Soil Water Regime Evaluation after Biochar Amendment

Abstract

In this paper, we have evaluated soil water regime in top soil layer based on agronomic classification. The study site was located in Malanta (near Nitra city, Slovakia). The whole site was divided into plots with the size 6 × 4 m separated by 0.5 m bands. Our field experiment began on March 2014 when a certificated biochar was applied to a depth 0-15 cm of soil profile in different rates. We have compared two plots: one with application of biochar in amount of 20 t/ha (B20) and second plot was without biochar amendment (Control). The soil water content in 0-15 cm depth was monitored by the 5TM sensors in 5 minute interval and stored using the EM 50 data loggers. Two sensors were installed at each plot and average value was used based on good correlation coefficient between them. Monitored period was from 12.8. to 22.10.2015 and the experimental area was cultivated with maize. Average daily value of soil water content and soil water storage were used to soil water regime evaluation. Results showed that 1) soil water content was higher at Control plot (we had expected higher values of soil water content at B20 plot based on scientific studies); 2) year 2015 was extremely hot and vegetation period and monitored period as well, were very dry. Therefor was soil water content below the hydrolimit wilting point (θWP) during a dominant part of monitored period. These results reflected also soil water regime evaluation, when deficit of soil water for plants was during long time of monitored period. Optimal soil water storage for plants was only 13 days at Control plot and 3 days at B20 plot. Our hypothesis, that this type of biochar (with specific characteristics) will improve soil water regime, was not confirmed.