Zdenek Kviz

Spatial Variability and Pattern of Selected Properties of Agricultural Soils in the Czech Republic Measured by Indirect Proximal and Remote Sensing

Spatial and temporal variabilities of soil properties were monitored within a 12-ha field over several consecutive years. Particle-size distribution, total carbon content (Ct), and pH were monitored. Soil samples were taken from points on a regular square grid. Additionally, the variability of soil properties was evaluated by proximal measurement methods including draft force measurements, soil electrical conductivity (ECa), and crop yield mapping. Remotely sensed bare-soil satellite images were obtained and digital elevation models were made. All the observed variables showed spatial variability, but the spatial patterns of Ct, pH, EC, and crop yield were temporally stable. Results were processed using statistical and geostatistical methods. Variograms and their parameters were used to describe spatial dependencies between observed variables. Significant dependencies were observed between monitored soil properties and indirect methods, indicating utility in the proximal approach.

Influence of Overall Straw Management on Next Crop Germination, Growth and Final Yield when Using Conservation Tillage Technologies

For the purpose of simulation of straw and chaff distribution quality across working width of a combine harvester after its passage, different straw management variants with even and uneven plant remains placement were established. It has to be stated in advance that all measurement were carried out under normal field conditions under conventional machinery operation which is commonly used in practice. The influence of non-even distribution of plant residues and their excessive amount placed on the field surface after harvest on next plant germination, growth and yield was observed.

Parallel Plate Mass Flow Sensor for Forage Crops and Sugar Beet

Measurements described in this paper were realized in order to find out whether there is some relationship between mass flow of plant material passing through a parallel plate capacitive sensor and its output signal. This possibility of mass flow determination could be useful for the aim of forage crops or sugar beet yield maps creation. A parallel plate capacitive throughput sensor was designed for that purpose. The capacitive sensor and the whole oscillating circuit were driven at 27 MHz frequency. The laboratory set-up consisted of a conveyer belt, carrying a measured quantity of material into sensor, equipped with an electronic measurement apparatus. Material passed through the sensor between its plates. Laboratory tests were carried out with forage crops and with sugar beet. Resulting coefficients of determination ranged from R2=0.95 to 0.97 for forage crops and around R2=0.98 for sugar beet. It was possible to conclude from our measurement that forage and sugar beet mass flow determination by means of the parallel plate capacitive sensor is a promising way. The results showed a strong linear relationship between the feed rates of plant material passing through the sensor and tested measuring capacitive sensor circuit output signal.

Capacitance Sensor for Forage Mass Determination

Non-contacting methods for material properties determination and crop yield determination are the best solution especially for rough conditions in agriculture, however, it requires reliable and durable sensors as a source of primary data. The capacitance sensor based technique can be used for forage material mass determination in order to utilize obtained data for yield maps creation.