Мікробіота ризосфери Salix sp. за умов використання різних агротехнічних прийомів

Abstract

Проаналізовано кількісні показники мікробоценозу ризосфери деяких видів енергетичної верби (Salix viminalis, Salix triandra x Salix viminalis 'Inger') при внесенні різних видів добрив та без удобрення. Встановлено, що при зниженій кількості мікроорганізмів ґрунт за умов вирощування верби характеризується високою інтенсивністю мінералізаційних процесів порівняно з плодовими культурами (Malus sp.). Достовірне підвищення чисельності мікроорганізмів у деяких еколого-трофічних групах у ризосфері верби реєстрували при внесенні муніципального компосту компонентів стічних вод.

The study has established the regularities of distribution of certain physiological groups of microbial cenosis in conditions of growing of fruit and energy plants. In case of willow, the numbers of ammonifiers, micromycetes, actinomycetes, cellulolytic and oligonitrophilic microorganisms were observed to reduce compared to the control. In case of apple-trees, the number of microorganisms was higher but still within the control values. Growing of willows leads to stabilization of soil solution reaction, higher concentration of ammonium nitrogen, and lower concentration of nitrate nitrogen and potassium, compared with the control. We have established decreased concentrations of humus vs. control in both cases – growing of willows and apple-trees, which figure correlates with the number of pedotrophs. Notwithstanding the lowered number of some physiological groups of microorganisms, the soil with willows was characterized by highly intensive mineralization processes, in particular those of transformation of organic matters. An open-field long-term fertilization experiment was set up during 2011 with willow (Salix triandra x Salix viminalis ’Inger’), grown as an energy crop. The brown forest soil was treated during June 2011, May 2013, and May 2016 with municipal biocompost (MBC), municipal sewage sludge compost (MSSC), willow ash (WA) and sulfuric urea (SU) and two times (2011, 2013) with rhyolite tuff (RT). Thus, the most indicative changes in the soil microbiota against the control plot were found in case of the use of municipal sewage sludge compost; rise in the number of intestinal bacteria, ammonifiers, micromycetes and actinomycetes. In case of the use of municipal biocompost rise in the levels of intestinal bacteria, microscopic fungi, actinomycetes, pedotrophs and cellulolytic bacteria were found. While calculating the mineralization/immobilization index, it was shown that the most significant deviation from the control plot was found in rhyolite tuff treated soil – a decrease by 6 times, and in case of willow ash by 2.3 times, which proves the inhibition of mineralization of the organic substances in the soil.