Corn Grain Yield Research Articles

Influence of tillage methods on food security and its agrophysical and water-physical properties

To maintain the pace of the agriculture industry and assist bridge the gap between food supply and demand, best-implemented, sustainable, and optimal solutions are needed. Soil and water resources, research and development, extension, agricultural education, and related infrastructure development must be prioritized to boost food production and enhance soil and water management. Research has been carried out on the effect of various methods of main tillage - chiseling with various types of chisel rippers and moldboard plowing - on the agro- and water-physical parameters of light chestnut soil. Differences in soil density and moisture levels have influenced the development of corn plants. On the variants with deep chisel tillage, the accumulation of dry and raw plant biomass and the yield of corn grain were higher. Thus, the methods of main tillage allow to regulate the agro- and water-physical state of the soil and to have a significant effect on the productivity of plants. On the basis of the data obtained, for high-quality main tillage, providing optimal indicators of its density, crumbling, reserves of total and available moisture in the soil, it is possible to recommend the use of an experimental chisel ripper CR-2.4.

Совершенствование технологии производства кукурузы на зерно в условиях Приамурья

The yield of corn grain depends on the tillage methods used in the cultivation technology of wide-row crops. To make comprehensive assessment of the use of various combinations of the cultivator’s working tools, the authors carried out a two-year study to improve the technology of growing corn for grain by optimizing the system of mechanized cultivation of wide-row crops. The essence of optimization is to change the combination of working tools in a combined tillage unit and change the width of their arrangement along the row spacing width and the depth of soil cultivation. Integrated deep tillage contributes to the destruction of weeds from a larger area between the rows and provides optimal conditions for the growth and development of corn. In 2021, use was made of a tillage unit with a combination of working tools - two one-side flat cutting shares (edges) with overlapping of the working tool edge and a V-shaped share in the center of the inter-row spacing. This combination resulted in a corn yield of 3.62 t/ha. Compared to other types of tillage, the increase was from 0.61 to 1.10 t/ha. This year, in comparison with 2022, in the early phases of the growth of corn and the development of its reproductive parts from April to May, excessive moisture was observed, while in June and July the moisture level was insufficient. In 2022, the use of two universal V-shaped shares with overlapping the working tool edge, inserting wheel spiders in the center of inter-row spacing ensured a yield of 9.15 t/ha. Compared to other types of tillage, the increase was from 0.33 to 1.99 t/ha. The provision of a high yield level in 2022 was facilitated by excessive moisture in the period from April to June and the accumulation of moisture in the soil. The choice of a combination of working tools should be determined by weather conditions.

Features of the use of growth regulators in the cultivation of corn for grain in Western Siberia

The results of three-year studies (2020-2022) on the effectiveness of the use of various growth regulators in the cultivation of corn hybrids for grain in the forest-steppe zone of Western Siberia are presented. The studies were carried out on leached chernozem of the Novosibirsk region of the Novosibirsk region and on gray forest soil of the forest-steppe zone of the Novosibirsk Ob region. It is shown that in the forest-steppe of Western Siberia it is effective to use modern innovative growth regulators and chelate fertilizers in the process of corn grain production. It has been shown that on soil types it is effective to apply growth regulators Ecofus 0.001%, Epin-Extra 0.04% l/ha and chelated organosilicon fertilizer Siliplant 0.01% with a working solution flow rate of 300 l/ha in the phase of four to six maize leaves on six hybrids. It was statistically determined that the yield of corn grain depended on the element of technology by 33, genotype - 27 and the conditions of the year 23% and green mass, respectively, 35, 29 and 25%. It was shown that growth regulators and chelate fertilizers improved the parameters of the yield structure of corn hybrids.

The effect of harvest at different growth periods on grain yield and yield components of sweet corn (Zea mays L. saccharata Sturt)

Bu çalışmada farklı olgunlaşma dönemlerinde yapılan hasadın tatlı mısırın (Zea mays L. saccharata Sturt) tane verimi ve verim unsurlarına etkisinin belirlenmesi amaçlanmıştır. Çalışma tesadüf bloklarında bölünmüş parseller deneme desenine göre 3 tekerrürlü olarak Harran Ovası koşullarında 2016 ve 2017 yıllarında yürütülmüştür. Araştırmada Baron, Vega, Jübile, GSS 5649 ve Merit hibrit tatlı mısır çeşitleri materyal olarak kullanılmıştır. Zadoks skalasına göre erken süt olum (Z73), orta süt olum (Z75), geç süt olum (Z77), erken sarı olum (Z83), orta sarı olum (Z85) ve geç sarı olum (Z87) gelişim dönemlerinde hasat yapılmıştır. Araştırma sonuçlarına göre; koçan uzunluğu (cm), koçanda tane sayısı (adet koçan-1), koçanda tane ağırlığı (g koçan-1) ve tane verimi (kg da-1) gibi özellikler, gelişme dönemlerinde yapılan hasat bakımından istatiksel olarak önemli bulunmuştur (P≤0.01). Koçan kalınlığı 37.4 ile 39.2 mm, koçan uzunluğu 16.5 ile 18.1 cm, koçanda tane sayısı 415.0 ile 587.4 adet koçan-1, koçanda tane ağırlığı 61.7 ile 98.0 g koçan-1 arasında değişmiştir. Tane verimi 491.1 ile 810.3 kg da-1, bintane ağırlığı 131.5 ile 227.7 g ve hektolitre ağırlığı 47.1 ile 71.1 hL kg-1 arasında değişmiştir. Koçan uzunluğu, koçanda tane sayısı ve tane verimi değerleri erken gelişme dönemlerinde yapılan hasatta daha düşük, geç gelişme dönemlerinde yapılan hasatlarda ise daha yüksek bulunmuştur. En yüksek tane verimine orta sarı olum (Z85) ve geç sarı olum (Z87) dönemlerinde, en düşük tane verimine ise erken süt olum (Z73) döneminde ulaşılmıştır. Merit ve Jübile çeşitlerinin tane verimi değerleri diğerlerine göre daha yüksek bulunmuştur. Tane verimi bakımından en uygun hasat zamanı Baron ve Merit çeşitleri için geç süt olum dönemi, Vega çeşidi için orta süt olum dönemi, Jübile çeşidi için orta sarı olum dönemi ve GSS 5649 çeşidi için ise geç sarı olum dönemi olarak belirlenmiştir.

Effect of rhizobacteria Paenibacillus polymyxa KB and chelate complex of biogenic silicon on photosynthetic pigments and yield of corn grain

Effect of rhizobacteria Paenibacillus polymyxa KB and chelate complex of biogenic silicon on photosynthetic pigments and yield of corn grain

Planting models and mulching materials management to improve anti-oxidant defense system, grain hormone balance and production of maize in semi-arid regions

The water shortage and weeds damage have become severe problems in the dry-land farming system of China, the farming commonly using mulching materials strategy as a water-saving and weeds precaution agricultural technology. However, it is still unclear whether various mulching applications under different cultivation models can improve the antioxidant defence system, herbicide tolerance, and grain hormone balance, photosynthetic capacity and grain yield of corn. Therefore, during 2018–2019, a two-year study was conducted, and the following six treatments were used: CT: traditional planting; SM: corn stalk mulch; FM: plastic mulch; RT: ridges cultivation without plastic mulch; RP: Plastic mulch covering ridges and furrows; RPS: Plastic covering on ridges and straw on furrows. The results revealed that the RPS treatment enhanced the soil water storage in the jointing and filling stages, and obtained a higher chlorophyll stability index, IAA, Z + ZR, ABA, corn yield and other plant hormone content, compared with the control plot. Furthermore, this improvement is attributed to the reduction of oxidative damage of malondialdehyde (MDA) content at different growth stages. The RPS and RP treatments considerably improved the superoxide dismutase (SOD) and catalase (CAT), also decreased considerably the MDA, H2O2 and O2− contents at various growth stages. The RPS treatment had a higher ability to reduce the H2O2 and O2−, and the better anti-oxidant enzyme activity due to the lower level of lipid peroxidation, which can efficiently protect the photosynthesis mechanism and significantly improve (54.8%) biomass, (49.5%), WUEg, (89.1%), WUEb and (98.0%) grain yield are higher than CT treatment. In conclusion, RPS treatment has a great potential in improving grain hormone balance, antioxidant defence system and corn production in semi-arid areas.

CONTROL OF CORN POLLUTION IN THE CONDITIONS OF THE RIGHT-BANK FOREST STEPPE

This article presents the results of studies of the main elements and methods of controlling the development of weeds in corn crops and the identified changes in water and nutrient properties of the soil. The optimal tank mixtures and technological combinations of new soil and insurance herbicides have been determined, which provide a high level of technical efficiency on a wide species spectrum of weeds that clog corn crops. In particular, for farm conditions, the complex nature of the formation of the type of weediness, which changes during the growing season of the crop, was noted. The results of assessments of the dynamics of weed vegetation indicate a gradual increase in cenotic tension due to the gradual transition of dominant species of weeds, such as Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus-galli L., Elytrigia repens (L.) Gould , Sonchus arvensis L, Cirsium arvense L., Convolvulus arvensis L. in the middle tier of sowing with a simultaneous increase in the frequency of their determination by 1.1-1.3 times. It was established that the best growth and development of the total leaf surface of corn plants (2.15-2.26 pcs./m2) was noted on the herbicide agro background and complete removal of weeds, and with natural weediness of the crops - a negative effect on growth processes, size and duration of functioning of leaves (1.14 pcs./m2). According to the research results, the technical efficiency against weeds of the first wave reached 100% when combining soil and insurance herbicides - Dual Gold - 1.5 l/ha (before sowing) + Stellar - 1.25 l/ha + Surfactant Metolate - 1.25 l/ha (by stairs); during the second and subsequent waves of weeds, protection systems that combine vegetative and soil deterrent effects are best controlled (Stellar - 0.8 l/ha + Akris - 1.5 l/ha + Surfactant Metolate - 0.8 l/ha and Kelvin Plus - 0.3 kg/ha + Akris - 1.5 l/ha + PA Hasten - 1 l/ha). The highest yield of corn grain (6.98 t ha-1 and 6.81 t ha-1) was obtained from the combination of soil and insurance preparations Akris (before sowing) + Kelvin Plus and PAR Hasten (after the steps) and Dual Gold (before sowing) + Stellar and surfactant Metolat (by stairs); Akris + Stellar + metolat surfactant (yield - 6.68 t ha-1) was singled out among post-emergence herbicide mixtures; with autonomous use of the preparations Stellar and Kelvin Plus, the yield was 6.35 t ha-1 and 6.22 t ha-1, respectively. The identical economic expediency of using such variants of herbicide application on corn Akris, 1.5 l/ha + Stellar, 0.8 l/ha + Metolat surfactant, 0.8 l/ha and Stellar, 1.25 l/ha + Metolat surfactant, has been confirmed ,1.25 l/ha, which was 43% higher than in the control with natural weeding and 33.2-33.4% higher than in the option of inter-row cultivation with manual weeding.

Evaluating C trends in clayey Cerrado Oxisols using a four-quadrant model based on specific arylsulfatase and β-glucosidase activities

Management practices that promote the stabilization of extracellular enzymes in soil matrix, increasing their potential activity, favor the formation and stabilization of soil organic carbon (SOC). In this study, we present a four-quadrant model to evaluate C trends in clayey Cerrado Oxisols, based on the relationship between SOC and the average activities of arylsulfatase and β-glucosidase per unit of SOC (average specific enzyme activity, ASEA). This model assumes that areas under the same long-term soil use and management practices achieve a balance between ASEA and SOC. However, due to the greater sensitivity of soil enzymes, this balance is temporarily altered after the adoption of agricultural management practices that improve or degrade the overall soil quality (SQ). To calibrate the model, relationships were established between SOC and ASEA (0 to 10 cm soil samples) and the relative cumulative grain yield of soybean and corn in long-term field experiments. Threshold values for SOC and ASEA were defined as the equivalent of 50% of the maximum cumulative corn and soybean yields. These thresholds were used to divide an ASEA vs. SOC scatter plot into four quadrants. Quadrants 1 (high SOC/high ASEA) and 3 (low SOC/low ASEA) represent stable patterns of high- and low-quality soils, respectively. Quadrants 2 (low ASEA/high SOC) and 4 (high ASEA/low SOC) represent transitional patterns of soils undergoing biological degradation (C loss) and regenerative processes (C gain), respectively. A dataset containing 102 soil samples from commercial farms with contrasting management histories was used to validate the four-quadrant model, whereas a dataset of 1212 soil samples from representative Cerrado agricultural areas was used to characterize trends in soil C. The ASEA/SOC four-quadrant model provides a simple graphical representation that allows farmers to identify locations where soil management is following SOC gain or loss trajectories quickly and easily. This information can be used to make sound management decisions.

INFLUENCE OF EXTRA-ROOT NUTRITION ON BIOENERGETIC PRODUCTIVITY OF CORN GRAIN

Maize is a crop with a high yield potential and depends on technologies adapted to the conditions of the region. To form a high yield, the crop needs a balanced diet. One of the most effective means of influencing the yield and quality of corn grain is the application of mineral fertilizers. Foliar fertilization of corn crops can be an effective agronomic measure to stimulatephysiological processes under the influence of growth regulators on the development of corn in the initial stages, providing plants with trace elements during the growing season. Studies have shown that the growth of the leaf surface of plants of maize hybrids increased significantly with the growth and development of plants and reached maximum values before the flowering phase, followed by a slight decrease in the area of the leaf apparatus in subsequent growing seasons. The highest indicators of leaf surface area were observed in the areas where growth stimulant Regoplant and microfertilizer Chelatin Zinc were applied foliarly in the phase of 3-5 leaves of corn. Thus, the leaf area of the middle-early hybrid of maize DKS 3795 was 0,429 m2/plant, which is more than in the control plots by 0,026 m2/plant. Accordingly, the leaf area of the medium-ripe hybrid DKS-3511 was at the level of 0,467 m2/per plant, which is greater than the control plots by 0,035 m2/per plant. One of the ways to increase the efficiency of energy use in the production of crop products is to optimize technological methods and increase the yield per unit area. Energy analysis, which is a concentrated expression of the law of conservation and conversion of energy, allows you to compare energy consumption and energy content (receipt) in the harvest. Energy costs for growing maize hybrid 3511 for grain in control areas (without treatment with drugs) increased to 58,75 GJ, with the introduction of microfertilizers and growth regulators to 70,52 – 75,31 GJ. The energy coefficient was highest in the areas where plant growth stimulant Regoplant and microfertilizer Chelatin Zinc were applied – 1,94.

Ефективність застосування післясходових гербіцидів у посівах кукурудзи на зерно в Cхідному Лісостепу України

Goal. To determine the effect of multi-component post-emergence herbicides with a wide spectrum of action on crop weediness and corn grain yield in the conditions of the Eastern Forest Steppe of Ukraine. Methods. Field, analytical and statistical. Results. Annual cereal weeds predominated in number and raw mass of corn for grain crops, with dicotyledons annual and perennial species occupying the second and third positions, respectively. A decrease in the technical efficiency of post-emergence herbicides at high average daily air temperatures during the cultivation period was revealed. Thus, according to the results of the first accounting, the highest effectiveness in protection against cereal annual weeds was provided by the preparation rymsulfuron + dykamba + nikosulfuron (61%), dicotyledonous annuals and perennials — topramezon + dykamba (83 and 53%, respectively). According to the second record, more effective control of the number of cereal annual weeds was in the versions rymsulfuron + dykamba + nikosulfuron and nikosulfuron + rymsulfuron (respectively 61 and 61%), dicotyledons — rymsulfuron + dykamba + nikosulfuron and topramezon + dykamba (87 and 90%). Topramezon + dykamba was the best against dicotyledonous perennial weeds. The total number of weeds was most controlled by rymsulfuron + dykamba + nikosulfuron (61 and 65%, respectively). According to the records of the accumulation of raw mass by weeds, more improved control of annual cereal species was provided by rymsulfuron + dykamba + nikosulfuron (74%) and nikosulfuron + rymsulfuron (75%), dicotyledons — rymsulfuron + dykamba + nikosulfuron (99%) and topramezon + dykamba (99%), dicotyledonous perennials — topramezon + dykamba (77%). The total wet weight of weeds was better controlled by the herbicide rymsulfuron + dykamba + nikosulfuron (80%). The highest level of increase in the yield of corn grain was obtained in the option of application of the herbicide rymsulfuron + dykamba + nikosulfuron (2.72 t/ha). Conclusions. The use of the herbicide rymsulfuron + dykamba + nikosulfuron in corn crops in the phase of 4–5 leaves is promising for effective control of problematic weeds and ensuring an increase in grain yield in the conditions of the Eastern Forest-Steppe of Ukraine.

Міграція нітратного азоту за внесення азотних добрив у виробничих посівах кукурудзи

Goal. To determine the dynamics of the migration of nitrate nitrogen in the soil during the active growing season of corn with the application of nitrogen fertilizers in production conditions. Methods. Field — to determine the dynamics of nitrate nitrogen migration, laboratory-analytical — to determine the content of mineral nitrogen in the soil, mathematical-statistical — to assess the reliability of the obtained data. Results. It is proven that the fractional application of nitrogen fertilizers provides prolonged saturation of the soil with mineral nitrogen at elevated, high, or very high levels during the active growing season of corn. The maximum content of mineral nitrogen was fixed in the upper layer of the soil 0–20 cm. It was established that in typical chornozem, when N136 is applied in the soil layer 0–20 cm, the nitrate nitrogen content decreased over time — from May to September by 5.9 times, with depth — by 2.8–4.8 times in the layer of 100–120 cm compared to its content in the upper layer of 0–20 cm. With the application of N119 and N134, its growth in the soil layer of 0–20 cm was established in the interval between pre-sowing application and top dressing, where the content of nitrate nitrogen decreased at a depth of 100–120 cm compared to the content in the upper layer of 0–20 cm by 1.2–6.1 times. The highest yield of corn grain was obtained with fractional application of N136 and N134 (r = 0.77–0.84). Conclusions. It was established that with the fractional application of N119–N136, the content of nitrate nitrogen in the soil decreased with depth and over time, ensuring the formation of corn grain yield in production conditions of more than 10 t/ha. In dryland areas with deep underground water, it is unlikely that they will be contaminated with nitrate nitrogen at a fractional application of N119–N136/ha, where its maximum content is fixed in the soil layer of 0–20 cm.

Corn (Zea mays L.) and sorghum (Sorghum bicolor (L.) Moench) yield and nutritional quality affected by drought stress

Comparison of drought tolerance of crop plants is important for planning efficient cropping strategies and increasing yield production. The objective was to investigate the effects of drought stress including control (S1), 80 (moderate, S2) and 60% (severe, S3) of crop essential irrigation (determined by evaporation from the Class A evaporation pan) on grain yield and nutritional quality of different corn (Zea mays L.) (Maxima (sensitive) and 704 (tolerant)) and sorghum (Sorghum bicolor (L.) Moench) (Kimia (sensitive) and Payam (tolerant)) genotypes. The experiment, conducted in 2019, was a split plot based on randomized complete block design with three replicates. Plants yields and nutritional quality including relative water content (RW), fiber, protein, starch, tannin, and chlorophyll were measured. Although water stress did not significantly affect RW in corn, it significantly affected RW in sorghum. Fiber concentration was the highest at the severe stress in both corn genotypes (9.36% in 704 and 10.35% in Maxima), and sorghum Payam genotype (14.54%). The lowest (13.29%) and the highest (14.35%) corn protein content were obtained for Maxima in the medium and control level of stress, and for 704 genotype it ranged from 13.51 to 13.77%. Sorghum protein was the highest in the sensitive and tolerant genotypes in control and severe stress, respectively. Treatments S3 and S2 resulted in the highest (14.58%) and the lowest (12.47%) protein content for sorghum Kimia genotype. Although sorghum plants were tolerant in stress conditions, corn plants could also tolerate the stress up to some level by adjusting their physiological characteristics.

ВПЛИВ КОЛІСНИХ РУШІЇВ ПОСІВНОГО АГРЕГАТАНА ВРОЖАЙНІСТЬ ЗЕРНА КУКУРУДЗИ

The purpose of research: еstimation of influence of soil compaction by running wheels of the tractor with a row seeder on productivity and economic efficiency of cultivation of corn on grain. Research methods: hypothesis, experiment, field observation, laboratory, visual and comparative calculation method. Research results: Field studies were conducted in soil and climatic conditions of Western Ukraine. The experimental field was characterized by sod-podzolic light loam soils. Climatic conditions of research – the average daily air temperature during the growing season of corn - +16.9 ° C, rainfall – 263 mm. Väderstad's eight-row Tempo 8 seed drill, which was aggregated with a Fendt 722 tractor, was used in the research. In the process of performing the technological operation of such a sowing unit, two sowing machines work on the tracks of the tractor wheels. According to the results of research it was established that the number of cobs in the rows on the tracks of the tractor was 42.2-49.6 thousand pieces. / ha and was lower by 6.4-8.8 thousand units / ha (11.4-17.2 %) compared to uncompacted areas of the field. There was also a decrease in the weight of grain in the cob on the tracks of the tractor by 4-30 g, depending on the hybrid. The grain yield of corn sown on the tracks of the tractor was lower by 2.27-2.51 t/ha (16.5-27.9 %) compared to this figure on uncompacted rows. Seed yield of the studied hybrids (average value for all eight rows of rows) is 8.33-13.21 t/ha. Due to the fact that in ¼ rows (in two rows on the tracks of the tractor) recorded lower yields, the average yield of corn grain decreased by 0.57-0.66 t/ha (4.1-6.9 %) compared to this figure on uncompacted rows. Due to the negative impact of the running energy system on the soil during sowing, the economic indicators of maize cultivation deteriorate. If the soil compaction is eliminated or minimized by the running gear of the energy source, the profit may increase and according to the studied maize hybrids will be 19217-53921 UAH / ha. As a result of soil compaction by running systems of the sowing unit, the profit is reduced by 4104-4536 UAH/ha. Conclusions. In the rows located on the tracks of the tractor, due to soil compaction, the conditions of plant growth and development deteriorate, which is reflected in lower indicators of crop structure elements (number of cobs, grain weight of cobs, etc.) and reduced yield and efficiency of maize cultivation. Key words: research, corn, tractor running system, soil compaction, yield, efficiency.

Productivity of corn and beans as affected by season and source of nitrogen

Enhanced-efficiency fertilizers, which provide a reduction in nitrogen (N) losses, can be a viable alternative for the anticipation of topdressing for the moment of sowing, besides reducing operations for the rural producer. This study aimed to determine the effect of the period of application of enhanced-efficiency nitrogen fertilizers on the grain yield of corn and common bean in the Cerrado region in the direct seeding system. The experiment was carried out during two crop seasons (2019/2020 and 2020/2021), under field conditions. The completely randomized blocks experimental design was used, being arranged in a 2x4+1 factorial, with four replicates. Treatments consisted of the combination of the following two periods of nitrogen application: at sowing and recommended (four open leaves of corn and third trefoil in beans); and of the four following types of nitrogen fertilizers: 1. urea + NBPT + Zeolite; 2. urea + B + Cu + Zeolite; 3. Super N; and 4. Urea. Additionally, a control treatment (without N) was included. Nitrogen values for application in the treatments were adjusted so that 150 kg ha-1 N was applied to the corn, cultivated in summer, and 90 kg ha-1 N was applied to the common bean, cultivated in winter. It was concluded that nitrogen sources and period of nitrogen application did not affect corn grain yield, yield components, and common bean grain yield. The application of nitrogen in corn or common bean provided significant increases in crop grain yield.

The Response of Morphological and Physiological Traits and Grain Yield of Corn to Planting Method and Sugarcane Residue Compost

The Response of Morphological and Physiological Traits and Grain Yield of Corn to Planting Method and Sugarcane Residue Compost

Effects of Liquid Urea Application Frequency on the Growth and Grain Yield of Corn (Zea mays L.)

ABSTRACT Efficient nitrogen (N) management is considered one of the most important strategies for increasing sustainable crop yield along with maximizing nitrogen use efficiency (NUE). The aim of the study was to evaluate the effects of liquid urea (LU) application frequency on the growth, yield, and NUE of grain corn (Zea mays L.). The application frequencies urea were two split (2S) applied equally at 10 and 28 days after sowing (DAS), three split (3S) applied equally at 10, 40, and 65 DAS, and four split (4S) applied equally at 10, 30, 50, and 70 DAS organized by following randomized completely block design with four replicates. Results showed that stem diameter, ear length, fresh and dry stover weight, fresh cob weight, husk weight, kernel row/cob, and grain yield were higher in the LU treatments than granular urea (GU). Among all the treatments, the grain corn receiving LU3S had the highest stem diameter (2.03 cm), cob weight (248.25 g), 100 grain weight (29.08 g), N uptake (133.96 kg/ha), and NUE (72.84%). The corn grain yield of LU3S was 6.77 t/ha compared to the GU2S, which was only 4.95 t/ha. The N uptake along with NUE was significantly higher in LU3S treatment than other treatments. The results of this study suggest that the yield and NUE of corn were significantly affected by the urea source and application frequency of LU while LU3S was the most efficient treatment for maximizing the growth and yield of grain corn grown in tropical soil.

Effective hybrids of Zea mays L. under conditions of changes in the boundaries of agro-climatic zones under the influence of global warming

The studies were carried out in the European part of Russia in the steppe zone. The response of five Zea mays L. hybrids from different maturity groups to the spatial variability of regional conditions (climate, soil quality, agricultural technology) was studied. The obtained data are necessary for scientifically substantiated selection of agro-ameliorative measures and schemes for managing the production processes of agricultural plants in the context of changes in the boundaries of agro-climatic zones under the influence of global warming. It has been established that the limiting factor in the sustainable production of corn grain in areas with insufficient heat supply is the short duration of the growing season, therefore, earlier sowing dates for early ripening and cold-resistant hybrids are necessary. For areas with insufficient moisture supply, the conditions of moisture deficiency in the summer months reduce the yield of corn grain, so it is necessary to combine the early sowing of mid-season hybrids and the methods of moisture-saving technologies.

Single-Plant Grain Yield in Corn (Zea mays L.) Based on Emergence Date, Seed Size, Sowing Depth, and Plant to Plant Distance

The lack of seedling emergence uniformity in corn (Zea mays L.) is concerning for producers in the Midwestern U.S. These producers believe that just a few hours delay in emergence can increase interplant competition and decrease single-plant yield, thus reducing overall crop yield. It is speculated that lack of uniformity in seedling emergence occurs due to a variation in seed size within a commercial bag of seed, and variation in seed depth placement at sowing throughout the field. Due to these concerns, producers evaluate size seed variation within the bag before sowing. To date, research has investigated sowing dates, growing degree days, or varying sowing depths to simulate a delay in seedling emergence. These studies are important for understanding the effects of delayed emergence on overall yield, but they fail to examine the effect of inter-plant competition on single-plant yield. The objective of this study was to understand the effect of seed size and sowing depth on emergence and subsequent single-plant yield in a bare soil and a perennial groundcover (PGC) cropping system. Commercially sized seed and seed sized further in the laboratory to obtain a narrower seed size distribution were sown in Kentucky bluegrass and bare soil systems and at two sowing depths of 3.18 and 6.35 cm. The two-year experiment was planted in a split-plot design with four replications. Individual plants were flagged at emergence, and harvested individually. Seed placement was crucial to uniform emergence in both cropping systems, while seed size did not affect emergence in either system. The PGC cropping system delayed seed corn emergence and reduced grain yield as much as 50%. Single-plant yield decreased with delayed corn emergence in both cropping systems. Yield decrease as a function of emergence date followed either a quadratic or linear trend in each growing season, likely related to post emergence environmental factors. This information is important for producers and seed companies to understand the effect of seed size and sowing depth on yield and emergence. This study demonstrates that uniform sowing depth is more important than seed size distribution.

Seed Size, Planting Depth, and a Perennial Groundcover System Effect on Corn Emergence and Grain Yield

The intensive corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices currently used in the Midwestern U.S. concern producers and stakeholders. The negative impact of these two-crop rotations on the environment affects water quality and soil erosion and increases flooding risks. Due to these concerns, cover crops and, specifically, perennial groundcover (PGC) cropping systems have gained greater interest. These perennial species have growing patterns compatible with corn and soybean, and can help rebuild the ecosystem while maintaining good cash crop yields. In addition, producers also are interested in the possible effect of seed size and planting depth on uneven emergence in corn. The successful adoption of PGC systems ultimately depends on the successful corn seedling emergence and consistent yield. The objective of the study was to understand the effects of seed characteristics and placement on emergence, grain yield, and grain quality in corn planted using a Kentucky bluegrass (Poa pratensis L.) (KBG)-PGC and a bare-soil cropping system and to determine grain quality attributes and grain moisture dry-down in a PGC field when compared to a conventional cropping system. Commercially-sized seed and seed sized in the laboratory to represent a narrower seed size distribution were planted in KBG-PGC and bare soil systems at two planting depths (3.18 and 6.35 cm). The two-year experiments were planted in a split-plot RCB design with four replications. Individual plants were flagged at emergence, and ears from each plant were harvested individually. Separating the seed lot into different size distributions did not affect seed germination under ideal (standard germination and speed of germination tests) or stressful (cold test) conditions. Seed size distribution also did not influence emergence rate and yield in a conventional tillage (bare soils) or KBG-PGC system. These results indicate that seed sizing specifications and seed size cutoffs currently used by seed companies are suitable for uniform emergence and maximum grain yield in both cropping systems. Seed placement was crucial to uniform emergence in both cropping systems, while seed size distribution did not play a role in emergence for either system. The PGC cropping system delayed seed corn emergence and reduced grain yields as much as 50%. This information is important for those producers considering adopting a PGC system because it demonstrates that uniform planting depth is more important than seed size distribution.

Effects of Corn Intercropping with Soybean/Peanut/Millet on the Biomass and Yield of Corn under Fertilizer Reduction

Corn (Zea mays L.) is one of the key grain crops in China. In fields, the two crops of soybean (Glycine max L.) and peanut (Arachis hypogaea L.), which have nitrogen-fixing capacity (NFC), are generally used to intercrop with corn to improve plant physiology and production ability of corn even under fertilizer reduction. To explore a more scientific and reasonable way to plant corn, and simultaneously reduce the use of chemical fertilizers and pesticides, the impacts of corn intercropping with two NFC crops (including soybean and peanut) and the a non-NFC crop (i.e., millet (Setaria italica)) through five planting patterns, including three intercropping patterns (2 corn rows to 2, 3, and 4 NFC-crop rows or 2, 4, and 6 millet rows) and two sole crop patterns of corn and soybean, peanut, or millet under normal (600 kg/ha) and reduced (375 kg/ha) levels of NPK (N:P2O5:K2O = 15:15:15) fertilization levels on the activity of N-metabolism-related enzymes in corn rhizosphere soil and corn leaves, and plant biomass and yield of corn were researched in this study. The results showed that fertilizer reduction significantly decreased the plant biomass and grain yield of the sole crop corn. The intercropping type and planting pattern both had significant effects on the activities of N-metabolism-related enzyme of soil alkaline protease (S-ALPT), and glutamine oxoglutarate aminotransferase (GOGAT), glutamate synthetase (GS), and nitrate reductase (NR) in the leaves of corn plants. The intercropping type of corn with soybean through the planting pattern of 2 corn rows to 4 soybean rows significantly improved the activities of N-metabolism-related enzymes in soil and corn leaves even under the fertilizer reduction. The intercropping pattern of corn-soybean was the most beneficial to increase the total nitrogen content in soil and corn leaves. In addition, the intercropping significantly increased the soil microbial diversity under normal fertilizer. Furthermore, fertilizer reduction significantly increased soil microbial diversity of the corn sole crop. Therefore, it is concluded that for corn in intercropping systems, the best and the worst companion crop were, respectively, soybean and millet.