Soybean Sowing Research Articles

EFFECT OF PRE-EMERGENT HERBICIDES ON SOYBEAN CROPS GROWN IN ROTATION WITH SUGARCANE

The need for sugarcane field reform has driven the expansion of soybean cultivation in rotation with sugarcane. Weeds are one of the main reasons for this reform, requiring specific management in rotation. The use of pre-emergence herbicides in soybean is a viable option, but its effectiveness in sandy soils requires further study. In this experiment, we evaluated the performance of pre-emergence herbicides on sugarcane straw, focusing on the control of Digitaria horizontalis. We conducted a field experiment with 11 treatments and four replications, applying herbicides immediately after soybean sowing. All herbicides, except diclosulam, provided efficient control of D. horizontalis, with over 80% control in all evaluated periods. The clomazone+sulfentrazone association showed the highest residual effect, keeping the area clean for up to 21 days after application. Weed-free control resulted in productivity equivalent to 66% of the maximum obtained. The use of cell division inhibitors allowed soybean cultivation to grow without weed competition. We conclude that the use of pre-emergence herbicides in soybean under sugarcane straw resulted in productivity gains due to effective D. horizontalis control. Poaceae plants may have a higher competitive capacity with crops compared to other families; therefore, even with few plants per square meter, species like D. horizontalis can reduce crop productivity. The use of cell division inhibitor molecules, either alone or combined with PROTOX inhibitors, allowed the soybean crop to remain free of weed competition.

Effects of LDPE and PBAT plastics on soil organic carbon and carbon-enzymes: A mesocosm experiment under field conditions

Although the effects of plastic residues on soil organic carbon (SOC) have been studied, variations in SOC and soil carbon-enzyme activities at different plant growth stages have been largely overlooked. There remains a knowledge gap on how various varieties of plastics affect SOC and carbon-enzyme activity dynamics during the different growing stages of plants. In this study, we conducted a mesocosm experiment under field conditions using low-density polyethylene and poly (butylene adipate-co-terephthalate) debris (LDPE-D and PBAT-D, 500–2000 μm (pieces), 0%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%), and low-density polyethylene microplastics (LDPE-M, 500–1000 μm (powder), 0%, 0.05%, 0.1%, 0.5%) to investigate SOC and C-enzyme activities (β-xylosidase, cellobiohydrolase, β-glucosidase) at the sowing, seedling, flowering and harvesting stages of soybean (Glycine Max). The results showed that SOC in the LDPE-D treatments significantly increased from the flowering to harvesting stage, by 12.69%–13.26% (p < 0.05), but significantly decreased in the 0.05% and 0.1% LDPE-M treatments from the sowing to seedling stage (p < 0.05). However, PBAT-D had no significant effect on SOC during the whole growing period. For C-enzyme activities, only LDPE-D treatments inhibited GH (17.22–38.56%), BG (46.7–66.53%) and CBH (13.19–23.16%), compared to treatment without plastic addition, from the flowering stage to harvesting stage. Meanwhile, C-enzyme activities and SOC responded nonmonotonically to plastic abundance and the impacts significantly varied among the growing stages, especially in treatments with PBAT-D (p < 0.05). These risks to soil organic carbon cycling are likely mediated by the effects of plastic contamination and degradation soil microbe. These effects are sensitive to plastic characteristics such as type, size, and shape, which, in turn, affect the biogeochemical and mechanical interactions involving plastic particles. Therefore, further research on the interactions between plastic degradation processes and the soil microbial community may provide better mechanistic understanding the effect of plastic contamination on soil organic carbon cycling.

Temporal variability in soybean sowing and harvesting according to K-means and silhouette scores

Understanding the impact of seasonal variations on soybean productivity is crucial for optimizing agricultural practices. Given the influence of climatic factors such as temperature and rainfall on crop phenology, this study aims to analyze the effects of sowing and harvesting soybean cultivars in different seasons. This research investigates whether sowing soybeans in November and December leads to varying outcomes in terms of productivity and morphological characteristics, focusing on identifying the most stable cultivars across different climatic conditions. The study employed a comprehensive methodology, including data standardization, statistical tests (Levene, Shapiro-Wilk, ANOVA, Wilcoxon), and K-means clustering, to analyze 40 soybean cultivars across two seasons. Statistical preprocessing ensured data accuracy, while clustering helped identify cultivars with consistent responses to climatic changes. All computational analyses were performed using Python in the Google Colab environment. The findings revealed no significant difference in productivity between the two seasons, despite variations in temperature and rainfall. However, the moisture content of the grains (MTG) showed significant differences, influenced by higher rainfall in March and April and increased temperatures in December. K-means clustering highlighted SYN2282IPRO as the most stable cultivar and 77HO111I2X-GUAPORÉ as the most sensitive to climatic changes. The results emphasize the need for careful cultivar selection based on specific adaptability to seasonal variations. This study underscores the potential of computational tools like K-means clustering in agricultural optimization, offering a data-driven approach to selecting stable soybean cultivars. The adaptable methodology can be tailored to different geographical regions, soil types, and climate conditions, enhancing its relevance and applicability. These insights contribute to a better understanding of the complex interactions between climatic variables and soybean phenology, providing a foundation for improving agricultural practices in the face of climate change.

Development and Evaluation of a Universal Seed Discharger for Precision Planting in Corn-Soybean Cropping System

Aiming at solving the problem of a wide variety of crop planting and addressing the concept of precision agriculture, a pneumatic universal seed-metering device suitable for corn and soybean was designed. According to the physical size of the above two crops crop planting, a seeding plate, a hole, and a guide tube were designed. The pressure distribution inside the seeding plate was studied, when the pressure, the diameter of the hole, and the rotation speed of the metering plate changed. Through the coupling simulation method of DEM and CFD, the effects of the air suction hole diameter, the air pressure intensity, and the seeding plate speed on the seeding performance were explored. The results showed that when the air suction hole diameter was 5.9 mm, the air pressure intensity was 3.5 kPa, and the seeding plate speed was 23.8 r/min, and the performance of corn seeding was the best, among which the seeding qualification index was 95.35%, the replay index was 1.45%, and the missed seeding index was 3.23%. When the air suction hole diameter was 6.1 mm, the air pressure intensity was 3.5 kPa, and the rotation speed of the seed plate was 24 r/min, the performance of soybean sowing was the best, in which the sowing qualification index was 95.76%, the reseeding index was 3.47%, and the missed sowing index was 0.77%. The bench verification test and the comparative test were carried out. The results showed that the seed-metering device had good seeding performance and could be applied to the general seeding operation of corn and soybean.

System fertilization in integrated crop-livestock management favors microbial processes, soil quality and production profitability

Integrated crop-livestock systems with no tillage (ICLS-NT) have emerged as more responsible modes of production. Different fertilization strategies can optimize the productivity and profitability of ICLS-NT. However, it is necessary to understand how these strategies can change soil quality. This study aimed to investigate how different fertilization strategies within the ICLS-NT impact the biochemical and chemical attributes of the soil, as well as the productivity and profitability of the system. An ICLS-NT experiment was conducted with beef cattle grazing in winter and soybean cultivation in summer, structured in a 2×2 factorial arrangement, starting in 2019 and evaluated after 3 years (2021/2022 harvest). The first factor was the timing of fertilization: conventional Fertilization (CF - application of phosphorus and potassium during soybean sowing), and system Fertilization (SF - application of phosphorus and potassium in pasture). The second factor was the application of 100 kg ha–1 of nitrogen to the Brachiaria pasture: with application (+N) or without application (–N), resulting in four treatments distributed in three blocks. The system fertilization showed greater biochemical activity, nutrient availability, forage accumulation, increased animal stocking, and animal weight gain, regardless of the level of nitrogen. The strategy SF+N also provided an increase of 438 kg ha–1 in soybean grain productivity, which added to profits from animal production culminating in 407.35 US$ ha–1 of net income more than what was obtained in reference treatment (CF–N). The findings highlight that applying fertilizers after the crop phase is an effective strategy for replenishing soil nutrients, activating microbial processes and improving soil quality. This approach means a more sustainable agricultural practice, reducing environmental impact and at the same time reinforcing profitability in ICLS-NT.

Managing interspecific competition to enhance productivity through selection of soybean varieties and sowing dates in a cotton-soybean intercropping system

ContextProductivity and benefits in intercropping systems are influenced by the overlapping period and competitive dynamics between species, which are contingent upon variety selection and planting schedules. However, there is limited research on improving the productivity of intercropping systems by adjusting sowing dates for combinations with minimal plant height differences. MethodsA two-year field experiment utilizing a strip intercropping with four rows of cotton and five rows of soybeans was conducted. Three soybean varieties (Qihuang 34, Jidou 12, and Jidou 17) with varying plant heights and types, along with early and late sowing dates, were examined. ResultsIntercropping cotton and soybeans resulted in higher yields than monoculture, with Jidou 12 identified as the most suitable variety for intercropping with cotton. The land equivalent ratio (LER) for the cotton-soybean intercropping system averaged between 1.04 and 1.15 over two years. Notably, intercropping cotton with late-sown Qihuang 34, Jidou 12, and Jidou 17 demonstrated increased LER by 4 %, 5 %, and 3 % respectively, compared to early-sown. This demonstrates that adjusting the soybean sowing date can modulate the competition dynamics between cotton and soybean, mitigating interspecific competition. Furthermore, intercropping cotton with late-sown Jidou 12 exhibited superior performance in terms of dry matter, canopy photosynthesis, photosynthetically active radiation, and root morphology in cotton compared to other treatments. Within the distance of 100–150 mm from the soybean, cottons were more competitive than soybeans, indicating subtle interspecific competition between the two species. ConclusionsBy carefully selecting soybean varieties and adjusting sowing dates, temporal complementarity and spatial niche differentiation can be achieved, alleviating interspecific competition and enhancing the productivity of cotton-soybean intercropping systems.

A Method for Estimating Soybean Sowing, Beginning Seed, and Harvesting Dates in Brazil Using NDVI-MODIS Data

Brazil, as a global player in soybean production, contributes about 35% to the world’s supply and over half of its agricultural exports. Therefore, reliable information about its development becomes imperative to those who follow the market. Thus, this study estimates three phenological stages of soybean crops (sowing, beginning seed, and harvesting dates), identifying spatial–temporal patterns of soybean phenology using phenological metric extraction techniques from Normalized Difference Vegetation Index (NDVI) time-series data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Focused on the state of Paraná, this study validates the methodology using reference data from the Department of Rural Economics (DERAL). Subsequently, the model was applied to the major Brazilian soybean area cultivation. The results demonstrate strong agreement between the phenological estimates and reference data, showcasing the reliability of phenological metrics in capturing the stages of the soybean cycle. This study represents the first attempt, to the best of our knowledge, to correlate the vegetative peak of soybeans with the beginning seed stage at a large scale within Brazilian territory. Amidst the urgent need for the accurate estimation of agricultural crop phenological stages, particularly considering extreme weather events threatening global food security, this research emphasizes the continual importance of advancing techniques for soybean monitoring.

Sowing Date as a Factor Affecting Soybean Yield—A Case Study in Poland

Soybean is the crop of the future, especially for countries with a high demand for food and feed protein. Therefore, soybean cultivation is moving north to countries at higher latitudes, where temperatures, photoperiodism, and rainfall distribution are not always able to meet soybean requirements. The aim of this study was to evaluate three sowing dates as a factor influencing soybean cultivars yield and seed chemical composition in agroclimatic conditions of south-western Poland. In the years 2016–2019, a field experiment was conducted in Lower Silesia region, near Wroclaw, with three sowing dates: early (mid-April), 10-day delayed (at the turn of April and May), and 20-day delayed (first half of May), and two soybean cultivars: Merlin and Lissabon. In this location, soybean sowing is recommended in mid-April, possibly at the turn of April and May. The cultivars tested differed in yield and yield component values in the years of research, but generally, the Lissabon was better suited to local conditions. Results were discussed with findings of other domestic research, to investigate the problem of the soybean sowing date in Poland. The recommended sowing date for soybean was found to vary from region to region. These differences are due to the length of the growing season in each location and the varied adaptation of cultivars to the local climatic conditions.

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.

Dolomitic lime and silicate in no‐till: Nutritional status, soil fertility, and soybean agronomic performance

AbstractLimestone is the most widely used agricultural input for soil acidity correction and calcium (Ca) and magnesium (Mg) fertilization. However, other materials have the potential to fulfill these purposes, such as steel slags, also known as silicates. Silicates have higher solubility than limestone, serving as agents for increase pH in no‐till, in addition to being a source of Ca, Mg, and silicon (Si). This study aimed to compare the effects of surface application of dolomitic lime and calcium magnesium silicate on soil chemical properties, soybean [Glycine max (L.) Merr.] nutritional status, and grain yield under no‐till. The experiment was installed in the northwest Paraná State, Brazil, on a Rhodic Eutrustox. Lime and silicate rates were applied by broadcasting before the sowing of soybean. Silicate treatment increases soil Ca2+, pH, and base saturation up to a depth of 0.10 m. By contrast, liming effects on soil chemistry were restricted to the 0.05 m top layer after 24 months of application. The acidity correction and Ca2+ supply to greater soil depths and the increased leaf Si as a beneficial element provided by silicate treatment contributed to increasing soybean yield in the 2018/2019 and 2019/2020 seasons. Lime application, regardless of the rate, did not improve soybean yield. Waste from the steel industry can be used as acidity correctives and source of Si, Ca, and Mg, improving the agronomic performance of soybean.

Nitrogen fertilization and desiccation times of palisadegrass pasture driving C and N-cycling traits in an Oxisol under soybean in a crop-livestock system

The pasture management and desiccation times before sowing may affect the following grain crop in crop-livestock system. To explore the impacts of N fertilization applied to the palisadegrass (Urochloa brizantha) pasture and the desiccation time before soybean (Glycine max L.) sowing on attributes related to C and N cycling and on soybean yield, we conducted an experiment with palisadegras pasture grazed for 18 months receiving 300 kg ha−1 of N (+N, urea) or without N fertilization (–N), desiccated at 1, 15, 30, 45, or 60 days before soybean sowing. Assessments at the soybean sowing and at R3 stage showed that desiccation times had only minor effects on soil attributes. However, pasture N fertilization (+N) significantly decreased the soil basal respiration (9.6 vs 8.4 μg g−1 day−1 of CO2-C) at soybean sowing; at R3, +N decreased soil organic C (20.8 vs. 19.7 g kg−1), total N (2.1 vs. 2.0 g kg−1), and urease activity (62.6 vs. 42.4 μg g−1 h−1 of NH4+-N). Conversely, +N increased labile C (164 vs. 346 mg kg−1) at R3, and nitrification rate at sowing (6.6 vs. 11.6%) and R3 (2.32 vs. 5.26%). Ammonification rate increased at sowing (0.02 vs. 0.03 μg g−1 day−1 of NH4+-N) due to N fertilization but decreased at R3 (0.06 vs. -0.08 μg g−1 day−1 of NH4+-N). Besides causing negative variations in most of the soil attributes related to C and N cycling, fertilization of palisadegrass pasture with 300 kg ha−1 of N decreased soybean yield (5040 vs. 4770 kg ha−1). Desiccation times of palisadegrass did not affect the soil attributes related to C and N cycling and soybean yield so that short desiccation times before soybean sowing can optimize the forage use in the livestock phase and allow the biomass recovery after grazing for soil mulching in the no-till system of the integrated grain crop.

Influence of Mechanization on Yield and Economics of Soybean

The present study was conducted at farmers fields of Adilabad district, Telangana state, India during kharif seasons of 2019 to 2021 (for 3 seasons) to appraise the effect of mechanization on soybean yield as well as economics. In this study, sowing by tractor operated seed cum fertilizer drill and harvesting by combined harvester was compared with the farmer’s practice (Bullock drawn seed drill sowing and manual harvesting and threshing). In comparison to the conventional method, the sowing of soybean with tractor operated seed cum fertilizer drill and harvesting with combined harvester found to be superior in seed yield and average soybean productivity with mechanization was 1870 kg ha-1, with a yield increase of 2.20% over conventional method of sowing (1830 kg ha-1). Similarly, the economics of soybean were found to be highest with mechanization in terms of gross returns (Rs 79064 ha-1) and net returns (Rs 52464 ha-1) with a B:C ratio of 2.97:1 compared to conventional method which generated the gross returns of Rs. 77150 ha-1 and net returns of Rs 46966 ha-1 with a B:C ratio of 2.56:1.

Performance of seedlings and yield of soybean genotypes under soil compaction

AbstractThe identification of soybean genotypes tolerant to soil compaction makes it possible to reduce productivity loss under stress conditions. Added to this, the prior selection of these genotypes will result in greater assertiveness in the positioning of cultivars in the field. Thus, the objective was to evaluate the susceptibility of soybean genotypes to compaction in greenhouse and field conditions; verify which characteristics of seedlings under high resistance to root penetration are correlated with crop production in compacted soil; and to validate the substrate mechanical impedance method for evaluating the susceptibility of plant genotypes to soil compaction. Seeds of 20 genotypes were sown in a substrate mechanical impedance system under controlled conditions. The characteristics evaluated were total root length, total root surface area, mean root diameter, total root volume, taproot length, shoot length, root dry matter and seedling shoot dry matter. In the field experiment, half of the planting area was compacted, constituting two treatments, soil with and without compaction. The percentage of seedling emergence, initial plant height, stem diameter, number of nodes, internode length, number of lateral branches, shoot dry matter, final plant height, absolute and relative growth rate, number of pods, weight of 100 seeds and grain yield. In addition, the number of days between soybean sowing until plant flowering and grain harvest was recorded according to genotype and soil compaction level. In a controlled environment, genotypes tolerant to soil compaction show greater plasticity of root characteristics and smaller alterations in the shoot of seedlings. In the field, these genotypes show smaller reductions in growth rate, height, number of pods and grain yield. The shoot dry matter and the root dry matter of soybean seedlings in a mechanical impedance system present a positive and negative correlation, respectively, with soybean yield in compacted soil, indicating that the genetically determined susceptibility to soil compaction stress was similar throughout ontogenesis. The substrate mechanical impedance system used to evaluate the performance of soybean seedlings under stress, facilitates the decision‐making in breeding programs focused on identifying genotypes expressing soil compaction tolerance.

Features of the formation of the height of soybean varieties of different maturity groups

The article presents the results of the analysis of the formation of the height of soybean plants, their weight, attachment of the lower beans on the plant in different groups of soybean maturity. The research was conducted in 2022–2024 at NATASHA AGRO LLC of the Chernihiv region. Soy varieties, early ripening - Diadema Podillia, Tenor, Satalia; mid-early ripening – Churayvna, Sakuza, Mentor; medium-ripe - Pallador, Prescott, Azimuth. The Churayvna soybean variety served as a control. The soil of the experimental site is a meadow-chernozem dusty-loamy soil. The area of the sowing area is 78 m2, the accounting area is 25 m2, repetition three times. The predecessor is corn. The method of sowing is35 cm wide rows. Soybean sowing rate is 550,000/ha of similar seeds. It has been established that the formation of the height of soybean plants is influenced by varietal characteristics. Soybean plants reach their maximum height in the bean filling phase, while the tallest were the mid-ripening varieties Pallador –92,2 cm, Prescott –89,0 cm, and the mid-early - Sakuza –90,4 cm. The lowest height of soybean plants was recorded in early-ripening Tenor soybean varieties –77,1 cmand Diadema Podillya –73,6 cm. In the varieties Pallador, Prescot, Azimuth of the medium-ripening group, the height of the attachment of the lower bean was from 15 to16 cm. For these varieties, this is a positive indicator, which will reduce losses when harvesting with a combine harvester . Varieties Tenor, Satalia had a low bean attachment of 11–11,8 cm, both in favorable and unfavorable years of research. The height of plants of different varieties of soybeans in the phase of the 2nd trifoliate white leaf is almost the same. Differences in indicators are observed in the phase of the beginning of budding, the largest increase is during the flowering period - the filling of beans. Sakuza varieties stood out –86,6 cm, Pallador –96,1 cm, Prescott –81,4 cm.

Volunteer soybean (Glycine max) interference in bean (Phaseolus vulgaris) crops: ethoxysulfuron and halosulfuron critical level of damage and selectivity

This study aimed to determine the negative impact of volunteer soybean plants on bean crop yield and the tolerance of bean genotypes to the herbicides ethoxysulfuron and halosulfuron. To determine the impact of volunteer soybean plants on bean crops, a field experiment was developed, with sub-sub-plots, and four replications. The main plots contained two bean cultivars, while the sub-plots received two soybean sowing times (0 and 7 days after the beans had been sown), while the sub-sub plots contained five soybean plant densities (0, 5, 10, 20, and 40 plants m-2). The tolerance of the bean genotypes was evaluated with two experiments in a completely randomized design with three replications. They were arranged in a 28 x 3 factorial design (bean genotypes x herbicide doses). Each soybean plant per m2 reduced bean crop yield by 4%. The recommended doses of ethoxysulfuorn and halosulfuorn resulted in tolerance levels above 70% for all the studied bean genotypes. Highlights: The herbicides ethoxysulfuron and halosulfuron, are registered in Brazil for the control of volunteer soybean plants in bean crops. To date, the impact generated by volunteer soybean plants competing with bean plants is unknown. The tolerance of 28 bean cultivars to herbicides ethoxysulfuron and halosulfuron was determined using dose label and double the dose. The impact of volunteer soybean plants on bean crops was determined using two bean cultivars and two soybean sowing times. The bean genotypes displayed a highly variable response to the herbicides ethoxysulfuron and halosulfuron; however, when the label recommended dose of the herbicides was used, the tolerance levels observed were over 70%. Each soybean plant is capable of causing a 4% reduction in bean plant grain yield, regardless of the establishment time of the soybean plants or the bean genotype.

АГРОБИОЛОГИЧЕСКАЯ ОЦЕНКА МАСЛИЧНЫХ КУЛЬТУР В УСЛОВИЯХ ЛЕСОСТЕПИ ЦФО РФ

This article presents the results of environmental tests of the most promising very early soybean lines of Krasnodar breeding in the conditions of the Forest-steppe of the Central Federal District of the Russian Fed-eration, which were involved in hybridization. In the obtained hybrid populations of F4 in the conditions of Krasnodar, very early elite plants with a growing period of 90-100 days, plant height of at least 70 cm, and increased productivity were isolated. Their offspring in generations F6 and F7 underwent selection evalua-tion in the latitudinal and climatic conditions of the forest–steppe of the Central Black Soil region on the ba-sis of the Lipetsk Rapeseed Research Institute - a branch of the Federal State Budgetary Research Center V.S. Pustovoit All-Russian Research Institute of Oil crops, Lipetsk. As a result of the conducted studies, it was found that in the typical weather conditions of the Central Black Soil region in 2021 and with the dates of soybean sowing in the Lipetsk region in the 2nd decade of May, the earliest genotypes ripened in late August – early September. The duration of their growing seasons was 96-103 days. In the abnormally cold and rainy conditions of 2022, the growing season of these genotypes increased to 110-123 days. The yield of the earliest of the studied soybean genotypes in the conditions of 2021 varied in the range of 2.04-2.46 t/ha, in the condi-tions of 2022 – in the range of 2.07-2.91 t/ha. A two-year analysis of the productivity of the studied soybean genotypes in various weather conditions allowed us to identify 7 breeding lines that form a yield of more than 2.0 t/ha, both in close to optimal and in abnormally cold weather conditions with excessive precipitation.

Optimal Planting Density and Nutrient Application of Soybeans: A Case Study in Northeastern China

In the context of the Chinese government’s policy guidance, there is black soil protection and ecological environment protection. The purpose of this paper is to solve the problem that the soil ecology of the black soil in Northeast China is changing year by year, and it is necessary to explore the sowing and fertilization strategy under the new situation; most Chinese growers rely excessively on their personal experience in the process of soybean sowing and fertilization. In this study, we used “Heihe 43” soybeans and used regression experimental design methods to analyze the effects of planting density, nitrogen, phosphorus, and potassium fertilizer application on soybean yield and to determine the optimal planting density and fertilizer ratios. The study reveals that the optimal soybean planting density in Northeast China is 45.37 × 104 plants/ha, with nitrogen at 98.4 kg/ha, phosphorus at 218.96 kg/ha, and potash at 47.62 kg/ha. Under these conditions, soybean yields can reach 3816.67 kg/ha. This study can provide a theoretical method for decision-making to obtain the optimal planting density and fertilizer ratio for different regions of the farming system.

Crop-Livestock Integration Improves Physical Soil, Agronomic and Environmental Aspects in Soybean Cultivation.

Soybean is one of the most widely grown crops in the world and technologies are increasingly needed to increase productivity without impacting environmental degradation. In this context, the aim was to evaluate the action of forage plants of the genus Brachiaria sp. in crop-livestock integration on physical soil, agronomic and environmental aspects of soybean cultivation. The experiment was conducted in a subdivided plot design with seven integrated systems corresponding to the previous cultivation of Paiaguas palisadegrass, Xaraes palisadegrass and Ruziziensis grass in monocropping and intercropped with maize, as well as maize in monocropping. In the subplots, two grass management systems were evaluated: free growth and a grazing simulation cut. The bulk density and least limiting water range were assessed using soil samples and, after the pastures were desiccated when the soybean crop was planted, straw decomposition and plantability. A soil physics diagnosis by the bulk density and least limiting water range showed that the Paiaguas palisadegrass and Xaraes palisadegrass improved the soil environment due to biological soil loosening. The remaining mulch biomass did not affect soybean sowing and the adoption of Brachiaria sp. grass in the off-season, in addition to contributing to the provision of environmental services, and did not compromise grain productivity in succession.

Seed Yield, Yield Components, and Damaged Seed Rate in Soybean Sown in June and July in Kanagawa Prefecture

Seed Yield, Yield Components, and Damaged Seed Rate in Soybean Sown in June and July in Kanagawa Prefecture

Sustainability of different cropping systems under varying sowing dates in Marathwada region

The field experiments were carried out at Instructional Farm, AICRP on Dry land Agriculture, Marathwada Agricultural University, Parbhani during the rainy season of 2001-2005 on eight different cropping systems consisting of important food, pulse and oilseed crops of Marathwada region under varied weather conditions. The resultsrevealed that intercropping of sorghum (CSH-9)+ pigeonpea, pear millet + pigeonpea and castor + soybean sown in 26 meteorological week (MW) produced the highest grain yield and average productivity of the system during all the years of experimentation as compared to rest of the cropping systems. Similarly, castor + soybean produced the highest sorghum grain equivalent which was at par with soybean + pigeonpea, Arborium cotton + soybean and cotton (NHH-44) + soybean. The sowing of all the crops and cropping systems on 26 MW recorded significantly highestsustainable yield index (0.52) as compared to sowing of all cropping systems on delayed sowing dates.