Analysis of cultivate interventions on the changes of inorganic nitrogen content in the soil during spring barley growing | Analýza vplyvu pestovateľských zásahov na zmeny obsahu anorganického dusíka v pôde pri pestovaní jačmeňa siateho f. jarnej (Hordeum vulgare)

In our trial we researched the impact of soil cultivation, fertilization, depth of soil samples taking, date of soil sampling and vegetation period on changes of nitrate nitrogen, ammonium nitrogen and inorganic nitrogen content in the soil during the monitored vegetation periods (2001/2002 - 2004/2005). This experiment was realized on research-experimental basis of Slovak University of Agriculture in Nitra - Dolná Malanta. Three systems of tillage were used in the field trial: conventional tillage system - medium depth ploughing (B1) up to 0.25 m; reduced tillage - shallow ploughing (B2) up to 0.20 m and minimalization tillage system - disk ploughing (B3) up to 0.15 m, with three variants of fertilization: 0 - unfertilized control, PH - mineral NPK fertilization according to its content in soil and PZ - NPK fertilization according to its content in soil with plough down of post harvest residues. The cultivated crops on experimental base was spring barley (Hordeum vulgare), varieties Jubilant and Nitran, undersowing with red clover with grain maize as its before-crop. The content of nitrate nitrogen in the soil was significantly variable and this was confirmed by its high variation coefficient (73.15%). The changes of ammonium nitrogen content in the soil were not so notable and coefficient of variation was low (23.12%). The variation coefficient of inorganic nitrogen was slightly higher (37.39%), but significantly effected by nitrate nitrogen dynamics. Content of ammonium nitrogen was statistically highly significantly influenced by two observed factors - date of soil samples taking and vegetation period. The inorganic nitrogen content in soil was highly significantly affected by date of soil samples taking and vegetation period and significantly affected by fertilized variant. There was no influence of cultivation on observed forms of inorganic nitrogen. This fact confirms the possibility of the minimalization tillage system utilization.