Phosphorus content and stratification in the soil layer 0-30 cm in conventional (CT) and no-till (NT) tillage systems long term experiment

Abstract

Phosphorus in the soil is an essential nutrient less mobile than nitrogen and there is a need to determine its spatial variability. Attention is also paid to its loss because it is a pollutant of the environment. The aim of the study was to determine the patterns of phosphorus (P) distribution in the soil, stratification, after ten years of no-tillage (NT) system compared to the conventional tillage system, moldboard plowing (CT). The tillage systems were fertilized with the same amount of NPK fertilizers and urea and tillage was done on a conventional system (CT). The crop and sowing date are the same. Sampling was done with a soil probe sampling kit Eijkelkamp 04.01.SB. A soil layer of up to 30 cm (in 10 cm intervals) was sampled and analyzed in the laboratory. The soil was air-dried and ground, and in each of the samples the content of readily avaliable P (as P2O5) determined by the AL method according to EgnerRiehm (spectrophotometrically). The obtained values of readily available P in the NT system in the layer 0-10 cm are 32.79 mg/100g which is the highest in relation to the layers 10-20 cm - 25.54 mg/100g and 20-30 cm - 18.89 mg/100g and the values of same layers at CT. There is no such pronounced stratification and the values are 23.52, 23.21 and 22.55 mg/100g per layer in CT. The results of the study show a pronounced vertical stratification of P in the no-till (NT) system. The results show the need to raise the phosphorus level above the maximum value of the optimal content, above 25 mg/100g, in order to create a reserve before changing the conventional (CT) to the no-till (NT) system.