g plant⁻¹ TH inoculum (TH8) was the only treatment to significantly increase fruit yield, with net returns for smallholders estimated at USD 1104.46 ha⁻¹. Therefore, under the tested conditions, TH8 could be used to grow cutleaf groundcherry in Amazonian Spodosols.