Forms Of Potassium Research Articles

Soil-ecological assessment of soils of abandoned lands of diggerent age in the southeast of West Siberia

The aim of the study. Assessment of the current state of agrophysical properties of soils, their soil-ecological status by calculating the soil-ecological index (SEI), as well as the study of vegetation cover of different-age abandoned lands in the forest-steppe zone of West Siberia within the Novosibirsk region. Location and time of the study. Novosibirsk Region, 2017–2022. Methods. Soils of the Predsalair drained plain (right-bank part of the Novosibirsk region) were studied. Twelve soil sections were studied on leached and podzolized chernozems, as well as on dark gray forest soils. Some of the studied soils had different degrees of washout prior to abandonment. The abandoned lands were young (2–4 years), middle (5–15 years) and old (more than 15 years). The age of these lands, i.e. the duration of their spontaneous self-revegetation, was determined based on satellite imagery data, information from local authorities and the methodology developed by the Institute of Soil Science and Agrochemistry of the Siberian Branch of the Russian Academy of Sciences. The study of vegetation cover was carried out according to standard methods. Soil samples were collected as a solid column; humus content, acidity, mobile forms of phosphorus and potassium, granulometric composition were determined. Samples were also taken to determine soil density (volumetric mass). For soil-ecological assessment the methodology of soil-ecological index (SEI) calculation was used. The methodology for SEI calculating combines soil fertility, climatic and geomorphologic soil factors. The SEI was calculated according to the methodology developed at the В.V. Dokuchaev Soil Institute by I.I. Karmanov. The following soil properties were also measured: granulometric composition by the sieve-pipette method, organic carbon (humus) by potassium dichromate digestion and pH by potentiometric method. Results. The article presents the agrophysical properties of soils, their soil-ecological assessment (SEI) and describes the vegetation cover of different-aged abandoned and revegetating lands in the forest-steppe zone of West Siberia within the Novosibirsk region. The vegetation revealed a smooth change in the species composition of plants, including a decrease in the proportion of annual and biennial species. The total aboveground production increased during the first 5–7 years of revegetation, afterwards reaching a plateau depending on the type of the formed community and conditions. Low values of SEI (38–41) were obtained for young and middle-aged abandoned lands in comparison with the virgin land (63), being caused by the lower content of nutrient elements and humus. In the long-term abandoned lands soils, that were not washed away, had an average SEI value of 55, while soils of old fallow lands previously washed away had an average 45. Conclusions. Based on the soil ecological condition in the studied abandoned lands, it can be concluded that the return of young and middle-aged lands to agricultural turnover makes sense as pastures and hayfields. Their use as arable land is inexpedient, mostly because of different degrees of washout due to their location on slopes of different length and steepness, as well as insufficient restoration of their properties. The old abandoned lands (in case of the absence of soil erosion) may well be returned to agricultural use, including as arable land.

FORMATION OF YIELD AND QUALITY OF SUGAR BEET SEEDS DEPENDING ON THE USE OF ABSORBENT

Implementation of intensive sugar beet cultivation technologies is impossible without high-quality seeds. The quality of sugar beet seeds is determined by a complex of genetic factors controlled by breeders, as well as by environmental and agronomic conditions of their cultivation and methods of post-harvest and pre-sowing seed preparation using modern technologies. That is why the study of the effect of the use of absorbent granules for growing sugar beet seeds on the formation of their yield is particularly relevant. The aim of the study was to find out the effect of the use of absorbent granules when applied to the soil before planting on the growth and development of seedlings, as well as the yield and quality of sugar beet seeds. It was found that the introduction of MaxiMarin absorbent granules into the soil before planting sugar beet uterine roots contributed to better moisture supply to the plants. In all phases of growth and development of seeds, the soil moisture content with the absorbent was significantly higher than in the control - without its application. Absolute soil moisture in the phase of rosette formation was 4.8%, in the phase of stemming and formation of ground vegetative mass - 9.9%, in the flowering phase - 4.5%, and in the phase of seed maturation - 5.4% higher compared to the control. Similar results were obtained over the years of research. Soil moisture in all phases of growth and development of seedlings was significantly higher when the absorbent was applied to the soil before planting root crops compared to the control. Optimal moisture supply contributed to better use of mineral nutrients. For example, when the absorbent was applied before planting the seeds, the content of mobile forms of phosphorus and potassium in the soil at the end of the growing season was lower, respectively, by 13 and 20 mg/1 kg of soil. The application of the absorbent influenced the biometric parameters of the seed heads. On average, over three years, the seedlings were 58.2 cm taller with the MaxiMarin absorbent, there were 1.2 times more first-order shoots on which seeds of sowing fractions were formed, and the density of fruit placement on the seedlings was higher - for every 10 cm of shoots, 9.0 more fruits were formed. The increase in biometric parameters after the introduction of absorbent granules into the soil and, especially, the number of first-order shoots on which seeds of sowing fractions are formed and the density of fruit placement on the shoots provided an increase in seed yield in combination with soil, climatic and agrotechnical conditions provided a significant increase in seed yield - by 0.15 t/ha compared to the control. Seed germination was 4% (NIR0.05 = 1.4%) higher compared to the control. The analysis of the seed fractional composition showed that when the absorbent was applied to the soil, fewer small seeds of the 2.5-3.5 mm diameter fraction were formed, which, according to the national standard for harvested seeds, do not belong to conditioned seeds and are wasted during post-harvest cleaning, and more - seeds with a diameter of more than 5.5 mm, which, as a rule, have higher germination and in the process of pre-sowing preparation at seed plants after grinding are converted into the sowing fraction of seeds with a diameter of 4.5-5.5 mm. Thus, according to preliminary data, it can be concluded that the introduction of an absorbent into the soil before planting seeds contributes to the creation of a better water regime - providing seeds with moisture throughout the entire period of their vegetation, more complete use of mineral nutrients, which ultimately leads to an increase in yield and seed quality.

Study and evaluation of the chemical composition of bottom sediments of the Volga-Akhtunisky flood

The chemical composition of the bottom sediments of the Volga-Akhtuba floodplain was assessed. Chlorides (36 mg/kg) were found to be one of the predominant anions, while calcium (27 mg/kg) and sodium (27 mg/kg) were the predominant cations. In terms of pH, the bottom sediments were weakly alkaline throughout the studies. The agrochemical composition of bottom sediments of the studied water body corresponded to lime sapropel due to the content of organic matter in them (4.21%), as well as common forms of nitrogen (0.58%), phosphorus (0.27%) and potassium (1.1%). To assess the chemical and toxicological parameters in samples of bottom sediments, the quantitative content of metals and pesticides was determined. It was found that their content does not exceed the maximum permissible concentrations. An analysis of the IR spectrum data made it possible to establish that the IR spectrum contains absorption bands characteristic of bentonite clays, which have good fertilizing and water-retaining properties.

The influence of agrotechnologies of organic farming on the content of humus, phosphorus and potassium in the soil.

Organic agriculture is becoming an increasingly popular direction in modern agriculture. At the same time, some researchers and practitioners still have doubts about the ability of this technology to maintain the balance of nutrients in the soil. The article is a contribution to the study of the influence of long-term organic farming on agrochemical soil parameters. The aim of the study was to study the influence of organic farming technology on the content of humus, mobile forms of potassium and mobile forms of phosphorus in the soil of the most important components for fertility - humus, mobile forms of potassium and mobile forms of phosphorus in the non-carbonate chernozems of Western Siberia. The chernozems of Western Siberia are characterized by a high content of humus and nutrients, have optimal properties for agricultural crops. A statistically processed comparison of the quantitative content of humus, mobile forms of potassium and mobile forms of phosphorus in fields with long-term use of organic farming technology, and in similar fields where this technology was not used, was carried out. The article includes a brief geographical, geological, climatic characteristics of the place of the experiment, a description of the applied agricultural technologies and fertilizers. As a result, it was found that the use of organic farming technology has a positive effect on the state of soils, which is confirmed by an increase in the content of humus, mobile forms of potassium and mobile forms of phosphorus.

Potassium Buffering Potential in Some Burne Soils of North Iraq

This research was conducted to study potassium buffering potential behavior in some burned soils of Baweza – Mosul and Zawita- Dohuk , in north of Iraq. Potassium forms and the buffering potential phenomenon were studied by using thermodynamic parameters according to quantity- intensity ratio (Q/I) at 298 oK) The main results could be summarized as follows A great affection for the firing processto cause a high potassium availability and lost by leaching. The ARKe value ranged widely from 0.02 to 0.08 (mol L-1)1/2, the potassium labile pool (LK) rangedfrom 7.951 to 27.919 cmolc kg-1, the potential buffering capacity (PBCK) ranged between 285.47 and 369.48 cmolc kg-1 (mol L-1)-1/2, the free energy of exchange (-G) were range between 3291.8 and 4819.8 kJ mole-1 and the Gapon selectivity coefficient (kG) values fluctuated within the range 8.44 to 12.88 (L mol-1) 1/2.PF values were 0.018 to 0.025 .

ВЛИЯНИЕ БИОСТИМУЛЯТОРА БИОДУКС И МИНЕРАЛЬНЫХ УДОБРЕНИЙ НА ПРОДУКТИВНОСТЬ ПРОСА

The aim of the study was to determine the optimal dose of the «Biodux» biostimulator, containing a complex of biologically active polyunsaturated fatty acids of the fungus Mortierellaalpina, for presowing treatment of millet (Panicum miliaceum) seeds. The study was conducted in 2019-2020. in the conditions of the Pre-Kama region of the Republic of Tatarstan. The experimental plot is located on light gray forest soil, which has a slightly acidic reaction (pHsalt. = 5.3), an increased content of mobile forms of phosphorus (142-148 mg/kg) and potassium (153-162 mg/kg), the average content of organic matter (3.6-3.8%). Agrochemical analyzes of the soil were performed by generally accepted methods: GOST 26213-91 (organic matter content); GOST 26207-91 (content of mobile compounds of phosphorus and potassium according to the Kirsanov method in the modification of TsINAO); GOST 26483-85 (pH value). The effect of the biostimulator on the yield of millet variety Varyag was studied against the background of a complete mineral fertilizer, calculated to obtain 3.0 t/ha of grain (N78-84P69-74K88-94). The doses of «Biodux» for seed treatment were 1, 3, 4 and 6 ml/t. The agrometeorological conditions of the vegetation periods during the years of the study were favorable for the growth and development of millet. The presence of a close curvilinear correlation between the increments of the millet yield and increasing doses of the biostimulant was established. For the description of this dependence for two years, a polynomial equation of the second degree was better suited: in both cases, the coefficient of determination (R2) of the increase in millet grain yield from the doses of the tested biostimulant «Biodux» was 0.97. The greatest increase in the yield of millet was provided by the average (3 ml/t) dose of «Biodux», which increased the yield of grain by 14-15% compared to the background level. Increases in grain yield from mineral fertilizers exceeded the maximum increase from the «Biodux» biostimulator by 3.1-3.6 times.

ANALISIS KADAR HARA PUPUK ORGANIK BERBASIS AMPAS SAGU LOKAL MERAUKE

Fertilization is one of the efforts made to add nutrients in the soil and can increase plant growth and yield. Currently, organic fertilizers based on local resources have been developed considering the negative impact of excessive inorganic use. The use of fertilizers made from local resources in Merauke Regency is important to develop and study its potential. The purpose of this study was to analyze the potential combination of organic fertilizer content based on sago dregs. The study lasted for 1 month with organic fertilizer fermentation carried out at the Agrotechnology Laboratory, Faculty of Agriculture, Musamus University and the nutrient levels of organic fertilizers in the form of nitrogen, phosphorus, potassium, iron, zinc, pH, and water content were analyzed at the Biotrope Laboratory. The treatment in this study consisted of various organic materials in Merauke Regency with the main ingredients of sago dregs, namely lamtoro leaves + pig manure (P1), sago dregs + pig manure (P2), sago dregs + lamtoro leaves (P3), sago dregs + lamtoro leaves. + pig dung (P4), sago dregs + chicken manure (P5) and sago dregs + cow dung (P6). The treatment used a ratio of 2:1 (v/v) on each composition of the treatment material. The results of the analysis show that the nutrient content of organic fertilizer based on sago dregs varies depending on the composition of the material and has the potential to be used to increase crop production. The highest nitrogen, C/N and C-Organic levels were obtained in the treatment of sago dregs + pig manure, the highest phosphorus content was obtained in the treatment of sago dregs + chicken and the highest potassium was found in the composition of lamtoro leaf compost + pig manure.

Post-pyrogenic transformation of biogeochemical properties of grey forest soils under technological load

Purpose. Detection of post-pyrogenic transformation of biogeochemical properties of soils in pine forests of the Kharkiv region under technogenic loading. Methods. Determination of the pH of the water extract by the potentiometric method, the content of humus and gross nitrogen according to the Tyurin method, the granulometric composition according to Kachynskyi, the mobile forms of phosphorus and potassium according to Machigin. The content of mobile forms of heavy metals was determined by the atomic absorption method. Results. There is a certain dependence of the post-pyrogenic transformation on the age of fire impact on the soil. Relatively recent consequences of a fire of medium intensity on the soil were marked by a clear reaction of the complex of their properties. Physical-chemical properties of soils in the post-fire period deteriorate due to a significant decrease in the amount of nutrients in the soil: humus burns, nitrate nitrogen content decreases. The acid-alkaline reaction according to the pH index in the soils affected by fires shifts to neutral, which should be explained by the saturation of the absorbing complex of soils with alkaline earth elements. Forest lowland fires significantly transform the morphological appearance of the upper part of the soil profile. Under the influence of fires, there are changes in pH, the content of exchangeable cations, gross and mobile forms of nitrogen, etc. The behavior and content of heavy metals in the forest floor is determined, in addition to the effect of fire and the geochemical state of the region, the speed of water migration and biological absorption, and the topography of the area. The concentration of heavy metals in the surface horizons of the soils of pine forests increases several times and exceeds the background concentrations as a result of the mineralization of the forest floor and grassy vegetation from combustion and subsequent migration of chemical elements. Conclusions. As a result, the surface horizons of soils change, in particular, a new pyrogenic horizon is formed, which differs in a certain way from natural analogues. Fires, on the one hand, improve the conditions for seed penetration into the soil, but worsen the conditions for the germination, growth and development of coniferous tree species. The concentration of heavy metals in the surface horizons of pine forest soils is an ecological hazard. Further research on the transformation of soil properties under the influence of pyrogenic factors is of significant theoretical and practical importance in the development of scientific approaches to the restoration of ecosystems in the post-fire stage of development.

КАЧЕСТВО ЗЕРНА СОРТОВ ЯРОВОЙ ПШЕНИЦЫ В СВЯЗИ С ПРИМЕНЕНИЕМ МИНЕРАЛЬНЫХ УДОБРЕНИЙ И ЗАЩИТЫ РАСТЕНИЙ В УСЛОВИЯХ ПРЕДВОЛЖЬЯ РЕСПУБЛИКИ ТАТАРСТАН

Studies to study the grain quality of the main varieties of spring wheat included in the state register in the 7th region were carried out in 2020-2021. under the conditions of Avangard LLC, Buinsky municipal district of the Republic of Tatarstan, on chernozem soils typical for this zone with agrochemical characteristics: humus content - 7.0-8.5%, mobile forms of phosphorus - 182-255 mg / kg, potassium - 159-193 mg / kg and pH salt – 5,5-5,8. Agrochemical analyzes of soils were carried out at the Federal State Budgetary Institution CAS "Tatarsky" by generally accepted methods: GOST 26213-91 (humus content), GOST 26484-85 (pHsal.), GOST 26207-91 (mobile forms of phosphorus and potassium). The meteorological conditions of 2020 were characterized by sufficient soil moisture and moderate temperature conditions during the growing season of spring wheat (STC-1.28) and had a positive impact on the future yield and grain quality. Meteorological indicators for the growing season of the research object in 2021 were extremely unfavorable for the formation of the crop. May and June were extremely dry, HTC-0,17-0,27. In the Pre-Volga zone of the Republic of Tatarstan, under conditions of unstable moisture, the effect of fertilizers on the yield is very variable. In a dry year, the effectiveness of mineral fertilizers is insignificant: only such varieties as Ekada 109, Yoldyz and Burlak gave a significant increase in yield by 10.6-11.9%. Conducted observations, records and analyzes in 2020 and 2021 showed that fertilizers in combination with a plant protection unit provided a sustainable increase in grain quality indicators. On average, over 2 years, in the Yoldyz variety, compared with the control and the standard variety Simbirtsit, the amount of mass fraction of gluten increased by 3.5%, and in the Ekada 109 and Burlak varieties by 4,1 and 4,3%.

Development of Bacteria biofertilizers using locally isolated rhizosphere populations and agricultural refuse and their impacts on growth of local test crops

Biofertilizers are the preparations of live microorganisms added to the root, seed or soil to promote plant growth. In this study, Plant Growth Promoting Bacteria able to solubilize insoluble phosphate (P) and potassium (K) forms were isolated, characterized and identified. Two isolates that demonstrated excellent solubilization of potassium or phosphate from abundant and bio-available waste biomass (rice husk and cattle bone) were used to produce biofertilizers by solid-state fermentation. The biofertilizers were applied to grow three food security crops, Zea mays, Solanum lycopersicum, and Arachis hypogea, in a screenhouse, and monitored for growth impacts. Treatments A, B, and A + B biofertilizers caused a significant (p < 0.05) increase in plant dry weights. The highest microbial colonization was obtained from treatment A + B (for S. lycopersicum) with a microbial count (log 2.89 (108) cfu/g), whereas treatment with B (for A. hypogea) had the least microbial count (log 2.73 (108) cfu/g). Maximum values of experimental parameters: shoot height, leaf number, plant dry weight and leaf width were obtained with the combined application of both biofertilizers. P and K solubilizing PGPB have shown potential for use as biofertilizers in growing these key crops under the soil conditions and in the environment studied.

ВЛИЯНИЕ ЭЛЕМЕНТОВ ТЕХНОЛОГИИ НА УРОЖАЙНОСТЬ И КАЧЕСТВО ЗЕРНА ЯРОВОЙ ПШЕНИЦЫ НА ЧЕРНОЗЕМНЫХ ПОЧВАХ ПРЕДВОЛЖЬЯ РЕСПУБЛИКИ ТАТАРСТАН

The article presents the results of two-year experiments (2020-2021) conducted in the conditions of Volga region of the Republic of Tatarstan. The effect of mineral fertilizers on the content of the mass fraction of gluten and protein in wheat grain was studied. The productivity and grain quality of several wheat varieties included in the State Register for the 7th region were compared when using fertilizers at a dose of N10-14P24-26K16-37 and chemical plant protection products. It was found that from the application of fertilizers and the use of the plant protection unit, an increase in grain yield for the studied varieties was obtained from 0.32-0.92 t/ha compared with the control. The field experiment was conducted in LLC Avangard of Buinsky district of the Republic of Tatarstan. The soil is leached chernozem and has the following agrochemical characteristics: humus content – 7.0-8.5%, mobile forms of phosphorus – 182-255 mg/kg, potassium – 159-193 mg/ kg and salt pH – 5.5-5.8.&#x0D; Agrochemical analyses of soils were performed in Federal State Budgetary Institution “Tatarskiy” by generally accepted methods: GOST 26213-91 (humus content), GOST 26484-85 (pHsol.), GOST 26207-91 (mobile forms of phosphorus and potassium).&#x0D; Meteorological conditions in 2020 were characterized by sufficient soil moisture and a moderate temperature regime during the growing season of spring wheat (GTK-1.28) and had a positive impact on the value of the future harvest.&#x0D; Meteorological indicators for the growing season of the research object in 2021 were extremely unfavorable for the formation of the crop. May and June were acutely arid, GTC-0.27. The precipitation in July (57% of the norm) did not have a significant impact on the formation of the spring wheat crop. From the application of fertilizers and the use of plant protection products, an increase in grain yield for the studied varieties from 0.32 to 0.92 t/ha was obtained compared to the variant without fertilizers and plant protection products. Improving the nutritional conditions of plants by applying mineral fertilizers led to an increase in the protein content of spring wheat grains and the protein content was 0.6 ... 0.8 higher, depending on the varietal characteristics of spring wheat, than on an unfertilized background. Under the conditions of chernozem soils of the Pre-Volga zone of the Republic of Tatarstan, the best results over the years of research were obtained in variants where the application of mineral fertilizers was combined with the use of plant protection products of such spring wheat varieties as Yoldyz, Burlak and Ekada 109. In the same variants, the highest protein content was noted in grain. The use of chemical protection against the background of mineral fertilizers in the varieties Yoldyz, Burlak, Ekada109 contributed to a significant increase in the gross collection of protein per unit area.

Arbuscular mycorrhizal fungi in cocoa plantation affected by different elevations and soil physical-chemical properties

Arbuscular mycorrhiza fungi (AMF) play an essential role in various agroecosystems since they build symbiosis mutualism with plants. Understanding the differences in the distribution and diversity of AMF in cocoa plants with different elevations is important to explore the bio-ecological aspects of AMF. This study examined the differences in the number and types of AMF spores in cocoa plantations at three different elevations: <500, >500-1000, and >1000 masl. Environmental factors such as the physical and chemical properties of the soil were also investigated. This study found that the number of AMF spores was higher in the lowlands (<500 masl) than in the highlands. Rarefaction curves show that all soil samples taken are adequate for diversity analysis. Multivariate analysis with NMDS followed by the goodness of fit statistical test using the Bray Curtis method showed that a clear distribution pattern in the AMF community structure was significantly influenced by chemical and physical factors of the soil in the form of phosphorus, potassium, sodium, magnesium, total nitrogen, clay, and soil texture.

Do the Soil's Physiochemical Properties Fluctuate with Season and Soil Depth in the Ecological Critical Areas (ECA) of Sundarbans, Bangladesh?

The Ecological Critical Areas (ECA) of Sundarbans is located outside of Sundarbans Reserved Forest at 10 km extended landward, which is threatened to reach a critical state due to human activities. Aquaculture is the dominant land use in the ECA and the tree coverage is going to deplete at an alarming rate due to the deterioration of site conditions, which significantly influence the productivity of aquaculture and the establishment of the plantations on the dikes of the fishpond. The present study aimed to assess some static and dynamic soil physiochemical properties of the fishpond dikes located in the ECA of Sundarbans. Soil samples were collected from the western part (Satkhira district) of ECA of Sundarbans during the pre-monsoon and post-monsoon seasons. The bulk density, pH, and electrical conductivity of the studied areas varied from 1.05-1.18 g/cm3, 7.30-8.54, and 1.05-2.13 ms/cm respectively. However, the concentration of available form of Nitrogen, Phosphorus, Potassium and Sodium were 0.5-0.72 mg/g, 0.03-0.06 mg/g, 10.5-12.88 mg/g and 16.89-20.53 mg/g respectively. Some of these parameters showed significant variation among the zones, seasons, and soil layers. However, the stock of available nitrogen, phosphorus, potassium, sodium and organic carbon varied from 52.5- 84.96 kg/ha, 3.15-7.08 kg/ha, 1.10-1.52 t/ha, 1.77-2.42 t/ha and 173.47-199.43 t/ha respectively. As pond soil provides all the important nutrients with water, the findings of this study will help to take proper management interventions for the dike greening initiatives and productivity of fishponds in the ECA of Sundarbans.

Loss of Nutrients Through Soil Water Erosion in Calcic Chernozem

Abstract The application of technology for water erosion control plays an essential role in development of sustainable agricultural systems. The paper presented observes the study results from a period of six years in terms of losses of mineral nitrogen and available forms of phosphorus and potassium in the cultivation of wheat and maize on sloping terrains (on calcic chernozem soil type) under the influence of water erosion processes. The impacts of four different types of technology (conventional technology performed along the slope; conventional technology applied across the slope; surface mulching; and minimum tillage with vertical mulching) on nutrient losses were tested. On average, the annual losses of mineral nitrogen, available forms of phosphorus and potassium in wheat production along the slope utilizing conventional technology were 6.0 kg·ha−1y−1, 1.6 kg·ha−1y−1, 5.9 kg·ha−1y−1, and 11.3 kg·ha−1y−1, 2.1 kg kg·ha−1y−1, 10.8 kg kg·ha−1y−1 in maize production. The lowest losses in these elements occurred with minimal employment of tillage system, as they reached values of 2.3 kg·ha−1y−1; 0.6 kg·ha−1y−1, 2.0 kg·ha−1y−1, respectively, in wheat production, and 1.7 kg·ha−1y−1, 0.3 kg·ha−1y−1, 1. kg·ha−1y−1, respectively, in maize production.

Leaf-litter decomposition and nutrient release dynamics of some savanna agroforestry tree species: A model for soil improvement strategies

The application of leguminous agroforestry tree species using leafy biomass to improve soil fertility in the savanna alfisols is observed to be uncommon. Although, if applied, leguminous leafy biomass increases soil organic matter and improves its fertility potentials for crop productivity. This research investigated leaf-litter decomposition and nutrient release of some selected agroforestry tree species. Five species of agroforestry tree leafy biomass were selected (Faidherbia albida, Leucaena leucocephala, Gliricidia sepium, Senna siamea, Albizia lebbeck) and the effect of the biomass placement patterns of the litter bags in the soil was investigated; viz-a-viz surface placement (above-ground level) and embedded placement at 15cm depth (below-ground level) arranged as 5×2 factorial in Randomized Complete Block Design with four replicates. The data were analyzed using Analysis of Variance, while the means were separated using Duncan Multiple Range Test (p≤0.05). The soil results showed that the pH of the study area was near neutral (6.20) and loamy sand in nature. The leafy biomass of all the agroforestry tree species tested were noted to release nutrients two weeks after decomposition. However, it was observed that the species of leafy biomass and placement patterns had significant influence on both weight loss and nutrient release. The rate of leaf-litter decomposition and nutrient release (mineralization) were significantly higher in biomass embedded in soil at 15cm depth (below-ground level) than the surface placement (above-ground level). The nutrients released in the form of nitrogen, phosphorus, potassium, calcium, magnesium, sodium and organic carbon from leafy biomass embedded in the soil reached more than 50% in the 14 days of biomass decomposition. G. sepium leafy biomass among other species decomposed and released nutrients more rapidly, both at embedded and surface placements. It is therefore recommended that G. sepium leafy biomass be used as an alternative organic based fertilizer to improve soil fertility for increased crop production in savanna alfisols.

Effects of Potassium Deficiency on the Growth of Tea (Camelia sinensis) and Strategies for Optimizing Potassium Levels in Soil: A Critical Review

Potassium is among the three essential macronutrients for tea plants, along with nitrogen and phosphorous, and plays important roles in growth and stress response. Potassium is absorbed by plants in larger amounts than any other mineral element except nitrogen and, in some cases, calcium. At present, more than 59% of China’s tea gardens are in a state of potassium deficiency, which negatively affects tea quality and yield. This paper reviews the effects of potassium deficiency on tea plant growth and stress response, details factors affecting potassium supply and demand in tea gardens, examines the interactions between potassium and other elements in soils, and provides strategies for optimizing potassium levels in soils. Potassium is positively correlated with the elements nitrogen, copper, and zinc. Sufficient potassium dramatically improves the yield and quality of tea: it accelerates metabolism, promotes synthesis of catechins, and strengthens biotic and abiotic resistance by activating and regulating different enzymes. Moderate application of potassium fertilizers, along with potassium-solubilizing bacteria, can regulate the ratio of different forms of potassium and increase available potassium in soils of tea gardens. We suggest that research on potassium occurring in soils and its interaction with other elements be strengthened, so as to improve the efficient use of potassium fertilizers in tea gardens and maintain the balance of elements in soils.

Вплив удобрення та вапнування на баланс і вміст форм калію в дерново-підзолистому ґрунті

Goal. To determine the effect of plant by-products and mineral fertilizers in combination with different doses of dolomite flour on the balance and content of different forms of potassium in soddy podzolic cohesive-sandy soil. Methods. Field (the study of the effect of fertilization and liming on the change in potassium content in the soil), laboratory (the determination of the content of potassium forms in the soil), calculation (the assessment of potassium balance), statistical (the variance analysis of the reliability of research results). Results. The research during 2 rotations of a 4-field crop rotation established that liming 1.9–5.6 tons of dolomite flour with the subsequent annual entering into the soil of an average of 5 tons of by-products of crops in combination with the application of mineral fertilizers at a dose of N112P87K105 per 1 ha of the crop rotation area created the positive balance of potassium in the soil at its intensity of 167–206%. A rapid increase in the content of mobile potassium in the soil in these variants was observed only during the first 4 years of research, in subsequent years it varied within the reached level. Fertilization and liming had a positive effect on the content of all forms of potassium available to plants: water-soluble, exchangeable, and non-exchangeable. During 8 years of research, their content increased by 57.1–121, 40.5–59.5, and 7.8–12.3%, respectively. Conclusions. The use against the background of liming and fertilization of by-products of crop rotation makes it possible to return to the soil 74.0–76.3% of the economic removal of potassium and, in combination with the application of 105 kg/ha of potassium with mineral fertilizers for 1 ha of crop rotation, to create a positive balance of the element at the level of 82.8–88.1 kg/ha. The content of mobile forms of potassium in the soil layer of 0–20 cm in the first 4 years of research in the variants with fertilizer increased from 53–57 to 89–102 mg/kg of soil, in the following 4 years it almost did not increase with certain variations over the years. Under the influence of the studied components of the fertilizer system in crop rotation, the content of all forms of potassium in the soil — water-soluble, exchangeable, and non-exchangeable — increased. Compared to the control, application of N112P87K105 per 1 ha of crop rotation area contributed to an increase in their content by 21.4 and 16.2%, respectively, for a combination of 3.8 t of CaMg(CO3)2 and N112P87K105 — by 57.1–121, 40.5–59.5, and 7.8–12.3%, respectively. However, increasing the dose of dolomite flour from 3.6 to 5.8 t/ha in the crop rotation fertilizer system did not significantly increase the content of non-exchangeable potassium in the 0–20 cm layer of soddy podzolic soil.

Cracks as Efficient Tools to Mitigate Flooding in Gas Diffusion Electrodes Used for the Electrochemical Reduction of Carbon Dioxide.

The advantage of employing gas diffusion electrodes (GDEs) in carbon dioxide reduction electrolyzers is that they allow CO2 to reach the catalyst in gaseous state, enabling current densities that are orders of magnitude larger than what is achievable in standard H-type cells. The gain in the reaction rate comes, however, at the cost of stability issues related to flooding that occurs when excess electrolyte permeates the micropores of the GDE, effectively blocking the access of CO2 to the catalyst. For electrolyzers operated with alkaline electrolytes, flooding leaves clear traces within the GDE in the form of precipitated potassium (hydrogen)carbonates. By analyzing the amount and distribution of precipitates, and by quantifying potassium salts transported through the GDE during operation (electrolyte perspiration), important information can be gained with regard to the extent and means of flooding. In this work, a novel combination of energy dispersive X-ray and inductively coupled plasma mass spectrometry based methods is employed to study flooding-related phenomena in GDEs differing in the abundance of cracks in the microporous layer. It is concluded that cracks play an important role in the electrolyte management of CO2 electrolyzers, and that electrolyte perspiration through cracks is paramount in avoiding flooding-related performance drops.

Changes in agrochemical indicators of light gray forest soil and productivity of meadow clover depending on the level of mineral nutrition against the background of the aftereffect of liming in the conditions of the South-East of the Volga-Vyatka region

The research was carried out in a long-term stationary experiment, launched in 1978 on light gray forest soil in the conditions of the Nizhny Novgorod region. In 2020-2021, the effectiveness of various doses of mineral fertilizers (N0P0K0, N15P40K60, N30P80K120, N45P120K180) was studied against the background of liming when laying the experiment (in doses 0; 0.5;1.0;1.5; 2.0; 2.5 of hydrolytic acidity) on the yield of meadow clover Martum of the 1st and 2nd years of use. It has been established that the studied lime doses introduced in 1978, by August 2021 had not affected the change in agrochemical parameters of light gray forest soil (acidity, content of mobile forms of phosphorus and potassium, humus) and the yield of meadow clover of the 1st and 2nd year of use. A long-term use (1978-2021) of single and double doses of mineral fertilizers did not provide the accumulation of humus, mobile forms of phosphorus and potassium as compared to their initial content in arable layer of light gray forest soil. Increased content of mobile forms of phosphorus and potassium (Р2О5 per 34.1 mg/kg, К2О per 22.3 mg/kg) was observed by long-term application of three-fold doses of mineral fertilizers. Application of mineral fertilizers in a dose of N45P120K180 enabled to obtain 36.5 and 37.9 t/ha of green mass during the 1st and the 2nd year of use and the highest total yield of 74.4 t/ha that is 12.0-22.2 t/ha higher than the control and all the rest variants of mineral fertilizers application.

INFLUENCE OF DEFICIT FERTILIZER SYSTEMS ON THE DYNAMICS&#x0D; OF PHOSPHATE AND POTASSIUM CONTENT AND THEIR&#x0D; BALANCE IN LONG-TERM EXPERIMENTS ON SOD-PODSOLIC&#x0D; LOAMY SAND SOIL

The results of multi-year research to assess the impact of fertilizer systems and the effect of residual amounts of phosphorus and potassium introduced with mineral and organic fertilizers in the preceding period on the balance of nutrients and fertility of&#x0D; medium-cultivated sod-podzolic loamy sand soil in article are presents. It was established that application of N80P37K95 at high productivity of cultivated crops (59,6 cfu/ha) was insufficient for maintaining the achieved level of soil fertility with negative&#x0D; balances of mobile forms of phosphorus (–14 kg/ha) and potassium (–50 kg/ha). The exclusion of a particular nutrient element from the fertilization system for a long period contributes to the intensification of degradation processes in the soil, causing the loss of humus by 0,19–0,53 % for the 20-year period of the study, with annual losses of mobile phosphorus and potassium of 1,0–3,6 and 2,6–8,3 mg/kg of soil.