Winter Wheat Grain Yield Research Articles

Periods of ammonium nitrate application during the cultivation of soft winter wheat variety Krasa Dona in the southern part of the Rostov region

The studies were carried out in the southern part of the Rostov region in 2017-2019 on typical carbonate chernozem. Studied was the efficiency of periods of ammonium nitrate application (N30, N30+30 ) in autumn when the vegetation season is finished, in spring in the thawed soil, and during the tillering phaseon the yield and quality of winter wheat grain of Krasa Dona variety by different seed sowing rates (500, 600, 700 pcs/m2). Soft winter wheat variety Krasa Donacultivated after sunflower has shown a good reaction to double nitrogen top-dressing in autumn and in spring (N30 in autumn when the autumn growing season is finished + N30 in spring on thawed soil). In this variant there has been formed the largest yield of 6.09-6.18 t/ha. The productivity excess over the control variant (without nitrogen top-dressings) was 2.38-2.63 t/ha, depending on the seeding rate, which significantly exceeded the level of LSD05 in the experiment (LSD05 = 0.24 t/ha). In addition, in this variant with the seeding rate of 500 pcs/m2 the maximum economic efficiency was obtained. The profitability was 121.3 %, and the contingent net income was 34,268 rub/ha. The application of nitrogen fertilizing provided an increase in the mass of 1000 grains to 42.6-43.0 g (39.8-40.2 g in the control) and increased the gluten content in the grain to 20.5-21.8 % (18.6-18.8 % in the control).

Increasing of wheat grain yield by use of a liquid fertilizer

Wheat is a vital crop in Georgia and in the world. Because of the increase in the rate of population growth, improving the grain yield is the way to meet food demand. Proper crop nutrition plays a vital role in maintaining the world’s food supply. Fertilizer is essential for accomplishing this.One of the most important means for increasing the wheat yield is fertilizer, especially, organic fertilizer. The present research was carried out to study the effects of different doses (150ml, 200ml and 300 ml on ha) of humic organic fertilizer “Ecorost” on yield of winter wheat cultivar “Tbilisuri 15”. The humic liquid fertilizer "Ecorost" is a peat-based organic-mineral fertilizer. The product is active and saturated due to the use of the latest technology and living bacteria found in peat. The field trials were conducted in 2017-2019 at the Experimental Site of Scientific Research Center of Agriculture in Dedopliskharo- arid region (Eastern Georgia).Liquid fertilizer was applied two times: in tillering stage in early spring and two weeks after - in stem elongation stage. Results indicated that the highest wheat grain yield (4t/ha) was achieved when the plants were fertilized with 300 ml on 1 ha ofEcorost. Applications of liquid fertilizer “Ecorost” increased grain yield of winter wheat by 16.2% in comparison with standard nitrogen fertilization. Thus, liquid fertilizer “Ecorost” had a significant effect on wheat grain yield compared to control standard nitrogen fertilizer.

Low-tillering winter wheat cultivars are more adaptable to late sowing

AbstractGlobal warming increases the risk of pests and weeds before wintering, and decreases the grain yield of winter wheat. Therefore, the sowing date should be delayed properly. But the variety of winter wheat that can adapt to late sowing remains unclear. Here, we selected two winter wheat cultivars and evaluated four sowing date treatments on 1 October (early sowing), 8 (normal sowing), 15 (late sowing) and 22 (latest sowing) over two wheat-growing seasons at the experimental Station of Shandong Agricultural University (35°96′N, 117°06′E), Daiyue District, Taian, Shandong, China. We examined the effects of sowing date on a few traits, and found that, compared with normal sowing, though spike number decreased, grain yield was maintained above 9300 kg/ha under late and latest sowing. The main reason was that the more accumulated N from jointing to anthesis resulted in a higher grain number per spike. The higher net photosynthetic rate after anthesis, through optimizing N distribution in the canopy and increasing Rubisco content of flag leaves, improved dry matter accumulation rate and contribution ratio of vegetative organs, ultimately, ensured consistent grain weight. The grain yield of high-tillering winter wheat cultivars decreased from 9370 to 8346 kg/ha. The main reason was that spike number, accumulated N from jointing to anthesis and net photosynthetic rate decreased significantly, which reduced the dry matter accumulation rate, and only satisfied less grains to achieve consistent grain weight. Therefore, low-tillering winter wheat cultivars are more adaptable to late sowing, and can reduce the harm of global warming.

Correlations between grain yield and related traits in winter wheat under multi-environmental traits

Abstract. In a series of field trials, a database of quantitative traits associated with winter wheat grain yield has been collected. The aim of the present study is to determine the relationships between the winter wheat (Triticum aestivum L.) traits of productivity in environments causing the maximum possible variation of each of the traits. In order to determine the correlations between the quantitative characters studied, all possible statistical methods have been applied (regression analysis, PCA, Multiple Correspondence analysis), which complement each other. It was found that the nature of the correlations between traits depends to a large extent on the methods for their evaluation. There are high and significant correlations between grain yields and the grain number per spike (weight of grain per spike and number of grains per m2) even under strong genotype by environment interaction of all the traits in trails. The established results are related to possible options for increasing winter wheat grain yield by breeding.

Within-Field Relationships between Satellite-Derived Vegetation Indices, Grain Yield and Spike Number of Winter Wheat and Triticale

The aims of this study were to: (i) evaluate the relationships between vegetation indices (VIs) derived from Sentinel-2 imagery and grain yield (GY) and the number of spikes per square meter (SN) of winter wheat and triticale; (ii) determine the dates and plant growth stages when the above relationships were the strongest at individual field scale, thus allowing for accurate yield prediction. Observations of GY and SN were performed at harvest on six fields (three locations in two seasons: 2017 and 2018) in three regions of Poland, i.e., northeastern (A—Brożówka), central (B—Zdziechów) and southeastern Poland (C—Kryłów). Vegetation indices (Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), modified SAVI (mSAVI), modified SAVI 2 (mSAVI2), Infrared Percentage Vegetation Index (IPVI), Global Environmental Monitoring Index (GEMI), and Ratio Vegetation Index (RVI)) calculated for sampling points from mid-March until mid-July, covering within-field soil and topographical variability, were included in the analysis. Depending on the location, the highest correlation coefficients (of about 0.6–0.9) for most of VIs with GY and SN were obtained about 4–6 weeks before harvest (from the beginning of shooting to milk maturity). Therefore, satellite-derived VIs are useful for the prediction of within-field cereal GY as well as SN variability. Information on GY, predicted together with the results for soil nutrient availability, is the basis for the formulation of variable fertilize rates in precision agriculture. All examined VIs were similarly correlated with GY and SN via the commonly used NDVI. The increase in NDVI by 0.1 unit was related to an average increase in GY by about 2 t ha−1.

Optimized split nitrogen fertilizer increase photosynthesis, grain yield, nitrogen use efficiency and water use efficiency under water-saving irrigation

This study aims to investigate optimization of the basal-top-dressing nitrogen ratio for improving winter wheat grain yield, nitrogen use efficiency, water use efficiency and physiological parameters under supplemental irrigation. A water-saving irrigation (SI) regime was established and sufficient irrigation (UI) was used as a control condition. The split-nitrogen regimes used were based on a identical total nitrogen application rate of 240 kg ha−1 but were split in four different proportions between sowing and the jointing stage; i.e. 10:0 (N1), 7:3 (N2), 5:5 (N3) and 3:7 (N4). Compared with the N1, N2 and N4 treatments, N3 treatment increased grain yield, nitrogen and water use efficiencies by 5.27–17.75%, 5.68–18.78% and 5.65–31.02%, respectively, in both years. The yield advantage obtained with the optimized split-nitrogen fertilizer application may be attributable to greater flag leaf photosynthetic capacity and grain-filling capacity. Furthermore, the N3 treatment maintained the highest nitrogen and water use efficiencies. Moreover, we observed that water use efficiency of SI compared with UI increased by 9.75% in 2016 and 10.79% in 2017, respectively. It can be concluded that SI along with a 5:5 basal-top-dressing nitrogen ratio should be considered as an optimal fertigation strategy for both high grain yield and efficiency in winter wheat.

Statistical Analysis versus the M5P Machine Learning Algorithm to Analyze the Yield of Winter Wheat in a Long-Term Fertilizer Experiment

To compare how different analytical methods explain crop yields from a long-term field experiment (LTFE), we analyzed the grain yield of winter wheat (WW) under different fertilizer applications in Müncheberg, Germany. An analysis of variance (ANOVA), linear mixed-effects model (LMM), and MP5 regression tree model were used to evaluate the grain yield response. All the methods identified fertilizer application and environmental factors as the main variables that explained 80% of the variance in grain yields. Mineral nitrogen fertilizer (NF) application was the major factor that influenced the grain yield in all methods. Farmyard manure slightly influenced the grain yield with no NF application in the ANOVA and M5P regression tree. While sources of environmental factors were unmeasured in the ANOVA test, they were quantified in detail in the LMM and M5P model. The LMM and M5P model identified the cumulative number of freezing days in December as the main climate-based determinant of the grain yield variation. Additionally, the temperature in October, the cumulative number of freezing days in February, the yield of the preceding crop, and the total nitrogen in the soil were determinants of the grain yield in both models. Apart from the common determinants that appeared in both models, the LMM additionally showed precipitation in June and the cumulative number of days in July with temperatures above 30 °C, while the M5P model showed soil organic carbon as an influencing factor of the grain yield. The ANOVA results provide only the main factors affecting the WW yield. The LMM had a better predictive performance compared to the M5P, with smaller root mean square and mean absolute errors. However, they were richer regressors than the ANOVA. The M5P model presented an intuitive visualization of important variables and their critical thresholds, and revealed other variables that were not captured by the LMM model. Hence, the use of different methods can strengthen the statement of the analysis, and thus, the co-use of the LMM and M5P model should be considered, especially in large databases involving multiple variables.

Genetic improvement of grain yield and bread-making quality of winter wheat over the past 90 years under the Pannonian Plain conditions

Studies on genetic gains in a historical set of wheat cultivars mostly refer to grain yield and the associated agronomical and physiological traits, while less attention is paid to the improvement of wheat quality. In order to analyze the breeding progress in grain yield and with an emphasis on the main grain and flour properties, twenty-five winter wheat cultivars released in the Southern Pannonian Plain between 1930 and 2015 were grown in three consecutive seasons in Novi Sad (Serbia). The results from this study showed that grain yield increased linearly with an average rate of 45.5 kg ha−1 yr−1, implying that grain yield progress under conditions of the Southern Pannonian Plain have not reached the plateau. Protein and wet gluten content decreased significantly with year of cultivar release, with a bi-linear trend. On the other hand, sedimentation value and gluten index increased in modern wheat cultivars, indicating improved protein quality. Also, the main flour traits related to stronger gluten and high sedimentation value, such as extensograph energy, farinograph resistance and alveograph deformation work, showed improvement with year of cultivar release. Although there were no significant changes in Gluten score, subunits N, 7 + 9 and 5 + 10 at the Glu-A1, Glu-B1 and Glu-D1, respectively, were the most prevalent in modern cultivars. Improvement of the main grain and flour traits could be related with increased frequency of 7 + 9 and 5 + 10 subunits in modern wheat cultivars.

Alternate furrow irrigation improves grain yield and nitrogen use efficiency in winter wheat

The objective of this study was to determine whether grain yield and nitrogen (N) use efficiency (NUE) in winter wheat (Triticum aestivum L.) could be improved by alternate furrow irrigation (AFI). During the 2009–2010 and 2010–2011 crop seasons, the effects of AFI on grain yield, NUE (and its components), the recovery of 15N-labeled fertilizer, N uptake and distribution, and soil nitrate-N were evaluated under field conditions. The irrigation regimes were: W0, non-irrigated; W2, every furrow irrigated at jointing and anthesis; W3, every furrow irrigated before wintering and at jointing and grain filling; and AFI, each of two neighboring furrows irrigated either before wintering or at grain filling, and every furrow irrigated at jointing. Our results show that grain yield, above-ground nitrogen uptake (AGN; including N from fertilizers and soil), and NUE were lowest in the W0 treatment and tended to increase with increasing irrigation frequency. Grain yield, AGN (including N from fertilizers and soil), NUE, nitrogen uptake efficiency (UPE), 15N-recovery efficiency, and N accumulation in grains were significantly higher in the AFI treatment than in the W2 treatment. AGN increased due to a higher amount of N derived from both fertilizers and soil. More N was derived from soil than from fertilizers; thus, the proportion of N derived from fertilizers decreased. No significant differences in grain yield and NUE were observed between the AFI and W3 treatments. AGN decreased when soil N luxury uptake and N accumulation in stems and leaves decreased. Greater N utilization efficiency and a higher N harvest index were observed in the AFI treatment compared with the W3 treatment. In addition, AFI increased nitrate-N contents in the upper soil layer (0–60 cm) and reduced nitrate-N movement to deeper soil compared to the W2 and W3 treatments. Therefore, AFI may be an appropriate irrigation method for improving NUE and decreasing water consumption in winter wheat without reducing yield.

УРОЖАЙНОСТЬ И КАЧЕСТВО ЗЕРНА ОЗИМОЙ ПШЕНИЦЫ ПРИ ПРИМЕНЕНИИ УДОБРЕНИЙ И ПРЯМОМ ПОСЕВЕ НА ЧЕРНОЗЕМЕ ОБЫКНОВЕННОМ В УСЛОВИЯХ СТАВРОПОЛЬЯ

The problem of reducing crop yields during the transition from classical technology of cultivation to the technology without tillage (no-till) can be solved by the most effective use of fertilizers. The purpose of the research was to study the influence of mineral fertilizers on the yield and quality of winter wheat grain under direct sowing in the Stavropol Territory. Studies were carried out in 2015-2019 on the experimental field of the North Caucasus Federal Agricultural Research Centre. Winter wheat was sown using two cultivation techniques for growing crops with and without disturbing the soil through tillage. Preceding crops – pea and sunflower. Fertilizers were added to the rows simultaneously with the Triticum vulgare L. sowing; topsoil dressing was carried out using N52 according to the method of splitting dividers. Options (amount of fertilizers added to the rows): 1. Without fertilizers; 2. N6Р26; 3. N12Р52; 4. N24Р104; 5. N52Р52; 6. N52Р52К52; 7. N52; 8. N104Р52К52. In the third year of direct sowing (2017–2019), winter wheat showed high responsiveness to the addition of all doses of fertilizers in rows. The yield increase in case of pea being preceding crop varied between 0.76-3.06 t/ha; sunflower – 0.51–2.75 t/ha. N104P52K5 contributed to the highest and most stable yield – 6.89 t/ha and 5.92 t/ha after pea and sunflower, respectively. The increase from 1 kg of the active substance of the fertilizer was 14.7 and 13.2 kg of grain. The use of this dose of fertilizer minimized crop losses compared to the first year of wheat cultivation using no-till farming and classical agricultural technique. At the same time, the 3rd and 4th class grain was formed. Higher content of raw gluten compared to other doses of fertilizers was noted likewise: 1.6–9.8 % (preceding crop – pea) and 1.1–11.5 % (preceding crop – sunflower) more. Nitrogen fertilization played a significant role in increasing yields only after sunflower (the average increase was 0.21–0.86 t/ha).

CONSERVATION SOIL FERTILITY SOUND USE SYSTEM OF FERTILIZATION AND SEEDING RATE WINTER WHEAT

The biological yield potential of modern winter wheat varieties has been established. The market, changes of organizational and ownership structures in the agricultural sector are studied. The problem of stable and reliable production of winter wheat grain and improvement of its quality has been disclosed. The works of domestic and foreign scientists have been analyzed and their significant contribution to the creation of modern cultivation technology ensuring high profitability of winter wheat has been determined. Grain yields for competitive production are proved. The article is based on the importance in the technological regulation of cultivation of such components as rational fertilization, reasonable sowing norms, which allow to manage the production process of winter wheat crops and to receive high yields, to increase the economic efficiency of cultivation of crops. The efficiency of application of the increased background of fertilizer at the seeding rate of 3.0 million pieces is theoretically substantiated and experimentally proved. us. / ha to realize the genetic potential of winter wheat under the conditions of PE "Zetto", which is located in the village. Klekotina of Shargorod district, Vinnytsia region in the zone of Right-bank Forest Steppe of Ukraine. The system of agrotechnical measures and their combination in the technology of cultivation is optimized and economically justified, which ensures stable high yield and good quality of winter wheat grain. It is established that for optimization of production processes of plants and rational use of natural and climatic potential of the region and material and technical resources for the purpose of stable grain production. Taking into account the complex of unsolved problems concerning the optimal rate of sowing of winter wheat seeds on the increased backgrounds of fertilizers in relation to the specific soil and climatic conditions of cultivation and biological features of modern varieties and hybrids, technological aspects of cultivation are proposed, which preserve fertility. Key words: winter wheat, soil fertility, land use, variety, seeding rate, fertilizer system.

Optimizing nitrogen application for drip-irrigated winter wheat using the DSSAT-CERES-Wheat model

Improper application of nitrogen fertilizer for winter wheat production in the North China Plain (NCP) limits N use efficiency and increases the risk of non-point pollution. Crop simulation models may help with the assessment of N fertilizer management, to improve nitrogen use efficiency and to mitigate environmental pollution. In this study, the DSSAT-CERES-Wheat model was calibrated and validated with two-year field experiment, which coupled with five N rates (0, 120, 180, 240, and 300 kg ha−1) and three irrigation levels (40, 30, and 20 mm per irrigation) under drip irrigation. The calibrated DSSAT-CERES-Wheat model performed well in simulating the anthesis date (nRMSE=1.47%, d=0.89), maturity date (nRMSE=0.97%, d=0.92), shoot biomass (nRMSE=10.97%, d=0.92), grain yield (nRMSE=6.19%, d=0.96), and actual evapotranspiration (nRMSE=9.96%, d=0.76) of drip-irrigated winter wheat in two years. The calibrated model was subsequently used to evaluate drip-irrigated winter wheat production in response to six N rates (0, 120, 180, 240, 300, and 360 kg ha−1) under 40 meteorological scenarios, and the results showed that grain yields, water use efficiency, irrigation water use efficiency, and net margins increased with increasing N application rates until it reached 180 kg ha−1. Above 180 kg ha−1, negligible changes were measured in these values as the N rate increased. The nitrogen physiological efficiency and nitrogen partial factor productivity were greatly improved at a N rate of 180 kg ha−1, compared with those at a N rate of 240, 300, and 360 kg ha−1. Consequently, N rate of 180 kg ha−1 was the optimal nitrogen application rate for drip-irrigated winter wheat production. These results may provide a scientific basis for nitrogen management of drip-irrigated winter wheat in the NCP.

Legacy effects of soil fertility management on cereal dry matter and nitrogen grain yield of organic arable cropping systems

The yields of crops in organic farming are typically lower than in conventional farming, although this depend greatly on local climatic conditions and on crop and soil management. A long-term study over three consecutive 4-year cropping cycles at three locations in Denmark compared organic arable cropping systems varying in fertilization management (green manure crops, cover crops, livestock manure) to study the long-term effects of soil fertility management on crop yields. The analysis of the results showed that the nitrogen (N) derived from cover crops has a legacy effect on the dry matter and N grain yield of spring barley being traceable 5-8 years back in time. The net N input of crop residues and manure for the crop cycles 1-4 and 5-8 years prior to the winter wheat had a significant effect on both the dry matter and N grain yield of wheat.The management of organic cropping systems should focus on reducing the weed pressure, promoting soil fertility and increasing the soil N supply to optimize crop yields. For both winter wheat and spring barley, the weed pressure reduced both crop dry matter and the N grain yield. A cover crop as pre-crop had a significant positive effect on both dry matter and N yield of spring barley, while a cover crop in the rotation did not significantly affect grain yield of winter wheat. For both winter wheat and spring barley, manure application was most effective in increasing crop yields. However, N in applied crop residues also had considerable yield-enhancing effects. For winter wheat, the N inputs from crop residues from previous crop rotation cycles (1-4 and 5-8 years) significantly increased yields, while for spring barley, N input in crop residues from incorporated cover crop and the long-term crop rotation cycle (5-8 years) significantly enhanced both dry matter and N grain yield. These legacy effects of soil fertility management through enhancing and retaining organic N inputs of organic arable cropping suggest that a holistic approach to soil and crop management is necessary, and this needs to focus on increasing weed suppression, soil fertility and targeting manure inputs for enhanced N uptake.

Evaluating the effects of plastic film mulching patterns on cultivation of winter wheat in a dryland cropping system on the Loess Plateau, China

Plastic film mulching (PFM) can increase or stabilize crop yields worldwide when applied to agricultural planting systems, especially in arid and semi-arid areas. Although the adverse effects that are caused by residual plastic film, such as plastic pollution, are becoming a global concern, the application of PFM will not be replaced by other materials in the short-term in agriculture. It is important to understand the various PFM patterns (different mulching periods and coverage rates) that impact on soil physicochemical properties and characteristics of crop growth. Therefore, based on a field experiment that we established in 2002, we conducted consecutive field observations from 2013 to 2016 to determine the optimum PFM mulching period and coverage rate. Three mulching periods were included: (I) summer fallow period (FM), (II) growth period (GM), and (III) whole growth year (WM). Two coverage rates were included: (i) 50%, half mulching (HM), and (ii) 100%, total mulching (TM). That is, there were six different PFM treatments. No mulching (NM) over the growth years was considered the CK treatment. PFM increased canopy height and leaf area index of winter wheat (Triticum aestivum L.) in the growing season by 29.5% and 19.4%, respectively. Average winter wheat grain yields of various PFM patterns were 5318.5 kg ha−1 and 4557.7 kg ha−1 in 2013–2014 and 2015–2016, respectively; these yields were 13.8% and 23.7% higher than NM in 2013–2014 and 2015–2016, respectively. However, the difference in the growth characteristics and grain yield of winter wheat under various PFM patterns resulted from the change in the mulching period and coverage rate. Winter wheat grain yield and biomass increased with GM and WM compared with FM and NM in normal rainfall years. PFM coverage rates improved yield significantly (P < 0.05) and influenced soil nutrient concentrations. HM maintained or increased soil organic matter (SOM) and total nitrogen concentrations, but TM decreased SOM concentration by 8.3%. Water use efficiency (WUE) and rainfall use efficiency (RUE) were improved by various PFM patterns. Furthermore, WM had the most significant impact on SOM concentrations, GM was second, and FM was minor. Considering the costs and benefits of PFM patterns, the half coverage rate of PFM during the whole year (FWH) had the best index (BI) value, and the total coverage rate of PFM during the growth period (FGT) and the half coverage rate of PFM during the growth period (FGH) had higher BI values than other PFM patterns; the values for BI for FWH, FGT, and FGH were 10.3, 8.9, and 8.5, respectively. In conclusion, ignoring the amount of PFM pollution in the environment (or use biodegradable film instead of polyethylene film), FWH was the best PFM pattern with the highest WUE and RUE in dryland rainfed agriculture. But, to decrease the amount of PFM application and pollution, FGH was more beneficial for soil health with a low coverage rate and short mulching period. FGH was the optimal pattern for PFM when applied to winter wheat on the Loess Plateau, China based on our field experiment.

Carbon emission and water use efficiency response to tillage methods and planting patterns of winter wheat in the North China Plain

BackgroundImplementing sustainable farming practices for winter wheat (Triticum aestivum L.) in the North China Plain may be a way to reduce carbon emissions. No tillage generally results in less net CO2 loss from farmland, but no tillage also reduces the grain yield and water use efficiency (WUE) of winter wheat. Wide-precision planting of winter wheat may enhance the grain yield and WUE; however, it is not known precisely how tillage and planting patterns affect CO2 exchange, grain yield and WUE.MethodsIn this study, two tillage methods (conventional tillage, T and no tillage, NT) and two planting patterns (conventional planting, C and wide-precision planting, W) were used in two consecutive winter wheat growing seasons.ResultsCompared with the T treatments, the NT treatments had significantly lower cumulative net CO2 emissions in 2015–2016 and 2016–2017 (30.8 and 21.3%, respectively), and had lower grain yields (9.0 and 9.4%, respectively) and WUE (6.0 and 7.2%, respectively). The W treatments had a compensating effect on grain yield failure and reduced cumulative net CO2 emissions more than C treatments, thereby increasing WUE, reducing carbon emissions per unit water consumption, and increasing the yield carbon utilization efficiency (YCUE). The lowest cumulative CO2 emissions and highest YCUE were observed for NT with W treatment. Results from this analogous tillage experiment indicated that NT and W farming practices provide an option for reducing carbon emissions and enhancing WUE and YCUE for sustainable winter wheat development.

Effect of Tillage Systems on the Yield and Quality of Winter Wheat Grain and Soil Properties

This study aimed to evaluate the yield and quality of winter wheat grain and soil properties in three tillage systems (TS): (1) Conventional (CT), (2) reduced (RT), and (3) no-tillage (NT). In the CT system, shallow ploughing (at a depth of 10–12 cm from soil surface) and pre-sow ploughing (at a depth of 18–22 cm from soil surface) were performed after the harvest of the previous crop (peas). In the RT system, the shallow ploughing was replaced by field cultivation, whereas pre-sow ploughing was by a tillage unit. In the NT system, a herbicide treatment with glyphosate (4 L ha−1) replaced the ploughing measures, whereas a tillage unit including a cultivator, a string roller, and a harrow was used before wheat sowing. Higher wheat yields were recorded in CT than in NT (by 4.3%) and in 2016 compared to 2015 (by 23.4%). The tillage system differentiated spike number m−2, whereas study years affected spike number m−2, grain weight per spike, and 1000 grain weight. Study years also influenced all quality traits of the grain, whereas tillage systems—only grain uniformity and ash content of the grain. A less uniform grain with a higher ash content was produced in NT than in CT and RT systems. Organic C content in the soil was higher in NT than in CT and RT systems. In turn, total nitrogen and phosphorus contents were higher in the soil from NT and RT than CT, whereas potassium and magnesium contents—in RT and NT compared to the CT system.

Predicting within-field variability in grain yield and protein content of winter wheat using UAV-based multispectral imagery and machine learning approaches

ABSTRACT Prediction of crop yield and quality is an essential component of successful implementation of precision agriculture. Given the recent commercialization of low-cost multispectral cameras mounted on unmanned aerial vehicles and advances in machine learning techniques, prediction systems for crop characteristics can be more precisely developed using machine learning techniques. Therefore, the model performances for predicting wheat grain yield and protein content between the machine learning algorithms based on spectral reflectance and plant height (e.g. random forest and artificial neural network) and the traditional linear regression based on vegetation indices were compared. Although the machine learning approaches based on reflectance could not improve the grain yield prediction accuracy, they have great potential for development in predicting protein content. The linear regression model based on a 2-band enhanced vegetation index was capable of predicting the yield with a root-mean-square error (RMSE) of 972 kg ha−1. The random forest model based on reflectance was capable of predicting the protein content with an RMSE of 1.07%. The reflectance may have been linearly correlated with total biomass; thus, it was also linearly correlated with grain yield. There was a nonlinear relationship between the grain yield and protein content, which may have resulted in the higher model performance of the machine learning approaches in predicting protein content. However, this relationship would be variable according to the environment and agronomic practice. Further, field-scale research is required to assess how this relationship can be varied and affect the model generality, particularly when predicting protein content.

ФОРМИРОВАНИЕ УРОЖАЙНОСТИ И КАЧЕСТВА ЗЕРНА ОЗИМОЙ ПШЕНИЦЫ В УСЛОВИЯХ СРЕДНЕГО ПОВОЛЖЬЯ

The research was carried out on the experimental field of FSBEI HE Ulyanovsk SAU in 2017-2019. The purpose of the research was to identify the influence of agroclimatic conditions in the region on the formation of yield and quality of winter wheat grain Saratovskaya 17 against various doses of mineral fertilizers. The experience scheme provided 4 options: 1. Control (without fertilizers); 2. N20P20K20; 3. N40P40K40; 4. N60P60K60. It was found that precipitation during the resumption of vegetation-flowering had a significant impact on the yield of winter wheat grain (R2=0,78). To characterize the humidification of the territory, hydrothermal coefficient was calculated according to G. T. Selyaninov. In 2019, it was 0.21, which characterizes the period as very dry. In 2017 and 2018 weather conditions for winter wheat were more favorable (SCC 0.92 and 0.75-insufficiently moist). An increase in yield was observed at a SCC of 0.92 (2017) in all variants of the experiment. The correlation coefficient between the yield of the studied crop and the SCC indicator was 0.84, which indicates a significant dependence of winter wheat productivity on hydrothermal conditions that develop during the period from the resumption of vegetation to flowering of the crop. It is important to note that the main factor affecting the accumulation of gluten in winter wheat grain Saratovskaya 17 and changes in its elastic-elastic properties are the conditions of mineral nutrition of plants. The coefficient of determination shows that 60% of the gluten quality was determined by the conditions of plant nutrition and did not depend on the prevailing weather conditions.

КРЕМНИСТЫЕ ПОРОДЫ В СИСТЕМЕ УДОБРЕНИЯ ОЗИМОЙ ПШЕНИЦЫ

The research was carried out on the experimental field of Ulyanovsk SAU named after P. A. Stolypin on a typical medium-loamy Chernozem with a humus content of 4.6 %, available phosphorus and potassium of 155 and 176 mg / kg, рНKCl 6,7 units. In the experiments winter wheat of Saratovskaya variety 17 was grown using zeolite from the Yushansky deposit in the Ulyanovsk region as a fertilizer and fertilizers based on it enriched with amino acids and urea. The scheme of experiment consisted of 4 variants: 1. Control (without fertilizers); 2.Pure zeolite 500 kg / ha; 3. Zeolite enriched with amino acids, 500 kg / ha; 4. Zeolite enriched with urea (at the rate of 40 kg a. r. per ha), 500 kg / ha. The accounting plot area is 20 m2, their placement is randomized, repetition is 4 times. The results of research have shown a positive effect of zeolite and fertilizers based on it on the activity of soil microorganisms, the nutritional regime of the soil, yield and product quality. It was found that when applying to the soil, the activity of soil microflora increases by 9-18 %, the content of mineral forms of nitrogen in the arable layer increases by 0.82-2.17 mg/kg, mobile phosphorus by 5-8 mg/kg, and exchange potassium by 5-6 mg/kg of soil. The latter was accompanied by an increase in yield of winter wheat grain: when applying zeolite in pure form by an average of 0.46 t/ha (12.1 %), zeolite enriched with amino acids by 1.17 t/ha (30 %), and zeolite enriched with urea by 1.35 t/ha (35 %).

Impact of potassium humate on crop yield and quality of winter wheat grain

Impact of potassium humate on crop yield and quality of winter wheat grain