M. Kulhánek

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

BackgroundAgricultural 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.MethodsThe 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.ResultsEfficiency 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.Graphical abstractPossible modes of action of bio-effectors.

Effect of bioeffectors and recycled P-fertiliser products on the growth of spring wheat

BackgroundThe recycling of waste products into P fertilisers in agriculture is advisable from the perspective of sustainability. Bioeffectors (BEs), which have the ability to increase the plant uptake of P from recycled fertiliser products, may increase the fertiliser value of these products. This paper investigated the effect of a range of different recycled fertilisers on the growth and P uptake of wheat in pot experiments conducted at three different locations in Europe. Furthermore, investigations were undertaken as to whether the addition of a range of bioeffectors could significantly enhance P availability, P uptake and plant growth.ResultsBE additions were found not to significantly increase the aboveground biomass of wheat plants or the uptake of P when plants were fertilised with recycled fertiliser products. This was shown across a range of pot experiments with soils of different P status. Only in the case of the positive control P fertiliser (TSP) was a positive effect of Proradix and RhizoVital on plant growth observed in one of the experiments, while in the same experiment RhizoVital and Biological fertiliser DC had a negative impact on plant biomass when the P fertiliser was Thomas phosphate. With regard to P uptake, there was only a slight positive effect of Proradix in plants not supplied with P fertiliser in this experiment. Clear differences were seen in the efficiency of P fertilisers. Generally, sewage sludge ash performed quite poorly (20–40 % of TSP), while sewage sludge, Thomas phosphate, P-enriched slag and the fibre fraction of pig manure all had a high availability of P (>74 % relative to TSP). Compost composed mainly of garden/park waste and sewage sludge was intermediate in availability (40–70 %). The elemental composition of the harvested wheat plants was significantly affected in all cases by the different P fertilisers added. The BE treatments significantly affected the elemental composition of the aboveground biomass in one of the experiments where the product Proradix had the greatest effect on elemental composition.ConclusionsIn conclusion, the experiments revealed a wide difference in the bioavailability of P in the different waste products, but the added microorganisms demonstrated a limited capacity to influence plant P uptake across a range of soils and waste products.

Waste silicate minerals as potassium sources: a greenhouse study on spring barley

After 1989, the use of potassium (K) mineral fertilizers in the Czech Republic dropped from ∼55 kg K ha−1 to a mean rate of ∼6.5 kg in the last decade. In order to test alternative solutions for K fertilization, the trioctahedral mica mineral zinnwaldite (8% K), orthoclase (10% K) and waste mica from Cínovec (Krušné Hory Mts/Erzgebirge, Czech Republic), consisting primarily of zinnwaldite, were applied as the only K sources for spring barley. The minerals were treated in three different types of high-energy mills under different working conditions. Application rates in the range 139–820 mg K kg−1 were tested in quartz sand cultures. In all treatments, plant growth, total plant biomass and the K content in the plant tissues increased in the order zinnwaldite > waste mica > orthoclase. K fractionation and K plant uptake were significantly influenced by the milling method used. The effect of 195 mg K kg−1 as zinnwaldite on K uptake from K-depleted soils was positive; however, it was smaller than in sand cultures because of the relatively high content of non-exchangeable K in the soils. Direct use of waste mica as a K fertilizer is limited by the increased fluorine and heavy metal content.

Soil pH changes in long-term field experiments with different fertilizing systems.

Vasak F., Cerný J., Buraňova S., Kulhanek M., Balik J. (2015): Soil pH changes in long-term field experiments with different fertilizing systems. Soil & Water Res., 10: 19–23. The changes of soil pH in long-term 14-year field experiments with different fertilizing systems are described. The field experiments were located at four sites of the Czech Republic with different soil and climatic conditions (Cervený Ujezd, Hněvceves, Lukavec, and Prague-Suchdol). At each site, the same fertilizing systems and crop rotation (potatoes – winter wheat – spring barley) were established. Six experimental treatments were applied to crop rotation: (1) unfertilized treatments (control); treatments with organic fertilization: (2) farmyard manure (FYM), (3) sewage sludge (SS); treatments with mineral fertilizers: (4) nitrogen (N), (5) nitrogen with straw application (N + straw), and (6) nitrogen with phosphorus and potassium (NPK). The long-term effect of fertilizers significantly depends on soil conditions. At the site Prague-Suchdol minimal differences in the soil pH were observed by all treatments. This is caused by the high buffering capacity of Chernozems against the soil acidification. At Cervený Ujezd (Haplic Luvisol), Hněvceves (Haplic Luvisol), and Lukavec (Stagnic Cambisol) sites, soil pH decreased by all treatments. Only at Hněvceves site the soil pH did not change with N treatment. The highest soil pH decrease in the treatment with NPK (ΔpH –0.89) and N + straw (ΔpH –0.70) was observed at Hněvceves site. By the treatments FYM and SS the highest decrease was registered at Cervený Ujezd (ΔpH of about –0.30 and –0.63, respectively). The highest decrease in control treatment (ΔpH of about –0.63) was observed at Lukavec site. The results showed that to evaluate long-term soil pH changes a whole complex of factors must be examined.

Efficiency of foliar selenium application on oilseed rape (Brassica napus L.) as influenced by rainfall and soil characteristics

ABSTRACT The Czech Republic is characterized by a low Se soil content, resulting in Se deficiency in crops, humans, and animals. This study investigated the response of oilseed rape to foliar application of selenate solution in a microscale field experiment conducted at two locations differing in soil and climatic conditions but with comparable total Se contents. Sodium selenate (Na2SeO4) was applied at two rates (25 and 50 g Se ha−1). The potential effect of Se application on the uptake of essential elements was also evaluated. The foliar Se application resulted in an effective stepwise increase in the Se contents of all the plant components studied (leaves > stems > roots > siliques ~ seeds), as expected. No significant influence of Se fortification on the other investigated macro- and microelements was observed. However, the soil and climatic conditions influenced the Se uptake, such that a higher Se content was observed in plants grown in the most acidic location (Cambisol soil) that had a higher oxidizable carbon content and higher average annual rainfall compared to the less acidic location (Luvisol soil). These observations indicated the necessity to optimize the Se application for the particular soil and climatic conditions to achieve a maximum biofortification effect.

Winter wheat fertilizing using nitrogen–sulphur fertilizer

Precise field experiments were established on two sites with winter wheat under different soil-climatic conditions in the Czech Republic. Four treatments were fertilized with same dose of nitrogen (200 kg N ha−1) and increasing dose of sulphur (0, 10, 20 and 40 kg S ha−1) using nitrogen–sulphur (N–S) fertilizer with calcium sulphate form. Soil and plant aboveground biomass samples were taken in the stages of development BBCH 26–28; 30–32; 37–39; 49–51. The winter wheat grain yield ranged between 7.20 and 10.86 t ha−1 and had an increasing trend with increasing sulphur dose. Although the differences were usually not statistically significant, there were found increasing tendencies of bioavailable sulphur content in soil with increasing S split doses. Soil S content decreased with time probably due to plant uptake. Sulphur dose did not influence the S content in plant aboveground biomass. The total S contents in grain after harvest ranged between 0.09% and 0.14% and were not significantly influenced with the fertilizing treatment. The same statement is valid for the S content in straw, which ranged between 0.03% and 0.11%. Both, S content in winter wheat seeds and straw were strongly influenced by the site conditions.

Nitrogen uptake by winter wheat (Triticum aestivum L.) depending on fertilizer application

The influence of the injection of nitrogen fertilizers with the CULTAN system (Controlled Uptake Long Term Ammonium Nutrition) on nitrogen uptake by winter wheat (Triticum aestivum L.) was observed at small-plot field experiments under conditions of the Czech Republic (central Europe) during 2007–2013. The CULTAN system consisting in the injection of all the nitrogen in one dose was compared with conventional broadcast surface fertilization which is carried out in three partial nitrogen doses. The total nitrogen dosage was 150 kg N.ha−1. If the CULTAN fertilization was carried out at the beginning of tillering of winter wheat (BBCH 22) instead of at the end of tillering (BBCH 29), the CULTAN-treated winter wheat did not suffer from nitrogen deficiency at the BBCH 45 (boot stage) and BBCH 51 (beginning of heading) growth stages. Nitrogen utilization efficiency and biomass production efficiency were significantly higher with the CULTAN treatment compared to the conventional fertilization whereas nitrogen up...

Use of Active Microrganisms in Crop Production - A Review

Phosphorus, other elements and natural resources are scarce, and so it is necessary to find alternative strategy to increase availability of nutrients for plants. One possible way could be application of so-called bioeffectors (BE) which should improve the mobilisation of nutrients (especially phosphorus) from less available forms in soil, improve plant growth and contribute to mycorrhiza development. BEs are commercially supplied products which contain active substances (live microorganisms and active natural compounds). BEs can be used in organic agriculture, because their application represents no risk for the environment. Several studies and experiments are focused on impact of bioeffectors’ application and their active compounds on plants. Experiments were performed under different conditions (field, pot, greenhouse), on various testing plants and on various bioeffectors. These BEs have been used as a fertilizer, fungicide or molluscicide and they were applied either to soil, seed or leaf. Application should increase growth of root system and above-ground part of plants and also nutrient uptake. These products are developed for a wide variety of crops (e.g. maize, wheat, tomatoes, rape, spinach, grass, ornamentals). This review summarizes the most recent knowledge in this scientific field.

Evaluating of soil sulfur forms changes under different fertilizing systems during long-term field experiments

The aim of this work was to evaluate the changes of different soil sulfur forms during long-term field experiments supplied with sewage sludge (SS), farmyard manure (FYM) or mineral fertilizers. The experiment was established at three different sites with the crop rotation of potatoes, wheat and barley. Fertilizing system was based on the same nitrogen dose per the whole crop rotation. Soil samples from the beginning of the experiment (1996) and at the end of each crop rotation were analysed after all three crops harvest. Similar tendencies of changes in water extractable (Sw), adsorbed (Sads), 1 mol/L HCl estimated (SHCL) sulfur and their sum of (∑S) related to the fertilizing systems were observed among all studied sites. A decreasing tendency of ∑S in soil was observed during the experiment (except for the year 2005). The biggest decrease was always visible compared to control treatment. Mineral fertilizers (S added with superphosphate) appeared to be the best source of SHCL. Application of SS increased the Sw content in soil samples after potatoes harvest, whereas a decreasing tendency among the following crops was visible.