The Combined Applications of Microbial Inoculants and Organic Fertilizer Improve Plant Growth under Unfavorable Soil Conditions

The performance of two bio-inoculants either in single or in combined applications with organic fertilizer was tested to determine their effect on plant growth and yield under normal and unfavorable field conditions such as low pH value and low content of P. Arbuscular Mycorrhiza Fungi (AMF; three species of Glomus) and the plant-growth-promoting bacterial strain Kosakonia radicincitans DSM16656 were applied to barley in a two-year field experiment with different soil pH levels and available nutrients. Grain yield; contents of P, N, K, and Mg; and soil microbial parameters were measured. Grain yield and the content of nutrients were significantly increased by the applications of mineral fertilizer, organic fertilizer, AMF, and K. radicincitans, and the combined application of organic fertilizer with AMF and with K. radicincitans over the control under normal growth conditions. Under low-pH and low-P conditions, only the combined application of the organic fertilizer with K. radicincitans and organic fertilizer with AMF could increase the grain yield and content of nutrients of barley over the control.European Union’s Horizon 2020 Research and Innovation ProgramProject EXCALIBUR under grant agreement No. 817946EU project SUSTAINABLE, EU grant agreement no. 10100770

Animal bones char solubilization by gel-entrapped yarrowia lipolytica on glycerol-based media

Citric acid was produced with free and k-carrageenan-entrapped cells of the yeast Yarrowia lipolytica in single and repeated batch-shake-flask fermentations on glycerol-based media. Simultaneous solubilization of hydroxyapatite of animal bone origin (HABO) was tested in all experiments. The highest citric acid production by free yeast cells of 20.4 g/L and 18.7 g/L was reached after 96 h of fermentation in the absence and presence of 3 g/L HABO, respectively. The maximum values for the same parameter achieved by gel-entrapped cells in conditions of single batch and repeated-batch fermentation processes were 18.7 g/L and 28.1 g/L registered after 96 h and the 3d batch cycle, respectively. The highest citric acid productivity of 0.58 g L−1 h−1 was obtained with immobilized cells in repeated batch mode of fermentation when the added hydroxyapatite of 3 g/L was solubilized to 399 mg/L whereas the maximum efficiency of 89.0% was obtained with 1 g/L of HABO.This work was supported by Projects CTM2008-03524, CTM2011-027797 (Ministerio de Ciencia e Innovación, España), P09-RNM-5196 (Junta de Andalucía, Proyecto de Excelencia), and EU COST FA0905. N. Vassileva is grateful for the SABF PR2010-0422—Ministerio de Educacion, España

Simulating the soil phosphorus dynamics of four long‐term field experiments with a novel phosphorus model

Phosphorus is a nonrenewable resource, which is required for crop growth and to maintain high yields. The soil P cycle is very complex, and new model approaches can lead to a better understanding of those processes and further guide to research gaps. The objective of this study was to present a P-submodel, which has been integrated in the existing Carbon Candy Balance (CCB) model that already comprises a C and N module. The P-module is linked to the C mineralization and the associated C-pools via the C/P ratio of fresh organic material. Besides the organic P cycling, the module implies a plant-available P-pool (Pav), which is in a dynamic equilibrium with the nonavailable P-pool (Pna) that comprises the strongly sorbed and occluded P fraction. The model performance was tested and evaluated on four long-term field experiments with mineral P fertilization, farmyard manure as organic fertilizer and control plots without fertilization. The C dynamics and the Pav dynamics were modelled with overall good results. The relative RMSE for the C was below 10% for all treatments, while the relative RMSE for Pav was below 15% for most treatments. To accommodate for the rather small variety of available P-models, the presented CNP-model is designed for agricultural field sites with a relatively low data input, namely air temperature, precipitation, soil properties, yields and management practices. The CNP-model offers a low entry threshold model approach to predict the C-N and now the P dynamics of agricultural soils.Fachagentur Nachwachsende Rohstoffe http://dx.doi.org/10.13039/501100010812Peer Reviewe

Combining biochar with low rate of chemical fertiliser boosts maize biomass yield, regardless of tillage system, under humid conditions

Biochar application to soils increases biomass and crop yields, especially with rates higher than 100 t ha−1. Yet, there is limited knowledge on the combined effect of biochar and chemical fertiliser under different tillage systems. The objective of this study is to investigate the effect of maize-cob biochar (BC) (rates of 5 and 10 t ha−1) combined with chemical fertiliser micro-dosing (MD) at a rate of 25% of the recommended quantity on total shoot dry matter (DM) and plant height of maize cultivated under flat (F) and tied-ridge (R) practices during a humid season in Tanzania. The results indicate that combining 5 t ha−1 BC with 25% MD increases DM at harvest by 83% (4.16 t ha−1) compared to the control (2.27 t ha−1) and was in the same range as the DM obtained from the treatment with the recommended fertiliser rate (100% FD). The treatments with single applications of 25% MD, 5 t ha−1 BC, and 10 t ha−1 BC only tended to exceed the control of DM yield. Therefore, we recommend that small-scale farmers aiming at DM for livestock or grain yield with limited access to chemical fertilisers to combine biochar with 25% MD, rather than applying biochar or low chemical fertiliser rates alone

Evaluación nutricional y de la actividad antibacteriana de frutos de Coccoloba uvifera L (Original)

Coccoloba uvifera L., is a species of the Polygonaceae family, very common on the coasts and beaches of the American and Caribbean intertropical region. Known as Beach Grape, it is of great value to stabilize areas of mobile beach dunes, as well as to prevent coastal erosion. In addition, its fruits are edible and different parts of the plant are used for therapeutic and medicinal purposes; however, little research has been done in Cuba, so the objective of the research was to evaluate the nutritional potential and antibacterial activity of C. uvifera fruits that grow on the coasts of the province of Granma. Internationally recognized methods were used for nutritional analysis, preliminary phytochemical analysis, and in vitro antibacterial activity. The nutritional analysis was carried out by the methods described by the Association of Official Analytical Chemists, giving as results values of dry matter higher than 84 %, and values of crude protein, crude fiber, sucrose and starch, which guarantee energy availability and make them an alternative nutritional raw material. The phytochemical screening carried out on extracts of different polarity allowed the identification of various families of secondary metabolites, the ones with the highest relative abundance are: alkaloids, coumarins, flavonoids, phenols and reducing carbohydrates. The inhibition halos measured by the diffusion method by surface dissemination in disc (Bauer-Kirby) show the moderate antibacterial action of the extracts.Coccoloba uvifera L. es una especie de la familia Polygonaceae, muy común en las costas y playas de la región intertropical americana y del Caribe. Conocida como uva de playa es de gran valor para estabilizar zonas de dunas móviles de playa, así como para evitar la erosión costera. Además, sus frutos son comestibles y diferentes partes de la planta son aprovechadas con fines terapéuticos y medicinales; sin embargo, en Cuba ha sido poco investigada, por lo cual el objetivo de la investigación fue evaluar el potencial nutricional y la actividad antibacteriana de frutos de la C. uvifera que crecen en las costas de la provincia de Granma. Se emplearon métodos internacionalmente reconocidos para el análisis nutricional, el análisis fitoquímico preliminar y la actividad antibacteriana in vitro. El análisis nutricional se realizó por los métodos descritos por la Association of Official Analytical Chemists, dando como resultados valores de materia seca superiores al 84 %, y valores de proteína cruda, fibra cruda, sacarosa y almidón, que garantizan disponibilidad energética y los convierten en una materia prima nutricional alternativa. El tamizaje fitoquímico realizado a extractos de diferente polaridad permitió la identificación de diversas familias de metabolitos secundarios. Los halos de inhibición medidos por el método de difusión por diseminación superficial en disco (Bauer-Kirby), muestran la acción antibacteriana moderada de los extractos

Morphological and physiological responses of Coccoloba uvifera (L.) L. seedlings of different origin to salt stress

The salinity of soils and water for irrigation is a limitation that influences the productivity of crops that has increased worldwide and affects the morphology and physiology of plants since it causes osmotic stress and ionic toxicity and impairs the absorption of water and nutrients. The effect of salt stress on some morphological and physiological traits in Coccoloba uvifera (L.) L. (sea grape) seedlings from different origins was evaluated and the traits whose behavior under salt stress could be used as an effective criterion of tolerance to salinity were determined. A completely randomized design experiment with ten repetitions was performed. The factors under study were salinity (0, 5, 15, and 25 dS m-1), which was maintained for a period of sixteen weeks, and the second factor was the origin of the plant material. The salinity level and the seedlings’ origin significantly influenced the morphological and physiological variables controlled. However, it is necessary to carry out in situ experiments to obtain more information related to the mechanisms used by sea grape to tolerate salinity conditions, because in the consulted sources no research focused on evaluating the effect of salinity and the origin on the morphology and physiology of C. uvifera seedlings in Cuba has been found. The results of the research provide preliminary information to understand the negative effect of salt stress on this type of plant. The behavior of some controlled traits under salt stress can be used as an effective criterion of tolerance to salinity

Handling the phosphorus paradox in agriculture and natural ecosystems: scarcity, necessity, and burden of P

This special issue of Ambio compiles a series of contributions made at the 8th International Phosphorus Workshop (IPW8), held in September 2016 in Rostock, Germany. The introducing overview article summarizes major published scientific findings in the time period from IPW7 (2015) until recently, including presentations from IPW8. The P issue was subdivided into four themes along the logical sequence of P utilization in production, environmental, and societal systems: (1) Sufficiency and efficiency of P utilization, especially in animal husbandry and crop production; (2) P recycling: technologies and product applications; (3) P fluxes and cycling in the environment; and (4) P governance. The latter two themes had separate sessions for the first time in the International Phosphorus Workshops series; thus, this overview presents a scene-setting rather than an overview of the latest research for these themes. In summary, this paper details new findings in agricultural and environmental P research, which indicate reduced P inputs, improved management options, and provide translations into governance options for a more sustainable P use