Application Of Mineral Fertilizers Research Articles

The impact of cultivation technology elements on the productivity of the soybean (Glycine max (L.) Merr.) variety ‘Hoverla’ in the Prykarpattia region

Purpose. To study the formation of the productivity of the ‘Hoverla’ soybean variety using different elements of cultivation technology. Methods. Field, laboratory, statistical (calculation­comparative, mathematical­statistical). Results. The effectiveness of spring chisel ploughing for the cultivation of the soyabean variety ‘Hoverla’ in the soil and climatic conditions of the Prykarpattia region was established. The positive effect of the studied tillage methods on the phytosanitary condition of the crop was noted. In particular, the combination of autumn ploughing and spring chisel ploughing with the application of N30P30K30 mineral fertiliser and double foliar spraying of crops with a growth regulator led to an increase in the competitiveness of plants against weeds and reduced the number of weeds by 46.2% compared to the control. The implementation of the above measures also contributed to an increase in yield to 2.48 t/ha, or 57.0% on average over three years. At the same time, the yield of forage units and digestible protein increased by 1.35 and 0.3 t/ha respectively. Conclusions. Spring chisel ploughing, together with autumn ploughing and a rational combination of the predecessor’s by­products, the proposed doses of mineral fertiliser and growth regulator in the conditions of the Prykarpattia region, helped to reduce the weediness of crops by 46.2% and increase the yield of the ‘Ho­verla’ soybean variety by 57.0%.

Microbiomes-Plant Interactions and K-Humate Application for Salinity Stress Mitigation and Yield Enhancement in Wheat and Faba Bean in Egypt’s Northeastern Delta

Salinity, resulting from climate change and excessive mineral fertilization, burdens farmers and negatively impacts soil and water ecosystems in the Northeastern Nile Delta. Organic and biological approaches are crucial for addressing these issues. This study examined the effects of individual and combined inoculations with cyanobacteria, yeast, and Arbuscular Mycorrhizal Fungi (AMF), with or without K-Humate and reducing Nitrogen, phosphorus and potassium (NPK) mineral fertilizers application rates to crop quality of wheat and faba bean. In preliminary laboratory experiments, the interactive effects of these microbiomes on plant antioxidant and soil enzyme production were examined under salinity stress. Results showed that co-inoculation, especially with K-Humate, yielded superior outcomes compared to individual inoculations. These findings were validated by a field trial conducted in saline-alkaline soil in the Northeastern Nile Delta region. All biological treatments 25% of recommended doses, and enhancing salinity tolerance, increasing yield, and improving enhanced rhizosphere microbial activity, including soil enzyme activity, AMF colonization, spore density, and the total numbers of bacteria, cyanobacteria, and yeast. These effects were further amplified by K-Humate and were more pronounced with combined inoculations than with individual ones, leading to improved soil fertility and significant increases in both crop quantity and quality compared to control treatments. The triple treatment, combining cyanobacteria, yeast, and mycorrhizae in the presence of K-Humate while reducing the mineral NPK rate by 75%, achieved superior increases in the productivity of wheat grains and faba bean seeds, reaching 54.72% and 128.92%, respectively, compared to the 100% NPK mineral control. This treatment also significantly improved crop quality, with notable increases in nitrogen, potassium, phosphorus, and protein percentages in wheat grains and faba bean seeds. Microbiomes-interaction increased potassium uptake over sodium, enhancing the plant’s potassium/sodium ratio and improving salt stress tolerance. This approach reduces reliance on costly mineral fertilizers, enabling bio-organic farming in marginal lands, optimizing resource utilization, and preserving natural resources.

Impact of soil bacteria on amylose synthesis in maize kernels under the substitution of manure nitrogen for mineral fertilizer nitrogen

Long-term and large-scale application of mineral fertilizer destroys soil microbial structure and crop quality. To reduce the harm of mineral fertilizer, a 6-year localization experiment was conducted to study the effects of replacing 0 % (CF), 25 % (M25), 50 % (M50), 75 % (M75), and 100 % (M100) of 225 kg ha−1 mineral fertilizer nitrogen with manure nitrogen on soil bacterial community structure and crop quality. The results showed that an increase in soil Longimicrobiaceae elicited a reduction in amylose. The impact of soil bacteria on the soluble sugar showed no significant difference. Compared with CF, substitution treatments significantly reduced Ktedonobacteria and C0119 by 53.42–81.28 %, and significantly decreased cyanobacteria, cellulolysis, aerobic chemoheterotrophy, phototrophy, photoautotrophy and oxygenic photoautotrophy by 3.27–196.58 %, and significantly increased dark sulfur oxidation, dark thiosulfate oxidation, nitrogen fixation and chitinolysis by 15.73–508.50 %. M50, M75, and M100 significantly reduced Holophagae and Subgroup 7 by 24.96–37.91 % relative to CF. M75 significantly increased Chao index, whereas significantly reduced Simpson index compared with M25. The Simpson indices of M75 and M100 were significantly lower than that of CF. Bacillaceae and Env.OPS 17 can be used as the main basis for the classification of soil samples in the equivalent substitution of nitrogen mineral fertilizer with manure.

Rice straw biochar and NPK minerals for sustainable crop production in arid soils: a case study on maize-wheat cropping system

Maize and wheat are the main cereals grown in Egypt. However, the country relies on grain imports to meet its local demands. In order to improve their production, appropriate fertilization programs are needed. The present study investigates the effects of amending a clayey soil of an arid region with rice straw biochar and NPK mineral fertilizers, individually or in combination, for increasing growth and productivity of maize and wheat crops. Additionally, impacts of these additives on soil biological activities and carbon (C) transformations in soil were a matter of concern herein. To achieve this objective, a field research of a randomized block design was conducted during the summer (maize) and winter (wheat) seasons of 2020/2021. The following treatments were considered: unmodified control (CK), 100% N inputs in the form of biochar (reference organic treatment, RSB) (T1), 100% mineral treatment (reference inorganic treatment, T2), 75% RSB + 25% NPK minerals (T3), 50% RSB + 50% NPK minerals (T4) and 25% RSB + 75% NPK minerals (T5). Additional doses of mineral fertilizers were added to treatments from T3 to T5 to maintain NPK inputs within the recommended doses. Key results showed that all additives significantly enhanced plant growth parameters and productivity. They also increased soil organic carbon level by the end of the growing season hence reduced soil bulk density, even for the treatment that received only mineral NPK applications (T2). All additives also upraised soil cation exchange capacity (CEC), soil available nitrogen (N), and soil salinity. However, sole application of biochar recorded the least increase in soil salinity. Combined mineral-organic treatments not only recorded the highest increases in soluble and microbial fractions of organic carbon and nitrogen in soil; but also noted the greatest improvements in growth and grain productivity of maize and wheat versus sole applications of mineral fertilizers or biochar. The alkaline nature of biochar was buffered by soil while no significant differences were observed in harvest index among treatments. In conclusion, combined use of biochar and mineral fertilizers, especially T5 is recommended for increasing soil fertility and wheat and maize grain productvity.

Technological and technical solutions to the problem of basic soil nutrition in the system of precision agriculture in Northern Kazakhstan

Climatic-soil conditions of Kazakhstan allows to produce demanded grain at the international level. However, as a result of low technologies for land cultivation and application of mineral fertilizers, soil fertility decreasesin the production of grain. There is only one way that raises the low fertility of the soil is transfer of missing elements, that is, the application of mineral fertilizers. In the application of minimum and zero technologies of grain production, it is not provided for the introduction of the main amount of mineral fertilizers under the ground and such machines are not producedin the market of agricultural machinery of the CIS countries. At the request of farmers, the production of their subseries has begun.

Analysis of organic matter stock dynamics in arable soils of Yamal: simulation experiments with the ROMUL model

The goal of this work is to analyze the dynamics of soil organic matter (SOM) in arable soils of Yamal using computational experiments with the ROMUL model. Soil temperature and moisture dynamics were simulated using the SCLISS model. The Yamal experimental station was organized in 1932. The soil is Plaggic Podzol. The thickness of humus horizon (PY) is 30 cm. Pools, kg/m2: SOM – 9.32 and 13.75; N – 0.46 and 0.66 for 0–20 and 0–30 cm respectively. Background: soddy-green-moss tundra near Salekhard. Soil: Folic Podzol: litter (O, 2 cm) and humus-accumulative (AY, 4 cm) and illuvial ferruginous (BF, 6 cm) horizons. Pools, kg/m2: SOM – 1.38 and 2.69, N – 0.03 and 0.18 for 0–2 and 2–6 cm respectively. The quantity and quality of background fall was estimated according to literature data. Clarification of the amount of fall was carried out by the method of inverse problem solving (spin-up). Peat application was simulated: starting application in the dose of 12 kg/m2 and maintenance (every 6 years) in doses 4, 8 and 12 kg/m2, N 1%. Application of mineral fertilizers, 2 variants: a) N 4 g/m2 (40 kg/ha) in peatting years and b) application of the same dose of nitrogen every year. The duration of computational experiments is 30 and 90 years. Computational experiments showed that after the starting peatting of Folic Podzol at the rate of 12 kg/m2 after 30 years, only 15% of the applied detritus remained. Maintenance peatting of 8–12 kg/m2 leads to an increase in SOM pool to 20–30 kg/m2 and excessive accumulation of detritus. Application of 4 kg/m2 of peat once every 6 years for 90 years shows the dynamics of SOM pools from Folic Podzol to Plaggic Podzol which is confirmed by field survey data. Application of mineral nitrogen (4 g/m2) once every 6 years does not affect SOM pools. Annual application of mineral N (4 g/m2) increases SOM pools due to intensified humification. This fact requires experimental verification.

Effect of biochars on the concentration of plant-available elements in the soil

To solve environmental problems and reduce economic costs, it is necessary to improve mineral fertilizer application systems by developing and introducing new technologies, including the use of biochars. Due to the lack of effective monitoring of soil changes, it is difficult to adjust fertilizer application rates. This determines the importance of information on the elemental composition of biochar ameliorants used to reduce the mobility of heavy metals in the soil. The use of biochar for remediation of contaminated soils is based on its ability to immobilize heavy metals and organic pollutants. In this work biochars were used, obtained by slow pyrolysis of organic materials of different types: pine sawdust, cattle manure, wheat straw, pine nut shells and brewer's grains. The effect of biochars (biochar application at a dose of 10 t ha−1) on the concentration of 13 elements (C, N, K, P, Mg, Ca, Fe, Mn, Pb, Ni, Cr, Cd, Co) in the soil was analyzed. The data collected after growing of spring wheat (Triticum aestivum L.) on the sod-podzolic soils were analyzed. It has been established that the heavy metals concentrations in the studied soils reclaimed with biochars are significantly lower than the maximum allowable concentrations for soils (MAC). The content of lead (Pb) in soils treated with biochars is 9 or more times lower than the MAC level, and biochar, produced from manure, significantly reduces the concentration of this metal in the soil.

Combined Application of Chemical Fertilizer and Organic Amendment Improved Soil Quality in a Wheat–Sweet Potato Rotation System

The long-term excessive use of chemical fertilizers may result in soil degradation, but manure and straw application is considered to be an effective approach for alleviating this problem. The aim of this study is to examine the long-term impacts of different fertilization patterns on soil quality variables in a wheat–sweet potato rotation system. Four treatments were conducted in a field trial for a duration of twelve years, including (1) no fertilizer (control, CK); (2) application of mineral fertilizers (NPK) alone; (3) NPK with crop straw return (NPKs); (4) combined use of NPK and farmyard manure (NPKm). Thirteen physical, chemical, and biological soil parameters were measured. The results showed that the NPKm and NPKs significantly improved the proportion of macroaggregates (>0.25 mm) by 24.7% and 21.9% compared to the NPK alone, respectively. The proportion of microaggregates (0.053–0.25 mm) under the NPKm was 47.4% significantly higher than the NPKs. Additionally, the NPKm resulted in a 22.2% and 19.6% increase in the SOC content than the NPK and NPKs, respectively. In terms of soil-available K, the NPKs resulted in levels that were 42.1% and 49.6% higher than the NPKm and NPK alone, respectively. Long-term fertilization significantly decreased soil pH by 0.95–1.85 units compared to the control, whereas manure application could alleviate soil acidification, as shown when the pH increased by 10.6–18.7%. The NPKm and NPKs resulted in significantly increased soil pHs by 10.6% and 18.7% compared to the NPK alone, respectively. In addition, the NPKm and NPKs increased N-acetyl-β-D-glucosaminidase activity by 52.6% and 60.3% compared to the NPK alone. Determined by the minimum data set method, the NPKm treatment exhibited the highest soil quality index, followed by the NPKs and NPK. Our findings suggested that the combined use of chemical fertilizers with organic amendments proved beneficial for enhancing soil quality.

Influence of crop rotation, the treatment of crop residues, and the application of nitrogen fertilizers on soil properties and maize yield

AbstractThis inquiry is aimed at discerning the impact of various agricultural practices, such as crop rotation, the incorporation of plant residues, and the application of mineral fertilizers, on soil health and crop productivity, notably focusing on maize production. Cultivation included maize (Zea mays), velvet beans (Mucuna pruriens), soybeans (Glycine max), and vetch (Vicia sativa). After harvest, maize seeds were sown across all 48 plots to evaluate the influence of preceding crop rotation on soil properties and maize yield. Hypotheses posited in the study suggested that crop rotation, nitrogen fertilizer application, and the incorporation of crop residues positively impact soil fertility. The study further argues that the utilization of cover crops in crop rotation aids in nitrogen retention within the soil and enhances yield. The results were processed utilizing a two‐way analysis of variance (ANOVA) with interaction and post hoc comparisons. The findings confirm that crop rotation, nitrogen fertilizer application, and incorporation of crop residues influence soil fertility. The study found that crop rotation and nitrogen fertilizers have a significant impact on soil properties. Crop rotations such as “velvet beans‐maize” and “soybeans‐maize” increased soil fertility by 10%–15% compared to crop rotations of “vetch‐maize” and maize monocultures. Nitrogen fertilizers increased the total nitrogen content in the soil by 5%–10% in both years. Crop residues also positively affected soil properties, increasing pH and total nitrogen by 1%–5%. The study demonstrates that crop rotation, nitrogen fertilizers, and crop residues can be effective management methods for improving soil fertility and reducing the risk of nitrate leaching.

Листовые подкормки при возделывании козлятника восточного на орошении

To strengthen the fodder base of animal husbandry in the Lower Volga region, first of all, it is necessary to expand the range of fodder crops and varieties, to optimize their nutritional regime, to create optimal conditions for their cultivation, in other words, to ensure the production of a large amount of valuable fodder in a relatively limited area, in this regard, the improvement of cultivation technology of eastern goatgrass is relevant. The purpose of the research was to increase the efficiency of cultivation of oriental goatgrass in the Lower Volga region through the use of mineral fertilizers and growth stimulants. Experiments to study the dependence of productivity of oriental goatgrass in the form of green mass on leaf fertilization with water-soluble mineral fertilizers were conducted from 2016 to 2023 on an irrigated plot with irrigation regime of 70...85...70 % NV by sprinkler machine “Valey”. In the experiment in 2017, varieties of oriental goatgrass Krivich, Yubilyar, Kazbek were sown. The general background before sowing was applied mineral fertilizers in the form of azofosk at a dose of N24P24K24. In each cutting in the phase of active growth of plants were fertilized with potassium monophosphate with and without a sticking agent at the rate of 0.5 kg/ha for one fertilizer. On average for seven years, the largest leaf area - 43.7 thousand m2/ha and photosynthetic potential - 7.87 million m2 x dn./ha of oriental goatgrass in the experiment were in the variety Jubilar in the variant of potassium monophosphate with a sticking agent. On average for seven years, the largest leaf area - 43.7 thousand m2/ha and photosynthetic potential - 7.87 million m2 x dn/ha of oriental goatgrass in the experiment were in the variety Jubilar in the variant of potassium monophosphate with a sticking agent. Also on this variant the maximum yield of green mass - 92.7 t/ha, dry matter content - 23.2 t/ha, fodder units - 20.4 t/ha and exchangeable energy - 1.62 GJ/ha were observed.

Влияние предпосевной обработки семян и агрохимикатов на урожайность озимой пшеницы

High yields cannot be achieved without the use of fertilizers, but how much they can pay off in modern economic realities and in drought conditions is unknown. In this regard, it is important to have new knowledge about effective systems of application of mineral fertilizers and agrochemicals in winter wheat cultivation in the zone of chestnut soils of the Lower Volga region. Therefore, the purpose of our research was to study the effect of growth stimulants in pre-sowing seed treatment and leaf fertilization with liquid fertilizers on the productivity of winter wheat in the Volgograd region. On average for 2021-2023 years, the minimum photosynthetic potential of winter wheat - 1288 thousand m2 day/ha was formed on plots without UAN 32 and growth regulators, and the highest - 2063 thousand m2 day/ha on plots with two fertilizers UAN 32 and growth regulator Emistim. Autumn fertilization with UAN 32 increased dry aboveground biomass of winter soft wheat in the variety Kamyshanka 6 at earing phase by 13%, two and three fertilizations by 26 and 27%, respectively. Growth regulator Polidon increased dry aboveground biomass of winter wheat at earing phase by 4%, Alfastim by 7%, Emistim by 12%. In the phase of milk ripeness dry biomass from growth regulator Polidon increased by 6%, Alfastim by 11%, Emistim by 14%. The lowest plant height of the variety Kamyshanka 6 was formed on the control - 0.89 m, the highest was on plots with two fertilizers and all variants on factor B and averaged 0.94 m, which is 0.05 m higher than the control. Spikelet length in the experiment was maximum in plots with two fertilizers and growth regulator Emistim. The minimum biological yield of winter wheat Kamyshanka 6 - 4.04 t/ha was obtained in the control variant, the maximum yield - 5.66 t/ha was observed in plots with two fertilizers UAN 32 and application of Emistim.

The influence of cultivation technologies on the contamination of spring wheat crops and yield in the conditions of the Nizhny Novgorod region

The article presents the results of research of the influence of various cultivation technologies on the contamination of spring wheat crops and its yield for 2022–2023 in the conditions of the Nizhny Novgorod region on light gray loamy forest soil. There were studied the technologies various in methods of primary soil tillage (traditional, minimal – Mini-till, without tillage – No-till), and intensification level (basic, intensive). Spring wheat of the ʻZlataʼ cultivar was cultivated in the chain of rotation: clean fallow – peas - spring wheat. During the research period, it was established that the No-till technology contributed to an increase in the total contamination of spring wheat crops on an average for two years in the "tillering" phase (before herbicide treatment) to 36.2 pcs/m2 (84.7 % higher than the total contamination of wheat crops when cultivated using Mini-till technology and by 118.1 % –using traditional technology) and in the phase of "full grain ripeness" (before harvesting) up to 30.1 pcs/m2 (110.5 % higher than the total contamination of wheat crops cultivated using Mini-till technology and by 155.1 % according to traditional technology). It has been established that intensification of wheat production (application of mineral fertilizers in a dose of N70P50K50 before pre-sowing cultivation; using fungicide and herbicide in the "tillering" phase) results on average among studied technologies in decreasing the total contamination of crops during the "full grain ripeness" phase on average for two years up to15.7 pcs/m2 which is 38.2 % lower compared to the basic intensification degree of wheat cultivation technologies. It was found that the cultivation of spring wheat using traditional technology and Mini-till technology provides high yields: 3.09–3.43 t/ha, that is 0.63–0.96 t/ha higher than its yield when cultivated using No-till technology. There were no differences in the level of yield of spring wheat over the years of observation when cultivating it using traditional and Mini-till technologies. The intensification of spring wheat production makes it possible to increase the level of its yield for each of the studied technologies.

Mycorrhizal inoculation and fertilizer microdosing interactions in pearl millet (Pennisetum glaucum) under greenhouse conditions.

Soil fertility is a major constraint to agricultural development in the Sahel region of Africa. One alternative to reducing the use of mineral fertilizers is to partially replace them with microbes that promote nutrition and growth, such as arbuscular mycorrhizal fungi (AMF). Mineral fertilizer microdosing is a technique developed to enhance fertilizer efficiency and encourage smallholder farmers to adopt higher mineral fertilizer applications. A pot experiment was set up to study the effects of AMF inoculation on the mineral nutrition of pearl millet under mineral fertilizer microdosing conditions. The experimental setup followed a randomized complete block design with five replicates. The treatments tested on millet were an absolute control and eight microdoses derived from the combination of three doses of 15- 10-10 [nitrogen, phosphorus, and potassium (NPK)] mineral fertilizer (2 g, 3 g, and 5 g per pot), three doses of urea (1 g, 2 g, and 3 g per pot), and three doses of organic manure (OM) (200 g, 400 g, and 600 g), combined with and without AMF (Rhizophagus irregularis and Rhizophagus aggregatum). The parameters studied were growth, root colonization by AMF, and mineral nutrition. Plant height, stem diameter, root dry biomass, and percentage of root mycorrhization were measured. The results revealed a significant effect of the fertilizers on the growth of pearl millet compared to the control. AMF and OM treatments resulted in the highest biomass production. AMF combined with microdoses of NPK improved N and calcium (Ca) concentrations, while their combination with organic matter mainly improved the K concentration. Combining AMF with microdosed NPK and compost enhanced zinc (Zn) and nickel (Ni) concentrations. Root colonization varied from 0.55 to 56.4%. This investigation highlights the positive effects of AMF inoculation on nutrient uptake efficiency when combined with microdosing fertilization.

Yield and quality of spring barley grain depending on the influence of precursors and mineral fertilizers under the conditions of the Central Black Earth region

The barley crop (Hordeum sativum L.) for the Central Black Earth region of Russia is a promising area for producers of all types of ownership. Barley is a valuable universal crop rich in complete protein and starch. In Russia, up to 70 % of barley is used for feed purposes. The feed value of barley is higher than that of wheat and corn, since it has a more balanced amino acid composition of protein, especially lysine. The protein complex of barley contains more than 20 amino acids, 5 of which are essential. The purpose of the research was to investigate the yield and quality of spring barley grain depending on the eff ect of predecessors and mineral fertilizers under the conditions of the Central Black Earth region. The object of the study was the spring barley variety Knyazhich. The following predecessors were studied such as grain corn, sunfl ower, sugar beet and soybeans. The fertilizer application rates were such as N10P10K10, N30P30K30, N50P50K50 and N70P70K70. It was found that the highest yield of spring barley was obtained with sugar beet as a predecessor. Thus, with a low background of mineral nutrition N10P10K10 it was 3.84 t/ha, with an average N30P30K30 it was 4.87 t/ha, with a high N50P50K50 it was 5.48 t/ha and with an intensive N70P70K70 it was 5.33 t/ha. Thus, the analysis of the eff ectiveness of the studied predecessors and the application of mineral fertilizers under spring barley indicate that for the predecessors sugar beet and soybeans, mineral fertilizers in the dose of N50P50K50, the highest profi t of 30343.5 and 25747.1 rubles/ha and a high bioenergy coeffi cients of 4.84 and 4.51 were obtained.

Effect of Prolonged Action of Mineral Fertilizers under Conditions of Temperature Stress on Silage Maize Yield in the Steppe Zone of the Southern Urals

In modern agriculture in the Southern Urals, an important agronomic technique is to counteract drought. Of particular importance in increasing the feed base is the cultivation of maize for silage, which ensures maximum yields in extreme conditions. The aim of the study was to determine the potential possibilities of increasing the yield of green mass of maize for silage under the influence of temperature stress in conjunction with the prolonged action of mineral fertilizers and precursors in arid conditions. The study was carried out in the central zone of the Orenburg region from 1993 to 2022 on a stationary site with the southern carbonate heavy loamy chernozem soils with a humus content of 3.2–4.0%. The experiment was carried out with and without mineral fertilizers. The content of nitrate nitrogen in the soil was determined by the ionometric method of Tyurin, mobile phosphorus – by Machigin, exchangeable potassium – by Maslova. A thermostatic-weight method was used to determine soil moisture. On average, over 30 years of research, when cultivating maize for silage in a 6-field crop rotation, an increase in yield was noted with the use of mineral fertilizers from 0.23 to 0.84 t/ha. The annual application of mineral fertilizers in permanent sowing of maize provided an increase in the yield of green mass of 2.51 t/ha. In years with severe aridity, the yield of leaf-stem mass on a fertilized background decreased by an average of 1.61 t/ha. In very dry years, maize plants consumed less nitrate nitrogen (by 2 or more times) than in years with different humidity, but at the same time, potassium consumption increased.

Trend of soil salinization in Africa and implications for agro-chemical use in semi-arid croplands

Soil salinization is a gradual degradation process that begins as a minor problem and grows to become a significant economic loss if no control action is taken. It progressively alters the soil environment which eventually negatively affects plants and organism that were not originally adapted for saline conditions. Soil salinization arises from diverse sources such as side-effects of long-term use of agro-chemicals, saline parent rocks, periodic inundation of soil with saline water, etc. In Africa, soil salinization has not been adequately documented particularly in the croplands. The objective of this study was to identify trends of cropland salinization in Africa and how its relationship with long-term land use practices affected the soil environment. The study analysed soil salinization between 1965 and 2020 using measured electrical conductivity (EC), spatial modelling with environmental covariates, and national statistics on cropland expansion and application of mineral fertilizers, herbicides, and pesticides. The results showed increasing trends of EC in Africa due to climatic and land use drivers. Increasing trends of EC, which evidenced salinization, was found in 31 million hectares of topsoils and 18 million hectares of subsoils. About 2 million hectares of croplands were depicted with salinization and >25 million hectares at the risk of salinization in the arid and semi-arid areas. The study also found statistical relationships between semi-arid cropland salinization and trends of agro-chemical use and cropland sizes. There were significant (p < 0.001) positive correlations between semi-arid cropland salinization and trends of cropland expansion and applied nitrogenous fertilizers. It found that increasing trend of applied mineral nitrogenous fertilizers could double the odds of salinization in semi-arid croplands while cropland expansion could increase the odds of semi-arid cropland salinization by >10 %. These findings present ground-breaking baseline information for future works on sustainable land-use practices that can control cropland soil salinization in Africa.

Effect of Organic Manure on Crop Yield, Soil Properties, and Economic Benefit in Wheat-Maize-Sunflower Rotation System, Hetao Irrigation District.

The combined application of manure and mineral fertilizer represents an effective strategy for enhancing crop yield. However, the relationship between soil fertility and crop yield remains unclear in saline-alkaline soil. Here, a 9-year field experiment (2015-2023) was conducted to investigate the effects of manure application and crop rotations on crop yield and economic efficiency as well as potential associated mechanisms in the Hetao Irrigation District. The results showed that in the third cropping rotation cycle, combined application of manure and mineral fertilizers (NPKO) caused a 6.2%, 38.9%, 65.3%, and 132.2% increase in wheat, sunflower, wheat equivalent yield, and the economic income of sunflower, respectively. The average grain yield had a positive correlation with soil organic matter and nutrient supply. This suggested that the soil organic matter had a positive effect on the crop yield due to its impact on nutrient supply. Simultaneously, the sunflower seed setting rate increased by 65.2% under NPKO. The linear regression model revealed that each additional input of 20 Mg ha-1 of manure resulted in an increase of 3.56 kg ha-1 in crop phosphorus harvest and a 0.05 Kg ha-1 increase in wheat equivalent yield compared to NPK. In conclusion, our results highlighted that manure application promotes soil properties and improves crop yield.

Performance of coal slime-based silicon fertilizer in simulating lead-contaminated soil: Heavy metal solidification and multi-nutrient release characteristics

High-ash coal slime-based silica fertilizer (CSF) has the potential to provide mineral nutrients and passivate lead (Pb) in the soil to ensure the sustainable development of the coal industry and agriculture. This study investigated the performance and passivation mechanism of CSF, which contains potassium tobermorite and potassium silicate as the main components for soil improvement. Leaching experiments showed that low-crystalline muscovite was the only crystalline phase for CSF etching and that the silicon (Si), calcium (Ca), and potassium (K) in CSF had significant citric solubility. Soil cultivation and planting trials confirmed the ability of CSF to neutralize soil acidity, increase available soil Si and K, improve exchangeable Ca content, reduce the bioefficacy of Pb (exchangeable Pb by 19–75 % and carbonate-bound Pb by 6–18 %), and increase residual state Pb content. Compared to untreated Pb-contaminated soil, the 0.4 % CSF treatment reduced Pb in Chinese cabbage (Brassica rapa) by 25 % and increased plant biomass, Ca, and K by 37 %, 36 %, and 4 %, respectively. At the same time, soil pH increased by 0.58, and residual state Pb increased by 5 %. In CSF-treated soils, lead silicate is the dominant form of Pb present in the residual state. First-principle calculations showed that Pb3Si2O7 (cohesion energy −1.98 eV) formed by the passivation of Pb by CSF had greater stability in the soil compared to lead carbonate (PbCO3) (cohesion energy −1.38 eV) and lead sulfate (PbSO4) (cohesion energy −1.41 eV). This work shows the promising application of coal slime mineral fertilizers prepared using hydrothermal methods for soil improvement.

The LTAR Cropland Common Experiment in the Upper Chesapeake Bay.

Dairy production is a key agricultural enterprise in the Upper Chesapeake Bay (UCB) basin, where phosphorous (P) and nitrogen (N) loading contribute to eutrophication. Import of forages and grains and application of mineral fertilizers contribute to nutrient imbalances in the basin. The UCB Long-Term Agroecosystem Research Cropland Common Experiment aims to evaluate diverse crop rotations that minimize the need for imported feed, maximize year-round living cover, and reduce nutrient losses. UCB's plot-scale experiment was established in 2018, incorporating an ongoing cropping system study that was established by the Pennsylvania State University in 2010. An alternative dairy cropping rotation (including silage and grain corn [Zea mayes L.], alfalfa [Medicago sativa L.]/orchardgrass [Dactylis glomerata L.] mix, winter rye silage [Secale cereale L.], and sorghum-sudangrass [Sorghum × drummondii (Steud.) Millsp. & Chas]) that employed manure injection, integrated pest management, and less frequent manure application was compared to a prevailing, conventionally managed silage corn-alfalfa rotation with higher manure application rates. A field-scale experiment was established in 2019 to monitor alternative production practices (manure injection and avoidance of neonicotinoid seed treatment) and prevailing practices in three fields on a commercial dairy farm. Findings suggest that crop rotation diversification, manure injection, and integrated pest management have the potential to increase the economic and environmental sustainability of dairy cropping systems, but long-term evaluation is needed for confirmation.

Effects of the integrated use of organic and inorganic phosphorus sources in micro-doses on the yield and profitability of cowpea (Vigna unguiculata L. Walp) Cultivation

An experiment was conducted in the field to evaluate the effect of phosphorus fertilization in microdose using organic and mineral fertilizers on the yield and profitability of cowpea cultivation. To achieve this, a balanced application of NPK and granular compost was provided to supply the same amount of phosphorus to the cowpea. Three treatments were compared in a split-plot design with three replications, where the treatments were in large plots and the cowpea varieties, numbering four (4), were in small plots. The three treatments are as follows: (i) T0 control treatment without fertilizer application, (ii) T1 application of two grams of NPK per hole, and (iii) T2 application of 9.375 grams of granular compost per hole. The results show a significant difference in yield parameters between treatments (pod yield, grain yield, and straw yield). The mean comparison test revealed that the control treatment and NPK are quite similar for these parameters. Thus, with compost, an increase of 69.17% in grain yield, 55.47% in pod yield, and 41.67% in straw yield was noted compared to the control. The VCR (value-cost ratio) and gross income were significantly improved by compost. The application of organic or mineral fertilizers for cowpea cultivation is profitable due to relatively high VCRs: 3.34 for NPK and 6.79 for compost. Therefore, the use of compost for cowpea cultivation proves to be economically more profitable, as it yields higher returns.