Higher Soybean Yields Research Articles

Analysis of the Synergistic Effect of Endophytic Bacteria and Metabolites on Yield in Soybean Roots Under Biochar with Nitrogen Fertilization

The appropriate application of nitrogen fertilizers and biochar to the soil is beneficial for soybean growth, and a combination of biochar and nitrogen can improve low-nitrogen fertilizer utilization efficiency. However, the effect of the combination of biochar and nitrogen fertilizer on soybean roots is still unclear. Therefore, in this study, we investigate the changes in endophytic bacterial communities and metabolites in soybean roots under different combinations of biochar and nitrogen fertilizer treatments by setting different fertilization levels and using high-throughput sequencing and non-targeted metabolomics techniques. The results showed that applying 20 t/ha of biochar and 180 kg/ha of nitrogen fertilizer (C2N1) resulted in the highest soybean yield. By studying the endophytic bacterial community in soybean roots, it was observed that the dominant phyla were Proteobacteria, Bacteroidota, and Actinobacteriota, and the dominant genera were Bradyrhizobium, Streptomyces, and Rhizobacter. Moreover, a metabolic pathway analysis revealed that glycosylphosphatidylinositol (GPI)-anchor biosynthesis was the most significant metabolic pathway in the C0N1 vs. C0N0 comparison group, and glycerophospholipid metabolism was the most significant metabolic pathway in the C2N1 vs. C1N1 comparison group; they were both associated with regulatory mechanisms such as plant growth promotion and nutrient cycling. Structural equation modeling indicates that both endophytic bacteria and metabolites have a significant positive impact on yield. Bradyrhizobium and Rhizobium are observable variables with significant positive effects on endophytic bacteria, while Phe-Thr and 7-allyloxycoumarin are observable variables with significant positive effects on metabolites. Endophytic bacteria not only have a direct impact on crop yield, but also indirectly affect crop yield through their effects on metabolites. This study has important scientific value and guiding significance for improving soybean yields.

Effects of Different Intertillage Practices on Soil Biochemical Properties and Soybean Yield in Soybean Fields

Heilongjiang Province, China, is a major soybean-producing area where low temperatures in early spring and poor soil moisture retention are the main limiting factors leading to low soybean yields. To improve land productivity, this study was conducted in Heilongjiang Province, China, from 2020–2021 via a field plot trial method, where four different intertillage treatments were set up in 2020: conventional intertillage (T1), early intertillage (T2), conventional subsoiling (T3), and early subsoiling (T4). In 2021, the effects of intertillage on soil biochemical characteristics and soybean yield formation were systematically analyzed under the T5 treatment (subsoiling at the stage of full development from the fourth to the fifth compound leaf) and the T6 treatment (soil culture at the stage of full development from the fourth to the fifth compound leaf). The results of the experiment revealed that deep loosening in advance improved the chemical properties of the soil. Compared with those of the T1 treatment, the contents of the organic carbon, total nitrogen, and available phosphorus and potassium in the early subsoiling treatments (T4, T5, and T6) were significantly increased. Intertillage time and depth had a strong influence on the soil microbial characteristics. Early medium intertillage could significantly increase the species abundance of bacteria and fungi in the soil, whereas subsoiling could increase the relative abundance ratio and uniformity of the dominant species. Compared with that in the T1 treatment, the yield of soybean in the T4 treatment was significantly greater, with yield increases ranging from 18.71% to 19.36%. In summary, the intertillage measures of one deep loosening and one medium soil cultivation at the stage of full development from the fourth to the fifth compound leaf and one large soil cultivation at the stage of full development from the sixth to the seventh compound leaf can be adopted on the basis of early deep loosening 4–5 d after soybean sowing to achieve high soybean yields. The results provide a theoretical basis for increasing the yield and efficiency of soybean fields under corn–soybean rotation, as well as innovation and development of cultivation systems

Molecular and genetic basis of plant architecture in soybean.

Plant architecture determines canopy coverage, photosynthetic efficiency, and ultimately productivity in soybean (Glycine max). Optimizing plant architecture is a major goal of breeders to develop high yield soybean varieties. Over the past few decades, the yield per unit area of soybean has not changed significantly; however, rice and wheat breeders have succeeded in achieving high yields by generating semi-dwarf varieties. Semi-dwarf crops have the potential to ensure yield stability in high-density planting environments because they can significantly improve responses to fertilizer input, lodging resistance, and enhance resistance to various abiotic and biotic stresses. Soybean has a unique plant architecture, with leaves, inflorescences, and pods growing at each node; internode number greatly affects the final yield. Therefore, producing high-yielding soybean plants with an ideal architecture requires the coordination of effective node formation, effective internode formation, and branching. Dozens of quantitative trait loci (QTLs) controlling plant architecture have been identified in soybean, but only a few genes that control this trait have been cloned and characterized. Here, we review recent progress in understanding the genetic basis of soybean plant architecture. We provide our views and perspectives on how to breed new high-yielding soybean varieties.

Quality assessment of soybean seeds submitted to industrial seed treatment and stored in a natural and controlled environment

Seed quality is a limiting factor in the search for high soybean yields. However, fungi and insect pests can negatively interfere with their performance, and industrial seed treatment (IST) is a tool used to minimize the attack of pathogens and pests. The treated seeds are often stored until sowing, which can lead to a reduction in their quality. This work aimed to evaluate the physical and physiological quality of soybean seeds submitted to IST, with subsequent storage in a natural and controlled environment. The experiment was conducted in a split-split-plot design in a completely randomized scheme (time x storage systems x IST) with four replications. Soybean cultivar 55I57RSF IPRO was subjected to IST with fungicide (metalaxyl-M, thiabendazole, and fludioxonil) and insecticide (thiamethoxam and cyantraniliprole), combined or not with polymer and dry powder, with subsequent storage in a controlled and natural environment. The moisture content, thousand-seed weights, germination, first germination count, germination speed index, accelerated aging, seedling length, dry matter transfer, and emergence sand test were evaluated. IST did not affect the moisture content and weight of a thousand seeds. However, storage in a controlled environment provided a greater reduction in moisture content and a smaller reduction in the weight of a thousand seeds. IST negatively affected germination, first germination count, germination speed index, and accelerated aging test. IST negatively affected plant length, except in the treatment where only insecticide was applied. The dry mass transfer was negatively affected but with less intensity in seeds subjected only to the application of insecticide or fungicide and the combination of insecticide, fungicide, and polymer. Seed emergence in the sand was negatively affected by all treatments. Regardless of the treatments, all responses evaluated showed a reduction throughout storage, with greater intensity in seeds stored in the natural environment.

Controlled Traffic Farm: Fuel Demand and Carbon Emissions in Soybean Sowing

Soil compaction between crop rows can increase a machine’s performance by reducing rolling resistance and fuel demand. Controlled Traffic Farm (CTF) stands out among modern techniques for increasing agricultural sustainability because the machines continuously travel along the same path in the field, reducing plant crush and compacting the soil in the traffic line. This study evaluated fuel consumption and CO2 emissions at different CTF intensities in different soil management strategies for soybean crop. The experimental design involved randomized blocks in a split-plot scheme with four replications. The plots constituted the three types of soil management: conventional tillage, no-tillage with straw millet cover, and no-tillage with brachiária straw cover. The subplots constituted for agricultural tractors were passed over in traffic lines (2, 4, and 8 times). We evaluated agricultural tractor fuel consumption, CO2 emissions, and soybean productivity. The straw cover and tractor-pass significantly affected the fuel consumption and greenhouse gas emissions of the soybean cultivation. Fuel consumption and CO2 emissions were reduced due to the machine-pass increase, regardless of soil management. Thus, a CTF reduces rolling resistance and increases crop environmental efficiency. Bare-soil areas increased by 20.8% and 27.9% with respect to fuel consumption, compared to straw-cover systems. Brachiária straw and millet reduce CO2 emissions per hectare by 20% and 28% compared to bare soil. Lower traffic intensities (two passes) showed (13.72%) higher soybean yields (of 4.04 Mg ha−1). Investigating these effects in other types of soil and mechanized operations then becomes essential.

Knockout of miR396 genes increases seed size and yield in soybean.

Yield improvement has long been an important task for soybean breeding in the world in order to meet the increasing demand for food and animal feed. miR396 genes have been shown to negatively regulate grain size in rice, but whether miR396 family members may function in a similar manner in soybean is unknown. Here, we generated eight soybean mutants harboring different combinations of homozygous mutations in the six soybean miR396 genes through genome editing with clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated nuclease (Cas)12SF01 in the elite soybean cultivar Zhonghuang 302 (ZH302). Four triple mutants (mir396aci, mir396acd, mir396adf, and mir396cdf), two quadruple mutants (mir396abcd and mir396acfi), and two quintuple mutants (mir396abcdf and mir396bcdfi) were characterized. We found that plants of all the mir396 mutants produced larger seeds compared to ZH302 plants. Field tests showed that mir396adf and mir396cdf plants have significantly increased yield in growth zones with relatively high latitude which are suited for ZH302 and moderately increased yield in lower latitude. In contrast, mir396abcdf and mir396bcdfi plants have increased plant height and decreased yield in growth zones with relatively high latitude due to lodging issues, but they are suited for low latitude growth zones with increased yield without lodging problems. Taken together, our study demonstrated that loss-of-function of miR396 genes leads to significantly enlarged seed size and increased yield in soybean, providing valuable germplasms for breeding high-yield soybean.

Impact of boron fertilisation on soybean grain yield as affected by associated physiological factors

ABSTRACT High soybean yields generally requires fields to have an adequate supply of boron (B). However, there remains uncertainty around how different cultivars might respond to differing levels of available B. The objective of this study was to evaluate the effect of B fertilisation on physiological efficiencies, yield, and export of B in various soybean cultivars. A randomised block experiment was carried out under field conditions in Region, Brazil consisting of 10 soybean cultivars and two levels of B fertilisation (without application and with application of 3 kg ha−1 of B). Water-use efficiency, instantaneous carboxylation efficiency, B content in the seed, export of B, and grain yield were evaluated. There was a significant interaction between B fertilisation x genotypes for all variables evaluated. In general, B fertilisation improved physiological and nutritional characteristics, increasing grain yield and B seed content on average by 21% and 35%, respectively. The soybean cultivars 7110 and Soyoro showed increases in all physiological and agronomic variables evaluated with B fertilisation. The results of this research confirm that B fertilisation improves the physiological and agronomic performance of the majority of soybean genotypes evaluated.

INCREASE IN LEAF SURFACE AND PHOTOSYNTHETIC ACTIVITY OF SOYBEAN PLANTS DEPENDS ON SOWING RATE AND ROW WIDTH

An essential condition for obtaining high soybean yields is the presence of an optimal leaf surface area. An important condition for obtaining the optimal leaf area in plants is the formation of a certain density of plants per unit area. It is known that the optimal area of the leaf surface, for which a high yield of soybean seeds is formed, is considered to be an area within the range of 40–50 thousand m2/ha. The purpose of the research was the determined dependence of the formation of the leaf surface area and the photosynthetic activity of soybean plants under the influence of the sowing rate and the width of the rows. The research was conducted during 2021–2023 at the experimental field of the VSP "Zalischytskyi Vocational College named after E. Khraplyvyh NUBiP of Ukraine". The following methods were used in the research process: field, laboratory, mathematical and statistical using generally recognized methods and methodical recommendations. The experiment was conducted on dark gray podsolized soil. The experiment was based on a three-factor scheme, where Diadema Podillia and Mentor varieties were factor A, and row width was factor B (15 cm – control, 30 cm and 45 cm); factor C is the sowing rate (500 thousand/ha - control, 600 and 700 thousand pieces of similar seeds per 1 ha. The predecessor is winter wheat. The conducted studies showed that the maximum leaf surface area was the Mentor variety - it reached 37,7-44,7 thousand/m2/ha during the seeding period. In the variety Diadema Podillia, the area of the leaf surface grew more slowly and reached the maximum size – 36,3-43,0 thousand m2/ha during the seeding period. The largest assimilation surface of soybean plants was formed at seed sowing rates of 500-600 thousand/ha in the Mentor variety, and in the Diadema Podillia variety at seed sowing rates of 600-700 thousand/ha. and for row widths of 30 and 45 cm in both varieties. It was established that the photosynthetic potential of Diadema Podillia soybean during the period of germination - full maturity was within the range of 1,95-2,21 million m2 days/ha, in the Mentor variety – 2,16-2,56 million m2 days/ha.

Assessing the Impact of N Fertilizer on Soybean Yield and Quality Using a Modeling Approach

HighlightsSimulating the effect of high N fertilizer rates with the CSM-CROPGRO-Soybean model for Brazil.Simulated and observed plant tissue N accumulation increased with an increase in N fertilizer rates.N use efficiency decreased with N fertilization on soybeans under long-term scenarios.Both model simulations and observations indicate only a small response in crop yield to high N fertilization.Abstract. Soybean [Glycine max (L.)] is one of the main sources of food protein in the world. To achieve a high yield and grain protein concentration, soybean requires a large amount of nitrogen (N). Many studies have evaluated N fertilization in soybean, with the hypothesis that symbiotic N fixation may not be sufficient to supply N for high-yielding soybean. This study aimed to evaluate the performance of the CSM-CROPGRO-Soybean model with field data to determine the impact of N fertilizer on soybean and explore long-term scenarios. The experiments consisted of a combination of available water management and N fertilizer levels over eight crop seasons. After calibration and evaluation, the CSM-CROPGRO-Soybean model was used to explore the soil and plant N balance. We also applied the model to explore different N fertilization rates in long-term scenarios. The results showed that the model was able to simulate soybean growth with a very good agreement for all sites (D-statistic ranging from 0.63 to 0.99). The observed and simulated crop yield gains from N fertilization were small and not proportional to the amount of N fertilizer applied. The model underestimated the effect of N fertilizer on grain protein concentration increment, but there was a consistent trend towards an increase in protein concentration observed in measured data. Simulations of soil inorganic N balance suggested very high losses of N by volatilization for urea-N fertilization treatments. The long-term scenarios showed that using N rates above 600 kg ha-1 is potentially inappropriate, and a higher crop N use efficiency was obtained with no N fertilizer. Keywords: Ammonia volatilization, Crop yield, Crop N use efficiency, CROPGRO-Soybean model, Grain protein concentration, Nitrogen balance.

Role of Organic Fertilizer Types on Nutrient Absorption and Soybean Yield in Teak-based Agroforestry Systems

Background: Indonesia’s soybean production is insufficient to meet the demand for domestic soybean consumption as 86.4% demand is met from imports. Climatic conditions strongly influence soybean production and its quality in Indonesia, so the agroforestry system are used to to boost soybean production. However, the weakness of the agroforestry system is the low light intensity resulting in lower production. This study examines the effect of various organic fertilizers on nutrient uptake and soybean yields in teak-based agroforestry systems. Methods: The study used a complete randomized block design with one factor, namely the type of fertilizer with seven levels, namely inorganic fertilizer (Urea 50 kg/ha, SP36 100 kg/ha and KCl 100 kg/ha), Indigofera tinctoria compost, corncob compost, peanut green manure, chicken manure, goat manure and cow manure (dose of 5 tons/ha) and repeated three times. Result: The type of fertilizer affects nitrogen and potassium uptake, root length and biomass, number of leaves, plant biomass and 1 ha soybean yield in a teak-based agroforestry system. Indigofera tinctoria compost produced the highest nitrogen and potassium uptake, 13.83 g and 2.77g. Nitrogen uptake is positively correlated with root length and plant biomass. The highest soybean yield in the peanut green manure treatment was 1.6 tons. Organic fertilizers increased nutrient uptake and soybean yields under teak stands compared to inorganic fertilizers.

PENINGKATAN PERTUMBUHAN DAN HASIL KEDELAI YANG DITANAM DALAM KONDISI JENUH AIR MELALUI PEMBERIAN P ANORGANIK DAN KOMPOS TANDAN KOSONG KELAPA SAWIT DI ULTISOL

[ENHANCING GROWTH AND YIELD OF SOYBEAN GROWN UNDER WATER-SATURATED CONDITIONS BY INORGANIC P AND EMPTY FRUIT BUNCH COMPOST AMENDMENTS IN ULTISOL]. The saturated soil culture practices with which to obtain high yield of soybean in Ultisol, characterized by high acidity, nutrient deficiencies and imbalances, should be developed. This study was conducted to evaluate the beneficial effects of empty fruit bunch (EFB) compost combined with inorganic P application on growth and yield of soybean under water-saturated culture in Ultisol. This research was carried out from September to December 2022 in the rice field located in Kemumu Village, Arma Jaya District, North Bengkulu Regency, Bengkulu Province at an altitude of ±541 m above sea level. The field experiment was performed in factorial scheme based on a randomized complete block design with three replications. The experimental treatments included EFB compost as first factor at four levels (0, 5, 10, and 15 t/ha) and application of SP36 as second factor at four rates (0, 75, 150, and 225 kg/ha). Results show that Ultisol amended with a combination of 15 t/ha EFB compost and 75 kg/ha P2O5 resulted in the highest number of seeds per plant (about 142.266 seeds). The number of productive branches, fresh shoot weight, root dry weight, and root nodule weight was the highest in soil solely ammended with EFB compost at 15 t/ha. The sole P application at 225 kg/ha significantly (p<0.05) increased root dry weight and root nodule weight. Thus, under saturated soil culture, application of EFB compost and inorganic P in sole or combination would be the recommended nutrient management practice for enhancing soybean agronomic prformances in this acid soil.

Identification of High-Yielding Soybean Lines with Exceptional Seed Composition Qualities

In current markets, the primary uses for soybean seeds are in products derived from their oil or protein content. However, growers are compensated based on seed yield, so a more valuable crop is one that does not compromise on yield when compared with existing options, with an optimum combination of protein and oil. A negative correlation of seed protein with seed yield and oil makes the simultaneous improvement of these traits difficult but not impossible through conventional breeding. Selections of lines with exceptional yield and seed composition were made from two recombinant inbred line (RIL) soybean mapping populations to identify high protein and/or high oil lines with yields comparable to elite cultivars. The performance of these RILs was evaluated in multiple environments, and several genotypes were identified with yields comparable to those of high-yielding check cultivars with seed protein and/or oil content superior to the checks. These genotypes will provide breeders with additional sources of germplasm for continuing efforts to improve seed composition traits without compromising seed yield and provide growers with more profitable cultivars.

Identification of Modern High-Yield Soybean Genotypes for Potassium-Use Efficiency in Sandy Soil of the Brazilian Cerrado

Soybean is the main leguminous crop in Brazil, mostly grown in tropical soils with low potassium (K) availability. Therefore, the identification of new genotypes with efficient K uptake and utilization in environments with low exchangeable K content is an economically viable alternative to maximize crop yield in Brazil. A study was conducted to investigate the response of 25 modern high-yield soybean genotypes for K-use efficiency in a sandy tropical soil of the Brazilian Cerrado. Treatments were distributed in a completely randomized design in a 2 × 25 factorial scheme: two levels of K fertilization [20 mg K dm−3 (low level) or 200 mg K dm−3 (high level)] and 25 soybean genotypes with three replicates. Plant morphological traits, leaf K, and crop production components were measured. Based on grain production data, K-use efficiency (KUE) and response efficiency (RE) to K fertilization were calculated. Leaf area, shoot dry matter, pod number per plant, 1000-grain weight, and grain yield were the crop characteristics most limited by low soil K availability. The soybean genotypes “TMG7061 IPRO”, “BMX Bônus IPRO”, “RK6719 IPRO”, and “RK8317 IPRO” were classified as efficient in the use of soil K and are the most suitable genotypes to be cultivated in agricultural soils with low K availability. The genotypes “98R35 IPRO”, “HO Maracaí IPRO”, “BMX Bônus IPRO”, and “RK7518 IPRO” were classified as responsive to K fertilization and are the most recommended genotypes for cultivation in agricultural areas with the application of high K fertilizer rates. The genotype “BMX Bônus IPRO” simultaneously combines characteristics of K-use efficiency and response to K fertilization and hence can be grown in both K-deficient and optimal soils.

Применение комбинации физических полей для повышения посевных качеств семян сои

One of the main conditions for obtaining a high soybean yield is maintaining optimal sowing and harvesting times, as well as pre-sowing seed treatment aimed at increasing the sowing qualities of the seed material. In the Amur region, the optimal sowing time is considered to be the period when the average daily air temperature reaches 10–14º degrees Celsius. In this connection, as studies have shown, mid-ripening and late-ripening soybean varieties are sown at the end of May, usually on the 20th-25th, and early-ripening varieties are sown a week later. Maintaining these sowing dates contributes to better development of soybean plants, which allows the necessary work to care for the crops to be carried out in favorable conditions. The studies carried out show that all sowing work in the region must be carried out in the shortest possible time and no later than June 5. In addition to the conditions listed above, to increase soybean yields, it is necessary to pay due attention to other indicators, such as the quality of sowing work, selection of sowing method, compliance with seeding standards, sowing density and depth of seed placement in the soil, etc. Also, one of the promising ways to improve the sowing qualities of soybean seeds is to improve the mechanization used during pre-sowing treatment. The presented article presents the results of research on improving the pre-sowing qualities of seed material through the use of thermal and electromagnetic physical fields in combined processing of soybean seeds. Keywords: SEEDS, SOYBEANS, SOWING QUALITIES, SEED MATERIAL, THERMAL AND ELECTROMAGNETIC TREATMENT, SOWING, EFFICIENCY

The adaptability of soybean high yield varieties and farmer preferences in dry land area

Soybean development is currently directed to dry land areas. To support this program, IAARD has released some new varieties with a yield potential above 3 tons/ha. The aim of this study was to know the adaptability of new varieties of soybean and farmers preference in dry land areas. The field experiment was conducted in Grobogan Regency, using factorial randomized block design with two factors. The first factor was fertilizer dosage combined with bio fertilizer and the second factor was five soybean varieties. Farmer preference test was performed by interviewing the respondents. Measurements of the farmer attitudes, opinions, and perceptions was done using Likert scale. The results showed that Grobogan variety was better adapted to the dry land conditions of Grobogan Regency. The application of fertilizers combined with biofertilizers increased soybean growth and production. The highest plant (52.42 cm) and the highest soybean yield (2.165 t/ha) were obtained in the farmer’s dosage treatment combined with biofertilizers. The order of farmers preference for the tested varieties was Grobogan, Biosoy, Devon, Dega and Detap. These preferences were mostly based on crop productivity, seed size, seed availability, and ease of selling the yield.

Foliar application of manganese sources on glyphosate-resistant soybean in no-tillage

The glyphosate herbicide when applied in post-emergence in transgenic soybean can influence manganese (Mn) nutrition, with differentiated response when parceled out. The objective of this study was to evaluate the soybean response to Mn sources applied via leaf, in different phenological stages. Two experiments were carried out in areas with different Mn contents in the soil, using four Mn sources, sulphate and nitrate (experiment A), phosphite and Mn-EDTA (experiment B). Leaf application of Mn was done at V8 and V12 (150+150 g ha-1), V8 (single application at 300 g ha-1) and V12 (single application at 300 g ha-1). In experiment A, the plants treated with nitrate, in split application, had greater leaf area and height of insertion of the first pod. The nitric source resulted in higher soybean yield when applied at V12. On the other hand, sulphate provided plants with higher height at harvest and higher yield with split application. In experiment B, it was found a larger leaf area with application of Mn-EDTA in V12. The application of phosphite provided higher at harvest height when applied in V8 and higher leaf Mn content when applied in V12. The insertion of the first pod was lower in plants treated in V12 with phosphite or with Mn-EDTA and V8. The Mn-EDTA source resulted in higher yield of transgenic soybeans at a dose of 300 g ha-1, applied at V8 or V12, in no-till area with low Mn content in the soil.

Utilizing the CROPGRO Simulation Model to Optimize Management Practices for Achieving High Soybean Yields

A study was conducted during the kharif (June–September) season of 2018 at G.B.P.U.A.&T., Pantnagar, Uttarakhand, India to calibrate and validate the CROPGRO-soybean model for Terai region and determine the optimal management practices for soybean variety PS1347. The experiment followed a Two Factorial Randomized Block Design, involving two fertilizer treatments with three sowing dates replicated thrice. The CROPGRO model was calibrated and validated using the field data of 2018 and 2017, respectively. The RMSE% between the observed and simulated values of different crop stages and yield indicators were between 3.24% and 14.22%. Subsequently, the crop yield for different management practices was also simulated. The model encompassed yield simulations for various management practices viz., six tillage methods, five fertilizer treatments, nine sowing dates, and six irrigation levels. To achieve error minimization, soybean yield was simulated for four consecutive years (2015–2018) under various management practices, and the data was averaged. The simulation results indicated that the optimal management practices for achieving the highest soybean yield include sowing the seeds on the 20th June after implementing a tillage regimen involving three ploughings and two harrowing operations and further nourishing the crop with fertilizer dose of N:P:K:S::25:60:40:20 and applying 90 mm of irrigation. These findings will aid in optimizing management practices and developing sustainable and efficient approaches to achieve higher soybean yields with minimal inputs.

Responses of soybean, Glycine max (L.) Merr. to dolomite and calcite fertilization in an upland field converted from a paddy field

ABSTRACT Dolomite [CaMg(CO3)2] is used widely for soybean, Glycine max (L.) Merr. production in Japan to amend soil pH, although magnesium (Mg) in the dolomite can inhibit soybean growth and yield. The aim of this study was to determine the effect of Mg on soybean production in a paddy – upland rotation field in 2019–2020 by comparing the application of dolomite and calcite (CaCO3). The field test included three replications with three lime applications: control (no lime), dolomite, and calcite. The amounts of calcite and dolomite applied in each year were 253 and 259 g m−2, respectively. The soil pH was almost similar following the applications of calcite and dolomite, whereas the soil exchangeable Mg content was higher following the dolomite application than following the other applications. The shoot weight from the flowering stage to the harvest stage (R8) was significantly higher following the calcite application than following the other applications. However, the shoot weight at only R8 was significantly higher following the dolomite application than following the control application. In 2019–2020, the highest soybean yield was resulted from the calcite application (355 g m−2) followed by the dolomite application (312 g m−2) and the control application (260 g m−2). The severity of soil-borne diseases was lower following the dolomite application than following the control application, and even lower following the calcite application. Thus, the application of dolomite increased soybean yield by improving soil pH; however, Mg in the dolomite inhibited a further increase in soybean yield in a paddy – upland rotation field.

INTERACTIVE EFFECTS OF N FERTILIZATION AND BRADIRHIZOBIA JAPANICUM ON AGRONOMICAL TRAITS OF SOYBEAN IN SALT AFFECTED SOILS

Soil salinity has enormous negative impact on crop productivity leading to food insecurity and malnutrition, especially in arid regions. A field experiment was conducted during the summer seasons of 2018 and 2019 to evaluate the effects of various N fertilization rates in combination with Bradyrhizobium japonicum inoculation on the agronomic perfor-mance of soybean (Glycine max L) in saline soils (EC 5.8 dS m-1). The following fertilization treatments were applied: no fertilization (control), N0Р90К60, N30Р90К60, N60Р90К60 individually and in tandem with B. japonicum as a seed bio-inoculant. The experiment in a split-plot design, N fertilization as the main plot, the seed inoculation as the sub-plot was set up in three replicates. Soybean growth, nutrients uptake and yield parameters increased with increasing N fertili-zation rate, however, the effect was more pronounced with the seed inoculation. Averaged over the cropping seasons, the soybean yield was higher by 20.4%, 19.0%, 34.1% and 6.1% in the inoculated treatments of no-fertlization, N0Р90К60, N30Р90К60, N60Р90К60, respectively as compared to the similar fertilization treatments without the seed inoculation. As a result, fertilization rate of N30Р90К60 in with association B. japonicum inoculation was recommended as this study outcome due to the high soybean yield and quality seeds as the crucial components of sustainable agricultural production under salt-stressed field conditions.

Improvement of soybean yields using amendments on dryland soils of Aceh Besar, Indonesia

This study aimed to evaluate the response of soybeans to the application of various amendments to the sub-optimal dryland of Aceh Besar. A pot experiment was conducted in a greenhouse in Darussalam, Banda Aceh at an altitude of 3 m above sea level. The soil amendments used are biochar, compost, CaCO3 lime, and SP-36 phosphate fertilizer (SP-36). The experiment used a bifactorial 8 x 3 Randomized Block Design (RBD) in 2 replications. The first factor was the application of amendments consisting of eight levels, namely: control (without ameliorant or 0 t ha−1), applications of biochar 20 t ha−1, compost 20 t ha−1, CaCO3 4 t ha−1, SP-36, 4 t ha−1, biochar 10 t ha−1 + CaCO3 4 t ha−1, compost 10 t ha−1 + CaCO3 4 t ha−1, and biochar 10 t ha−1 + compost 10 t ha−1. The second factor is the three soil orders originating from the dryland farming system of Aceh Besar, namely: Andisols Saree, Inceptisols Cucum, and Ultisols Jantho. The soil used was taken from the top layer at a 0-20 cm depth. The soybean tested was the Anjasmoro variety with a potential yield of 2.03-2.25 t ha−1. The results showed that the application of amendments (Biochar, Compost, CaCO3, and SP-36) to three soil orders from the dryland of Aceh Besar could increase soybean growth and yield with a maximum yield of 2.2 t ha−1. In Andisols Saree and Inceptisols Cucum, the highest soybean yield was obtained when combined with biochar and compost at a dose of 10 tons ha−1. In Ultisols Jantho it was got when compost was given a single dose of 20 t ha−1. The growth and yield of Anjasmoro soybean varieties on Ultisols Jantho were better than those on Andisols Saree and Inceptisols Cucum.