Effect of Living Mulch on Soil Conditions and Morphometrical Indices of Sweet Cherry Trees

Abstract

In order to maintain natural biocenosis and to create optimal conditions for reproducing soil fertility, it is necessary to keep the soil under living mulch in organic orchards. But the effect of the living mulch on soil properties and biometric indices of trees has not yet been fully investigated. This work aimed at examining the effects of living mulch (compared with standard mechanical cultivation) on soil moisture, soil temperature and biometric indices of sweet cherry trees in the arid conditions of the Southern Steppe of Ukraine. The work was conducted from 2014 to 2019 in the Southern Steppe of Ukraine in Zelene village near the city of Melitopol (46°46’N, 35°17’E). In organic sweet cherry (Prunus avium L./Prunus mahaleb) orchard standard mechanical cultivation (MC) was compared with living mulch - spontaneous vegetation cover (LM). The soil moisture at 20 cm depth was significantly greater under LM (an average of 3,9%), the soil temperatures under LM plots were lower (an average of 1.5°C over 6 years of research), in comparison to MC. It was established that the trunk cross sectional area of sweet cherry trees was significantly reduced under LM - by 1.2-2.1 times. However, LM contributed to an increase in the shoot growth efficiency – by 1.5-2.9 times, compared to MC. The ratio of total leaf area to the trunk cross sectional area was also significantly greater in conditions of LM, since 2015 by 1.3-2.5 times. The weather conditions of the year significantly influenced the formation of the biometric indices of the trees - Year×orchard floor management system interactions were significantly throughout all years of research. Investigated sweet cherry cultivars (Valery Chkalov and Dilemma) respondend to the floor management systems in a similar way – their biometric indices did not differ significantly.