Effect of gypsum and potassium on corn yield and on the exchangeable bases of an acid soil in La Frailesca, Chiapas

Objective: To evaluate the residual effect of gypsum in corn crops 2 years after application, in a previously limed soil, as well as the result of a new addition of gypsum combined with potassium in La Frailesca, Chiapas. Design/methodology/approach: Composite factorial: initial arrangement (2017) with four levels of gypsum (0, 1.25, 2.5 and 5 t ha-1) and four levels of potassium (0, 60, 120 and 180 kg K2O ha-1). In 2019, the plots treated with gypsum were divided into two, adding the same amount of gypsum applied in 2017 to half of each of them, and leaving the other half to evaluate the residual effect to the initial treatment. The potassium doses were the same as the original ones. Corn kernel yield, pH, exchangeable bases, and percentage of aluminium saturation were measured at depths of 0 to 7 and 7 to 14 cm from groun level. Results: The greatest effect on yield was obtained with 2.5 t ha-1 of gypsum applied in 2017 without significant increases with higher gypsum doses. The exchangeable calcium content and pH increased, but the magnesium, potassium and aluminum in the soil decreased. Limitations on study/implications: The assumed of Asphalt Stain Complex was diagnosed. Findings/conclusions: The authors point out the need to be careful when recommending gypsum as an amendment; an excessive application generates an imbalance in the exchangeable potassium and magnesium of the soil, so the incorporation of these should be considered in the fertilization plan.Objective: To evaluate the residual effect of gypsum in corn crops (2 years after its application in a previously limed soil), as well as the result of a new addition of gypsum combined with potassium in La Frailesca, Chiapas, Mexico. Design/Methodology/Approach: We used a composite factorial design. The initial arrangement (2017) consisted of four levels of gypsum (0, 1.25, 2.5, and 5 t ha-1) and four levels of potassium (0, 60, 120, and 180 kg K2O ha-1). In 2019, the gypsum-treated plots were divided in half: the same amount of gypsum applied in 2017 was added to the first half and the other half was used to assess the residual effect of the initial treatment. The potassium doses were the same as the original. Corn grain yield, pH, exchangeable bases, and aluminum saturation percentage were measured at 0 to 7 and 7 to 14 cm below ground level. Results: The greatest effect on yield was obtained with 2.5 t ha-1 of gypsum applied in 2017; no significant increases were recorded with higher gypsum doses. The exchangeable calcium content and pH level increased, while magnesium, potassium, and aluminum in the soil decreased. Study Limitations/Implications: Suspected presence of Tar Spot Complex was diagnosed. Findings/Conclusions: An excessive application of gypsum generates an imbalance in exchangeable potassium and magnesium in the soil; therefore, producers must exercise caution in the use of these products as part of their fertilization plan

Technological proposal for a greater irrigated corn (Zea mays L.) pro-duction

Objective: Validate the experimental results of irrigated maize production of the Autumn-Winter cycles from the years 2019 to 2022. Design/methodology/approach: Establishment of six validation plots, three in the Cuxtepeques Irrigation District and three in Irrigation Units. Results: The production of corn grain is up to 64% higher with the INIFAP technology compared to the traditional one; however, the average yield obtained in the validation phase was 11.5 t ha-1 compared to 15.9 t ha-1 in the experimental phase. Limitations on study/implications: Findings/conclusions: It is necessary to have machinery for precision planting and fertilization, efficient irrigation infrastructure, access to credit and permanent technical assistance to achieve yields similar to those obtained experimentally. Keywords: Corn; Irrigation; Frailesca, Chiapas.  O Objective: To validate the experimental results of corn (Zea mays L.) production under irrigation during the 2019-2022 autumn-winter cycles. Design/Methodology/Approach: Six validation plots were established, three in the Cuxtepeques irrigation district and three in irrigation systems in Chiapas, Mexico. Results: Corn grain production is 64% higher with the INIFAP technology than the traditional methods; however, the average yield obtained in the validation phase (11.5 t ha-1) was lower than the yield of the experimental phase (15.9 t ha-1). Study Limitations/Implications: None. Findings/Conclusions: Production requires machinery for sowing and precision fertilization, efficient irrigation infrastructure, access to credit, and permanent technical assistance to achieve yields similar to those obtained in the experiment

Effect of the application of potassium on the yield of corn (zea mays L.) in La Frailesca, chiapas Mexico / Efeito da aplicação de potássio na produção de milho (zea mays L.) em La Frailesca, chiapas, México

In recently soil analysis in La Frailesca Chiapas, it has been detected that most soils have low exchangeable potasium (K) concentrations, therefore maize plants show symptoms of deficiency of this nutrient, which can affect the yield. The maize response was evaluated at four doses of K (0, 90, 180 and 270 kg K2O ha-1) in three locations with non-acid soils. A randomized block design with five replications was used, and potassium chloride (KCl) as a potassium source. KCl was applied by manual broadcasting and was incorporated to the soil 10 and 15 cm deep with a disc harrow. In all three locations a significant positive response was observed (p <0.05) to which a lineal-plateau model was adjusted, with an average increase in yield of 1 964 kg ha-1 (150% higher than without K) with 90 kg K2O ha-1. No response was observed to higher doses. The regression equation for the linear part of the response model is: Yield (kg ha-1) = 3 855 + 22 kg K2O ha-1. The agronomic efficiency of K at the dose of 90 kg K2O ha-1 was higher than the reference range (7 to 15 kg grain.kg-1 K2O). At the same time, this treatment had the highest net benefit and a marginal rate of return of 370%. Under the conditions of this study, the application of 90 kg K2O ha-1 presented the highest yield, economic benefit and agronomic efficiency

La producción de grano mediante el modelo granos del sur y su contribución a la soberanía alimentaria

The Grains of the South corn production model, implemented by INIFAP in the state of Chiapas, Mexico, during the Autumn-Winter 2015-2016 cycle, consists of four elements for its operation: technological supply, supplies and timely technical assistance, a multimedia transfer strategy for the development of capacities and the management of agro seed companies. Eighteen irrigated plots were established with different sources of supply, a characterization of producers and production units was carried out and two commercial hybrids generated by INIFAP were tested, with the aim of contributing to food security through the production of corn in irrigation units; the results indicate that in spite of the conditions of depletion of the aquifer mantles of the artesian wells, and the prevailing environmental conditions of high temperatures and precipitation decreased by 65%, the hybrids are statistically superior to the commercial hybrids of transnational companies, so that if at least three of the four elements of the model are met, it is possible to have an impact on approximately 6 million units of production and there by contribute to the reduction of imports of corn grains and have food security and thus sovereignty necessary for the almost 120 million Mexicans. Keywords:corn, food security, southeast of Mexico, transferEl modelo de producción de maíz Granos del Sur, implementado por el INIFAP en el estado de Chiapas, México, durante el ciclo otoño-invierno 2015- 2016, consta de cuatro elementos para su funcionamiento: oferta tecnológica, insumos y asistencia técnica oportuna, una estrategia multimedia de transferencia para el desarrollo de capacidades y la gestión de agro empresas semilleras. Se establecieron 18 parcelas en riego con diferentes fuentes de abastecimiento, se realizó una caracterización de productores y de las unidades de producción y se probaron dos híbridos comerciales generados por el INIFAP, con el objetivo de contribuir a la seguridad alimentaria mediante la producción de maíz en unidades de riego, los resultados indican que a pesar de las condiciones de abatimiento de los mantos acuíferos de los pozos artesianos, y las condiciones ambientales prevalecientes de altas temperaturas y precipitación disminuida 65%, los híbridos son superiores estadísticamente a los híbridos comerciales de compañías transnacionales, por lo que si se cumplen al menos tres de los cuatro elementos del modelo, se está en posibilidades de impactar en aproximadamente 6 millones de unidades de producción y con ello contribuir a la disminución de importación de granos de maíz y tener seguridad alimentaria y con ello la soberanía alimentaria necesaria para los casi 120 millones de mexicanos. Palabras clave: maíz, seguridad alimentaria, sureste de México, transferenci