Role of Combined Inoculation with Arbuscular Mycorrhizal Fungi, as a Sustainable Tool, for Stimulating the Growth, Physiological Processes, and Flowering Performance of Lavender

Arbuscular mycorrhizal fungi (AMF) are essential soil microorganisms for terrestrial ecosystems and form beneficial symbioses with the root systems of most agricultural plants. The purpose of this paper was to examine the effect of the community of six AMF on the growth, physiological response, and flowering performance in organic potted lavender culture. The mixture of AMF containing Rhizophagus irregularis, Claroideoglomus claroideum, Funneliformis mosseae, Funneliformis geosporum, Claroideoglomus etunicatum, and Glomus microaggregatum was added in a pot with peat, volcanic rock, and coconut bark. We analyzed the fresh shoot biomass, root biomass, total plant biomass, leaf area, flowering performance, photosynthesis rate, and photosynthetic pigment content. Pearson’s correlation coefficient was performed to get a better understanding of the relationships between the studied variables. The total plant biomass was more pronounced in plants with AMF-S20g (212.01 g plant−1) and AMF-S30g (220.25 g plant−1) than with AMF-S10g (201.96 g plant−1) or in untreated plants (180.87 g plant−1). A statistically significant increase for Chl a, Chl b, and Car was found for AMF-S20g and AMF-S30. Our findings suggest that the AMF mixture application in a growing substrate with peat, coconut bark, and volcanic rock improved plant growth, physiological processes, and ornamental value in mycorrhizal lavender plants. This environmentally friendly agricultural practice could be used for the sustainable production of lavender.

Influence of Copper Pollution of Haplic Calcic Chernozem With Various Contents of Sand Fractions on Morphobiometric Indicators of Spring Barley

The growth and development of plants is one of the criteria for assessing the degree of soil pollution with heavy metals. Morphological and anatomical changes in test plants affected by pollutants, such as growth retardation, shoot bending, and decreased root length and mass, indicate the worsening of environmental conditions. The effect of various ratios of soil and sand polluted with copper (Cu) on morphobiometric parameters of spring barley (Hordeum sativum distichum), Ratnik variety, was studied in a model vegetative experiment. Haplic calcic chernozem was used as a substrate with different ratios of soil/sand. It was determined that an addition of sand into the soil in the amounts of 25%, 50% and 75% of soil mass resulted in the alteration of the physical properties of the chernozem, which was reflected in the morphometric parameters of the plants. The most notable changes in the parameters were observed after pollution of soil-sand substrates with Cu(CH3COO)2 in the amounts of 250 mg/kg, 500 mg/kg, 1000 mg/kg and 2000 mg/kg. The maximum growth and development retardation of the barley plants was found at the maximum content of sand and the maximum concentration of Cu. The pollutant reduced the root length and, to a lesser degree, the height of the aboveground components of the plant, which as a result, decreased the total plant biomass. Keywords: trace elements, soil, agricultural crops, particle size distribution

Characteristics of Three Organic Fertilizers and Their Influence on the Mobility of Cadmium and Arsenic in a Soil-Rice (Oryza Sativa L.) System

The properties and effects of organic fertilizers are different, including the ability to improve soil fertility and the potential of stabilizing heavy metals in soils that have not been explored in depth. In this study, three organic fertilizers from different raw materials were characterized and evaluated. The mushroom residue organic fertilizer (MO) had higher C, H, and O contents and more functional groups (-OH, C-H, and C=O), and its application significantly increased pH (1.00~1.32 units), organic matter (OM) content (26.58%~69.11%) and cation exchange capacity (CEC) (31.52%~39.91%) of soil. MO treatment also reduced the toxicity characteristic leaching procedure (TCLP)-Cd (24.21%) and TCLP-As (18.44%) concentration in the soil. That inhibited the mobilization of Cd and As from soil to plant, especially to plant shoots, and positively affected the plant growth and biomass. Redundancy analysis (RDA) showed that 40.09 % of total plant variation was related to soil properties (pH, OM, and CEC). Furthermore, the heavy metal risk assessment for all organic fertilizers was at safe levels. This study provides a valuable reference for the selection of organic fertilizers. Besides, it recommends organic fertilizers as economic and multi-effect amendments with safe use and provides a new option for the ‘simultaneous production and remediation’ of farmlands with low pollution.

VARIATION OF SOME NEW MORPHOLOGICAL CHARACTERS IN THE FIELD PEAS (PISUM SATIVUM L.)

Peas, as a valuable nutritious and cultivated plant (Myers et al., 2010), have recently received special attention for the improvement of new varieties (Kreplak et al., 2019). They are increasingly adapted to any kind of environmental conditions. Thus, we want an increased production of grains, contents in active principles as high as possible (Pownall et al., 2010), but also to increase its proportion in the structure of crops on a farm. The Alvesta variety, studied for its specific morphological characters, is one of the newest creations. Even in the slightly drier conditions of the last period (two years), this variety formed plants with heights of 42-45 cm, with a total plant weight of 7.5 g. 10 knots were formed on a pea stem (at one node the floral and fruit raceme are caught and formed). Each plant formed 4 pods, weighing 6 g and 16 berries weighing 4.5-6 g. The bean had a diameter of 7 mm and the absolute weight of the berries was 215 g. Among these morphological characters were obtained significantly positive correlations in most cases. Insignificant situations were between the absolute mass of the berries with the size of the plant, with the number of nodes, with the total number of pods and with the number of berries on a plant. Only one insignificant negative correlation was observed between the number of nodes on the stem and the diameter of the grains. Regarding the variability of the determined characters, slightly higher values were found, mainly due to the existence of the dry bottom. And yet the Alvesta variety, with improved morphological characters proved to be a good adaptability to zonal cultivation conditions.

Cause of Death: Phytophthora or Flood? Effects of Waterlogging on Phytophthora medicaginis and Resistance of Chickpea (Cicer arietinum)

Chickpea production in Australia is constrained by both waterlogging and the root disease Phytophthora root rot (PRR). Soil saturation is an important pre-condition for significant disease development for many soil-borne Phytophthora spp. In wet years, water can pool in low lying areas within a field, resulting in waterlogging, which, in the presence of PRR, can result in a significant yield loss for Australian chickpea varieties. In these circumstances, the specific cause of death is often difficult to discern, as the damage is rapid and the spread of PRR can be explosive in nature. The present study describes the impact of soil waterlogging on oxygen availability and the ability of P. medicaginis to infect chickpea plants. Late waterlogging in combination with PRR reduced the total plant biomass by an average of 94%; however, waterlogging alone accounted for 88% of this loss across three reference genotypes. Additional experiments found that under hypoxic conditions associated with waterlogging, P. medicaganis did not proliferate as determined by zoospore counts and DNA detection using qPCR. Consequently, minimizing waterlogging damage through breeding and agronomic practices should be a key priority for integrated disease management, as waterlogging alone results in plant stunting, yield loss and a reduced resistance to PRR.

Ethno-botanical uses and taxonomic composition of some Aju Mbaise (Mbaise wraps)

This document focuses on the ethnobotanical uses and taxonomic composition of some Aju Mbaise (Mbaise wraps). A total of 31 plant species belonging to 24 families were identified in the wraps collected from the study area. These plants are used in the treatment of ailments such as hypertension, typhoid, malaria, boost fertility in females, post-partum (immediately after birth), treatment of diabetes, treatment of arthritis, and induce weight loss. Annonaceae family constituted 9.68% of the total plant family, followed by Acanthaceae, Combretaceae, Fabaceae, Malvaceae, and Rubiaceae with 6.45% each. Among the plant species, Cnestis ferruginea (Connaraceae) occurred in five wraps. This is followed by Alternanthera bettzickiana (Amaranthaceae), Craterispermum cerinanthum (Rubiaceae), and Napoleona imparalis (Lecythidaceae) found in four wraps while Acanthus montanus (Acanthaceae), Barteria nigritana (Passifloraceae), Nephrolepis exaltata (Nephrolepidaceae), Oxytenanthera abyssinica (Poaceae), Palisota hirsuta (Commelinaceae), Scleria naumanniana (Cyperaceae), and Sida rhomboidea (Malvaceae) are in three ailments each. These plant species and families with high occurrence are the most effectively used plant groups in the study for the treatment of these diseases.

How Biodiversity-Friendly Is Regenerative Grazing?

Regenerative grazing management (ReGM) seeks to mimic natural grazing dynamics to restore degraded soils and the ecological processes underpinning sustainable livestock production while enhancing biodiversity. Regenerative grazing, including holistic planned grazing and related methods, is an adaptive, rotational stocking approach in which dense livestock herds are rotated rapidly through multiple paddocks in short bouts of grazing to defoliate plants evenly and infrequently, interspersed with long recovery periods to boost regrowth. The concentrated “hoof action” of herds in ReGM is regarded vital for regenerating soils and ecosystem services. Evidence (from 58 studies) that ReGM benefits biodiversity is reviewed. Soils enriched by ReGM have increased microbial bioactivity, higher fungal:bacteria biomass, greater functional diversity, and richer microarthropods and macrofauna communities. Vegetation responds inconsistently, with increased, neutral, or decreased total plant diversity, richness of forage grasses and invasive species under ReGM: grasses tend to be favored but shrubs and forbs can be depleted by the mechanical action of hooves. Trampling also reduces numerous arthropods by altering vegetation structure, but creates favorable habitat and food for a few taxa, such as dung beetles. Similarly, grazing-induced structural changes benefit some birds (for foraging, nest sites) while heavy stocking during winter and droughts reduces food for seedeaters and songbirds. With herding and no fences, wildlife (herbivores and predators) thrives on nutritious regrowth while having access to large undisturbed areas. It is concluded that ReGM does not universally promote biodiversity but can be adapted to provide greater landscape habitat heterogeneity suitable to a wider range of biota.

The legume-rhizobia symbiosis can be supported on Mars soil simulants

Legumes (soybeans, peas, lentils, etc.) play important roles in agriculture on Earth because of their food value and their ability to form a mutualistic beneficial association with rhizobia bacteria. In this association, the host plant benefits from atmospheric nitrogen fixation by rhizobia. The presence of nitrogen in the Mars atmosphere offers the possibility to take advantage of this important plant-microbe association. While some studies have shown that Mars soil simulants can support plant growth, none have investigated if these soils can support the legume-rhizobia symbiosis. In this study, we investigated the establishment of the legume-rhizobia symbiosis on different Mars soil simulants (different grades of the Mojave Mars Simulant (MMS)-1: Coarse, Fine, Unsorted, Superfine, and the MMS-2 simulant). We used the model legume, Medicago truncatula, and its symbiotic partners, Sinorhizobium meliloti and Sinorhizobium medicae, in these experiments. Our results show that root nodules could develop on M. truncatula roots when grown on these Mars soil simulants and were comparable to those formed on plants that were grown on sand. We also detected nifH (a reporter gene for nitrogen fixation) expression inside these nodules. Our results indicate that the different Mars soil simulants used in this study can support legume-rhizobia symbiosis. While the average number of lateral roots and nodule numbers were comparable on plants grown on the different soil simulants, total plant mass was higher in plants grown on MMS-2 soil than on MMS-1 soil and its variants. Our results imply that the chemical composition of the simulants is more critical than their grain size for plant mass. Based on these results, we recommend that the MMS-2 Superfine soil simulant is a better fit than the MMS-1 soil and it’s variants for future studies. Our findings can serve as an excellent resource for future studies investigating beneficial plant-microbe associations for sustainable agriculture on Mars.

SYMBIOTIC PROPERTIES OF BLACK MEDIC OF THE MIRA VARIETY

The first Russian variety of black medic of the Mira was created and included in the State Register of Breeding Achievements. The study of the symbiotic properties of this variety showed that the most promising strains for pre-sowing inoculation were LX1 and 412b, the first increased the collection of dry matter and seeds by 96 and 115%, and the second – by 81 and 73%, respectively. Both strains can be used when cultivating this variety for feed and seeds. Inoculation with the LX6 strain increased seed productivity by 84%. Strains LX2, LX5 and LX6 increase the adaptive ability of varieties of the Mira, shifting the metabolism of the alfalfa-rhizobial system towards increasing seed productivity. The proportion of seeds in plants inoculated with the above-mentioned strains increases to 24–31% of the total plant weight, and in other symbiotic systems this indicator was 19–22%. Strain LX1 was isolated from nodules of plants belonging to the same population on the basis of which the Mira variety was created and it is the most genetically complementary to this variety. The yield of black medic of the Mira variety without inoculation for two years of use was 3.3 t/ha of dry matter, 0.67 t/ha of seeds. Pre-sowing inoculation of seeds with the LX1 strain increased the yield of this variety to 6.48 t/ha (+96%) of dry matter and seeds – to 1.44 t/ha (+115%). In the vegetation experiment, inoculation with the rhizobium strain LX1 significantly increased the height of plants by 4.2 cm, the leaf area by 0.69 cm2 (+49%), productivity by 176%. The total nitrogen content in the aboveground part of the plants reached 3.63%, the roots 3.31%, the control indicators were 3.02 and 2.77%, respectively.

Water Supply Increases N Acquisition and N Resorption from Old Branches in the Leafless Shrub Calligonum caput-medusae at the Taklimakan Desert Margin

Irrigation is the main strategy deployed to improve vegetation establishment, but the effects of increasing water availability on N use strategies in desert shrub species have received little attention. Pot experiments with drought-tolerant shrub Calligonum caput-medusae supplied with water at five field capacities in the range of 30–85% were conducted using local soil at the southern margin of the Taklimakan Desert. We examined the changes in plant biomass, soil N status, and plant N traits, and addressed the relationships between them in four- and seven-month-old saplings and mature shrubs after 28 months. Results showed that the growth of C. caput-medusae was highly responsive to increased soil moisture supply, and strongly depleted the soil available inorganic N pools from 16.7 mg kg−1 to an average of 1.9 mg kg−1, although the total soil N pool increased in all treatments. Enhancement of biomass production by increasing water supply was closely linked to increasing total plant N pool, N use efficiency (NUE), N resorption efficiency (NRE), and proficiency (NRP) in four-month saplings, but that to total plant N pool, NRE, and NRP after 28 months. The well-watered plants had lower N concentrations in senesced branches compared to their counterparts experiencing the two lowest water inputs. The mature shrubs had higher NRE and NRP than saplings and the world mean levels, suggesting a higher N conservation. Structural equation models showed that NRE was largely controlled by senesced branch N concentrations, and indirectly affected by water supply, whereas NRP was mainly determined by water supply. Our results indicated that increasing water availability increased the total N uptake and N resorption from old branches to satisfy the N requirement of C. caput-medusae. The findings lay important groundwork for vegetation establishment in desert ecosystems.