Winter Wheat Grain Yield Research Articles

Assessment of winter wheat yield depending on agrotechnical techniques and fertility of typical chernozem

The article considered the issues of increasing the yield of winter wheat grain, depending on the method of basic tillage, application of manure and mineral fertilizers. A correlation and regression analysis of the yield of winter wheat grain from the applied agrotechnical techniques, indicators of the fertility of typical chernozem were carried out. It was found that the greatest increase in yield in the grain-grass crop rotation was due to shaft-free tillage for maximum fertilization, and in the grain-tillage with the same doses of fertilizers - with the use of minimal tillage. Linear regression equations have been calculated to predict the yield of winter wheat grain from agrotechnical techniques.

Supplemental irrigation increases grain yield, water productivity, and nitrogen utilization efficiency by improving nitrogen nutrition status in winter wheat

Supplemental irrigation (SI) is considered as one of the effective water management practices for improving grain yield and nitrogen utilization efficiency (NUtE) in winter wheat (Triticum aestivum L.). However, whether SI increases grain yield and NUtE by improving the N status in winter wheat is unclear. Based on a two-year field experiment (2017–2018, 2018–2019), we studied the effects of different levels of SI (i.e., no SI (J0), volumetric soil water content at100% field capacity at 20 cm (J20), and volumetric soil water content at 100% field capacity at 40 cm (J40)) and winter wheat cultivars (i.e., large spike-type Shannong23 (SN23) and multi spike-type Shannong29 (SN29)) on grain yield, NUtE and N status in winter wheat of the North China Plain. Our results indicated that, grain yield had a significant positive correlation with the amount of photosynthetic N (PN) at anthesis. With an increase in the N accumulation in shoots at anthesis (NAA), the amount of PN increased first and then remained stable, whereas the amount of reserve N (RN) increased continuously. Compared with SN29, SN23 allocated more N to PN and storage RN and less to structural N (SN) and accumulation RN at anthesis and had higher NUtE. Supplemental irrigation at jointing stage significantly increased the amount of NAA and pre-anthesis N redistributed to grains, and its contribution to grains, while the highest grain yield, NUtE, and water productivity (WP) were reached in J20 and not J40. WP was positively related to the amount of NAA and was also affected by the N nutrition index (NNI) at anthesis. The NNI of winter wheat under J20 treatment is optimal (approximated 1). In J40, with the higher irrigation amount, actual crop evapotranspiration (ETc act), the amounts of NAA and RN, and the NNI at anthesis increased further, but the amounts of PN and grain yield were not affected, which explained the reductions in NUtE and WP. Overall, moderate SI increased winter wheat grain yield and NUtE by improving N nutrition status as indicated by the NNI. And the NNI at anthesis is an important indicator to help manage irrigation and improve grain yield, NUtE, and WP in winter wheat on the North China Plain.

Research results on the use of plant growth regulator Triacontanol in winter wheat crops in the conditions of the Lower Volga region

To determine of the most effective dose of Triacontanol treatment for foliar cultivation of crops in the tillering and heading phases of winter wheat and its effect on yield and grain quality. Triacontanol is a natural plant growth regulator capable of increasing crop yields, their growth by accelerating photosynthesis, protein biosynthesis. Make an analysis of the influence of different doses of Triacontanol on the duration of the phases of development of winter wheat. Reach the determination of the effect of different doses of Triacontanol on the yield and quality of winter wheat grain. The data on the study and determination of the most effective dose of Triacontanol treatment for foliar cultivation of crops in the tillering and heading phases of winter wheat and its effect on yield and grain quality are presented. Triacontanol is a natural plant which has growth regulator capable of increasing crop yields, their growth by accelerating photosynthesis, protein biosynthesis; The doses of Triacontanol and their effect on the duration of the phases of development of winter wheat have been determined; The influence of various doses of Triacontanol on the yield and grain quality of winter wheat has been established. The stages of tillering-earing development were chosen, because during this period, active development of plants takes place: the formation of main and lateral stems, the development of the vegetative mass and generative organs of wheat, therefore it is important and necessary to support their growth and development.

Controlled‐release nitrogen fertilizer management influences grain yield in winter wheat by regulating flag leaf senescence post‐anthesis and grain filling

AbstractControlled‐release nitrogen fertilizer (CRNF) is expected to meet the nutrient demands for crop growth with single fertilizer application, so as to achieve high‐yield, high‐efficiency, and labor‐saving cultivation. However, under current CRNF practices, a single application of CRNF in winter wheat (Triticum aestivum L.) usually fails to achieve satisfactory effects due to insufficient nitrogen (N) supply in the later growth stage, contributing to premature leaf senescence and poor grain filling. To determine a reasonable CRNF application strategy for improving the grain weight and yield of winter wheat, the responses of leaf senescence, photosynthetic capacity, grain‐filling characteristics, and grain yield to different CRNF types [polymer‐coated urea (PCU), sulfur‐coated urea (SCU), and urea‐formaldehyde (UF)] and fertilization practices [single fertilization (P1) and twice‐split fertilization (P2)] were investigated. The results showed that, compared with P1, P2 increased the activities of catalase, peroxidase, and superoxide dismutase, alleviated the accumulation of malondialdehyde, delayed flag leaf senescence, and enhanced the net photosynthetic rate (Pn) of the flag leaves, which promoted assimilate accumulation and transport to the grains. These advantages in P2 improved the grain‐filling process of wheat, with the active filling duration (T), average filling rate (G), and maximum filling rate (Gmax) in P2 all being higher than those in P1, which significantly increased the 1000‐grain weight (TGW) and grain yield of wheat. Among the three CRNFs, PCU showed advantages in Pn at the milk‐ripe stage (Zadoks growth stage, GS75), dry matter accumulation post‐anthesis, T, Gmax, and G, which contributed to TGW and grain yield. Overall, our study suggested that the twice‐split application of CRNF could substantially delay leaf senescence post‐anthesis and increase photosynthetic capacity, thus improving grain filling and productivity in winter wheat.

Efficient Irrigation Methods and Optimal Nitrogen Dose to Enhance Wheat Yield, Inputs Efficiency and Economic Benefits in the North China Plain

Nitrogen (N) and water irrigation are two vital factors influencing the agriculture sustainability in various regions across the world, such as the North China Plain (NCP). Exploring optimal N application and water-efficient irrigation methods are needed for achieving greater crop productivity benefits and increasing the efficiency of inputs (N and water) in winter wheat (Triticum aestivum L.) production in the NCP. For this reason, we conducted a two-year field experiment with four N application rates interacting with three irrigation methods to examine the effects of N fertilization and water-efficient irrigation on grain yield, biomass production, economic benefits, and N- and water-use efficiencies of winter wheat in the NCP. The optimal N fertilization rate was ≈200 kg N ha−1, achieving a high grain yield of winter wheat (≈6000 kg ha−1). At this N dose, the highest net economic benefit was also achieved by the local farmer due to the increased grain yield, which was accompanied by more water-efficient irrigation. N recovery efficiency, agronomy efficiency, and the partial factor productivity of wheat decreased sharply with the N application rate. Water-use efficiency was significantly increased through drip irrigation and sprinkler irrigation. Considering the wheat productivity, input (N and water) efficiencies, and economic performance, water-efficient irrigation accompanied with an N application rate of 200 kg N ha−1 is optimal for achieving high economic returns for local farmers in the NCP.

Assessment of the influence of hydrothermal conditions on the yield of winter wheat under different agricultural technologies in the grain-fallow-row crop rotation

The article considers the influence of hydrothermal conditions of the Kursk region on the yield of winter wheat grain under different agricultural technologies. The Central Chernozem region differs from other regions of Russia and over the past decades there has been an increase in temperature, the amount of precipitation exceeds long-term data and is unevenly distributed by seasons. The current situation creates a certain climatic risk of crop loss. During the research period, it was found that the hydrothermal regime is unstable over the years and it largely determines the yield of winter wheat for various types of agricultural technologies, especially in 2017–2018 and 2018–2019. The paper shows that the spring reserves of productive moisture did not affect the yield. The correlation analysis allowed us to assess the degree of correlation between the yield of winter wheat and hydrothermal factors.

The Formation of the Productivity of Winter Wheat Depends on the Predecessor, Doses of Mineral Fertilizers and Bio Preparations

Wheat is the main agricultural crop in many countries of the world, as well as the main food in the steppe zone, so the system of agrotechnical measures should be aimed at creating favourable conditions for obtaining a high yield. The issue of intensification of grain production is inseparable from the production and use of new biogenic effective drugs that have a positive effect on the growth and development of cultivated plants. The purpose of this study was to establish the effect of foliar fertilisation with bacterial preparations, precursors, and doses of mineral fertilisers on grain yield and productivity elements of winter wheat. The paper provides data on the results of the research of winter wheat of the Duma Odeska variety in the conditions of the Educational and Practical Centre of the Mykolaiv NAU in 2019–2021. During the study, generally accepted methods were used: monographic, systematic approach and systematic analysis, analysis and synthesis, field and statistical. The influence of the precursor, foliar feeding with modern bacterial biopreparations and the use of different doses of mineral fertilisers on the elements of the crop structure and grain yield of winter wheat was analysed. It was established that the yield level depended and changed on the precursor taken for foliar feeding of the bacterial preparation, the level of mineral nutrition and to a large extent on the influence of the weather conditions of the growing year. Over the years of research, precursors, mineral fertilisers, and treatment of plant sowing with biological preparations affected the number of productive stems, the number of grains from an ear, the mass of grain from one ear and the mass of 1,000 grains of winter wheat. The conducted studies confirmed the expediency of foliar fertilising in the main periods of vegetation with biological preparations to optimise the nutrition of winter wheat plants with the aim of forming a stable grain yield. The obtained scientific results of the research will contribute to the wide application of biological preparations, which will ensure the rapid and full growth and development of winter wheat plants, which will further contribute to increasing the yield and gross harvest of grain.

Influence of the application of mineral fertilizers on the yield and quality of winter wheat grain in the non-chernozem soil of Central Russia: A Review

Winter wheat is one of the most important agricultural crops with high yield potential, for a more complete implementation of which at the present stage requires the creation of flexible science-intensive cultivation technologies, which will include new low-cost elements and, undoubtedly, will increase the gross grain harvest. The reviewed article presents the results of field studies conducted in the Non-Chernozem soil of central region of Russia. The purpose of the work was to study the effect of mineral fertilizers on the productivity of winter wheat varieties, aimed at evaluating the reaction of winter wheat varieties according to cultivation technologies at a different level of intensity, to develop a cost-effective resource-saving cultivation technology and to determine the optimum conditions of winter wheat cultivation. Applying mineral fertilizers in the correct dose is fundamental to increasing the yield and quality of winter wheat in the Non-Chernozem Zone of central Russia. The nutrient-deficient soils in this region justify the use of mineral fertilizers. The authors reviewed existing studies on the use of mineral fertilizer and the quality and yield of winter wheat in the Non-Chernozem soil conditions in the central region of Russia. Various indicators were assessed, such as the winter wheat yield and the gluten, fibrin, and crude protein contents. The research outcome reveals a positive correlation between the appropriate use of mineral fertilizers and the increase in winter wheat yield and grain quality in the Non-Chernozem Zone of Central Russia.

The role of weather conditions in the formation of yield and quality of winter wheat grain in Central Chernozem Region

The article presents studies on the influence of weather conditions on the yield and quality of winter wheat food grain in Central Chernozem Region of Russia. At the same time, weather risks were identified and analyzed using correlation and regression analyses. To reduce them to a minimum, a set of measures is needed, one of which is the selection of modern varieties that are more adapted to a specific place of growth. The soft wheat variety Synthetic is shown as an example that weather conditions affect not only the yield of winter wheat, but also the quality of the crop grain. The level of yield was more influenced by precipitation than by air temperature. The thousand-kernel weight was closely and positively correlated with the air temperature; a negative correlation was found between the air temperature and the content of raw gluten in the grain.

Formation of the quality and yield of durum winter wheat grain depending on different types and doses of fertilizers

Formation of the quality and yield of durum winter wheat grain depending on different types and doses of fertilizers

Productivity of winter wheat (Triticum aestivum) as influenced by fertilizer rates in rainfed fields of south Kazakhstan

Today, the need for grain is increasing every day due to the growing human population on the planet. At the same time, global climate change has a negative impact on grain production. In the conditions of the south of Kazakhstan, the main limiting factor of agricultural crops is soil moisture, since during the growing season there is an insufficient amount of atmospheric precipitation, and the moisture reserve in the soil due to autumn-winter precipitation does not satisfy the water demand of crops. It was found that the highest yield of winter wheat grain (37.7 c/ha) on average over two years of research was formed on the variant with simultaneous application of phosphorus fertilizers at the rate of P45 kg/ha with direct sowing and feeding with nitrogen fertilizer at the rate of N70 kg/ha in early spring periods in the tillering phase of winter wheat, that is, the grain yield increased 2.9 times in comparison with the background without fertilizers. By optimizing the phosphate regime of winter wheat with the introduction of nitrogen fertilizers during the period of their greatest need in the tillering phase, it will balance the regime of their nutrition.Therefore, an experiment was conducted during 2019-2020 year at LLC «South-west Research Institute of Livestock and Crop Production» (South Kazakhstan) to determine the norms and terms of the introduction of mineral, micronutrient fertilizers and plant growth stimulants of wheat and the peculiarities of the soil and climatic conditions of the south of Kazakhstan. Winter wheat (cv. Glassy 24) in the conditions of rainfed agriculture in the south of Kazakhstan. During the period of the laying of productive organs in the phase of booting, stalking and formation of winter wheat grain, the reserves of productive moisture were good and fully satisfied the need of winter wheat for moisture in the indicated growing periods of plants, as a result, a consistently high yield of winter wheat grain was formed for rainfed conditions in the south of Kazakhstan.

Crop rotations with perennial herbs and bean cultures in the conditions of the lower Volga region

The relevance and novelty of this work is a comprehensive study of crop rotations in the cultivation of crops, methods of agriculture biologization, allowing to give the most complete and scientifically based assessment of their effect on the productivity of cultures and the state of the fertility of zonal soils of the dry-step zone of the lower Volga region. The average annual precipitation was 339.7 mm. The technology of cultivation of these crops was generally accepted for the research area. The placement of options: (A) is sequential and options (B) are placed in blocks in three tiers. The main tillage in the experiment is soil-free, treated with a SibPME stand to a depth of 25-27 cm. Zoned varieties of agricultural crops are cultivated. Records and observations were carried out according to the recommendations. During the period July-August, the largest amount of precipitation fell in 2016 – 119.0 mm; the smallest in 2017 – 6.0 mm, in other years this indicator was in the range of 32.8…86.0 mm. On average, over the years of research, the largest accumulation of crop residues, straw and roots in a 4-pole crop rotation with black steam is 3.4 t/ha. The amount of nitrogen entering the soil with straw and crop residues was noted in an 8-month crop rotation of 49.8/ kg/ha. The largest amount of biological nitrogen (according to Trepachev’s method) was accumulated under alfalfa crops of 34.4 kg/ha/. The analysis of soil samples for the content of humus over the years of research did not reveal significant changes. The best precursor for winter wheat is black steam. For perennial grasses, peas, the grain yield of winter wheat in some years is reduced by 4 … 12 c/ha. The analysis of the correlation dependence of crop rotation productivity showed that the highest dependence with precipitation for May- June is t = + 0.50 for grain and feed units and slightly less for protein-t = +0.26-0.50.

Yield and grain quality of baking winter wheat of different varieties

Purpose. Study the formation of yield and grain quality of baking winter wheat of different varieties.
 Methods. Laboratory, physico-chemical, mathematical and statistical.
 Results. The grain yield of baking winter wheat varied significantly depending on the variety. On average over two years of research, the highest yield (8.12–8.47 t/ha) was obtained in ‘Colonia’, ‘RGT Reform’, ‘Quebec’, ‘Tobak’, ‘Mescal’ and ‘Emile’ varieties. In ‘Bonanza’ and ‘Rivero’ varieties, this indicator was at the level of 7.48–7.53 t/ha. It should be noted that the stability index was high (0.92–0.98) for growing all varieties. In the favourable 2020 year, the grain yield ranged between 7.62 and 8.80 t/ha, while in the less favourable years it ranged between 7.34 and 8.26 t/ha depending on the variety. On average, over two years of research, the protein content of more than 13.0% was formed by ‘Emile’, ‘Bonanza’, ‘RGT Reform’ and ‘Quebec’ varieties, while in other the varieties it was 12.4–12.9%. The studied varieties of baking wheat had a high stability of protein content (0.98–0.99). Baking winter wheat grain had an average gluten content of 27.7–29.7%, depending on the variety, with high stability. Its highest content (29.5–29.7%) was obtained in ‘Emile’, ‘Quebec’ and ‘RGT Reform’ varieties. The gluten content in grain was directly proportional to the protein content. There is a direct very high correlation between these indicators (r = 0.91 ± 0.001). According to the Zeleny sedimentation test results, flour strength was high only in ‘Quebec’ variety, while in the other varieties it was medium. The grain of ‘Quebec’ and ‘RGT Reform’ varieties corresponds to valuable wheat; ‘Rivero’ and ‘Bonanza’ correspond to a good filler, while the rest of the varieties correspond to a satisfactory filler. The grain of ‘Quebec’, ‘Mescal’, ‘Rivero’ and ‘Colonia’ varieties is medium hard as the hardness was 54.1–59.1 units of instrument. Grain of the other varieties is soft with 48.3–51.1 units of instrument. Grain of ‘RGT Reform’, ‘Rivero’, ‘Emile’ and ‘Tobak’ varieties had the largest (794–812 g/l) grain unit. This indicator in the other varieties was at the level of 760–785 g/l. Flour strength is directly proportional to protein content. There is the direct high correlation between these indicators (r = 0.87 ± 0.002). Correlation between the protein content and the sedimentation index by Zeleny test was direct high (r = 0.79 ± 0.001). However, with grain hardness it was inversely weak, and with the grain unit direct moderate (r = 0.35±0.003).
 Conclusions. Yield of winter baking wheat varieties was in the range from 7.48 to 8.47 t/ha, protein content varied from 12.4 to 13.8%. Protein content highly correlated with the major baking properties of wheat grain. Baking winter wheat ‘RGT Reform’ and ‘Quebec’ varieties are recommended for stable grain production with good baking properties in the conditions of the Right-Bank Forest-Steppe.

The Analysis of Wheat Yield Variability Based on Experimental Data from 2008–2018 to Understand the Yield Gap

Among European countries, Poland has the largest gap in the grain yield of winter wheat, and thus the greatest potential to reduce this yield gap. This paper aims to recognize the main reasons for winter wheat yield variability and shed the light on possible reasons for this gap. We used long-term datasets (2008–2018) from individual commercial farms obtained by the Laboratory of Economics of Seed and Plant Breeding of Plant Breeding and Acclimatization Institute (IHAR)-National Research Institute (Poland) and the experimental fields with high, close to potential yield, in the Polish Post-Registration Variety Testing System in multi-environmental trials. We took into account environment, management and genetic variables. Environment was considered through soil class representing soil fertility. For the crop management, the rates of mineral fertilization, the use of pesticides and the type of pre-crop were considered. Genotype was represented by the independent variable year of cultivar registration or year of starting its cultivation in Poland. The analysis was performed using the CART (Classification and Regression Trees). The winter wheat yield variability was mostly dependent on the amount of nitrogen fertilization applied, soil quality, and type of pre-crop. Genetic variable was also important, which means that plant breeding has successfully increased genetic yield potential especially during the last several years. In general, changes to management practices are needed to lower the variability of winter wheat yield and possibly to close the yield gap in Poland.

Does temporary heat stress or low temperature stress similarly affect yield, starch, and protein of winter wheat grain during grain filling?

Temperature plays a critical role in wheat grain development. A controlled phytotron glasshouse study was done to investigate the effects of short-term low or high temperature stress on grain yield and the proportions of starch and protein in two wheat cultivars Ningmai 13 and Zhenmai 12. The duration of grain filling was longer under low temperature stress and was shorter under high temperature stress during various stages of grain filling. Grain filling rate, grain width, grain yield, contents of total starch and amylopectin of both cultivars were decreased by low or high temperature stress. However, the proportions of total protein, gliadin, and glutenin were increased dramatically after abnormal temperature stress. The significant increase in the proportion of protein was mainly caused by higher proportions of ω-gliadin and HMW-GS. For both cultivars, the formation of starch, protein, and grain yield was most sensitive to temperature stress during 15–17 days post anthesis (DPA), followed by 7–9 DPA for grain starch and yield formation, and 23–25 DPA for grain protein formation, respectively. Our study suggested that both high and low temperature stress after anthesis affected winter wheat grain yield, starch and protein accumulation, especially during the period of 15–17 DPA.

Increasing temperature during early spring increases winter wheat grain yield by advancing phenology and mitigating leaf senescence

High temperature usually reduces wheat yield, especially at critical growth stages, such as anthesis and grain filling. However, effects of increasing temperature during wintering period on winter wheat growth and development are rarely reported. Hence, this three-year field experiment evaluated how artificial warming during early spring (wintering period) affects winter wheat. The warming treatment (WT) advanced the wheat reviving, jointing, anthesis, and maturity stages, but the average temperature in each growing stage reduced, thus extending the duration of tillering, spike differentiation, and grain filling. Concurrently, the leaf area index and biomass accumulation were obviously increased. Additionally, WT showed a lower leaf senescence rate compared with that of control (CK). Also, the photosynthesis rate and SPAD of WT were increased relative to CK. WT increased superoxide dismutase and peroxidase activities, and reduced malondialdehyde content in flag leaf during the grain filling stage, suggesting WT during early spring could delay leaf senescence after anthesis, which contributed to a high filling rate and long filling duration. Correspondingly, the final spike number, kernel number, and kernel weight of WT were significantly increased compared with CK. In the three seasons, grain yield was increased by 18.2%–37.5% in WT compared with CK. Results of this study provided a new viewpoint that increasing temperature could shorten the wintering period but extend the effective growth phase, and increase grain yield in winter wheat.

Quantifying grain yield, protein, nutrient uptake and utilization of winter wheat under various drip fertigation regimes

Nitrogen (N), phosphorus (P) and potassium (K) are essential elements for crop growth. The absorption, accumulation process and distribution of these nutrients affect not only the growth and grain yield, but also the grain quality of wheat (Triticum aestivum L.). Various fertilization and irrigation practices can influence wheat growth as well as the absorption and utilization of nutrient elements. A four-season (2014–2018) experiment was conducted on drip-fertigated winter wheat on the Loess Plateau of China with three irrigation levels and three fertilization rates. Irrigation rates included normal irrigation (W1), mild deficit irrigation (W2) and more severe deficit irrigation (W3), while fertilization rates (N-P2O5-K2O) included F1 (175–117–150 kg ha−1), F2 (125–84–108 kg ha−1) and F3 (75–50–65 kg ha−1). The results showed that NPK uptake in aboveground biomass decreased as the water stress increased, but there was no significant difference between W1 and W2. When sufficient water and fertilizer were applied, the stem, leaf and rachis + glume obtained higher proportion of NP, while grain nitrogen and phosphorus harvest index (NHI and PHI) decreased. When the supply of water and fertilizer was insufficient, NHI and PHI increased, and the proportion of vegetative organs was relatively low. The average NPK requirement for 100 kg grain (GNR, GPR and GKR) varied 1.93–3.03, 0.37–0.41 and 2.26–2.93 kg over the four seasons. GNR and GKR increased with increasing irrigation and fertilization regimes. With the increase of irrigation amount, irrigation water use efficiency (IWUE) first increased and then decreased slightly, and the maximum IWUE occurred under W2. Yield and IWUE increased with the increase of fertilization rate, but there was no significant difference between F1 and F2. F2 obtained higher partial factor productivity than F1. F1 and F2 had no significant difference in protein content and protein yield, but they obtained significantly higher values than F3. Therefore, W2F2 was an efficient water and fertilizer management practice for drip-fertigated winter wheat, which promoted nutrients transfer to grains without significantly reducing grain yield and protein.

Performance Evaluation of the WOFOST Model for Estimating Evapotranspiration, Soil Water Content, Grain Yield and Total Above-Ground Biomass of Winter Wheat in Tensift Al Haouz (Morocco): Application to Yield Gap Estimation

The main goal of this investigation was to evaluate the potential of the WOFOST model for estimating leaf area index (LAI), actual evapotranspiration (ETa), soil moisture content (SM), above-ground biomass levels (TAGP) and grain yield (TWSO) of winter wheat in the semi-arid region of Tensift Al Haouz, Marrakech (central Morocco). An application for the estimation of the Yield Gap is also provided. The model was firstly calibrated based on three fields data during the 2002–2003 and 2003–2004 growing seasons, by using the WOFOST implementation in the Python Crop simulation Environment (PCSE) to optimize the different parameters that provide the minimum difference between the measured and simulated LAI, TAGP, TWSO, SM and ETa. Then, the model validation was performed based on the data from five other wheat fields. The results obtained showed a good performance of the WOFOST model for the estimation of LAI during both growing seasons on all validation fields. The average R2, RSME and NRMSE were 91.4%, 0.57 m2/m2, and 41.4%, respectively. The simulated ETa dynamics also showed a good agreement with the observations by eddy covariance systems. Values of 60% and 72% for R2, 0.8 mm and 0.7 mm for RMSE, 54% and 31% for NRMSE are found for the two validation fields, respectively. The model’s ability to predict soil moisture content was also found to be satisfactory; the two validation fields gave R2 values equal to 48% and 49%, RMSE values equal to 0.03 cm3/cm3 and 0.05 cm3/cm3, NRMSE values equal to 11% and 19%. The calibrated model had a medium performance with respect to the simulation of TWSO (R2 = 42%, RSME = 512 kg/ha, NRMSE = 19%) and TAGP (R2 = 34% and RSME = 936 kg/ha, NRMSE = 16%). After accurate calibration and validation of the WOFOST model, it was used for analyzing the gap yield since this model is able to estimate the potential yield. The WOFOST model allowed a good simulation of the potential yield (7.75 t/ha) which is close to the optimum value of 6.270 t/ha in the region. Yield gap analysis reveals a difference of 5.35 t/ha on average between the observed yields and the potential yields calculated by WOFOST. Such difference is ascribable to many factors such as the crop cycle management, agricultural practices such as water and fertilization supply levels, etc. The various simulations (irrigation scenarios) showed that early sowing is more adequate than late sowing in saving water and obtaining adequate grain yield. Based on various simulations, it has been shown that the early sowing (mid to late December) is more adequate than late sowing with a total amount of water supply of about 430 mm and 322 kg (140 kg of N, 80 kg of P and 102 kg of K) of fertilization to achieve the potential yield. Consequently, the WOFOST model can be considered as a suitable tool for quantitative monitoring of winter wheat growth in the arid and semi-arid regions.

Irrigation with Activated Water Promotes Root Growth and Improves Water Use of Winter Wheat

Magnetic or oxidation treatment of irrigation water can promote the transport of water and nutrients by the root system, improve the efficiency of water and fertilizer use and potentially increase yields. Hydroponic and field experiments were conducted to explore how irrigation with magnetized and/or oxidized water affects grain yield and water-use efficiency (WUE) in winter wheat with an emphasis on physiological changes in the root system. Hydroponic cultivation of winter wheat with pure groundwater and brackish water included the following treatments: control group (CK−G, CK−B); magnetization (GM, BM); oxidation (GO, BO); and the combination of magnetization and oxidation (G(M+O), B(M+O), G(O+M), B(O+M)). Field experiments only tested irrigation with various types of groundwater, including the control group (IG), magnetization treatment (IGM), oxidation treatment (IGO), and the combination of the two treatment methods (IG(M+O), IG(O+M)). Hydroponic cultivation revealed that the magnetic treatment and oxidation of both groundwater and brackish water can significantly improve the root vigor of winter wheat, i.e., improvements of 100.5–253.7% and 100.4–213.9% were seen in the groundwater and brackish treatment groups, respectively, relative to the control group. The root length density (RLD) of wheat increased by 67.6% (GM), 79.4% (GO), 7.5% (BM), and 40.0% (BO) relative to the respective control groups (CK−G and CK−B). Moreover, the root weight density (RWD) for BO and B(O+M) treatments improved significantly (66.7% and 55.4%, respectively) relative to CK−B. The maximal increases in root surface area density (RSD) were observed in treatments GO and B(O+M), which showed values 125% and 100%, respectively, higher than what was measured for the control groups. The root/shoot ratios of the GO and G(O+M) treatments improved significantly (by 75.3% and 62.0%, respectively) relative to CK−G. The results of field experiments showed that wheat in the IGO and IG(O+M) plots absorbed more water from the soil than wheat in the of IG plots (increases of 13.9% and 16.9%, respectively). Furthermore, the IGO and IG(O+M) treatments produced significantly higher grain yields and WUE than the IG plots, with IGO producing the maximum yield (11.7 × 103 kg ha−1) and IG(O+M) the highest observed WUE (30.3 kg ha−1 mm−1). Hence, the research provides clear evidence that the irrigation of winter wheat with magnetized and/or oxidized water can increase grain yields and WUE.

Influence of fertilisation and crop rotation on grain yield and quality of winter wheat (Triticum aestivum L.)

Abstract At the present time, crop rotations are constantly adapted to economic conditions and one or two main crops are grown in agricultural farms. This has a negative impact on the environment. The optimization of grain yield and quality of winter wheat are dependent not only on the appropriate crop rotation but also on the nitrogen fertilisation. The aim of this study was to examine the effect of crop rotations, fertilisation and preceding crop on grain yield and quality of winter wheat during the years 2015/2016 – 2017/2018. The grain yield of winter wheat after preceding crop pea in crop rotation with 40% proportion of cereals was statistically higher (5.91 t/ha) than in crop rotation with 80% share of cereals (5.55 t/ha). In the treatment with mineral fertilisation and organic manure Veget® incorporation, the grain yield was statistically higher (6.00 t/ha) than in the treatment with mineral fertilisation (5.50 t/ha). According the standard STN 46 1100-2:2018 based on the wet gluten content, the winter wheat grain was classified into the class E by mineral fertilisation + organic manure Veget® in all monitored years. In 2017 the winter wheat grain was categorized into the class P based on wet gluten content in crop rotations with 80% proportion of cereals in the treatment with fertilisers only after preceding crop winter barley.