Growth Of Agricultural Crops Research Articles

Azospirillum brasilense INOCULATION ON SEED GERMINATION AND INITIAL GROWTH OF SEEDLINGS OF NATIVE FOREST SPECIES

Inoculation of rhizobacteria in seeds and plants has been documented as a stimulant and promoter of germination and growth of agricultural crops, but there is little information on native forest species. Therefore, the present study aims to evaluate the potential of Azospirillum brasilense inoculation in the germination of seeds and initial growth of seedlings of native forest species. The following experiments were carried out: (I) germination of seeds in germination chamber, and (II) initial growth of seedlings in nursery, both with four forest species (Cassia leptophylla, Lafoensia pacari, Mimosa flocculosa and Schinus terebinthifolius). For the four species, in both experiments, two treatments were used: inoculation of seeds with concentrated solution of A. brasilense and no inoculation of seeds (control). Physiological aspects of seed germination and seedling vigor were evaluated in the first experiment (germination speed, and length and dry weight of seedlings), and seedling growth was evaluated in the second experiment (height, collar diameter and dry weight of seedlings). Inoculation of A. brasilense in seeds of C. leptophylla, L. pacari, M. flocculosa and S. terebinthifolius did not promote beneficial or promising results for seed germination and initial growth of seedlings, so its use to produce seedlings of these species is not recommended.

Klebsiella variicola improves the antioxidant ability of maize seedlings under saline-alkali stress

BackgroundSaline-alkali soil is mainly distributed in the northern and coastal areas of China. The Songnen Plain, located in the northeast of China, is a region with a relatively high concentration of saline-alkali soil and is also one of the more at-risk areas in the country. Every year, the increasing spread of saline-alkali soil areas has a serious impact on the growth of agricultural crops. The maize crop is sensitive to saline-alkali stress, which seriously affects its growth and development. Our previous study determined that Klebsiella variicola performs a variety of biological functions, as well as improves the rhizosphere microenvironment and promotes the growth and development of maize seedlings in saline-alkali soil environments. The present study further analyzed the mechanism that enables K. variicola to alleviate saline-alkali stress at the level of the antioxidant system.MethodsThe accumulation of O2− was observed directly via histochemical staining. The activities of several antioxidant enzymes were determined using the nitro blue tetrazolium and the guaiacol methods. The contents of non-enzymatic antioxidants were determined using the dithionitrobenzoic acid method.ResultsThe contents of the superoxide anion and hydrogen peroxide in leaves and roots of maize seedlings increased under saline-alkali stress conditions. The higher level of reactive oxygen species increased the degree of membrane lipid peroxidation. There were differences in the degree of oxidative damage and performance of the antioxidant defence system in maize seedlings under saline-alkali stress. Following the application of increasing concentrations of K. variicola, the activity of antioxidant enzymes increased by 21.22%–215.46%, and the content of non-enzymatic antioxidants increased as well, the ratios of ASA/DHA and GSH/GSSG in leaves increased by 4.97% and 1.87 times, respectively, and those in roots increased by 3.24% and 1.60 times, respectively. The accumulation of reactive oxygen species was reduced, and the content of H2O2 decreased by 26.07%–46.97%. The content of O2− decreased by 20.18%–37.01%, which alleviated the oxidative damage to maize seedlings caused by saline-alkali stress.ConclusionK. variicola reduced ROS-induced peroxidation to membrane lipids and effectively alleviated the damage caused by saline-alkali stress by increasing the activities of antioxidant enzymes in maize seedlings, thus enhancing their saline-alkali tolerance. A bacterial concentration of 1×108 cfu/mL was optimal in each set of experiments.

Arbuscular Mycorrhizal Fungus Stimulates Young Field-Grown Nectarine Trees

Although mycorrhizae applications have been widely used to improve the establishment and growth of agricultural crops, there have been no studies on their application in field-grown nectarine trees. In this work, a commercial arbuscular mycorrhizal fungus (AMF; Glomus iranicum var. tenuihypharum) was applied by means of fertigation to inoculate young “Flariba” nectarine trees grown in south-eastern Spain to evaluate its effect on plant water status, and vegetative and reproductive growth. Using minirhizotrons to measure the root dynamics over a complete growing season, revealed that AMF substantially increased root growth (51% increase compared with untreated trees), while no changes in plant water status or canopy development were noted. The productive response improved in inoculated trees, as demonstrated by a significantly higher yield, fruit size, number of fruits per tree and greater crop load efficiency values than in untreated trees. Given that the same amount of irrigation solution was applied in both treatments, the irrigation water use efficiency increased by 19.5% in AMF compared with untreated trees. The findings of this study suggest that a simple inoculation of AMF can be considered a good practice in semi-arid agro-systems to firmly establish efficient young nectarine trees and enhance their adaptation to field conditions.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture.

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

Nano carbon water retaining fertilizer on soil bacterial community structure and grape growth in grape field

In order to study the application of nano carbon water retaining fertilizer in agricultural production, and to explore the effects of its use on the bacterial community structure of agricultural soil and crop growth, a series of experimental studies were carried out in a grape field. In this paper, the coated slow-release fertilizer with soluble nitrogen particles as the core and nano carbon materials wrapped in the outer layer of nitrogen fertilizer was developed. The grape field used in the experiment was divided into experimental field and control field. The new nano carbon water retaining fertilizer was applied in the experimental field and ordinary nitrogen fertilizer was applied in the control field. Through Illumina Miseq high-throughput sequencing, the diversity and richness of bacterial communities in the original soil without planting and the soil of two groups of grape fields after grape ripening were detected, and the grape leaf area, single fruit weight and horizontal diameter of grape, and the titratable acid content of grape fruit in the two fields were detected and calculated. The results showed that Shannon index and Chao1 index of soil bacterial community diversity in the experimental field were higher than those in the control field; the grape leaf area in the experimental field was larger than that in the control field in the early, middle and late stages of shoot growth, with a difference of 8.56cm2 in the later stage; the single fruit weight and transverse diameter of grape in the experimental field were 1.94 g and 2.72 mm larger than those in the control field at 100 days after flowering, respectively; The difference of titratable acid content in grape fruit was the largest at 70 days after anthesis, which was 0.25% and 0.05% at 100 days after flowering. The results showed that nano carbon water retaining fertilizer had significant effects on soil community structure and grape growth in grape field, which could effectively reduce the influence of planting and fertilization on soil bacterial community diversity and richness, promote the growth of grape leaves and fruits, and improve grape quality.

Improvement of morpho-physiological, ultrastructural and nutritional profiles in wheat seedlings through astaxanthin nanoparticles alleviating the cadmium toxicity

Heavy metal accumulation in arable lands and water bodies has become one of the serious global issues among multitude of food security challenges. In particular, cadmium (Cd) concentration has been increasing substantially in the environment that negatively affects the growth and yield of important agricultural crops, especially wheat (Triticum aestivum L.). No doubt, nanotechnology is a revolutionary science but the comprehension of nanoparticle-plants interaction and its potential alleviatory role against metal stress is still elusive. Here, we investigated the mechanistic role of astaxanthin nanoparticles (AstNPs) in Cd stress amelioration and their interaction with wheat under Cd-spiked conditions. The AstNPs fabrication was confirmed through ultraviolet visible spectroscopy, where the particles showed characteristic peak at 423 nm. However, Fourier transform infrared, X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses confirmed the presence of stabilized spherical-shaped nanocrystals of AstNPs within the size range of 12.03–30.37 nm. The hydroponic application of AstNPs (100 mg L−1) to Cd-affected wheat plants increased shoot height (59%), shoot dry weight (31%), nitrogen concentration (42%), and phosphorus concentration (26%) as compared to non-treated Cd affected seedlings. Moreover, AstNPs-treated plants showed reduction in acropetal Cd translocation (29%) in contrast to plants treated with Cd only. Under Cd-spiked conditions, AstNPs-treated plants displayed an improved nutrient profile (P, N, K+ and Ca2+) with a relative decrease in Na+ content in comparison with non-treated plants. Interestingly, it was found that AstNPs restricted the translocation of Cd to aerial plant parts by negatively regulating Cd transporter genes (TaHMA2 and TaHMA3), and relieved plants from oxidative burst by activating antioxidant machinery via triggering expressions of TaSOD and TaPOD genes. Consequently, it was observed that the application of AstNPs helped in maintaining the nutrient acquisition and ionic homeostasis in Cd-affected wheat plants, which subsequently improved the physiochemical profiles of plants under Cd-stress. This study suggests that AstNPs plausibly serve as stress stabilizers for plants under heavy metal-polluted environment.

Phenotyping Latin American Open-Pollinated Varieties of Popcorn for Environments with Low Water Availability.

Drought is a common abiotic stress in tropical and subtropical regions that limits the growth and development of agricultural crops, mainly impacting grain yield. Acting through plant breeding is the most viable alternative for obtaining genotypes more tolerant of environments with stress. This work aims to select popcorn genotypes for environments with drought and to identify discriminating traits for the evaluation of drought tolerance in popcorn germplasm. Fifteen Latin American populations of popcorn were evaluated in water stress (WS) and well-watered (WW) conditions. The evaluated traits were based in morpho-agronomic, physiological and radicular descriptors. Data were submitted to individual and joint ANOVA and GT Biplot analysis. Variability was detected between populations for all traits in both conditions. The drought caused a reduction of 30.61% and 3.5% in grain yield and popping expansion, respectively. Based in GT biplot analysis, 880POP was the most stable in WS and WW, being indicated as a promising population for cultivation in environments with water limitation. This study is going to allow the establishment of a collection of great importance to maize germplasm and to provide information to facilitate the process of selection in breeding programs focused on drought tolerance.

PROCEDURE OF TENDENCY MAP ON THE BASIS OF GEOGRAPHICAL INFORMATION SYSTEM OF JALILABAD CADASTRY DISTRICT

As the inclination increases, soil erosion and, in general, the process of erosion on the slopes intensifies, the moisture content of the soil and soil-forming rocks decreases, the growth of agricultural crops and pastures weakens, and productivity decreases. Taking all this into account, we have developed a slope map with degrees based on the digital elevation model of the Jalilabad cadastral region (DEM file). Slope study and mapping is one of the key measures to protect soils from erosion as well as to combat erosion. When the slope reaches 3-4°, the washing of the soil is even faster. It is not recommended to plow the fields when the slope is 8-10° and more. From this point of view, as a result of our research, the inclination of the Jalilabad cadastral region has been studied. The lowest inclination range in the study area is 0-20. Low inclination is observed mainly in the plains of Jalilabad cadastral region. As you ascend to the heights, there is an increase in inclination. Taking into account the propensity in agriculture can lead to high yields. Key words: Inclination, Slope, Erosion, Geographic Information System (GIS), ESRI, ArcGis

Waterlogging tolerance: A review on regulative morpho-physiological homeostasis of crop plants

The natural environment is being drastically affected by climate change. Under these severe environmental conditions, the growth and productivity of agricultural crops have reduced. Due to unpredictable rainfall, crops growing in the field are often exposed to waterlogging. This leads to significant crop damage and production losses. In this review paper, the mor-phological and physiological adaptations such as development of aerenchyma, adventitious roots, radial root oxygen loss barrier, and changes in chlorophyll fluorescence parameters of crops under waterlogging are discussed. This will help to understand the effects of waterlogging on various crops and their adaptation that promotes crop growth and productivity. To meet the food requirements of a growing population, the development of waterlogging tolerant crops by screening and plant breeding methods is necessary for plant breeders. Better knowledge of physiological mechanisms in response to waterlogging will facilitate the development of techniques and methods to improve tolerance in crops.

Biochar and vermicompost improve growth and physiological traits of eggplant (Solanum melongena L.) under deficit irrigation

BackgroundDrought is one of the most important environmental stresses that can adversely influence soil properties, plant growth, and productivity of agricultural crops including eggplant as an important vegetable crop. In recent years, the use of agricultural wastes has been reported as a beneficial and sustainable measure in soil water retention and fertility enhancement. In this study, the effect of date palm and pistachio biochar, vermicompost and a combination of biochar and vermicompost was evaluated on eggplant growth, yield and water use efficiency under deficit irrigation.Materials and methodsThe experiment was done in a split-split plot based on randomized complete block design with three replications and under open field conditions. The main plot was deficit irrigation in three levels of 100, 75 and 50% of plant water requirement (PWR), and the sub-plots were vermicompost in two levels of 0, 1500 g m−2, and biochar in three levels of 0, 500 g m−2 of the pistachio biochar and 500 g m−2 of the date palm biochar.ResultsThe results showed that soil amendment with vermicompost and pistachio biochar and 100% PWR showed the best plant growth and performance. The early crop yield was highest under pistachio biochar and 50% PWR, while the total plant yield was highest under combined application of vermicompost and pistachio biochar at 100% PWR. The plant water use efficiency was maximum under mixed application of vermicompost and pistachio biochar at 50% PWR. Application of both pistachio biochar and vermicompost at 100% PWR resulted in the highest leaf concentrations of nitrogen, phosphorus, potassium, iron and manganese. The highest levels of physiologically important stress metabolites, including malondialdehyde, guaiacol peroxidase, superoxide dismutase and catalase enzymes were found in treatments without amendments or only with vermicompost and 50% PWR.ConclusionThe results indicate that under normal and particularly water deficit conditions, vermicompost and biochar increased eggplant vegetative growth, yield and water use efficiency.

Geochemical Patterns and Source Analysis of Soil Heavy Metals in an Iron and Manganese Ore Area of Longyan City

Bedrock and soil samples from different soil profile layers were collected in an iron and manganese ore area of Longyan City and total amounts of Pb, Cd, and As were determined. The geochemical patterns of three heavy metal elements in the soil were studied using ordinary Kriging interpolation and their sources were also analyzed. High concentrations of Pb and As were found near the mining area to the west, at the intersection of two rivers in the middle, and near the waste rock heap in the east of the study area, while the main area of Cd contamination is located near to the mining areas and ore dressing plant. Based on a horizontal section, the content of Pb, Cd, and As in soils from the high-value region of each layer decreased with horizontal distance from the mining area. Vertically, the concentrations of heavy metals in different soil layers were significantly correlated. Near the mining area, Pb, Cd, and As concentrations first increased and then decreased with depth. In other high-value regions, the concentrations of these three heavy metals decreased with soil profile depth. These heavy metals inherit the characteristics of the deposit and bedrock during the weathering process, and the content of Pb and As in the soil at different depths was significantly positively correlated with granite and diorite content. Although As has been artificially influenced by mining, this influence does not appear to be strong; parent rock in the study area shows higher concentrations of heavy metals, while at the same time, the Pb and Cd content of soil is significantly higher than in the rock indicating the influence of human activities including mining, transportation, and agricultural production. Further attention should now be paid to the quality and safety of agricultural products, crop growth, and possible environmental risks in the study area.

Microbial Diversity of Psychrotolerant Bacteria Isolated from Wild Flora of Andes Mountains and Patagonia of Chile towards the Selection of Plant Growth-Promoting Bacterial Consortia to Alleviate Cold Stress in Plants.

Cold stress decreases the growth and productivity of agricultural crops. Psychrotolerant plant growth-promoting bacteria (PGPB) may protect and promote plant growth at low temperatures. The aims of this study were to isolate and characterize psychrotolerant PGPB from wild flora of Andes Mountains and Patagonia of Chile and to formulate PGPB consortia. Psychrotolerant strains were isolated from 11 wild plants (rhizosphere and phyllosphere) during winter of 2015. For the first time, bacteria associated with Calycera, Orites, and Chusquea plant genera were reported. More than 50% of the 130 isolates showed ≥33% bacterial cell survival at temperatures below zero. Seventy strains of Pseudomonas, Curtobacterium, Janthinobacterium, Stenotrophomonas, Serratia, Brevundimonas, Xanthomonas, Frondihabitans, Arthrobacter, Pseudarthrobacter, Paenarthrobacter, Brachybacterium, Clavibacter, Sporosarcina, Bacillus, Solibacillus, Flavobacterium, and Pedobacter genera were identified by 16S rRNA gene sequence analyses. Ten strains were selected based on psychrotolerance, auxin production, phosphate solubilization, presence of nifH (nitrogenase reductase) and acdS (1-aminocyclopropane-1-carboxylate (ACC) deaminase) genes, and anti-phytopathogenic activities. Two of the three bacterial consortia formulated promoted tomato plant growth under normal and cold stress conditions. The bacterial consortium composed of Pseudomonas sp. TmR5a & Curtobacterium sp. BmP22c that possesses ACC deaminase and ice recrystallization inhibition activities is a promising candidate for future cold stress studies.

Evolution of Plant Na+-P-Type ATPases: From Saline Environments to Land Colonization.

Soil salinity is one of the major factors obstructing the growth and development of agricultural crops. Eukaryotes have two main transport systems involved in active Na+ removal: cation/H+ antiporters and Na+-P-type ATPases. Key transport proteins, Na+/K+-P-ATPases, are widely distributed among the different taxa families of pumps which are responsible for keeping cytosolic Na+ concentrations below toxic levels. Na+/K+-P-ATPases are considered to be absent in flowering plants. The data presented here are a complete inventory of P-type Na+/K+-P-ATPases in the major branches of the plant kingdom. We also attempt to elucidate the evolution of these important membrane pumps in plants in comparison with other organisms. We were able to observe the gradual replacement of the Na+-binding site to the Ca2+-binding site, starting with cyanobacteria and moving to modern land plants. Our results show that the α-subunit likely evolved from one common ancestor to bacteria, fungi, plants, and mammals, whereas the β-subunit did not evolve in green algae. In conclusion, our results strongly suggest the significant differences in the domain architecture and subunit composition of plant Na+/K+-P-ATPases depending on plant taxa and the salinity of the environment. The obtained data clarified and broadened the current views on the evolution of Na+/K+-P-ATPases. The results of this work would be helpful for further research on P-type ATPase functionality and physiological roles.

Water-deficit stress - Induced physio-biochemical changes in cotton (Gossypium hirsutum L.) Cultivars

Water stress is a serious global issue regarding growth of agricultural crops and sustainable food production for the large population. In the present situation due to low rainfall and unavailability of advanced irrigation methods, water deficit stress is the most limiting factor decreasing crop production in many regions of the world. In this study, to assess the drought tolerance mechanism in cotton cultivars was monitored by drought induced physio-biochemical changes. To assess the tolerance in cotton cultivars, a field experiment was conducted in split plot design in which the main plot consists of irrigated and complete rainfed conditions as a stress and cotton cultivars arranged in the main plot as a subplot. The overall comparative analysis revealed that hybrid was superior over their parents under well-watered as well as in water deficit conditions in terms of chlorophyll content, wax content, accumulation of compatible solutes, photosynthesis rate, stomatal conductance, transpiration rate and yield parameters. The findings from the results indicate that under water deficit conditions plants having a different adaptive mechanisms for coping with the stress situation. So, some of the adaptive mechanisms such as accumulation of sugars, polyphenols, amino acids, non-enzymatic antioxidants, and wax deposition helps to maintain osmotic balance, to protect cellular macromolecules, to detoxify the cells, and to scavenge free radicals under water deficit condition.

The Early-Warning and Inspection System For Intelligent Greenhouse Based on Internet of Things

The early-warning and inspection system for the intelligent greenhouse is an inspection robot based on the Internet of things and equipped with various sensors and intelligent cameras with 4G or 5G communication functions, such as temperature and humidity, light, gas, and flame. Which uses the wireless network transmission to the cloud computing platform for data analysis, sending warning information through smartphones to enable farmers to real-time monitoring in agricultural greenhouse crop growth status, temperature and humidity, illumination, CO 2concentration, plant diseases, and insect pests, etc., to achieve automatic control, scientific planting and raising the yield and increase their income. This paper mainly analyzes the hardware and software structure of this early-warning and inspection system, data transmission and processing, and Android application, so as to promote the application of intelligent planting.

Efficacy of Inorganic Phosphorus and Farmyard Manure on Production and Quality of Garlic (Allium sativum L.)

Organic and inorganic fertilizers improve soil fertility and give both macro and micronutrients to the soil for better growth of agricultural crops. Therefore, current study was designed to find out the efficacy of inorganic phosphorus (P) alone and in combination farmyard manure (FYM) applied in various doses on production and quality aspects of garlic. A field experiment was organized in a randomized complete block design, replicated thrice using different rates of P in the form of single super phosphate (SSP) and farmyard manure (FYM). Seven different treatments of various levels of P, either using inorganic phosphorus from SSP alone or in combination with organic phosphorus from FYM, i.e. T0 = control; T1 = 50 kg P.ha-1 (SSP); T2 = 70 kg P.ha-1 (SSP); T3 = 90 kg P.ha-1 (SSP); T4 = 25 kg P.ha-1 (SSP) + 25 kg P.ha-1 (FYM); T5 = 35 kg P.ha-1 (SSP) + 35 kg P.ha-1 (FYM); T6 = 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM)] were applied to the soil. All the growth, yield and quality parameters recorded showed significant response when P was applied in combination of inorganic and organic sources as compared with control and inorganic P alone. A combined treatment of 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM) gave comparatively better results in terms of plant height (66.87 cm), fresh leaf weight (2.70 g), leaf area plant-1 (83.83 cm2), relative leaf chlorophyll content (11.90), weight of bulb plant-1 (42.66 g), diameter of bulb (4.50 cm), number of cloves bulb-1 (8.50), bulb yield (4382.96 kg ha-1) and vitamin C content (6.43 mg 100 g-1). Thus, it was concluded from this study that a combined treatment of 45 kg P.ha-1 (SSP) + 45 kg P.ha-1 (FYM) should be applied for quality production of garlic under rainfed conditions of Rawalakot.

The physiological and biochemical responses to engineered green graphene/metal nanocomposites in Stevia rebaudiana

Stevia is a source of natural sweetener. Numerous researches showed that silver nanoparticles affected the yield and growth of agricultural crops. The effect of silver, graphene, and nanocomposite nanoparticles on a few biochemical and morphological parameters of the Stevia plant were studied. Synthesized Ag nanoparticles were confirmed by the absorption maxima and SEM micrograph. The use of nanocomposites at 40 mM, resulted in the higher chlorophyll content (25%) and increased accumulation of soluble sugars (27%), flavonoids (51%), total phenol (33%) and total protein (51%) as compared to the control plants. The plants treated with nanocomposite at a concentration of 60 mM, had more stevioside and rebaudioside content than plants treated with nanocomposite at a concentration of 40 mM.

Application of VIS-NIR spectroscopy for estimation of soil organic carbon using different spectral preprocessing techniques and multivariate methods in the middle Indo-Gangetic plains of India

Soil organic carbon (SOC) is the main source of soil nutrients, which are essential for the growth and development of agricultural crops. Precise and quick quantification of SOC is of utmost importance in crop husbandry and soil health/carbon sequestration quantification. In order to evaluate visible and near-infrared diffuse reflectance spectroscopy (VIS-NIR) as an alternative to precise and quick method of quantification of SOC in the Indo-Gangetic plains, 280 soil samples were collected covering Inceptisols, Entisols and Alfisols and their spectra recorded. Six preprocessing techniques ((reflectance, absorbance, multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky–Golay smoothing first derivative (SG-FD) and Savitzky–Golay smoothing second derivative (SG-SD)) and four multivariate methods (partial least-squares regression (PLSR), random forest (RF), support vector regression (SVR) and multivariate adaptive regression splines (MARS)) were evaluated to predict SOC from VIS-NIR spectra. The considerable prediction accuracy and robustness were achieved using the PLSR model (RV2 = 0.73, RMSEV = 0.07, and RPDV = 1.90), RF model (RV2 = 0.69, RMSEV = 0.07, and RPDV = 1.74), SVR model (RV2 = 0.57, RMSEV = 0.08), and RPDV = 1.50), and MARS model (RV2 = 0.63, RMSEV = 0.10, and RPDV = 1.05). Findings from this study identified the reliability of SOC determinations by examining how preprocessing techniques and multivariate methods affect spectral analyses.

Machine for carrying out work on deep soiling with the simultaneous application of liquid organic fertilizers

The necessity of carrying out work on deep loosening in lands newly introduced into agricultural circulation in soils of heavy mechanical composition, as well as destruction of the subsoil on old arable lands have been analyzed. Requirements for the work on deep loosening of the soil are grounded. The existing designs of reclamation rippers are considered and a passive two-row subsoiler with front shanks of a volumetric structure and rear curved shanks with additional plowshares is selected. The possibility of combining work on deep loosening and application of organic fertilizers to increase soil fertility, water and air permeability, and create the most favorable soil conditions for plant growth and development has been investigated. The existing rates of fertilization have been analyzed and the possibility of delivering an organic liquid to the enlarged pore space formed after soil loosening has been investigated. The influence of the ongoing agro-reclamation measures on increasing soil fertility, creating an optimal water and air balance for the growth and development of agricultural crops and the expected increase in yield are analyzed.

Phytotoxic effect of invasive species Amorpha fruticosa L. on germination and the early growth of forage and agricultural crop plants

AbstractInvasive plant species can inhibit the growth of native plants by competing for resources as well as by secreting allelochemicals. Indigobush (Amorpha fruticosa L.), a deciduous shrub adaptable to a wide range of environmental conditions, was introduced into Europe as a decorative and valuable honey plant. In this study, we assayed the phytotoxic effect of aqueous leaf extracts (1, 3 and 5%) obtained from A. fruticosa leaves on seed germination and seedling growth of four important agricultural species (Trifolium pratense L. [cultivar “VIVA”], Medicago sativa L. [cultivar OS‐100], Helianthus annuus L. [hybrid “Matej”] and Triticum aestivum L. [cultivar OS‐Olimpija]). Five parameters were analyzed: germination percentage, mean germination time, germination index, fresh weight of seedling root and shoot. The phytotoxicity of A. fruticosa leaf extract was compared to that of juglone, a strong allelochemical that is known to inhibit growth of numerous plant species. The results demonstrate that A. fruticosa phytotoxicity is dependent on both the plant species tested and leaf extract concentration, with higher concentration extracts having stronger phytotoxicity. The highest concentration (5%) leaf extract caused similar inhibition of seed germination and seedling growth to that of juglone. The results of this study suggest that the rapid invasion of A. fruticosa in agricultural areas may have a negative impact on growth and yield of valuable forage and agricultural crops.