THE IMPORTANCE OF SOIL FACTORS FOR CROPS IN AGRICULTURE

This article presents the high yields of crops due to the improvement of the factors and propertiesof soil that are necessary for plants. This is due to the fact that the application of organic fertilizers, ie composts, at 20 t/ha, the agrophysical and agrochemical properties of the soil are optimal, water, air, heat and nutrient regimesof the soil are improved at the level of plant demand. In this process, the growth, development and high yields of crops are ensured. KEYWORDS: Agriculture, soil productivity, agrophysical properties, agrochemical properties, fertilizers, nutrients, moisture, soil fertility.

Reducing Drought Stress in Plants by Encapsulating Plant Growth-Promoting Bacteria with Polysaccharides

Drought is a major abiotic stress imposed by climate change that affects crop production and soil microbial functions. Plants respond to water deficits at the morphological, biochemical, and physiological levels, and invoke different adaptation mechanisms to tolerate drought stress. Plant growth-promoting bacteria (PGPB) can help to alleviate drought stress in plants through various strategies, including phytohormone production, the solubilization of mineral nutrients, and the production of 1-aminocyclopropane-1-carboxylate deaminase and osmolytes. However, PGPB populations and functions are influenced by adverse soil factors, such as drought. Therefore, maintaining the viability and stability of PGPB applied to arid soils requires that the PGPB have to be protected by suitable coatings. The encapsulation of PGPB is one of the newest and most efficient techniques for protecting beneficial bacteria against unfavorable soil conditions. Coatings made from polysaccharides, such as sodium alginate, chitosan, starch, cellulose, and their derivatives, can absorb and retain substantial amounts of water in the interstitial sites of their structures, thereby promoting bacterial survival and better plant growth.

To The Characteristic Of Cenopopulations Dactylorhiza Dactylorhiza Fuchsii (Druce) Soo Of The Middle And Southern Taiga

The article presents materials on the ecological and phytocenotic characteristics of Dactylorhiza fuchsii (Druce) Soo in the southern and middle taiga phytocenoses of the Kirov region. In the course of the study, the typical habitats of the species were established. Vegetation analysis carried out using phytoindication scales by D.N. Tsyganov (1983), made it possible to establish fragments of ecological niches in the conditions of the southern and middle taiga. It was found that in the middle taiga phytocenoses, the species is more sensitive to changes in soil factors given by the researcher than in the southern taiga. Analysis of vegetation in terms of hemerobicity indicates the relative resistance of the species to anthropogenic impact.

Population dynamics, effective soil factors, and LAMP detection systems for Phytophthora species associated with kiwifruit diseases in China

China has the largest area of kiwifruit production in the world. Pathogens associated with root diseases of kiwi trees have not been investigated extensively. In this research, three Phytophthora species including P. cactorum, P. cinnamomi, and P. lateralis, which are pathogenic to kiwi trees in the main planting areas of China, were studied. The population densities of these species in 128 soil samples from 32 kiwi orchards in 2017 and 2018 were measured using multiplex real-time quantitative PCR, based on the ras-related protein gene Ypt1. P. cactorum was the most widely distributed of the three species in orchards of the Zhouzhi and Meixian Prefectures. We also used redundancy analysis (RDA) to examine soil factors in the kiwi orchards, to understand their effects on the population densities of the Phytophthora species. The RDA analysis indicated that soil temperature and pH were significantly correlated with the abundance of P. cactorum and P. cinnamomi. Besides, two loop-mediated isothermal amplification (LAMP) detection systems for P. cactorum were developed based on the tigA gene. The color-change detection system was proved to be accurate, sensitive, and faster than quantitative PCR. The results of this study, along with the LAMP detection systems, will be of great use in the control of Phytophthora diseases for the production of kiwifruits in China.

Ecological assessment of some Polygonatum odoratum (Mill.) Druce habitats

Polygonatum odoratum (Mill.) Druce – summer-green short-rhizome polycarpic, geophyte. The aim of thestudy is to assess the ecological-cenotic preferences of P. odoratum in pine forests on the territory of the specially protectednatural area “Medvedsky Bor” in the Nolinsky district of the Kirov region. The ecological preferences of the P. odoratumwere determined by processing our own geobotanical descriptions according to the ecological scales of D. N. Tsyganov(1983), the assessment of the habitat conditions of the P. odoratum cenopopulations was carried out taking into accountthe realized ecological valence (REV) and the coefficient of ecological efficiency (K.ec.eff.). As a result of the studies, it wasfound that P. odoratum in pine forests is characterized by a wide potential range for most of the factors considered, in particular, the habitation of P. odoratum on sandy soils is due to the wide potential range of endurance of individuals of thisspecies in relation to soil moisture and preference for soils poor in mineral nutrients. The range of the studied habitatsdoes not go beyond the potentially possible boundaries, therefore, the conditions of these territories are relatively consistent with the ecological needs of the species, but most of the soil factors are not optimal for the growth of individuals of theP. odoratum in both cenopopulations. This is evidenced by both the low indicators of the realized ecological valence, andthe low coefficient of ecological efficiency