In our pot experiment, the impact of a bacterial fertilizer, Bactofil® A10 and a mineral fertilizer Ca(NO3)2 applied in different rates was studied on some soil chemical and microbiological characteristics of a humic sandy soil (Pallag). Perennial rye-grass (Lolium perenne L.) was used as a test-plant. Samples were collec...ted four and eight weeks after sowing in each year. The experiment was set up in 2007-2009 in the greenhouse of
the UD CASE Department of Agrochemistry and Soil Science. The available (AL-extractable) nutrient contents of soil, among the microbial parameters the total number of bacteria, the number of microscopic fungi, cellulose-decomposing and nitrifying bacteria, the sacharase and urease enzyme activity, as well as the soil respiration rate were measured.
Statistical analyses were made by means of the measurements deviation, LSD values at the P=0.05 level and correlation coefficients were calculated. Results of our experiment were summarised as follows:
− The readily available nutrient content of humic sandy soil increased as affected by the treatments, in case of the available (AL-extractable) phosphorus and potassium content the higher value was measured in high-dosage artificial fertilizer treatment.
− The treatments had also positive effect on several soil microbial parameters studied. The higher-dosage mineral fertilizer treatments had a beneficial effect on the total number of bacteria, cellulose-decomposing and nitrifying bacteria. No significant differences were obtained between the effect of treatment in case of the total-number of bacteria, the number of microscopic fungi and nitrifying bacteria.
− On the sacharase enzyme activity the artificial fertiliser treatments proved to be unambiguously stimulating, the urease activity significantly increased on the effect of the lower-dosage Ca(NO3)2 artificial fertilizer treatment.
− The soil respiration increased in all treatments in related to the amounts applied, significantly increased in the highest rate of Ca(NO3)2 fertilizer addition.
− Some medium and tight positive correlations were observed between the soil chemical and microbiological parameters studied in case of both nutrient sources.
Summarizing our results, it was established that the organic and all the mineral fertilizer treatments had beneficial effects on the major soil characteristics from the aspect of nutrient supply. In majority of the examined soil parameters (AL-extractable phosphorus- and potassium, total number of bacteria, number of cellulose-decomposing and nitrifying bacteria, activity of sacharase enzyme) the high rate of Ca(NO3)2 mineral fertilizer treatment proved to be more stimulating, but at the same time the high rate bacterium fertilizer resulted in significant increases in
the nitrate-N content, the AL-potassium content of soil, the total number of bacteria, the number of cellulose-decomposing and nitrifying bacteria and the urease enyme activity.
Our examinations showed that the mineral fertilizer treatments proved to be more stimulating on most of the soil parameters studied but according to our results, it was established that Bactofil is efficiently applicable in the maintenance of soil fertility and the combined application of
mineral fertilizer and bacterium fertilizer may be a favourable opportunity – also in aspect of the environmental protection – in maintaining soil fertility.
A greenhouse pot experiment was conducted to compare the effects of manure with different origin (horse, cattle), various bedding materials (straw, sawdust) and diverse doses (30 t ha-1, 60 t ha-1) and the impact of food waste compost on the plant growth and the available plant nutrient content of soil. The study was condu...cted on humic sandy soil and consisted of 9 treatments in a randomized complete block design with four replications. Spinach (Spinacia oleracea L.) was grown as the test crop. The treatments were: 1. unfertilized control; 2. horse manure with straw (30 t ha-1); 3. horse manure with sawdust (30 t ha-1); 4. cattle manure (30 t ha-1); 5 food waste compost (30 t ha-1); 6. horse manure with straw (60 t ha-1); 7. horse manure with sawdust (60 t ha-1); 8. cattle manure (60 t ha-1); 9. food waste compost (60 t ha-1). Plant growth was monitored for 4 weeks. Shoot and root weights per pot were measured, total biomass weight per pot were counted.
On the basis of the results it can be concluded, that among treatments the application of horse manure with straw enhanced spinach growth most significantly compared to other treatments and to the non-treated control, resulted the highest weights of leaves and roots of spinach. At the same time even small dose (30 t ha-1) of this fertilizer caused increased plant available nitrogen and phosphorus of soil and the higher dosage further increased these values. The horse manure with sawdust applied in lower dose did not alter the leaves and roots weights, but higher portion (60 t ha-1) caused significantly decreased plant biomass. The results proved that the bedding material may significantly alter the composition of manure and may change the plant nutrition effect of organic fertilizer. Cattle manure and food waste compost in both applied doses enhanced plant growth. Both fertilizers increased the plant available nitrogen forms and phosphorus content of soil, but cattle manure caused higher increase.
Bioavailability of pesticides is determined by two major factors: soil characteristics and pesticides’ chemical feature. These factors result in a definite adsorption capability whose extent varies on a large scale. By revealing interactions between pesticides and soils it is of high interest to model bioavailability of widely used pesticides..., as it is a key element in terms of prospective toxicological aspects. Our work signifies steps forward improving pesticide soil mobility prediction models as we created model systems representing correctly natural relations. Comparison of different solvent extraction methods proved to be an efficient tool to gain information on the bioavailability of some widely used pesticides as well as to model actual environmental processes.
Comprehensive comparison has been made between different experimental methods by applying 5 extraction models showing diverse efficiency in extracting capability of pesticides. In some cases chloroform excelled in mobilizing pesticides from soil, however mostly application of humic acid solution as extraction model was found to be at least as efficient as methanol, chloroform or CaCl2-solution.
Four chemically much different pesticide (simazine, acetochlor, chlorpyrifos and diuron) were applied to two soil types (both sandy and brown forest). The extracted amounts were determined by GC/MS technique. Adsorption coefficients (Kd) were also calculated for the examined samples.
Obtained results for Kd indicated that chemical feature of pesticides seemed to be of utmost importance in terms of soil binding capability preceding the relevance of soil characteristics. Adsorption capability of chlorpyrifos proved to be the most pronounced preceding simazine and the least prone to bind to soil acetochlor and diuron
In the experiment adsorption characteristics of different soil types (humic sand, meadow soil, leached chernozem and meadow solonec) was examined on the basis of adsorption isotherms for Cr(III)-picolinate. The Langmuir equation was used to describe the isotherms by which the amounts of metal ions actually and maximally adsorbed by the soils we...re determined concerning the given complex. A comparison was made among the organically bound Cr(III)-picolinate, an inorganic Cr(III) compound and a Cr(VI) form examined in a previous study. Based on the adsorption isotherms, adsorption capacity of the Cr(III)-picolinate was found 20 times smaller on sandy soil and 50 times smaller on the chernozem comparing to that of the inorganic Cr(III)-chloride, thus, the bio-availability of the chromium for the plants is 20 and 50 times higher in case of the given soil types. For the well-known toxic Cr(VI)-form, the adsorption was 2 times higher in case of sandy soil and 5 times higher for chernozem than in case of the organic Cr(III)-complex compound.