Rates Of Mineral Fertilizers Research Articles

COMPARATIVE EFFECTS OF MINERAL FERTILIZER, COMPOST AND COMPOST – MINERAL FERTILIZER ON BIOLOGICAL, CHEMICAL AND PHYSICAL PROPERTIES OF SOIL

The rapid decline of organic matter in the tropics makes it necessary to incorporate compost or compost – mineral fertilizer into the soil to improve the soil organic matter content and fertility. The experiment to investigate the effects of mineral and organic base fertilizer on soil organic matter, nutrient content, aggregate stability and the fungi isolates was conducted in Ambrose Alli University, Ekpoma, Nigeria. Experimental design was a Randomized Complete Block Design with five treatments replicated thrice. The treatments were; control, Urea, NPK 15 15 15, Compost and Compost – mineral fertilizer. Compost and compost – mineral fertilizer rates was 10 and 4 tonnes / hectares (t ha-1) respectively. Maize was used as test crop. The soil at the experimental site was low in nutrients however, the application of compost and compost – mineral fertilizer significantly (p < 0.05) improved the organic matter content, soil nutrient status and aggregate stability compared to mineral fertilizer. The fungi isolates was higher in compost and compost – mineral fertilizer. The application of compost and compost – mineral fertilizer increased the soil pH to near neutral and reduces acidity. The application of compost – mineral fertilizer had multiple benefits in improving organic matter content, the chemical and physical and biological properties of the soil. In conclusion, compost – mineral fertilizer had significant improvement on the soil nutrients and aggregate stability compared to other treatments, therefore compost – mineral fertilizer can be effective in the sustainability of the soil fertility.

Influence of sowing rates of seeds and mineral fertilizers on yield of durum wheat varieties under light gray soils

The article shows the sowing rates of seeds and mineral fertilizers on the yield of durum wheat varieties Krupinka, Zilol and Nasaf. The highest grain yield of durum wheat was observed in varieties Zilol (59.6 c/ha) and Nasaf (60.7 c/ha) when nitrogen fertilizers N180P90K60 kg/ha were applied with a seeding rate of 4 million seeds, in the variety Krupinka (56.9 c/ha) with a seeding rate of 5 million seeds, and when applying nitrogen fertilizers N210P90K60 kg/ha.

Yielding capacity of amaranth grain (Amaranthus hypochondriacus) depending on fertilizers

The research was conducted on the research field of Lviv National Agrarian University on dark gray podzolic light loamy soil. Hydrothermal conditions differed from the average of many years data by more precipitation. In 2019, during the growing season it fell by 53 mm above the rate, in 2020 - by 129 mm, in 2021 - by 73 mm. The aim of the research to define the amaranth nutrition system in conditions of sufficient and excessive moisture, seven rates of mineral fertilizer application were studied: N0P0K0, N40P20K40, N80P40K80, N120P40K80, N160P80K120, N200P80K120, N200P80K160. Under the influence of fertilizers, plant height increased from 147.1 cm to 208.2 cm, panicle length - from 32.2 cm to 71.7 cm, seed weight from one plant - from 12.9 g to 27.8 g, weight of 1000 grains - 0.86 g to 0.91 g. The number of plants before harvest was in the range of 18-20 plants/m2. Increasing of the application rate of mineral fertilizers from N0P0K0 to N200P80K160 provides the increase of the yielding capacity of amaranth grain of the variety Kharkiv 1 from 2.31 t/ha to 4.88 t/ha, or by 2.57 t/ha. Yield depended mostly on nitrogen fertilizers, application of N40 on variants with the rate of N120P40K80 and N200P80K120 fertilizers resulted in a further increase of the yield by 0.41 t/ha and 0.34 t/ha. Increasing the potassium rate by K40 on variant N200P80K160 did not provide a significant (0.04 t/ha) increase of the yield. The highest level of yielding capacity is formed by the following structural elements: grain weight from one plant - 27.8 g and number of plants - 18 p/m2.

The Analysis of Wheat Yield Variability Based on Experimental Data from 2008–2018 to Understand the Yield Gap

Among European countries, Poland has the largest gap in the grain yield of winter wheat, and thus the greatest potential to reduce this yield gap. This paper aims to recognize the main reasons for winter wheat yield variability and shed the light on possible reasons for this gap. We used long-term datasets (2008–2018) from individual commercial farms obtained by the Laboratory of Economics of Seed and Plant Breeding of Plant Breeding and Acclimatization Institute (IHAR)-National Research Institute (Poland) and the experimental fields with high, close to potential yield, in the Polish Post-Registration Variety Testing System in multi-environmental trials. We took into account environment, management and genetic variables. Environment was considered through soil class representing soil fertility. For the crop management, the rates of mineral fertilization, the use of pesticides and the type of pre-crop were considered. Genotype was represented by the independent variable year of cultivar registration or year of starting its cultivation in Poland. The analysis was performed using the CART (Classification and Regression Trees). The winter wheat yield variability was mostly dependent on the amount of nitrogen fertilization applied, soil quality, and type of pre-crop. Genetic variable was also important, which means that plant breeding has successfully increased genetic yield potential especially during the last several years. In general, changes to management practices are needed to lower the variability of winter wheat yield and possibly to close the yield gap in Poland.

To the development of optimal methods for licorice seeds growing (Glycyrrhiza glabra L.) in irrigated lands of the Republic of Karakalpakstan

The research was carried out at the Nukus branch of the Tashkent State Agrarian University.The article presents the results of research on the development of optimal methods for growing licorice (Glycyrrhiza glabra L.) from seeds on salinity lands of the Republic of Karakalpakstan. In particular, the optimal rates of application of potassium geohumate for soaking licorice seeds, the rate of washing during soil desalination, the rates of mineral fertilizers and irrigation have been determined. The study of the effect of potassium geohumate on seed germination showed that soaking licorice seeds in a 0.05% solution of potassium geohumate for 3 days followed by drying the seeds in the open air provided the best germination on the 30th day after sowing and amounted to 72.6%, while the germination of licorice in the variant with the use of 0.03% potassium geohumate solution was 38.6%. The germination of the control variant was only 22.3%. It has also been established that the optimal rate of mineral fertilization for licorice is the application of 300 kg/ha of superphosphate, 150 kg/ha of potassium and 100 kg/ha of ammonium nitrate for 8 irrigations with a rate of 600 m3/ha.

Біологічні чинники оптимізації систем удобрення сільськогосподарських культур у сівозміні

Goal. With the use of biological testing to substantiate ecologically feasible fertilizer systems of crops for their cultivation in crop rotation on sod-podzolic soil; to investigate the possibility of reducing the rates of mineral fertilizers with the use of microbial preparations. Methods. Field stationary experiment, gas chromatographic (determination of nitrogen fixation activity in the root zone of plants), statistical (substantiation of the reliability of the obtained results), economic calculations (determination of the cost, profit, profitability, and payback of additional costs). Results. In the short crop rotation “potatoes — oats — lupine — winter rye” on the indicators of nitrogenase activity in the root zone of plants they determined the feasibility of action and after-effect of 40 t/ha of manure litter of cattle, organo-mineral fertilization, intermediate green manure (oil radish) and mineral fertilizers in low and medium rates. High doses of fats lead to a significant decrease in the activity of the nitrogen fixation process in the rhizosphere of plants and are excessive. The possibility of reducing the rate of technical nitrogen through the use of biological products without reducing crop yields is real for low and medium in the experiment of mineral agricultural backgrounds. The direct action and after-effect of the intermediate green manure promote the effectiveness of inoculation. Mineral intensive fertilizer system does not provide high efficiency of biofertilizers. A slight increase in crop yields from inoculation was detected with organic and organo-mineral fertilizers. Conclusions. Ecologically acceptable systems of crop fertilization in crop rotation can be realistically determined using biological testing. Mineral fertilizer rates for crops can be significantly reduced without reducing crop yields through the use of microbial preparations. It is recommended to use pre-sowing inoculation of seeds for growing crops on low and medium mineral agricultural backgrounds, as well as for the use of intermediate green manure.

PHOSPHORUS BIOTRANSFORMATION IN ROOT ZONE OF CORN PLANTS UNDER ACTION OF AHROBACTERYN AND MINERAL FERTILIZERS

Objective. To determine the intensity of phosphorus biotransformation in the root zone of corn plants under the action of the microbial preparation Ahrobacteryn and various rates of mineral fertilizers. Methods. Field experiment (on leached chernozem), microbiological (accounting for the number of phosphate-mobilizing bacteria in the rhizosphere of corn plants, biochemical (determination of phosphatase activity, the degree of mobility of phosphates in the rhizosphere soil of plants), statistical. Results. It was found that during the growing season, the number of bacteria that hydrolyze mineral phosphorus compounds and organic soil phosphates increases in the rhizosphere soil of corn plants under the influence of the microbial preparation Ahrobacteryn. Given the features of the influence of mineral fertilizers on the development of phosphate-mobilizing bacteria in the rhizosphere soil of corn plants, it is optimal to use fertilizers in doses not exceeding N90P90K90. At the same time, phosphatase activity of the rhizosphere soil reaches the highest values in the flowering phase; in the phase of milk-wax ripeness of corn grain, the parameters are significantly reduced due to the slowdown in the absorption of phosphorus by plants. The effect of inoculation increases the degree of phosphate mobility in the rhizosphere soil of plants, which is expressed in a decrease in their content due to increased uptake by plants. In the phase of milk-wax ripeness, the mobility of phosphates decreases from 0.42 (in the control without fertilizers) to 0.23 mg P2O5/dm3 of soil solution, which indicates increased absorption of phosphorus by plants. Conclusion. Under the influence of Ahrobacteryn, the processes of phosphorus transformation in the root zone of corn plants are activated, the number of phosphate-mobilizing bacteria increases, phosphatase activity improves and the degree of phosphate mobility, which has an effect on the absorption of phosphorus by plants. As a result, phosphorus removal increases with a crop yield from 51.2 (in the control without fertilizers) to 83.4 kg/ha (with Ahrobacteryn), the efficiency of phosphorus plant nutrition after introduction of N90P90K90 is 62.9 %.

The role of biochar in improving soil properties, water retention and potato yield in a Fluvisol under temperate monsoon climate

AbstractSoil amendment with biochar provides great potential for improving soil fertility. This study, conducted in Kanazawa, Japan, in 2018, evaluated the effects of soil amendment with biochar, carbonized from animal manure and slaughterhouse wastes, on some properties of a loamy sand‐textured Fluvisol and yield performance of potatoes. The laboratory experiment investigated the effects of biochar (0%, 1%, 2%, 4% and 8% (w/w)) on soil properties and water retention. The field experiment combined three biochar application rates (0, 2 and 4 t ha−1) with three mineral fertilizer rates (0%, 50% and 100% recommended nutrients from mineral fertilizers, (RNPK)). The treatments were applied in randomized complete blocks with three replicates. Soil amendment at the rates of 1%, 2%, 4% and 8% biochar (w/w) (i) reduced bulk densities by 1%–22%; (ii) increased soil porosity by 1%–16%; (iii) increased readily available soil water (RAW) by 10%–40%; and (iv) enabled 1–5 days more retention of the soil water content within the range of RAW. The combined application of 2 or 4 t ha−1 biochar with 100% RNPK increased yield by 219%–313% and 295%–340%, and increased water use efficiency (WUE) of potato by 59%–98% and 129%–163% under optimal irrigation conditions relative to the sole application of biochar and the control treatments, respectively. Considering agricultural and environmental sustainability, the integrated application of 2–4 t ha−1 biochar with a full dose of nutrients from mineral fertilizers is recommended for the loamy sand‐textured Fluvisol of the North‐central coast of Japan and other similar agroecologies.

Impact of Subsurface Application of Compound Mineral Fertilizer on Soil Enzymatic Activity under Reduced Tillage

Soil biochemical properties shaping soil fertility and agro-ecosystem productivity depend on the reduced tillage system and the dose and method of application of fertilizer; therefore, the research hypothesis put forward proposes that under reduced tillage system conditions, the subsurface application of a multi-component mineral fertilizer would increase soil enzymatic activity, thus favourably influencing the biodiversity of the soil environment. The objective of the three-year study was to evaluate the impact of subsurface application of varying mineral fertilizer rates on soil enzymatic activity under reduced tillage system conditions in soybean, winter wheat and maize rotations. The field experiment was set up as a split-plot design in four replicates. The first experimental factor included two methods of mineral fertilization application: fertilizer broadcast over the soil surface (S); fertilizer applied deep (subsurface placed) using a specially designed cultivator (Sub-S). The other factor was the rates of the mineral fertilizer (NPKS): 85 kg∙ha−1 (F85) and 170 kg∙ha−1 (F170). The method of application and rate of mineral fertilizer did not have a significant effect on the organic carbon and total nitrogen content in the soil of the plots with all rotational crops. Subsurface application of fertilizer significantly increased available phosphorus content in soil under soybean and winter wheat crops; however, it significantly decreased soil pHKCl values within sites with all crops in the rotation compared to surface application. At the same time, deep application of mineral fertilizer significantly stimulated dehydrogenase activity in the soil under the winter wheat crops and acid phosphatase activity in the soil under all rotation crops. The higher level of mineral fertilization contributed to reduction of soil pHKCl under winter wheat and maize, and promoted an increase in the soil P content. Additionally, significant increases of dehydrogenases and urease activity in the soil under winter wheat and maize crops, alkaline phosphatase activity in the soil under all the studied crops, and acid phosphatase activity in the soil under the soybean crops were found, compared to mineral fertilizer in the amount of 85 kg NPKS∙ha−1. The results of the present study have demonstrated a positive effect of subsurface application of compound mineral fertilizer on the soil biochemical parameters in reduced tillage. This may be a recommendation for the subsurface use of multicomponent mineral fertilizers in sustainable agriculture. However, a full objective characterization of the soil environment processes induced by in-depth application of mineral fertilizer in reduced tillage requires long-term monitoring.

Effect of integrated fertilizer application on soil properties and tef (Eragrostis tef [Zucc] Trotter) yield on Vertisols of Northwestern Ethiopia

Low soil fertility has become a serious constraint affecting agricultural productivity and food security in North-western Ethiopia. A field experiment was conducted to examine the effects of integrated use of compost and mineral fertilizer on soil properties and tef (Eragrostis tef [Zucc.] Trotter) yields for two years during 2018 and 2019 cropping seasons. The field experiment was arranged in a factorial combination of three rates of Urea/NPSB (0/0, 62.5/75 and 125/150 kg ha−1) and three rates of compost (0, 5 and 10 t ha−1) laid out in randomized complete block design (RCBD) with three replications. Results showed that combined use of compost and mineral fertilizer significantly (p < 0.05) increased soil pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), available sulfur (AS) and exchangeable bases but significantly (p < 0.05) decreased soil bulk density (SBD) compared to sole mineral fertilizer application and the control. Furthermore, application of 10 t ha−1 compost combined with 125/150 kg ha−1 Urea/NPSB gave the highest tef dry biomass (8.81 t ha−1) and grain yield (2.40 t ha−1). The economic analysis results also revealed that the highest net benefit (45,761 Birr ha−1) was achieved from the same treatment which was considerably greater than the highest rate of sole mineral fertilizer (37,228.5 Birr ha−1), the highest rate of sole compost (6656 Birr ha−1) and the control (5391 Birr ha−1). We concluded that integrated fertilizer application enhances soil fertility, crop yields and generates better income over individual addition of fertilizers.

Growth and Yield of Sugarcane Seed Crop as Influenced by Fertilizer Rates and Timing in Anakapalle, Andhra Pradesh, India

A field experiment was conducted in sugarcane over 2019-20 and 2020-21 cropping seasons at the Regional Agricultural Research Station of Anakapalle (Andhra Pradesh) on sandy clay soils. The objective was to determine the effect of organic and mineral fertilizer rates and timing on growth and yield of a sugarcane seed crop. The experiment was laid out following split plot design with three main organic fertilizer treatments and six N-K fertilizer sub treatments, in three replications. Results showed a significant increase in stalk height, numbers of tillers ha-1 and cane yield due to organic fertilizer, namely biofertilizer and trash mulching, in combination with 125% STBNK applied at 30 days interval + additional dose of 25% recommended K fertilizer applied one month prior to harvest.

Effect of Organic and Nitrogen Fertilizers on Soil Fertility and Wheat Productivity in a Newly Reclaimed Sandy Soil

Two field experiments were carried out in a newly reclaimed sandy soil under sprinkler irrigation system at El Ismailia Agricultural Research Station, El Ismailia Governorate, Egypt during the winter seasons of 2017/2018 and 2018/2019, to study the effect of organic amendment (compost and FYM) under different rates of nitrogen fertilizer (control, 75 and 100 % of recommended dose) on the fertility of study soil and wheat productivity. The treatments were arranged in a split-plot design with three replicates. Results indicated that 100% of recommended dose followed by 75% significantly increased all determined traits relative to control under the study conditions. Soil application of compost and FYM was superior for all growth characteristics, grain quality, and yield of wheat plants compared to control (without applications). The effect of compost or FYM combined with different rates of nitrogen mineral fertilizer increased plant height (cm), weight of 1000 grains (g), Straw yield (Mg acre -1), and weight of grains yield (Mg acre-1). The application of soil amendments increased N, P, and K concentrations in straw and grains. Application of organic amendments had a positive significant effect on available N, P, and K in soil. The interaction between soil amendments and different rates of nitrogen mineral fertilizer showed a significant effect on yield and its attributes, grain protein content, and total carbohydrate. Finally, it could be concluded that the application of farmyard manure with 75 % nitrogen of recommended dose improved the soil properties of sandy soil and increased the productivity of wheat plants.

Bio-Fertilizers Based on Digestate and Biomass Ash as an Alternative to Commercial Fertilizers—The Case of Tomato

The reutilization of agricultural wastes, as bio-fertilizers, is the key way to close the nutrient cycle and save mineral fertilizers. This hypothesis was verified in three consecutive seasons, treating tomato with three bio-fertilizers on the background of a standard rate of mineral fertilizer. The bio-fertilizers differed in their C:N ratio, which was 13:1, 21:1, and 6:1 for the A, B, and C fertilizers, respectively. They were applied at the rate of 200, 400, 800, and 1600 kg ha−1. The average fruit yield increased in the order: B &lt; C &lt; A. For the relevant fertilizer, the maximum commercial yield was 91, 87, and 101 t ha−1, for a respective rate of 1600, 200, and 400 kg ha−1. The number of fruits (CFN), as the dominant yield component, indirectly reflected the nitrogen (N) supply to plants. A shortage or excess of N on plots treated with the B or C fertilizers, resulted in a decreased CFN, leading to a yield decline. The year-to-year variability in the potassium (K) content reflected fairly well the variable weather conditions, responsible for water management by tomato. The conducted study showed that the tested bio-fertilizers can replace mineral fertilizer, as long as they are applied at well-defined rates.

Yield, biochemical properties and cooking quality traits of sweet potatoes (Ipomoea batatas) as affected by Nitrogen and Potassium Fertilizer rates

This study evaluated the effects of mineral fertilizer rates on biochemical properties, cooking quality traits and root yield of sweetpotatoes. The experimental design was 4 x 4 factorial in randomized complete block with three replications. The treatment factors were four varieties of sweetpotato (Ligri, Bohye, Dadanyuie and Apomuden) and four fertilizer amendments (T1: 30-30-30 kg /ha NPK, T2: 30-30-60 kg NPK+50 kg Muriate of Potash, T3: 30-30-90 kg/ha NPK+ 100 kg Muriate of Potash and T4: Control (No fertilizer). Results showed that the fertilizer rates did not influence root yield but variety had significant difference (P&lt;0.05). Apomuden recorded the highest average root yield of 14.5 t/ha which was significantly higher than Ligri 5.1 t/ha. Ligri recorded the highest dry matter and sugar contents of 34.63% and 67.98% respectively while Apomuden recorded the lowest dry matter content and starch content of 23.75% and 50.00% respectively. However, it recorded appreciable amount of beta-carotene and sugar contents of 32.38 mg/100g and 28.04% respectively. There were significant variety × location interactions effect (P &lt; 0.05) on average root yield and biomass yield. The significant varietal response observed in this study implies that choice of variety is an important factor to consider in sweetpotato production.

Рeculiarities of sunflower (Helianthus L.) growing on dried tury-podzolistic soil in the conditions of climate change

In the conditions of global warming, the area of cultivation of thermophilic crops, in particular sunflower, is shifted from the southern regions of cultivation to the Polissya zone. Therefore, it is necessary to investigate the efficiency of growing sunflower on drained soils without regulating the water regime with different fertilizer systems. The study analyzes the state of moisture supply of drained sod-podzolic soil during the growing season 2018–2019. It is established that in the summer total reserves of productive moisture in the 0–100 cm soil layer decreased to critical parameters (60 mm), and the groundwater level dropped to 2.5–3.0 m (depth bookmarks drains — 1.1 m). The results of the influence of different levels of fertilizer on the yield and quality of sunflower seeds (Jason hybrid), which was placed in the crop rotation after winter wheat, are presented. It is established that in the conditions of deficit of moisture in the soil, use of the norm of mineral fertilizers recommended for the Polissya zone (N60P60K90) with 40 t/ha of manure, increased 1.5 times more than norm (N90P90K135) against 4,0 t/ha of straw and the recommended one — against the background of straw and foliar fertilization with microfertilizer Yarilo were equivalent. When using them, the same seed yield was obtained — at the level of 2.30–2.33 t/ha. When applying the recommended rate of mineral fertilizers in conjunction with the straw of the predecessor, there was a decrease in seed yield by an average of 14.0%. Double fertilization of crops with complex chelated microfertilizerYarilo significantly increased the yield of sunflower on the options without mineral fertilizers and when using N60P60K90 on a background of straw. The oil content in the seeds was 47.5–50.1%, no significant dependence on the fertilizer system was observed. The most cost-effective fertilizer system was identified — N60P60K90 compatible with straw and microfertilizer Yarilo, at which the yield of sunflower seeds was 2.3 t/ha and the level of profitability was 43.5%.

УРАЖЕННЯ БУРЯКУ ЦУКРОВОГО ЦЕРКОСПОРОЗОМ І КАГАТНОЮ ГНИЛЛЮ ЗАЛЕЖНО ВІД ОСОБЛИВОСТЕЙ УДОБРЕННЯ

The results of field and laboratory research on podzolized heavy loam chernozem of the Right-Bank Forest-Steppe of Ukraine to study the effect of various fertilization systems on the infestation of sugar beet by cercosporosis and gray rot are presented. It has been found that changes in nitrogen, phosphorus and potassium nutrition have a different effect on the development of diseases. The semi-rotted cattle manure on straw bedding and mineral fertilizers in the form of aqueous ammonia, ammonium nitrate, granular superphosphate, mixed potassium salt, potassium chloride, ammonium nitrate phosphate fertilizer grade A and liquid complex fertilizers of grade 10–34–0 were used in the experiment. The rate of manure is 40 t/ha, the rate of mineral fertilizers – N120Р120К120. Fertilizers were applied in August during fall plowing, as well as in late autumn at the end of October, together with the soil subsurface loosening to a depth of 14–16 cm, and in spring – for presowing cultivation. The degree of the leaf apparatus damage by cercosporosis and the intensity of the disease development were determined. The resistance of root crops to gray rot was determined by a microbiological method. For this, cuttings from root crops were placed in Petri dishes with a provocative background of a pure culture of the fungus Botritis cinerea Pers. The conducted studies have established that, depending on the types, forms and timing of mineral fertilizers against the background of manure, the degree of the leaf apparatus infestation of beets with sugar cercosporosis varies from 24 to 48 % and increases both for insufficient and unbalanced phosphorus nutrition. At the same time, the improvement of nitrogen nutrition, especially with the late autumn application of aqueous ammonia, compared with its introduction for the August plowing, contributes to an increase in the degree of stability of the leaf apparatus of sugar beet to cercosporosis from 46.6 to 60.0 %. Improving the mineral nutrition of plants through the use of fertilizers helps to increase the resistance of root crops to decay. At the same time, depending on the fertilizer application system, the degree of stability compared to the control without fertilizers increases by 8.5–38.9 %. This was especially effectively promoted by the improvement of phosphorus nutrition of plants. A high correlation dependence was established between the damage of leaf apparatus of sugar beet by cercosporosis and the formation of a rotten mass of root crops (r = 0.85).

Влияние оптимальных доз органических и минеральных удобрений на урожайность зеленой массы и показатели качества кормов на пожнивных посевах смешанно возделываемых культур

Abstract. The article presents the results of studies on the effect of optimization of organic and mineral fertilizers on the yield of green mass and indicators of the quality of forage on stubble crops of mixed cultivated crops on poorly supplied with nutrients gray-meadow soils. The introduction of optimal rates of organic and mineral fertilizers on stubble crops of mixed crops of corn and sorghum increased the yield of green mass. With a yield of green mass of 372 c/ha in the control variant of mixed crops without fertilizers, in the variant of introducing the norm N120P150K150, this figure was 627 c/ha, which is 255 c/ha more in comparison with the control, i.e. by 68 %. It has been found that the introduction of optimal rates of organic and mineral fertilizers on stubble crops of mixed crops of corn and soybeans, along with an increase in the yield of green mass, has a positive effect on its quality indicators. Based on the research results, it was found that to achieve a high yield of green mass of joint crops of corn and soybeans, it is effective to introduce mineral fertilizers at the rate of N120P150K150 and the joint use of organic and mineral fertilizers at the rate of 10 t/ha (manure) + N70P125K90.

Biological Nitrogen Fixation and Denitrification in Rhizosphere of Potato Plants in Response to the Fertilization and Inoculation

The study aim was to evaluate the potential nitrogen fixation and denitrification in the rhizosphere soil of potato plants, crop yield and output quality in response to the different fertilization systems and the inoculation with Azospirillum brasilense 410. Field stationary experiment was conducted between 2016 and 2019 with potato in a crop rotation system on leached chernozem soil. Farmyard manure, 40 t/ha, applied prior to potatoes planting promotes nitrogen fixation (0.8–2.0 times compared to control). However, it has also affected denitrification (in 1.4–2.2 times higher compared to control). The lowest rate of mineral fertilizers used in the experiment, N40P40K40, was shown as most environmentally feasible. Under its use the increase of soil nitrogenase activity and low denitrification levels were observed. Same trends were also noted for the medium fertilizer rate, N80P80K80. The highest doses of mineral fertilizers, N120P120K120, substantially affected the denitrification process and reduced the nitrogen fixation activity (in 1.9–2.2 times). The combination of manure with the medium fertilizers rate has also resulted in high denitrification levels, while the soil nitrogen fixation activity has restored only at flowering stage. Crop inoculation with A. brasilense combined with the manure application, has not affected studied processes. However, crop inoculation after the green manure intercropping has shown the growth of nitrogenase activity. Used on the mineral fertilizers background inoculation has activated nitrogen fixation and has ensured the decrease of denitrification levels, subject to the fertilization background. High fertilizer rates have hampered the inoculation efficiency. Inoculation has promoted crop yields on unfertilized and mineral backgrounds or following green manure. Crop inoculation following organic and the organo-mineral backgrounds had no significant effect, probably due to the competition for A. brasilense from microorganisms that have created a competitive environment for A. brasilense. Despite its environmental expediency, inoculation combined with the low fertilizer doses underperforms the action of inoculation combined with the medium fertilizer rates showing the latter as the compromise between the environmental requirements and crop productivity. The use of inoculation has promoted the accumulation of starch and ascorbic acid and has contributed to the reduction of nitrate contents in the tubers of inoculated plants.

Efficiency of organic and bio-fertilization on reducing the rates of mineral fertilizers in Flame Seedless vineyards

This study was conducted during 2018, 2019 and 2020 seasons, on 10 years old Flame Seedless grapevines, grown on the experimental vineyard of Research Station Agriculture, EL-Matana, Esna, Luxor, Egypt to study the effect of organic and bio-fertilization on vegetative growth, nutrient status, and fruiting of Flame Seedless grapevines. The experiment was arranged in a complete randomized block design with seven treatments and three replications two vine per each. The obtained results could be summarized as follow: Using the recommended dose of nitrogen (RDN) via 50 or 25% mineral plus 50 or 75% or 50% organic and bio-form significantly increased, pruning wood weight, number of leaves/shoot and leaf area as well as leaf total chlorophyll and leaf nutrient composition compared to use RDN via mineral N fertilizer alone. No significant differences on these traits due to use RDN via 50% mineral plus 50 organic or bio, double form or 25% N plus 75 bio-form and triple born. All combined fertilization treatments significantly increased the yield and improved the cluster and berry traits compared to use RDN via mineral source only. It is evident from the foregoing results that double form 50% mineral plus 50% either organic or bio or triple form (25% N plus, 75 organic and bio.) improved the vegetative growth, yield and berry quality. In addition, it minimized the production costs and reduced environmental pollution.

Productivity of common Saint-John's wort (Hypericum perforatum L.) by using transplant reproduction method in the conditions of drip irrigation

The influence of plant nutrition area and mineral fertilizer rates on the productivity of St. John's wort (Hypericum perforatum L.) by using transplant reproduction method in the conditions of drip irrigation was studied. It was proved that the transplant method of cultivation of St. John's wort under drip irrigation is a very effective method of reproduction of this crop. Four variants of planting density per unit area were studied: 42 thousand plants / ha (cultivation scheme 60x40 cm), 56 thousand plants / ha (60x30 cm), 83 thousand plants / ha (60x20 cm) and 167 thousand plants / ha (60x10 cm). Yield recording of raw materials (air-dry tops) was carried out in the phase of mass flowering. In the first year of vegetation this period was in the first decade of August, in the second year – in the second decade of June. It was found that the increase in the number of planted plants of St. John's wort per 1 ha contributed to the increased plantation productivity. When having a cultivation plant density of 42,000 plants / ha, the yield of dry grass in the first year of vegetation was 3,02 t / ha. Increasing the number of plants to 56 thousand plants / ha provided 3,26 t / ha of raw materials. The highest yield of dried St. John's wort – 3,76 t / ha in the first year of vegetation was obtained in the variant with the largest number of planted plants per unit area - 167 thousand plants / ha. In the second year of vegetation of St. John's wort in the variant with the lowest plant density of 42 thousand plants / ha, the yield was 3,65 t / ha. The most productive plantation of the second year of vegetation was in the variant with a plant density of 83 thousand plants / ha, where the yield of dry raw materials was 3,96 t / ha. A further increase in the number of plants per unit area led to a decrease in crop yields. The influence of four variants of the main application of mineral fertilizers on the productivity of St. John's wort was also studied: N0P0K0 (reference), N60P60K60, N120P120K120 and N180P180K180. It was found that with increasing fertilizer application rate, the yield of dry raw materials increased. The most favorable conditions for growth and development of plants of St. John's wort developed in the variant with the maximum rate of fertilizer application - N180P180K180, where the yield of dry raw materials in the first year was 3,31 t / ha, and in the second year – 4,15 t / ha, which exceeded the reference result (without fertilizers) by 0,61 t / ha and 0,84 t / ha, respectively.