Influence of anthropogenic factors on humus in Phaeozems of Ashotsk land cadastral district

S.Z. Kroyan¹, S.K. Baghdasaryan², S.A. Markosyan³, N.S. Kroyan¹, M.H. Zadayan⁴* and A.O. Markosyan²

¹National University of Architecture and Construction of Armenia, Department of Engineering Geodesy, Teryan Str. 105, AM0009 Yerevan, Armenia
²Armenian National Agrarian University, Scientific Center of Soil Science, Agrochemistry and Melioration named after H. Petrosyan, 24 Admiral Isakov Ave, AM0004 Yerevan, Armenia
³Yerevan State University, Faculty of Biology, Department of Biology, 1 Alex Manoogian, AM0025 Yerevan, Armenia
⁴Center for Agricultural Research and Certification, State Non-Commercial Organization of the Ministry of Economy of the Republic of Armenia, Yerevanyan highway 2nd deadlock, building 4, AM1139 Merdzavan village, Armavir Marz, Armenia
*Correspondence: mhzadayan@gmail.com

Abstract:

The study was conducted on Phaeozems of the Ashotsk land cadastral region (ALCR), Republic of Armenia. Field investigations compared virgin and long-term cultivated soil variants. Total humus content was determined using the Tyurin method, and the qualitative composition of humus was analyzed according to the Kononova and Belchikova procedure. The results demonstrated that in the plough horizon of cultivated soils, the content and total stock of humic acids, fulvic acids, and non-hydrolyzable residue decreased by 18%, 15.6%, and 17%, respectively. Under prolonged agricultural use, both quantitative and qualitative humus characteristics changed considerably. Compared with virgin soils, total humus content declined by approximately 32%, while humic and fulvic acid fractions decreased by 16–18%. These findings confirm progressive deterioration of humus in cultivated Phaeozems and highlight the necessity of fertility restoration measures. Management practices that may be considered include the application of organic fertilizers (55–65 t ha⁻¹) combined with mineral fertilizers in prescribed doses (N90, P100, K60) and the implementation of minimum or zero tillage within adaptive landscape farming systems.

Key words:

fulvic acids, humic acids, humus, non-hydrolyzable residue, phaeozems

Humus content in a podzolized chernozem after a long-term application of fertilizers in a field crop rotation

H. Hospodarenko¹, I. Prokopchuk¹*, S. Prokopchuk¹ and А. Trus²

¹Uman National University of Horticulture, Faculty of Agronomy, Department of Agricultural Chemistry and Soil Science, 1 Instytutska street, UA20305 Uman, Ukraine
²Uman National University of Horticulture, Faculty of Engineering and Technology, Department of Applied Engineering and Labor Protection, 1 Instytutska street, UA20305 Uman, Ukraine
*Correspondence: pivotbi@ukr.net

Abstract:

The article presents the results of the research into influence of a long-term (50 years) application of different fertilizer rates and fertilizer systems in the field crop rotation on the humus composition and optical parameters of humic acids of a heavy- loamy podzolized chernozem of the Right Bank Forest-Steppe of Ukraine.
It was found that application of fertilizers significantly affects the dominance of humic acids over fulvic acids in the composition of soil, which indicates humate type of soil. Chroma index of humic acids is within 3.56–3.75 depending on a fertilizer. Indicators of the optical properties of humic acids of a podzolized chernozem have a high degree of humification.

Key words: