Potential of three microbial bio-effectors to promote maize growth and nutrient acquisition from alternative phosphorous fertilizers in contrasting soils

Abstract

Background: Agricultural production is challenged by the limitation of non-renewable resources. Alternative fertilizers are promoted but they often have a lower availability of key macronutrients, especially phosphorus (P). Biological inoculants, the so-called bio-effectors (BEs), may be combined with these fertilizers to improve the nutrient use efficiency. Methods:The goal of this study was to assess the potential of three BEs in combination with alternative fertilizers (e.g., composted manure, biogas digestate, green compost) to promote plant growth and nutrient uptake in soils typical for various European regions. Pot experiments were conducted in Czech Republic, Denmark, Germany, Italy, and Switzerland where the same variety of maize was grown in local soils deficient in P in combination with alternative fertilizers and the same set of BEs (Trichoderma, Pseudomonas, and Bacillus strains). Common guidelines for pot experiment implementation and performance were developed to allow data comparison, and soils were analyzed by the same laboratory.Results: Efficiency of BEs to improve maize growth and nutrient uptake differed strongly according to soil properties and fertilizer combined. Promising results were mostly obtained with BEs in combination with organic fertilizers such as composted animal manures, fresh digestate of organic wastes, and sewage sludge. In only one experiment, the nutrient use efficiency of mineral recycling fertilizers was improved by BE inoculation. Conclusions:These BE effects are to a large extent due to improved root growth and P mobilization via accelerated mineralization.

Plant growth promoting bacteria and humic substances: crop promotion and mechanisms of action

“…In the second year of experimentation, the increase of grain yield promoted by co-inoculation was also significant, but only until 75 kg N ha −1 . At higher N concentrations no effect of inoculation was observed in a typical and known effect [5]. The main difference between this two growth seasons was that the first year was marked by a severe drought stress while in the second the rain season had normal precipitation.…”

“…Thereby, economic reasons are moving sectors of traditional agriculture closer to those who do agriculture with less negative impact on the environment for socio-environmental reasons. Thereafter, increasing attention is being paid to the downside of high-input agricultural systems and much research is aimed at developing alternative ways to produce food, wood and plant for energy production in a sustainable and environmentally sound way [5].…”

Densely rooted rhizosphere hotspots induced around subsurface NH4 +-fertilizer depots: a home for soil PGPMs?

“…Results of in vitro Ca-P solubilization tests as a way to assess P-solubilizing potential of PGPMs and their potential to improve crop P acquisition must be critically evaluated for each soil type, and their chemical and physical properties [21]. For instance, it has been shown that maize P acquisition and biomass production after inoculation of PGPM in was strongly dependent on soil type and properties such as pH and overall fertility [48]. To increase the likelihood for identifying P-solubilizing PGPMs that are effective under field conditions, it is suggested to use the right in vitro test for PGPMs isolated from the right soil type: Ca-P or RP solubilization test for PGPMs isolated from alkaline soils; Fe-P/Al-P solubilization with PGPMs from acid soils; and phytate mineralization with those from soils rich in organic matter [21].…”

Development of shrimp shells-based compost and plant-based pesticide using bio-activators from Golden Apple Snails and their effects on the kenaf plant growth and pest population

“…The continuous application of fertilizers, pesticides, and other chemicals can harm organisms in the soil, induce pest and pathogen resistance, and change the vitamin and mineral content of crops. Indeed, if this practice is left as is, it will deleteriously affect the cycle of life survival (Xu et al 2012;Maheswari et al 2014;Nkbiwe et al 2016; Thonar et al 2017). However, agricultural farming is impossible to be undertaken without involving pesticides.…”

“…Organic fertilizer is developed to solve the negative effects of chemical fertilizer that can drain a nutrient rich soil and turn it into a nutrient-deprived soil. Plants growing on the nutrient-deficient soil suffer malnutrition and less vigorous (Maheswari et al 2014;Cheng et al 2014;Nkbiwe et al 2016;Thonar et al 2017).…”