The aim of this paper was to evaluate if accessible sulphur analyses in soil are relevant for Agrochemical Soil Testing (AZZP). This issue was assessed in the years 2014/2015. Samples to be taken in 2015 were selected according to results on sulphur analyses in Mehlich III extraction agent in 2014. It means that the first sampling was carried on in the autumn 2014 and second in the spring 2015. Plans were sampled together with soil in 2015. Seven regions were included in the sampling scheme (Brno, Planá (České Budějovice), Plzeň, Opava, Havlíčkův Brod, Liberec and Prague) and plots with winter wheat and winter rape were sampled. Majority (78 %) of soils samples measured on accessible sulphur content falls into the range 10,1 - 20,0 mg.kg-1. Average contents of accessible sulphur in soils in the autumn and spring were almost identical and there are no statistical differences amongst regions. Influence of fertilising on sulphur content in soils was not confirmed, however, sulphur fertilization positively influences the sulphur content both in rape and wheat plants. The content of accessible sulphur in soils in the spring positively correlates with sulphur content in rape. Based on current nutrient normative, 59 % of wheat plants are below the value when yield decrease may occur. In the case of rape it is more than 90 % of plants (samples). It does not seem to be suitable to include accessible sulphur measurement in soils into the AZZP system. The six-year cycle of AZZP is rather too long if soil sulphur mobility and dynamics is taken into account.

Accumulation of sediments in fishponds is a serious problem for today's aquaculture. High economical, organizational and time-consuming requirements are often the limit factor for many fish farmers. One of the available solutions has recently emerged bacterial-enzymatic mixtures, which thanks to modified bacteria cultures, have been able to reduce organic matter from sediment and improve overall physical and chemical water parameters. The aim of this diploma thesis was to verify the effect of the bacterial - enzymatic mixture PTP plus in laboratory and field conditions. For the laboratory experiment, was chosen a method with different concentrations of the PTP plus, under the controlled conditions of the glass containers. However, the results of the laboratory test did not confirmed significant effect of this bioenzymatic mixture on the reduction of the organic component of the sediment nor on the changes in the physical and chemical parameters of the water. But the influence at the visual properties of the water was confirmed in container with several times higher dose. Three small ponds near Bohuslavice near Konice, with a total area of approximately 2.5 hectares were chosen for the field experiment. The results of the field experiment also did not confirm the significant effect of the bio-enzymatic blend on the physical and chemical parameters of the water in the monitored localities. However, in the lowest location of the fishpond cascade, BOH I, was recorded slight reduction of sediment organic component.

The inaccessibility and cost of soil testing reduce effectiveness of fertilizer use on small-scale subsistence farms, and inadequate funding promotes adoption of soil tests in developing countries with minimal validation. For example, Mehlich-I extraction of phosphorus (P) currently used extensively in Guatemala may not be suitable for its broad range of soils. At least four alternatives are available but are relatively untested [Bray 1, Mehlich III, Olsen and pressurized hot water (PHW)]. Pressurized hot water is relatively simple and inexpensive, but is not yet tested against other extraction methods under variable P or potassium (K) fertilization levels. To determine whether PHW-extracted nutrients could be used to predict maize yield, as nutrient content and uptake, soil, plant tissue and grain samples were obtained from a multiple-site field study and calibration studies were conducted using five rates of P and three rates of K on soils incubated without plants or cropped with maize in greenhouse and field conditions. In the multiple-site field study, maize yield related significantly to PHW-extractable P (r2=0.36) and to leaf P concentration (r2=0.23), but Mehlich I did not. In the two soils used in the greenhouse study, maize yield, vegetative P concentration and total P uptake by maize were predicted by PHW extractable P (R2=0.72, 0.75 and 0.90, respectively). In the field experiment, grain yield was not improved by P or K application, but P content of maize leaf tissue did relate significantly with PHW-extracted P (R2=0.40), but Mehlich I did not. There were no yield responses to K application in any experiment, but relationships defined between extractable K for all five K-extraction procedures and soil applied K were similarly significant. In comparing P extraction methods, PHW was as good as or better than Olsen, Bray 1 and Mehlich III for relating soil P extraction to the parameters measured in these experiments, and these four alternative extraction methods were consistently better than Mehlich I. Mehlich I extraction should be replaced by one of the four alternatives tested, and PHW is the least expensive and, thus, most viable for use in Guatemala soils.