Changes in main agrochemical soil parameters as a result of factors from the agro-technical complex within the three-field field crop rotation

Iliyana Gerasimova, Vanya Lozanova, Maya Benkova, Ivaylo Kirilov, Zdravka Petkova

Abstract: The aim of presented experiments was to monitor the changes in some main agrochemical soil parameters as a result of factors from the crops agrotechnical complex. The influence of two increasing fertilizer norms and a non-fertilization control variant and two tillage systems (conventional and minimum) during the three-field crop rotation (wheat/triticale-maize-triticale/wheat) under non-irrigation conditions were studied. It was found that the applied mineral fertilization mainly influence on the content of sum of nitrate and ammonium nitrogen. The content of mobile phosphorus shows a slight increase, but the studied soil remains poorly stocked with this macronutrient. The content of available potassium is in a satisfactory reserve in both crop rotations. The reaction of the soil solution (pH) remains slightly acid, despite that the experimental area have been used for a long period for field research with intensive agricultural techniques. The organic matter content remains good due to the predominant humification processes over mineralization in the decomposition of residual plant residues in the soil after harvesting the main products from cultivated crops under non-irrigated conditions in the region of Haplic Vertisol in West Bulgaria. Increasing the nitrogen and phosphorus fertilizer norm by about 20% at T2 norm compared to T1 (from 120 to 140 kg/ha for nitrogen and from 80 to 100 kg/ha for phosphorus) does not lead to significantly higher yields in the three crops. The different variants for soil tillage systems do not affect the values of mineral nitrogen. Higher phosphorus content was observed in the variants with O2 tillage (discing) compared to the applied O1 tillage (plowing). For the study period there is no significant difference in the availability of digestible potassium between fertilized and non-fertilized variants. The reported differences between two methods of soil tillage (regardless of the rate of fertilization) are insignificant with inconsistent characteristics.

Keywords: crop rotation; humus; macronutrients; maize; pH; tillage; wheat and triticale

Date published: 2022-06-01